Cal. Water Code, § 375(a). Water Code Section 375(b) also provides the authority for pricing to encourage water conservation.
With regard to water delivered for other than agricultural uses, the ordinance or resolution may specifically require the installation of water-saving devices that are designed to reduce water consumption. The ordinance or resolution may also encourage water conservation through rate structure design.
Metropolitan’s Board of Directors has approved many policies and rules, codified in Metropolitan’s own Administrative Code, which further provide Metropolitan the authority to ensure the availability of its water during times of shortages. For example, Administrative Code Section 3107 requires that any territory annexed to Metropolitan comply with Metropolitan’s water use efficiency guidelines.
The Board has also ratified various policies and rules to implement a Water Supply Allocation Plan (WSAP) to address shortage conditions. Metropolitan’s WSAP provides a standardized methodology for allocating supplies during times of shortage. The WSAP is authorized pursuant to the following Board actions:
• By Minute Item 43514, dated April 13, 1999, the Board adopted the WSDM Plan. • By Minute Item 44005, dated June 17, 2000, the General Manager has the authority to reduce Interim Agriculture Water Program deliveries up to 30 percent prior to imposing any mandatory allocation under the WSDM Plan.
• By Minute Item 47393, dated February 12, 2008, the Board adopted the WSAP. • By Minute Item 48376, dated August 17, 2010, the Board approved adjustments to the WSAP.
A.4-40 Water Shortage Contingency Plan
• By Minute Item 48803, dated September 12, 2011, the Board approved adjustments to the WSAP.
• By Minute Item 74526, dated February 11, 2014, the Board adopted the Water Supply Alert Resolution.
• By Minute Item 49979, dated December 9, 2014, the Board approved adjustments to the WSAP.
In addition to the statutes and other legal authorities set forth above, Metropolitan is empowered to implement and enforce its shortage response actions pursuant to various resolutions. For example, on April 11, 2016, Metropolitan’s Board voted to adopt Metropolitan’s 2015 UWMP and authorized its submittal to the State of California as stated in Resolution 9209. Metropolitan’s 2015 UWMP contains Metropolitan’s December 2014 WSAP in Appendix 4. Metropolitan’s 2015 UWMP also describes in Section 2.4 Metropolitan’s WSAP and WSDM Plan, which guides Metropolitan’s planning and operations during both shortage and surplus conditions. Similarly, on May 11, 2021, Metropolitan’s Board voted to adopt Metropolitan’s UWMP and WSCP as stated in Resolutions 9279 and 9281, respectively. These two Resolutions authorize Metropolitan to implement and enforce its shortage response actions contained in the WSCP, which is attached as Appendix 4 to the 2020 UWMP.
Additionally, numerous agreements allow Metropolitan to take its core supplies and shortage response actions. Core supplies and supply augmentation actions are authorized by the agreements shown in 2020 UWMP Appendix 3: Justifications for Supply Projections, which include:
Colorado River Supplies
• 1931 Seven Party Agreement dated August 18, 1931
• Metropolitan’s 1930, 1931, and 1946 water delivery contracts with the Secretary of the Interior
• Consolidated Decree of the Supreme Court of the United States in Arizona v. California • 2003 Quantification Settlement Agreement (QSA) and related agreements • 2005 Settlement Agreement with Quechan Indian Tribe
• Colorado River Interim Guidelines for Lower Basin Shortages and the Coordinated Operations for Lake Powell and Lake Mead
• 1988 IID-Metropolitan Conservation and Use of Conserved Water Agreement • 1989 Approval Agreement
• 1989 Supplemental Approval Agreement
• August 2004 Forbearance and Fallowing Program Agreement with PVID • Landowner Agreements for Fallowing in PVID
• 2003 Delivery and Exchange Agreement between Metropolitan and Coachella Valley Water District
• 2004 Storage and Interstate Release Agreement among Metropolitan, the Colorado River Commission of Nevada, Southern Nevada Water Authority, and the United States • 2007 Lower Colorado Water Supply Project Contract among the United States, the City of Needles, and Metropolitan
Water Shortage Contingency Plan A.4-41
• 2007 Lower Colorado River Basin Intentionally Created Surplus Forbearance Agreement among the Arizona Department of Water Resources, PVID, IID, the City of Needles, CVWD, Metropolitan, SNWA, and the Colorado River Commission of Nevada • 2007 California Agreement for the Creation and Delivery of Extraordinary Conservation Intentionally Created Surplus among Metropolitan, PVID, IID, CVWD, and the City of Needles
• 2007 Agreement among the United States, the Colorado River Commission of Nevada, and the SNWA for the Funding and Construction of the Lower Colorado River Drop 2 Storage Reservoir Project
• 2007 Delivery Agreement between the United States and Metropolitan • 2008 Metropolitan Notice of Election to Participate as a Party to the Drop 2 Funding Agreement
• 2009 Agreement among the United States, Metropolitan, the Colorado River Commission of Nevada, SNWA, and the Central Arizona Water Conservation District for a Pilot Project for Operation of the Yuma Desalting Plant
• 2010 Yuma Desalting Plant Pilot Project Delivery Agreement between the United States and Metropolitan
• 2012 Agreement among the United States, Metropolitan, the Colorado River Commission of Nevada, SNWA, and the Central Arizona Water Conservation District for a Pilot Program for the Conversion of Intentionally Created Mexican Allocation to Intentionally Created Surplus
• 2012 Interim Operating Agreement for Implementation of Minute No. 319 of the International Boundary and Water Commission
• 2012 Lower Colorado River Basin Forbearance Agreement for Binational Intentionally Created Surplus
• 2012 Binational ICS Delivery Agreement
• 2013 Agreement between Metropolitan and IID Regarding Binational Intentionally Created Surplus
• 2015 Amendment 1 to the California Agreement for the Creation and Delivery of Extraordinary Conservation Intentionally Created Surplus • 2017 Agreement among the United States, Metropolitan, the Colorado River Commission of Nevada, SNWA, IID, and the Central Arizona Water Conservation District for a Pilot Program for the Conversion of Mexico’s Water Reserve to Binational ICS • 2017 Interim Operating Agreement for Implementation of Minute No. 323 • 2017 Binational ICS Agreement
• 2017 Binational ICS Delivery Agreement
• 2019 Lower Basin Drought Contingency Plan
• December 2019 Agreement for the Implementation of a Seasonal Land Fallowing Program
• Agreement for Seasonal Fallowing in Bard Unit (Farmer Fallowing Agreements A.4-42 Water Shortage Contingency Plan
• May 2020 First Amended Agreement for the Implementation of a Seasonal Land Fallowing Program
• Agreement Relating to Supplemental Water among The Metropolitan Water District of Southern California, the San Luis Rey Settlement Parties, and the United States • Amended and Restated Agreement between The Metropolitan Water District of Southern California and the San Diego County Water Authority for the Exchange of Water. This October 10, 2003 agreement provides for Metropolitan delivery of Exchange Water to SDCWA in exchange for conserved Colorado River water SDCWA makes available to Metropolitan at Lake Havasu.
• Agreement Between Imperial Irrigation District And San Diego County Water Authority For Transfer Of Conserved Water. This April 9, 1998 agreement, as amended, provides for IID to conserve water for transfer to SDCWA and establishes the price SDCWA pays to IID for the conserved water.
• Allocation Agreement. This October 10, 2003 agreement among the United States, CVWD, IID, SDCWA, Metropolitan, and the San Luis Rey Settlement Parties provides for the allocation of water conserved from the All-American Canal Lining Project and the Coachella Canal Lining Project, and Metropolitan’s assignment to SDCWA of it rights to both canal lining projects.
• Colorado River Water Delivery Agreement: Federal Quantification Settlement Agreement. By this October 10, 2003 agreement, among the Secretary of the Interior.
CVWD, IID, SDCWA, and Metropolitan, the Secretary agreed to deliver IID-SDCWA transfer water and canal lining water allocated to SDCWA to Metropolitan’s Colorado River Aqueduct Intake at Lake Havasu for diversion by Metropolitan.
State Water Project Supplies
• 1960 Contract between the State of California and The Metropolitan Water District of Southern California for a Water Supply
• Port Hueneme Water Agency Annexation: By Minute Item 41728, dated January 9, 1996, Metropolitan’s Board adopted Resolution 8487 granting the concurrent annexation of Annexation No. 32 to Calleguas Municipal Water District and The Metropolitan Water District of Southern California, and fixing Metropolitan's terms and conditions for the annexation
• 1996 Sublease Agreement between the Port Hueneme Water Agency and Metropolitan • 1967 and 1983 Water Exchange Contract and Agreements with Desert Water Agency and Coachella Valley Water District
• 1984 Advance Delivery Agreement with Desert Water Agency and Coachella Valley Water District
• The 2003 Exchange Agreement with Desert Water Agency and Coachella Valley Water District
• November 2012 Letter Agreement with Coachella Valley Water District • 2019 Amended and Restated Agreement for Exchange and Advance Delivery with Desert Water Agency and Coachella Valley Water District • 1997 Arvin-Edison/Metropolitan Water Management Agreement Water Shortage Contingency Plan A.4-43
• 1998 Turn-in/out Construction and Maintenance Agreement between DWR, Kern County Water Agency, Arvin-Edison, and Metropolitan
• 1998-2002 Water Delivery and Return Agreements with DWR, Kern County Water Agency, Arvin-Edison, and Metropolitan
• 2004 Point of Delivery Agreement with DWR, Kern County Water Agency, and Metropolitan
• 2004 Introduction of Water into the California Aqueduct with DWR, Kern County Water Agency, and Arvin-Edison
• 2007 First Amended and Restated Agreement Between Arvin-Edison Water Storage District and The Metropolitan Water District of Southern California for a Water Management Program
• 2000 Coordinated Operating Agreement between Metropolitan and San Bernardino Valley Municipal Water District
• 2001 Coordinated Operating Agreement between Metropolitan and San Bernardino Valley Municipal Water District
• 2011 Coordinated Operating, Water Storage, Exchange and Delivery Agreement among Metropolitan, Municipal Water District of Orange County, and Irvine Ranch Water District • 2013 San Gabriel Valley MWD Exchange and Purchase Agreement • 2019 Board Approval of the High Desert Water Bank Agreement with Antelope Valley East Kern Water Agency
• 2001 Kern Delta/Metropolitan Principles of Agreement
• 2002 Kern Delta and Metropolitan Boards of Directors Approval • 2007 DWR-Yuba County Water Agency Purchase Agreement
• 2007 DWR-Metropolitan Yuba Dry Year Program Participation Agreement • 2014 Amended DWR-Metropolitan Yuba Dry Year Program Participation Agreement • 2019 Amended and Restated Agreement Among The Metropolitan Water District of Southern California, Coachella Valley Water District, and Desert Water Agency for the Exchange and Advance Delivery of Water
• 2020 Amended DWR-Metropolitan Yuba Dry Year Program Participation Agreement • 2021 Coordinated Operating Agreement. The Coordinated Operating Agreement between Metropolitan and San Bernardino Valley District was approved by Metropolitan’s Board in March 2021. The agreement will terminate on December 31, 2035 unless there is an extension of the SWP Contract.
• 2013 San Gabriel Valley MWD Exchange and Purchase Agreement. The agreement between Metropolitan and San Gabriel Valley MWD was executed in September 2013. • 2013 Board Approval of the San Gabriel Valley MWD Exchange and Purchase Agreement. In August 2013, Metropolitan’s Board authorized entering into the agreement with San Gabriel Valley MWD.
A.4-44 Water Shortage Contingency Plan
In-Region Storage and Supplies
• November 1974 Memorandum of Understanding and Agreement on Operation of Lake Skinner
• November 1994 Memorandum of Understanding on Operation of Domenigoni Valley Reservoir (now known as Diamond Valley Lake)
• Elderberry Forebay Contract for Conditions for Use
• June 2002 Division of Safety of Dams Certificate of Approval • October 1991 Final EIR for the Eastside Reservoir Project (Diamond Valley Lake) • 1995 amendment to Metropolitan’s SWP contract to include Article 54, “Usage of Lakes Castaic and Perris”
• November 1974 Memorandum of Understanding and Agreement on Operation of Lake Skinner
• June 2002 Division of Safety of Dams Certificate of Approval • Principles for groundwater storage adopted by the Metropolitan Board in January 2000 • Resolution for Proposition 13 Funds adopted by the Metropolitan Board in October 2000 • Agreement executed with the DWR for Interim Water Supply Construction Grant Commitment Safe Drinking Water, Clean Water, Watershed Protection and Flood Protection (Proposition 13, Chapter 9, Article 4) providing for Metropolitan to administer $45 million in state Proposition 13 grant funds for groundwater reliability programs; October 2000
• Agreement executed for Long Beach Conjunctive Use Project, July 2002, amended in July 2003, October 2005, and November 2008
• Agreement executed for Live Oak Conjunctive Use Project, October 2002 • Agreement executed for Foothill Area Groundwater Storage Project, February 2003, amended in August 2006, April 2008, and February 2009
• Agreement executed for Chino Basin Programs, June 2003, amended in May 2004, August 2004, August 2005, May 2008, March 2009, September 2009, July 2010, and January 2015 • Agreement executed for Orange County Groundwater Storage Program, June 2003, amended in July 2004, December 2005, and July 2008
• Agreement executed for Compton Conjunctive Use Program, February 2005 • Agreement executed for Long Beach Conjunctive Use Project ― Expansion in Lakewood, July 2005, amended in April 2006, August 2007, November 2008, and February 2010 • Agreement executed for Upper Claremont Basin Groundwater Storage Program, September 2005, amended in April 2008
• Agreement executed for Elsinore Basin Conjunctive Use Program, December 2006, amended in May 2008
These agreements are described in more detail in Appendix 3 to Metropolitan’s 2020 UWMP.
If necessary, Metropolitan shall declare a water shortage emergency in accordance with CWC Chapter 3 (commencing with Section 350) of Division 1. In addition, Metropolitan shall coordinate with any city or county within which it provides water supply services for the possible proclamation of a local emergency, as defined in Section 8558 of the Government Code.
Water Shortage Contingency Plan A.4-45
A.4.7. Financial Consequences of and Responses for Drought Conditions A water shortage may be created by a reduction in water supply, an increase in water demand, or a combination of both. Metropolitan’s shortage response actions include supply augmentation, demand management, and operational flexibility, all of which could impact Metropolitan financially. For example, exercising the options to take water from supply augmentation programs may increase costs. Similarly, operational changes could result in higher system costs and lower revenues from on-system hydropower generation, and an increase in conservation and outreach efforts would also increase costs. On the other hand, if core supplies from the SWP or the Colorado River were reduced, variable power costs to move water into the service area would likely decrease. Additionally, effective demand management during shortages tends to decrease Metropolitan’s water sales when effective, thereby potentially reducing revenue for Metropolitan. From these various financial effects, there is a potential for expenditures exceeding revenues more than budgeted, thereby requiring unanticipated draws from reserves.
Variation in the amount of revenues is already part of Metropolitan’s financial planning.
Revenues vary according to regional weather and the availability of statewide water supplies. In dry years, local demands increase, and Metropolitan may receive higher than anticipated revenues due to increased sales volumes. In contrast, in wet years, demands decrease, and revenues drop due to lower sales volumes. In addition, statewide supply shortages such as those in 2009 and 2015 also affect Metropolitan’s revenues. Such revenue surpluses and shortages could cause instability in water rates. To mitigate this risk, Metropolitan maintains financial reserves, with a minimum and target balance, to stabilize water rates during times of reduced water sales. The reserves hold revenues collected during times of high water sales and are used to offset the need for revenues during times of low sales. Metropolitan’s practice of using reserves to buffer unexpected increases or decreases in budgeted revenue also applies to unexpected expenditure increases or decreases resulting from shortage responses.
Metropolitan uses its financial reserves to mitigate the impacts of water shortages. This policy applies to each of the six shortage levels described in this WSCP. Financial reserves create a buffer to reduce the financial impact of the water shortage. Other mitigation actions such as reducing operations and maintenance expenses, deferring capital projects, and rates/charges increases are part of Metropolitan’s biennial budget and rate design cycle, are not used routinely to mitigate financial impacts of water shortage response actions.
Metropolitan’s reserve policy provides for a minimum reserve requirement and target amount of unrestricted reserves at June 30 of each year. Funds in excess of the target amount are to be utilized for capital expenditures in lieu of the issuance of additional debt, or for the redemption, defeasance or purchase of outstanding bonds or commercial paper as determined by the Board. However, if the fixed charge coverage ratio (the amount necessary to cover all fixed costs) is at or above 1.2, amounts over the minimum may be expended for any lawful purpose of Metropolitan, as determined by the Board. Therefore, unrestricted reserves are intended to be available to address Metropolitan’s shortage response actions, as well as the consequences of those actions, so long as its fixed charge coverage ratio is at or above 1.2.
A.4-46 Water Shortage Contingency Plan
A.4.8. WSCP Adoption and Refinement Procedures
WSCP Public Notice and Adoption
Metropolitan provided notice of the availability of the draft 2020 UWMP (including Appendix 11 which will also be a new Appendix 11 to its 2015 UWMP) and WSCP, and notice of the public hearing to consider adoption of both plans and Appendix 11 to the 2015 UWMP in accordance with CWC Sections 10621(b) and 10642, and Government Code Section 6066, and Chapter 17.5 (starting with Section 7290) of Division 7 of Title 1 of the Government Code.
The public review drafts of the 2020 UWMP, Appendix 11 to the 2015 UWMP, and the WSCP were posted prominently on Metropolitan’s website, mwdh2o.com, on February 1, 2021, more than 60 days in advance of the public hearing on April 12, 2021. The notice of availability of the documents was sent to Metropolitan’s member agencies, as well as to cities and counties in Metropolitan’s service area. In addition, a public notice advertising the public hearing in English and Spanish was published in 12 Southern California newspapers. The notification in English language newspapers was published on February 1 and 8, 2021. The notification was published on January 28-30, 2021 and February 1, 4-6, and 8, 2021 in Spanish language newspapers, satisfying the requirement for non-English language notification. Copies of:
(1) the notification letter sent to the member agencies, cities and counties in Metropolitan’s service area, and (2) the notice published in the newspapers are included in the 2020 UWMP Section 5. Table 5-3 in the 2020 UWMP provides a list of participating member agencies and other appropriate agencies that Metropolitan coordinated with in its regional planning, as well as the cities and counties that were notified about the preparation of its 2020 UWMP, Appendix 11 to the 2015 UWMP, and WSCP. In addition, the list of newspaper publications is included in Table 5-4.
Metropolitan held the public hearing for the draft 2020 UWMP, draft Appendix 11 to the 2015 UWMP, and draft WSCP on April 12, 2021, at the Board’s Water Planning and Stewardship Committee meeting, held online due to COVID-19 concerns. On May 11, 2021, Metropolitan’s Board determined that the 2020 UWMP and the WSCP are consistent with the MWD Act and accurately represent the water resources plan for Metropolitan’s service area. In addition, Metropolitan’s Board determined that Appendix 11 to both the 2015 UWMP and the 2020 UWMP includes all of the elements described in Delta Plan Policy WR P1, Reduce Reliance on the Delta Through Improved Regional Water Self-Reliance (Cal. Code Regs. tit. 23, § 5003) which need to be included in a water supplier’s UWMP to support a certification of consistency for a future covered action. As stated in Resolutions 9279, 9280, 9281, the Board adopted the 2020 UWMP, Appendix 11 to the 2015 UWMP, and the WSCP and authorized their submittal to the State of California. Copies of Resolutions 9279, 9280, 9281 are included in the 2020 UWMP Section 5, and Resolution 9281 for the WSCP is attached to this WSCP as Attachment C.
Submission and Availability of Final 2020 UWMP, Appendix 11 to 2015 UWMP, and WSCP In fulfillment of CWC Sections 10632(c) and 10645(a) and (b), Metropolitan’s final 2020 UWMP, Appendix 11 to its 2015 UWMP, and its WSCP were posted on the mwdh2o.com website in May 2021, following their adoption by the Metropolitan board. This satisfies the requirement to make the plans available for public review and to make the WSCP available to Metropolitan’s customers (which are its member agencies).
In fulfillment of CWC Sections 10632(c), 10635(c) and 10644(a)(1), Metropolitan also mailed copies of the final 2020 UWMP, Appendix 11 to the 2015 UWMP, and WSCP (in electronic pdf format) to the California State Library and all cities and counties within Metropolitan’s service area within 30 days of Board adoption.
Water Shortage Contingency Plan A.4-47
In June 2021, in fulfillment of CWC Section 10621(f) and Sections 10644(a)(1), (2), and (b), Metropolitan’s final 2020 UWMP, Appendix 11 to the 2015 UWMP, and WSCP were electronically submitted to the State of California through DWR’s WUE data website https://wuedata.water.ca.gov/secure/.
WSCP Reevaluation and Improvement Procedures
The WSCP will be periodically re-evaluated to ensure that its shortage risk tolerance is adequate and the shortage response actions are effective and up to date based on lessons learned from implementing the WSCP. The WSCP will be revised and updated during the UWMP update cycle to incorporate updated and new information. For example, new supply augmentation actions will be added, and actions that are no longer applicable for reasons such as program expiration will be removed. However, if revisions to the WSCP are warranted before the UWMP is updated, the WSCP will be updated outside of the UWMP update cycle. In the course of preparing the Annual Assessment each year, Metropolitan staff will routinely consider the functionality the overall WSCP and will prepare recommendations for Metropolitan's Board of Directors if changes are found to be needed.
ATTACHMENTS
Attachment A – Water Surplus and Drought Management Plan Attachment B – Water Supply Allocation Plan
Attachment C – WSCP Resolution 9281
A.4-48 Water Shortage Contingency Plan
List of Acronyms and Abbreviations
AF
CRA
CUP
CVWD
CWC
DWA
DWR
IID
IRP
ICS
MAF
MWD
MWD Act
PVID
QSA
SNWA
SWP
TAF
USBR
UWMP
WSAP
WSCP
WSDM
Acre-feet
Colorado River Aqueduct
Conjunctive Use Programs
Coachella Valley Water District
California Water Code
Desert Water Agency
California Department of Water Resources
Imperial Irrigation District
Integrated Water Resources Plan
Lake Mead Intentionally Created Surplus
Million Acre-feet
The Metropolitan Water District of Southern California
Metropolitan Water District Act
Palo Verde Irrigation District
Quantification Settlement Agreement
Southern Nevada Water Authority
State Water Project
Thousand Acre-Feet
United States Bureau of Reclamation
Urban Water Management Plan
Water Supply Allocation Plan
Water Shortage Contingency Plan
Water Surplus and Drought Management
THE METROPOLITAN WATER DISTRICT
OF SOUTHERN CALIFORNIA
WATER SURPLUS AND DROUGHT MANAGEMENT PLAN
REPORT NO. 1150
AUGUST 1999
Attachment A
ACKNOWLEDGMENTS
The consensus reached in the Water Surplus and Drought Management Plan would not have been possible without the dedication and participation of the Rate Refinement Process Workgroup, comprises made by the General Manager, staff from Metropolitan's member agencies, Metropolitan staff, and the dedication and work of the consultants.
Metropolitan's Pro,[ect Management:
Program Manager: Brian G. Thomas, Assistant Chief, Planning and Resources Division Project Managers: Timothy A. Blair, Senior Resource Specialist Eddie A. Rigdon, Principal Resource Specialist
Metropolitan Support Staff:
Sydney B. Bennion Nancy E. Clemm
James V. Daber B. Anatole Falagan
Rafael G. Fernando Amy Gallaher
Brandon J. Goshi Lee Gottlieb
Michael E. Hollis Nina Jazmadarian
Kenneth M. Kules Anthony J. Liudzius
Dirk S. Marks Cynthia J. Miller
Ray Mokhtari Michael Morel
Christine M. Morioka Keith E. Nobriga
Dan Rodrigo Devendra N. Upadhyay
Project Consultants:
Jim Waldo, Gordon, Thomas, Honeywell, Malanca, Peterson & Daheim B. J. Mirk, Gordon, Thomas, Honeywell, Malanca, Peterson & Daheim Richard W. Atwater, Bookman-Edmonston Engineering, Inc.
Sanjay Gaur, DCSE
Virginia Grebbien, Bookman-Edmonston Engineering, Inc.
Wendy L. Illingworth, Foster Associates
Daniel Jones, Dan Jones Consulting
Dennis Underwood, MWD Agriculture Water Users
Member Agency, Sub-Agency, and Groundwater Basin Management Agency Participants:
Gary Arant, Valley Center Municipal Water District
Don Calkins, City of Anaheim
Robert Campbell, San Diego County Water Authority
Amy Chen, San Diego County Water Authority
Charles Darensbourg, Central and West Basin Municipal Water Districts Tom Erb, Los Angeles Department of Water and Power
Jerry Gewe, Los Angeles Department of Water and Power
Donald L. Harriger, Western Municipal Water District of Riverside County Gordon Hess, San Diego County Water Authority
Paul Jones, Central and West Basin Municipal Water Districts Donald R. Kendall, Calleguas Municipal Water District
Keith Lyon, Municipal Water District of Orange County
Mathew Lyons, City of Long Beach
George P. Martin, City of Anaheim
William R. Mills, Jr., Orange County Water District
Ronald C. Palmer, Foothill Municipal Water District
Karl Seckel, Municipal Water District of Orange County
Stanley E. Sprague, Municipal Water District of Orange County Matthew Stone, Municipal Water District of Orange County Roger W. Turner, Eastern Municipal Water District
Diem Vuong, City of Long Beach
Kenneth Weinberg, San Diego County Water Authority
Lee Willer, San Diego County Water Authority
Wyatt H. Won, Central and West Basin Municipal Water Districts
WATER SURPLUS AND DROUGHT MANAGEMENT PLAN
METROPOLITAN WATER DISTRICT OF SOUTHERN CALIFORNIA
TABLE OF CONTENTS
EXECUTIVE SUMMARY ..............................................................................................1 INTRODUCTION .............................................................................................................7 WSDM PRINCIPLES AND IMPLEMENTATION GOALS .......................................9 REGIONAL RESOURCES AND DEMANDS ..........................................................11 RETAIL DEMANDS ....................................................................................................13 DEMANDS ON METROPOLITAN ...........................................................................14 INTEGRATED RESOURCES PLANNING .............................................................17 SURPLUS AND SHORTAGE RESOURCE ACTIONS ..........................................19 SURPLUS ACTIONS ...................................................................................................19 SHORTAGE ACTIONS ..............................................................................................22 DESCRIPTIONS OF RESOURCE ACTIONS .........................................................23 ALLOCATION OF SUPPLY FOR M&I DEMANDS .............................................25 INTEGRATED RESOURCE MANAGEMENT STRATEGY ................................27 RESOURCE MANAGEMENT FRAMEWORK ......................................................27 SUPPLY CERTAINTY AND THE TIMING OF RESOURCE ACTIONS ...........29 PUBLIC AFFAIRS AND CONSERVATION ...........................................................31 APPENDIX A: RESOURCE AND STORAGE SIMULATION ................................33
EXECUTIVE SUMMARY
INTRODUCTION
The Water Surplus and Drought Management (WSDM) Plan for the Metropolitan Water District of Southern California (Metropolitan) is a ten-year plan that will be used to direct Metropolitan's resource operations to help attain the region's 100% reliability goal. The WSDM Plan recognizes the interdependence of surplus and shortage actions and is a coordinated plan that utilizes all available resources to maximize supply reliability. The overall objective of the WSDM Plan is to ensure that shortage allocation of Metropolitan's imported water supplies is not required.
The central effort in developing the WSDM Plan was a participatory process involving Metropolitan and its member agencies. Metropolitan staff and member agency representatives coordinated the Plan's development during a series of meetings of the Rate Refinement Team.
To lay a foundation for the WSDM Plan, participants in the Rate Refinement Process developed a set of proposed WSDM Principles and Implementation Goals which were subsequently adopted by the Metropolitan Board of Directors in September 1998. These Principles and Implementation Goals outline fundamental policies for guiding surplus and shortage management and establish a basis for dealing with shortages in an equitable and efficient manner.
WSDM PRINCIPLES AND IMPLEMENTATION GOALS
Guiding Principle
• Metropolitan will encourage storage of water during periods of surplus and work jointly with its Member Agencies to minimize the impacts of water shortages on the region's retail consumers and economy during periods of shortage.
Supporting Principles
• Maintain an ongoing coordinated effort among Metropolitan and its Member Agencies to encourage efficient water use, develop cost-effective local resource programs, and inform the public on water supply and reliability issues
• Encourage local and regional storage during periods of surplus and use of storage during periods of shortage
• Manage and operate Metropolitan's regional storage and delivery system in coordination with local facilities to capture and store surplus water in local groundwater and surface reservoirs • Arrange for secure sources of additional water from outside the region for use during periods of shortage
• Call upon sources of additional water from outside the region and water stored locally to meet the needs of consumers and protect the economy during periods of shortage WSDM Plan Implementation Goals
• Avoid mandatory import water allocations to the extent practicable • Equitably allocate imported water on the basis of agencies' needs Considerations to create an equitable allocation of imported water may include:
- Impact on retail consumers and economy
- Reclamation/Recycling
- Conservation
- Population and economic growth
- Investment in local resources
- Change and/or loss of local supply
- Participation in Metropolitan's Non-firm (interruptible) programs - Investment in Metropolitan's facilities
• Encourage storage of surplus supplies to mitigate shortages and improve water quality
SURPLUS AND SHORTAGE ACTIONS
The region's ability to implement a long-term WSDM Plan results from the significant investments Metropolitan and its member agencies have made in a variety of resources since 1991. These additional resources include increased local conservation and water recycling, improvements in the reliability of imported supplies, increased regional storage, and increased conjunctive use groundwater programs.
Together these improvements allow a comprehensive approach to water management.
The growing variety of resources available to the region is transforming Metropolitan from an agency with relatively modest storage capacity to one that will have storage sufficient to manage many shortages without impacts to its member agencies or retail customers. To attain this level of reliability, all storage programs and facilities, along with conservation, recycling, and other programs, must be managed as an integrated set of regional resources. To accomplish this, the WSDM Plan establishes the linkage between surplus and shortage resource management actions.
When imported supplies exceed projected demands for imported water within Metropolitan's service area, Metropolitan can operate available storage facilities to maximize the benefits of stored water to its member agencies. A number of factors affect Metropolitan's ability to divert surplus water into storage.
Some of these factors include facility outages, system capacity, water quality (including requirements for managing total dissolved solids), and varying supply and demand patterns. The WSDM Plan provides a description of storage options available to Metropolitan and a framework for storing water in these programs and facilities when surplus supplies are available.
Except in severe or extreme shortages (defined in the Introduction) or emergencies, Metropolitan's resource management will allow shortages to be mitigated without impacting retail Municipal and Industrial (M&I) customers. A list of resource management actions and their descriptions are provided below. This list emphasizes critical storage programs and facilities, and conservation programs that make up part of Metropolitan's response to shortages. The order in which these actions are presented does not imply the exact operational management of resources that would occur during a shortage, rather it represents a general framework and guide. In fact, several actions are likely to be taken concurrently.
Many factors will dictate the exact order in which these actions will be taken during shortages. One action, however, will have an assigned prioritization: the curtailment of Full Service (firm) deliveries will be last. The following summarizes the drought actions:
• Draw on storage in the Eastside Reservoir Project
• Draw on out-of-region storage in Semitropic and Arvin-Edison • Reduce/suspend long-term seasonal and groundwater replenishment deliveries • Draw on contractual groundwater storage programs in the region • Draw on State Water Project (SWP) terminal reservoir storage (per Monterey Agreement) • Call for extraordinary drought conservation and public education • Reduce Interim Agricultural Water Program (IAWP) deliveries • Call on water transfer options contracts
• Purchase transfers on the spot market
• Implement the allocation of Metropolitan's imported supplies to its member agencies For the ten-year period addressed by the WSDM Plan, 1999-2008, the majority of shortage contingencies will be managed by withdrawals from storage, groundwater management and options transfers. Shortages managed using these actions would not impact the quantity of water delivered to member agencies for consumptive uses. In fact, when coupled with other drought actions such as extraordinary conservation and reduction of agricultural deliveries, it is fully expected that an allocation of firm imported water supplies will not be necessary during the next ten years. Under this worse-case scenario, an approach to allocate Metropolitan's firm imported water supplies in a fair and equitable manner will be developed.
The overall policy objective of the allocation method will be to minimize the impacts to any one agency and the region as a whole. To meet that objective, the method of allocating firm imported supply will account for:
• Each agency's demands on Metropolitan,
• Each agency's local resources
• Each agency's total retail demands.
The WSDM Plan allocation method would address each of these supply and demand components and account for each agency's conservation and recycled water programs. A pricing structure will be coupled with the WSDM allocation method to accomplish two goals:
• Encourage conservation and water recycling
• Ensure that the regional impact of the shortage is as small as possible To provide as much water as possible without changing wholesale prices, the allocation of all available supplies will be made at the prevailing rates for firm deliveries. In order to encourage conservation to the level of allocation, the rate for agency usage from 100-102% of its allocation will be the Full Service rate plus $175. Usage above 102% of allocated supply will be charged at three times the Full Service rate. Any substantial change in Metropolitan's water rate structure may require these rates to be revised.
During severe or extreme shortage conditions, public outreach will play a critical role in shaping consumer response. Public information campaigns will send clear signals if extraordinary drought conservation is required. An effective public information campaign requires a joint effort among Metropolitan and its member agencies. Under this Plan, the administration of the Public Information and Government Affairs program will be the responsibility of a Drought Program Officer (DPO). The DPO will be responsible for integrating the various activities in these areas, coordinating efforts with Metropolitan's Board of Directors and member agencies, and designing the region-wide messages for the general public and various target audiences. Important constituencies are residential users, industrial and institutional users, business interests, agricultural users, elected officials, officials of various agencies such as the Department of Water Resources, and the media.
INTEGRATED RESOURCES MANAGEMENT
Throughout the Integrated Resources Planning process and the development of the WSDM Plan, extensive analysis of resource management strategies focused on maximizing supply reliability while minimizing overall resource costs. Various management strategies were analyzed trader shortage scenarios based on historical hydrologic data. The WSDM Plan presents a resource management framework to guide Metropolitan's integrated approach to supply management.
The resource management framework does not dictate a scripted response to shortage or surplus. The framework recognizes the complexity and variety of conditions that require action. Supporting this framework are general rules that describe the actions to be taken in each stage of surplus or shortage.
These rules depend on shortage stage, account for monthly delivery requirements, and depend on when various supplies would be available.
One of the fundamental trade-offs in dealing with supply shortages is the need to maintain flexibility while providing supply certainty to member agencies and consumers. A central focus of the WSDM Plan is the analysis of information about supplies and demands. When do various pieces of information about the supply/demand balance become more certain? When should this information impact policymaking and trigger various resource actions? The WSDM Plan addresses these questions and the actual implementation of the Plan during a shortage.
Appendix A of this report provides a ten-year simulation of projected demands and supplies showing an example of how the region can maintain 100% reliability.
INTRODUCTION
The Metropolitan Water District of Southern California (Metropolitan) provides water to a service area covering approximately 5,200 square miles. Over 16.5 million people live within the service area, which supports a $500 billion economy. Metropolitan provides supplemental supplies to twenty-seven member agencies, both retail and wholesale agencies, who in turn provide water to over three hundred cities and local agencies providing supplies at the retail level. In recent years Metropolitan supplemental deliveries have accounted for about one-half to two-thirds of the region's total water demands. With supplies from its Colorado River Aqueduct (CRA) and the State Water Project (SWP), Metropolitan delivers water for municipal and industrial (M&I) uses, agricultural uses, and augmentation of local storage.
As part of the implementation of the regional Integrated Resources Plan (IRP), Metropolitan and its member agencies have developed the Water Surplus and Drought Management (WSDM) Plan for Southern California. This ten-year plan will direct Metropolitan's resource operations to help attain the region's 100% reliability goal. Over this ten-year period, the WSDM Plan will be updated to account for changes impacting supplies from the Colorado River and California's Bay-Delta. In the past, Metropolitan has developed drought management plans that simply addressed shortage actions and primarily focused on issues of short-term conservation and allocation of imported water. The WSDM Plan recognizes the interdependence of surplus and shortage actions and is a coordinated plan that utilizes all available resources to maximize supply reliability. The overall goal of the WSDM Plan is to ensure that shortage allocation of Metropolitan's imported water supplies is no---At required.
Because it addresses both surplus and shortage contingencies, the WSDM Plans draws clear distinctions among the terms surplus, shortage, severe shortage, and extreme shortage.
Surplus: Supplies are sufficient to allow Metropolitan to meet Full Service demands, make deliveries to all interruptible programs (replenishment, long-term seasonal storage, and agricultural deliveries), and deliver water to regional and local facilities for storage.
Shortage: Supplies are sufficient to allow Metropolitan to meet Full Service demands and make partial or full deliveries to interruptible programs, sometimes using stored water and voluntary water transfers.
Severe Shortage: Supplies are insufficient and Metropolitan is required to make withdrawals from storage, call on its water transfers, and possibly call for extraordinary drought conservation and reduce deliveries under the IAWP.
Extreme Shortage: Supplies are insufficient and Metropolitan is required to allocate available imported supplies.
WSDM PRINCIPLES AND IMPLEMENTATION GOALS
The central effort in developing the WSDM Plan was a participatory process involving Metropolitan and its member agencies. Metropolitan staff and member agency representatives coordinated the Plan's development during a series of meetings of the Rate Refinement Team and the Integrated Resources Planning Workgroup. To lay a foundation for the WSDM Plan, participants in the Rate Refinement Process developed a set of "WSDM Principles and Implementation Goals." Guiding Principle
• Metropolitan will encourage storage of water during periods of surplus and work jointly with its Member Agencies to minimize the impacts of water shortages on the region's retail consumers and economy during periods of shortage.
Supporting Principles
• Maintain an ongoing coordinated effort among Metropolitan and its Member Agencies to encourage efficient water use and cost-effective local resource programs and to inform the public on water supply and reliability issues
• Encourage local and regional storage during periods of surplus and use of storage during periods of shortage
• Manage and operate Metropolitan's regional storage and delivery system in coordination with local facilities to capture and store surplus water in local groundwater and surface reservoirs • Arrange for secure sources of additional water from outside the region for use during periods of shortage
• Call upon sources of additional water from outside the region and water stored locally to meet the needs of consumers and protect the economy during periods of shortage WSDM Plan Implementation Goals
• Avoid mandatory import water allocations to the extent practicable • Equitably allocate imported water on the basis of agencies' needs Considerations to create an equitable allocation of imported water may include:
- Impact on retail consumers and economy
- Reclamation/Recycling
- Conservation
- Population and economic growth
- Investment in local resources
- Change and/or loss of local supply
- Participation in Metropolitan's Non-firm (interruptible) programs - Investment in Metropolitan's facilities.
• Encourage storage of surplus supplies to mitigate shortages and improve water quality
REGIONAL RESOURCES AND DEMANDS
Southern California receives its water supplies from a variety of different sources, both local to the region and imported from outside the region. These sources are summarized below.
Local Supplies
Local supplies include groundwater pumping of local aquifers, surface reservoir production, recycled water, and supplies imported through wheeling arrangements or through the Los Angeles Aqueduct, which is owned and operated by the City of Los Angeles. Local supplies have, in the past, provided as much as 2.1 million acre-feet (maf) of water to meet the region's water demands. By far the largest component of local supplies is groundwater pumping, providing over 75% of historical local supplies.
Colorado River Supplies
The distribution and management of Colorado River water is governed by a complex body of laws, court decrees, compacts, agreements, regulations, and an international treaty collectively known as the "Law of the River." Metropolitan's entitlement is established by the fourth and fifth priorities of California's Seven Party Agreement, included in Metropolitan's 1931 and 1946 contracts with the Secretary of the Interior. These priorities provide 550,000 acre-feet (af) per year and 662,000 af per year, respectively. In addition, Metropolitan holds a surplus water contract for delivery of 180,000 af. The physical capacity of the CRA is slightly in excess of 1.3 maf per year, based on a pumping capacity of 1,800 cubic feet per second (cfs). Metropolitan's long-held objective is to maximize the availability of Colorado River water, up to the maximum capacity of the CRA, subject to environmental, contractual, legal, political, financial, and institutional constraints. A California 4.4 Plan is being developed among California parties that will help ensure that full CRA deliveries are maintained, while addressing the concerns of the other Colorado River basin states that rely on the river. The California 4.4 Plan includes core transfers (such as the IID/MWD conservation agreement and the proposed IID/SDCWA transfer), system conservation (such as the lining of the All American Canal), offstream storage (such as the Arizona groundwater storage program), dry year option transfers (such as PVID land fallowing), and river re-operations.
State Water Project
Metropolitan is one of 29 water agencies that have contracted with the State of California, through the Department of Water Resources (DWR), for water deliveries from the SWP system. Metropolitan's contracted entitlement is for 2.01 maf per year, or about 48 percent of the total contracted entitlement of
4.2 maf per year. SWP deliveries to Metropolitan are made via the SWP's California Aqueduct.
Initial SWP facilities, completed in the early 1970's, have produced average supply yields adequate to meet just over half of the total contracted entitlement. While it was intended that additional SWP facilities would be constructed as SWP contractor demands increased up to their contracted entitlements, few facilities have been constructed since that time.
The SWP obtains its supplies primarily from the Sacramento River Basin. About half of the total supply diverted from the Delta for the SWP is regulated flow from the Feather River (a tributary to the Sacramento River), while the other half is unregulated flow from runoff downstream of Sacramento River reservoirs and from other rivers that flow into the Delta. The Sacramento River watershed is subject to wide annual variations in total runoff. The Sacramento River Index (SRI), which measures runoff in the watershed, has averaged about 18 maf per year over the last 90 years. However, runoff varies widely from year to year. For example, the SRI measured 7.8 mafin 1994 and 32.5 mafin 1995.
Figure 1 shows the historical total regional supply production by type. As shown in Figure 1, water supplies were as high as 4.25 mafin 1990 and within two years dropped to 3.4 mar, a 20% decrease. 4,500,000
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RETAIL DEMANDS
From 1982 through 1995, the region experienced retail water demands averaging 3.5 mar. In dry years retail demands are approximately 5 to 7% greater than normal years, while demands in wet years are about 6 to 8% below normal demands. Under normal weather conditions, assuming full implementation of conservation best management practices, total regional retail demands are projected to increase from about 3.7 mar in 1997 to almost 4.3 mar in 2010. Without conservation, demands in 2010 would be about 10 to 12% greater than projected. Increases in retail demand are driven by demographics and economics, including changes in population, housing, employment, and income. Figure 2 shows the historical and projected retail demands in Metropolitan's service area.
Figure 2. Regional Retail Water Demands
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The historical variability in demands from 1982 to 1997 is mainly due to weather and the economy. In 1983, extreme wet weather caused a significant drop in retail demands. During the period from 1985 to 1990, hot and dry weather coupled with a strong economy resulted in increased demand from 3.5 maf to
4.0 maf, a 14% increase. In 1991, the 5th year of a prolonged drought, conditions forced many communities to implement mandatory supply reductions. These mandatory reductions coupled with extraordinary drought conservation caused a 10 to 15% decrease in retail demands for the region. In addition, the period between 1992 and 1995 was very wet (with the exception of 1994, which was dry), and was a period of severe economic recession. Southern California alone lost some 700,000 jobs from 1990 through 1995. The combination of wet weather, economic recession, and conservation resulted in demands decreasing by over 17%.
DEMANDS ON METROPOLITAN
For many member agencies, Metropolitan's water deliveries represent a supplemental supply. Most member agencies have local water supplies, but agencies differ in how much their supplies alone can meet their respective retail demands. Local supplies are often base-loaded (maximized subject to various constraints) and purchases from Metropolitan are used to meet remaining demands. In addition, to meeting consumptive demands, Metropolitan's deliveries are used to replenish local groundwater and surface reservoirs. To project demands on Metropolitan, projections of member agency's retail water demands and local water supplies are made. Local supplies are then subtracted from retail demands to get consumptive demands on Metropolitan. A projection of Metropolitan's long-term seasonal and replenishment deliveries are made based on safe groundwater yield and weather/hydrology.
Metropolitan forecasts its demands for three different broad categories: Full Service, Seasonal (reservoir storage and groundwater replenishment delivered for shift or long-term storage purposes and sold at a discount), and Agricultural (deliveries of water sold at a discount for agricultural use). Overall, demands on Metropolitan can vary -+ 11 to 18% from normal conditions due to weather and hydrology.
The following four figures show historical and projected demands on Metropolitan by category. Figure 3 shows Basic Water Deliveries, Figure 4 shows Seasonal Water Deliveries, Figure 5 shows Interim Agricultural Water Program (IAWP) Deliveries, and Figure 6 shows Total Water Deliveries for Metropolitan.
Figure 3. MWD Basic Water Deliveries
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Figure 4. MWD Seasonal Water Deliveries
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Figure 6. MWD Total Water Deliveries
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INTEGRATED RESOURCES PLANNING
To ensure supply reliability under various drought conditions, Metropolitan and its member agencies developed an Integrated Resources Plan (IRP). The IRP, adopted by Metropolitan's Board of Directors in January 1996 and periodically updated, guides Metropolitan's resource and capital improvements investments. The region's ability to develop a long-term WSDM Plan results from the significant investments Metropolitan and its member agencies have made in resources since 1991. To date, these investments include:
• Local supplies: Metropolitan co-funded over 23 local projects and 200 conservation programs that will yield a total of 160,000 af per year. • Colorado River Aqueduct: Metropolitan developed transfers and storage programs to help ensure a full aqueduct. The landmark Metropolitan/Imperial Irrigation District Conservation Program (IID), will result in a savings of 107,000 af per year. Storage programs in Arizona and California, combined with the IID savings, yield a total of 280,000 af of annual core, dry year options, and storage supply. • State Water Project: Metropolitan and other parties negotiated the Bay-Delta Accord and the Monterey Amendment. The Bay-Delta Accord and subsequent efforts will increase the reliability of Metropolitan's entitlement deliveries. The Monterey Amendment provides access to 220,000 af of SWP storage. • In-Basin Storage: Metropolitan is constructing the Eastside Reservoir Project, with 800,000 af of storage (400,000 af of which is emergency storage for use in case of facility failure as a result of earthquake or other event). • Groundwater Conjunctive Use Storage: Metropolitan developed a conjunctive use storage program in the North Las Posas Basin in Ventura County with an anticipated capacity of 210,000 af and a dry-year withdrawal rate of up to 70,000 af. • Transfers and Storage: Metropolitan developed the Semitropic Storage Program, with 350,000 af of storage and dry-year withdrawals averaging about 60,000 af.
Metropolitan also approved the Arvin-Edison Storage and Transfer Program, with 250,000 af of storage and dry-year withdrawals averaging about 70,000 af.
Metropolitan is also exploring storage and transfer programs with the Coachella Valley Water District and the Cadiz Land Company.
As a result of these investments, it is anticipated that Metropolitan and its member agencies will be 100% reliable over the next 10 years even under a repeat of the 1991 drought condition. Figure 7 compares actual Metropolitan demands and supplies during 1991 (the last year in a multiyear severe drought) and projected demands and supplies in year 2005 (assuming a repeat of 1991 conditions). In 1991, the region faced shortages that required Metropolitan to allocate water under the Incremental Interruption and Conservation Plan (IICP). The reduction in deliveries came after demands had already been reduced as a result of local conservation. In addition, water had to be purchased from the Governor's drought emergency water bank. By the year 2005 with the investments made to date, Metropolitan's additional water supplies will be more than adequate to meet demands under a repeat of the 1991 drought event--even with increased demands due to growth.
Figure 7. Historical and Projected Metropolitan Supplies and Demands Under Drought Conditions ....
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SURPLUS AND SHORTAGE RESOURCE ACTIONS
Metropolitan's investments in water resources, facilities, and programs has transformed it from an agency with relatively modest storage capacity to one that will have storage sufficient to manage many shortages without negative impacts to its member agencies or retail customers. To attain this level of reliability, storage programs and facilities, along with conservation, recycling, and other programs, must be managed as an integrated set of regional resources. To accomplish this, the WSDM Plan recognizes the linkage between surplus and shortage resource management actions.
SURPLUS ACTIONS
The combination of Metropolitan's regional storage facilities, such as Lake Mathews, Lake Skinner, the future Eastside Reservoir Project, and the storage capacity available to Metropolitan in Castaic Lake and Lake Perris as a result of the Monterey Amendment, allows Metropolitan great flexibility in managing its water resources. The development of storage programs both outside and within the service area provides even greater flexibility in storing surplus water. Each of the storage facilities and programs plays an important role in achieving Metropolitan's reliability goal.
When imported supplies exceed projected demands for imported water within Metropolitan's service area, Metropolitan can operate storage facilities to maximize stored water to benefit its member agencies. A number of factors affect Metropolitan's ability to divert surplus water into storage. Some of these factors include facility outages, system capacity, water quality (including requirements for managing total dissolved solids), and varying supply and demand patterns. This section provides a description of storage options available to Metropolitan and a framework for storing water in these programs and facilities when surplus supplies are available.
Storage of Colorado River Supplies
Metropolitan has participated in a number of programs to maximize the reliability of supplies from the Colorado River. The landmark Metropolitan/Imperial Irrigation District Conservation Program will result in a savings of 107,000 af per year. These supplies will increase the reliability of Metropolitan's entitlement of Colorado River water. Other programs yield shortage benefits by increasing amounts of water stored for use during shortages. Between August 1992 and July 1994, Metropolitan and the Palo Verde Irrigation District conducted a Test Land Fallowing Program. Approximately 20,000 acres of farmland in the Palo Verde Valley were not irrigated, saving 186,000 af of water which was stored in Lake Mead for later use by Metropolitan. With Arizona and Nevada water agencies, Metropolitan is participating in a Central Arizona Groundwater Storage Demonstration Program that has encouraged the storage of water. To date, 139,000 af of supplies have been stored in groundwater basins in Central Arizona. The Desert Coachella program is an exchange and storage program with agencies situated along the Colorado River Aqueduct. Metropolitan releases Colorado River water for storage in the Coachella Groundwater Basin. Metropolitan then exchanges these supplies for the participating agencies' SWP supplies. These programs serve as models for future programs that could increase the reliability of Colorado River supplies. Metropolitan continues to explore other possible options that would increase the reliability of supplies. The California 4.4 Plan is being developed among California parties to increase storage programs for Colorado River supplies. In addition to core transfers and conservation programs, the California 4.4 Plan includes offstream storage (such as the Arizona groundwater storage program), dry year option transfers (such as PVID land fallowing), and river reoperations. These programs, in conjunction with favorable supply determinations by the Secretary of Interior, will ensure the highest possible reliability of Colorado River supplies.
In addition to the programs mentioned above, the Colorado River system itself contributes to the high reliability of Metropolitan's Colorado River supplies. Currently, the average Colorado River runoff exceeds basin-wide demands by over 1.0 maf per year. The Colorado River system also contains a great deal of reservoir storage capacity. The total storage capacity in the Colorado River Basin is approximately 60 maf, almost four times the Colorado River's average annual flow. For much of 1997, system storage levels were at 80% or more of total capacity. These factors allow the Bureau of Reclamation, operators of the Colorado River system, to store significant supplies for use during shortages.
Storage of State Water Project Supplies
Total storage capacity is a critical factor in comparing the operations of the Colorado River system with the SWP. On average, both systems have similar amounts of water available on an annual basis. The SWP's watersheds in the Sacramento River Basin have produced about 18 maf per year over the long term, as represented by the Sacramento River Index (SRI.) Long-term runoff on the Colorado River has averaged more than 16 maf annually since 1906. However, the ability to carry over unused water from a wet year for use in a dry year differs substantially between the two systems. State Water Project storage facilities have storage capacity of about 4.5 maf, while system storage in the Colorado River Basin totals nearly 60 maf. This gives the operators of the Colorado River reservoirs much more flexibility in storing unused water from a wet year for use in a subsequent dry year.
When water from the SWP cannot be put to immediate use in Metropolitan's service area, the water may be stored for future use. Provided storage capacity is available, the water may remain in either Oroville Reservoir (as SWP storage for delivery to all contractors the following year) or San Luis Reservoir (as carryover storage assigned to Metropolitan). Through the carryover storage program, as amended by the Monterey Amendment, Metropolitan can place a maximum of 200,000 af per year of allocated supplies in SWP surface reservoirs. The program also allows for carryover storage in non-project facilities, including surface reservoirs and groundwater basins. In the case of carryover storage in San Luis Reservoir, SWP supplies allocated to but unused by a contractor may, under certain conditions, be assigned as carryover if storage capacity is available at the end of the calendar year. However, carryover water stored for a contractor has lower priority than storage of SWP water and consequently "spills" first as San Luis Reservoir fills.
Also, in a wet year such as 1995, low demands may allow DWR to operate San Luis Reservoir nearly full, eliminating any possibility of contractor carryover storage into the following year. As a result, carryover storage on the SWP may not be possible, and even when possible, is subject to spilling.
Due to these carryover storage limitations, Metropolitan has invested a great deal to expand its ability to store surplus SWP supplies. Metropolitan has entered into a number of water transfer and storage agreements. The Semitropic Water Banking and Exchange program allows Metropolitan to store up to 350,000 afin the groundwater basin underlying the Semitropic Water Storage District. The storage and withdrawal capacities of the program are shared with other participants in the storage program, with Metropolitan's share equaling 35%. Dry-year withdrawals will average about 60,000 af.
Metropolitan and the Arvin-Edison Water Storage District have developed a program that allows Metropolitan to store water in the groundwater basin in the Arvin-Edison service area. The program would allow the storage and withdrawal of 250,000 af of supplies over the next 25430 years. Dry-year withdrawals will average about 70,000 af.
Storage in Regional Facilities
In addition to the storage of Colorado River and SWP supplies outside the region, Metropolitan has established a number of programs for storing supplies within the region. Metropolitan owns and operates two main surface reservoirs, Lake Mathews and Lake Skinner, which have a combined storage of about 226,000 af. Only a small portion of this capacity is available for shortages, with the balance being used to regulate flows in Metr0Politan's delivery system. The Eastside Reservoir Project, currently under construction, will have a total capacity of 800,000 af, with approximately 400,000 af of operational drought and seasonal storage and 400,000 af of emergency storage. Through the Monterey Amendment, Metropolitan obtained the fight to use up to 220,000 af of water stored in the SWP terminal reservoirs.
However, withdrawals from these terminal reservoirs must be replaced within five years.
Metropolitan and its member agencies have established the cyclic storage program to increase storage in groundwater basins within the service area. Regional groundwater basins offer an economical way for Metropolitan to improve supply reliability by storing water within the service area. This makes water readily accessible in times of need, either in emergency situations or during shortages. Some limitations are imposed by the fact that such water can generally only be used through pumping from the groundwater basin by an overlying member agency or local agency. Storage in groundwater basins takes place either by direct replenishment (spreading or injection), or through in-lieu means. Spreading (or injection) is desirable because direct measurement of the amount of stored water is a relatively simple, verifiable transaction. The main disadvantage to direct spreading is that spreading can occur only under certain conditions. For example, spreading cannot occur when spreading facilities are being used to capture local storm runoff for flood control purposes, or when the amount of local runoff precludes the need
for imported water to replenish the basins. Also, spreading basins require frequent maintenance to assure maximum efficiency. These and other conditions can limit the ability to deliver water for spreading at a time when surplus supplies are available.
In-lieu replenishment allows most member agencies to participate in groundwater replenishment without needing direct access to replenishment facilities. Their wells, in effect, become their replenishment facilities. Both direct and in-lieu replenishment from 1986 through 1990 served the region well during the critical drought years from 1991 through 1993.
The overall objective of the various storage programs is to maximize the availability of imported water during times of need by storing surplus water in a strategic manner and utilizing the storage available within the region. Many factors affect the availability of storage capacity and Metropolitan's ability to move water to and from various facilities. After reviewing the full range of shortage actions available to Metropolitan, a framework for prioritizing the full range of surplus and shortage actions will be presented.
In addition to pricing incentives used to encourage local agencies to store water in groundwater basins, Metropolitan has developed a conjunctive use contractual storage program with the Calleguas MWD in the North Las Posas Basin. Metropolitan will fund the construction of wells which will be called upon to meet demands during dry years. This program will yield a dry year supply of about 70,000 af.
SHORTAGE ACTIONS
Except in severe or extreme shortages or emergencies, Metropolitan's management of available resources will allow shortages to be mitigated without negatively impacting retail M&I demands. Below is a list of drought actions that will be taken during periods of shortage. The goal of these actions is to avoid, to the extent practicable, the allocation of Metropolitan's firm supplies. The order in which these actions are presented does not imply the exact operational management of resources that would occur. In fact, several actions are likely to be taken concurrently. Many factors dictate the particular order in which actions will be taken during an actual shortage, although it is clear that the last action will be the curtailment of firm deliveries to the member agencies.
• Draw on storage in the Eastside Reservoir Project
• Draw on out-of-region storage in Semitropic and Arvin-Edison • Reduce/suspend long-term seasonal and groundwater replenishment deliveries • Draw on contractual groundwater storage programs in the region • Draw on SWP terminal reservoir storage (per Monterey Agreement) • Call for extraordinary drought conservation and public education • Reduce IAWP deliveries
• Call on water transfer options contracts
• Purchase transfers on the spot market
• Implement an allocation of Metropolitan's imported supplies to its member agencies Even with dedicated programs to meet the reliability goal for the region, proper management and operations of these resources is critical to ensure reliability. The prioritization of both surplus and shortage actions need to account for several important criteria. It is also important to recognize that these criteria will need to be balanced. The criteria include:
Location: Out-of-region storage is more vulnerable than in-basin-storage due to the risks of seismic events. To only maximize out-of-region storage will put reliability at risk.
Take capacity: Surface reservoirs generally have the ability to be filled and drawn down very quickly.
Certain groundwater storage programs have limited take capacities--requiring several years at full take capacity to withdraw all available storage. Stored water will be balanced so that dry year supplies are maximized.
Cost: Programs vary with respect to their marginal operating costs. Program actions will be taken to maximize supply reliability while minimizing cost.
Flexibility: Not all storage programs and transfers offer the same flexibility to Metropolitan. Some programs can only meet specific overlying demands, while others can meet demands anywhere in the system.
DESCRIPTIONS OF RESOURCE ACTIONS
Draw on storage in the Eastside Reservoir Project: Withdrawals from the Eastside Reservoir Project would provide a flexible supply for meeting a shortage. Eastside Reservoir Project supplies can be drawn upon quickly. The amount of water drawn from the Eastside Reservoir Project before exercising other shortage actions will depend on the severity of the shortage and the overall condition of other resources available to Metropolitan.
Draw on out-of-region storage in Semitropic and Arvin-Edison programs: Out-of-region programs such as Semitropic and Arvin-Edison provide cost-effective shortage supplies. These supplies also provide flexibility, as they can be distributed as effectively as any SWP supplies coming into Metropolitan's service area. Exercising these programs relatively early in the order of actions reduces the risk of leaving supplies out-of-region. Based upon the ratio of storage capacity to take capacity, these programs will generally provide supplies over several years. This provides the rationale for calling on these programs relatively early in a shortage.
Reduce Long-Term Seasonal and Replenishment Deliveries, and call on cyclic storage accounts:
Certain interruptible supply programs provide benefits during shortage. Reducing deliveries to interruptible programs established for storage purposes, while continuing expected levels of groundwater production, allows limited supplies to go toward meeting direct consumptive uses. In addition, calling on cyclic storage accounts can extend the replenishment needs for several years. Most replenishment supplies would be expected to be interruptible for a minimum of two years before agencies would be allowed to claim a local supply adjustment on such supplies. Some programs have longer interruption requirements. For example, most Groundwater Recovery Programs are governed by contracts that require supply production through a three-year interruption in service.
Draw on contractual groundwater storage programs: In-region contractual groundwater programs provide cost-effective supplies that would be drawn upon during shortages. These programs are also limited by their take capacities and generally have several years of withdrawals in storage. For this reason, these programs might be called upon before withdrawing heavily from surface reservoir storage.
Draw on SWP terminal reservoir storage: The storage available in the SWP terminal reservoirs provides a flexible and cost-effective shortage supply. Supplies withdrawn from this program must be replaced within five years of withdrawal. For this reason, the storage in these reservoirs would be reserved for more serious shortage conditions and would be utilized after the programs and facilities listed above were used to meet the shortage.
Call for extraordinary drought conservation: Voluntary conservation programs have historically been effective in reducing water demand during drought. However, voluntary conservation programs are not without impact to the retail customer and can be perceived as a failure of water agencies to properly plan for shortages. Therefore, the call for extraordinary drought conservation will only be taken with the consent of Metropolitan's Board of Directors.
Reduce agricultural deliveries: The Interim Agricultural Water Program (IAWP) offers interruptible water to southern California's agricultural industry at discounted rates. These supplies will be interrupted as part of Metropolitan's shortage actions. Metropolitan will work with IAWP participants to provide as much advance warning of interruption as possible. The IAWP reflects current policies toward agricultural water users. The policies underlying this program are due to be reviewed during the ten-year period of the WSDM Plan. The WSDM Plan will be changed accordingly.
Call on water transfer option contracts: Transfer options programs provide cost-effective supplies when the region is faced with reducing deliveries to meet consumptive demands. These programs might also be used to increase storage levels in Metropolitan storage facilities. Replenishment of these facilities reduces the risk of leaving available supplies outside the region and helps to protect the region during extended shortages.
Purchase transfers on the spot market: During the 1987-92 drought, the Drought Water Bank proved to be one mechanism for California to reduce the overall impacts of the shortage. However, the cost of spot market supplies may cause Metropolitan to use them as a last increment of supply before the region implements reductions in M&I deliveries. It is likewise possible that availability and cost will make spot market options more favorable under certain conditions. If this occurs then spot market supplies will be sought prior to calls on option transfers. However, participation in the spot market may be restricted to those agencies that have already taken significant actions in response to the shortage.
Implement allocation plan: As the final stage in responding to shortages, Metropolitan will implement an allocation plan to deliver reduced supplies to its member agencies. The issues of allocation and the methods of allocation are outlined in the following section.
ALLOCATION OF SUPPLY FOR M&I DEMANDS
The equitable allocation of supplies is addressed by the Implementation Goals established for the WSDM Plan, with the first goal being to "avoid mandatory import water allocations to the extent practicable." The second fundamental goal is to "equitably allocate imported water on the basis of agencies' needs." Factors for consideration in establishing the equitable allocation include retail and economic impacts, recycled water production, conservation levels, growth, local supply production, and participation and investment in Metropolitan's system and programs. In the event of an extreme shortage an allocation plan will be adopted in accordance with the principles of the WSDM Plan.
INTEGRATED RESOURCE MANAGEMENT STRATEGY
Throughout the Integrated Resources Planning process and the development of the WSDM Plan, extensive analysis of resource management strategies focused on maximizing supply reliability while minimizing overall resource costs. Various management strategies were analyzed under shortage scenarios based on historical hydrologic data. Certain strategies yield high reliability but incur very high costs. This is the case for strategies that utilize relatively costly transfer programs early in a shortage while maintaining high storage levels. If a shortage is short, this results in high transfer costs and shortage storage programs that are not fully utilized. Other strategies draw more heavily on storage early in a shortage and do not use options transfer programs. Later in a shortage, the yields from these transfer programs, combined with low yields from depleted storage facilities, might not make up for continuing or deepening shortages. Overall, such approaches may be inexpensive to pursue at the wholesale level but have high costs associated with retail level impacts. The resource management framework presented results from extensive analysis of various strategies for managing available resources under a variety of surplus and shortage conditions. Although the extent to which various actions are exercised may still vary depending on specific shortage conditions, the ordering presented does reflect Metropolitan's anticipated order of actions during shortages.
RESOURCE MANAGEMENT FRAMEWORK
The analysis of surplus and shortage actions yields a water management framework that accounts for the degree or "stage" of surplus and shortage. These stages are defined by parameters such as storage levels and expected SWP supplies. Each stage has associated actions that could be taken as part of the response to prevailing shortage conditions. For example, Surplus Stage 1 might have as associated actions to place water in the highest-priority storage resources. Figure 8 shows the mapping between actions and stages. The darkly shaded diagonal area identifies actions that can be undertaken concurrently, while the lightly shaded areas show actions that will not be taken. For example, Metropolitan will not withdraw water from most storage resources during a surplus.
Figure 8 highlights several aspects of the WSDM Plan's approach to supply management. First and most importantly, it does not dictate a response to shortage or surplus. The framework recognizes the complexity and variety of conditions that could require various responses. Supporting this framework are general "rule curves" that dictate the extent to which particular actions are taken in various stages of surplus or shortage. For example, the rule curves indicate approximately how much water should be taken from the Eastside Reservoir Project before calling on supplies from the Semitropic or ArvinEdison storage programs. If a shortage were greater than the desired initial withdrawal from the Eastside Reservoir Project, then Stage 2 actions would be taken. The rule curves for a particular resource would take into account shortage stage, monthly delivery requirements, and when various supplies are available.
Surplus and Shortage Stages are determined by the total amount of water that would be stored or produced by exercising the actions in that Stage. Overall storage levels in each stage are determined by the extent to which storage is increased or reduced by earlier actions. Therefore, each Stage is defined by supplies (stored or produced) and an approximate overall level of storage remaining in all resources.
Up through Shortage Stage 4, the actions taken will not result in negative impacts to any consumptive uses. Shortage Stages 1 through 4 constitute shortage management without retail level impacts. The conservation efforts and reductions in IAWP deliveries in Shortage Stage 5 will result in retail impacts.
Action by the Metropolitan Board of Directors would be required before actions corresponding to Stages 5, 6, and 7.
The Stages and Actions Matrix (Figure 8) is read from the center moving outward. Moving from the center to the left, are actions that Metropolitan will take during surplus conditions. For instance, in a Stage 3 Surplus, Metropolitan will be adding water to the Eastside Reservoir Project, the Monterey Reservoirs (if any water is due for repayment), Contractual Groundwater Programs, and carryover storage on the State Water Project. Moving from the center to the right are actions that Metropolitan will take during periods of shortage. For instance, in a Stage 3 Shortage, Metropolitan will be pulling water from the Eastside Reservoir Project, the Semitropic and Arvin Edison programs, and interrupting deliveries of Long-Term Seasonal and Replenishment program water. In addition, the Stages and Actions Matrix allows for surplus actions to be taken during shortages and vice versa, but these actions are strictly a result of prudent water management. For example, in a Stage 6 Shortage, Figure 8 shows Metropolitan potentially filling the Eastside Reservoir Project, the Monterey Reservoirs, and contractual groundwater programs while calling on spot transfers and buying spot water. Through these actions Metropolitan will be ensuring that water supply opportunities during a drought are realized--ultimately adding to the drought reserves of southern California.
Figure 8 also highlights the on-going efforts by Metropolitan and its member agencies in the conduct of public outreach and active conservation programs. Through all conditions, effective pubilc outreach and conservation programs are an integral part of Metropolitan's management of resources. In addition to ongoing conservation and water efficiency programs, Stage 5 of the Stages and Actions Matrix calls for participation of the citizens of southern California to take extraordinary conservation measures to cut water demand during droughts.
Surplus Sta es
Surplus
Figure 8. Resource Stages and Actions Matrix
Actions
Make Cyclic Deliveries
Fill Semitropic, Arvin-Edison
Store supplies in SWP Carryover
Fill Contractual GW
Fill Monterey Res.
Fill Eastside
Conduct Public Affairs Program
Take from Eastside
Take from Semitropic, Arvin-Ed.
Cut L TS and Replen. Deliveries
Take from Contractual GW
Take from Monterey Res.
Call for Extraordinary Conservation
Reduce IAWP Deliveries
Call Options Contracts
Buy Spot Water
Implement Allocation Plan
Potential Simultaneous Actions
Shortage
Shortage Stages
Severe
Shortage
Extreme
Shortage
As with the listing of shortage actions earlier in the report, the Stages/Actions matrix in Figure 8 only highlights certain programs and response actions. However, unlike the discussion of actions earlier, Figure 8 is intended to convey Metropolitan's currently anticipated ordering for those actions listed. As the supply and demand outlooks, programs, and other factors continue to change, the analysis of the ordering of actions will continue during the ten-year period of the WSDM Plan.
SUPPLY CERTAINTY AND THE TIMING OF RESOURCE ACTIONS
One of the fundamental trade-offs in dealing with supply shortages is the need to maintain flexibility while providing supply certainty to member agencies and consumers. A central focus of the WSDM Plan is the analysis of information about supplies and demands. When do various pieces of information about the supply/demand balance become more certain? When should this information impact policymaking and trigger various resource actions? The WSDM Plan addresses these questions and the actual implementation of the Plan during a shortage.
Figure 9 shows a hypothetical shortage year. With respect to the supply and demand outlook, a typical shortage year will have periods of certainty and stability, and other periods of relative uncertainty and transition. Important supply components--such as the SWP, CRA, Los Angeles Aqueduct (LAA), and local supplies--are closely monitored through the early part of the year. These supplies and demands are fairly well-known through the April-September period. Storage is assessed in the post-summer period and decisions about certain programs, such as long-term (LT) seasonal deliveries could be made at this time.
Figure 10 presents the annual schedule for actions taken in response to shortage conditions. Starting in January, an initial supply/demand report will be presented to the Metropolitan Board of Directors. SWP allocations are still only estimates in January and become more certain towards April and May.
Demands for Metropolitan deliveries depend in part on how the winter hydrology develops and the condition of local supplies. These factors start to become known during the February-March period and will be reported to the Board in the Supply Report Update. By April-May, the outlook for imported supplies is known to a fairly high degree of certainty and a Final Supply Report will be produced. The May-September period will be one in which the import supply situation does not change drastically and drought policies can be implemented. Demands can be more or less than anticipated as a result of unusually hot or cool weather. At the end of summer, carryover SWP storage will be determined.
October through December is a transitional period during which early assessments of available supplies for the following year will be made. During this period, Board actions would determine the management of various Metropolitan programs such as long-term seasonal (LTS) and IAWP deliveries. The following list presents major information and decision points during the year.
Figure 9. Water Supply Outlook Throughout the Year
• SWP Allocation is Known
• Local Runoff is Known • LT Seasonal Decision
• LAA is Known • Post Summer Outlook:
• Changing SWP Allocation • CR Allocation is Known - Local Storage • SWP Interruptible Water - SWP Storage
• Unknown Local Runoff - Conservation Effort
• Changing LAA Forecast
J F M A M J J A s 0 N D
Month Information/Action
January Initial Supply/Demand Reports
February, March Updated Supply/Demand Reports
April, May Final Supply/Demand Report
Notification on Contractual GW and Options Transfer Programs Recommended Drought Actions
May-September Stable Policy Period
October Supply and Carryover Storage Report
November MWD Program Decisions - LT Seasonal, Replenishment, IAWP
PUBLIC OUTREACH AND CONSERVATION
Mechanisms are already in place to implement most of the water management actions and programs that are addressed in the WSDM Plan. Under the majority of supply and demand conditions, the actions of Metropolitan's Board of Directors, the General Manager, the operational activities of Metropolitan, and its member agencies would constitute all actions necessary to mitigate the shortage. Several aspects of the WSDM Plan, however, require additional attention to the administration of programs and actions. In particular, a shortage contingency requires special programs in the areas of public and governmental affairs and conservation. Metropolitan maintains an on-going public information program to encourage efficient water use. Public outreach programs are conducted at all times under both surplus and shortage conditions (see Figure 8). The actions discussed in this section constitute special actions in times of shortage.
Figure 10. One Year of a Hypothetical Shortage -
Supply and Demand Reports and Response Actions
I • Initial Supply/Demand Report I
• MWD Program Decision I • Updated Supply/Demand Report I - L TS, REPL Deliveries - Prelim. IA WP Decision
• Final Supply/Demand Report
• Notification, Calls on: • Supply Report
- Contractual GW Storage - SWP Carryover est.
- Options Transfers
• Recommended Drought Action
1 , 1, , f 1 , ,, 1 f 1 ,
J F M A M J J A s 0 N D 8 • Period of Stable Policy~
During shortage conditions, public outreach will play a critical role in shaping consumer response.
Public information campaigns need to send clear signals if extraordinary drought conservation is to achieve needed reductions in demands. Given Metropolitan's diverse set of customers and the varying impacts that shortages can have on different consumer groups, an effective public information campaign will require a joint effort among Metropolitan and its member agencies. Under this Plan, the administration of the Public Information and Government Affairs programs will be the responsibility of a Drought Program Officer (DPO). The DPO will be responsible for integrating the various activities in these areas, coordinating efforts with Metropolitan's Board of Directors and member agencies, and designing the region-wide messages for the general public and various target audiences. Important constituencies that have been identified in the process are residential users, business interests, agricultural users, elected officials, officials of various agencies (such as the Department of Water Resources), and the media.
Many conservation programs, such as Metropolitan's ultra-low flush toilet rebate program, are driven by member agency requests. Based on history, Metropolitan expects member agency requests to increase during droughts. Metropolitan is committed to increasing overall conservation program funding to meet member agency requests during droughts and attain higher levels of savings. These programs will be implemented by Metropolitan and member and local agency conservation staff. As many of the shortterm conservation objectives during a shortage would be dependent upon an effective public information program, the Drought Program Officer will also be responsible for monitoring the effectiveness of the augmented conservation programs. A monthly conservation reporting process will be implemented.
Quarterly estimates of regional conservation will be developed to track the progress of various actions in mitigating the shortage.
APPENDIX A: RESOURCE AND STORAGE SIMULATION
The Water Surplus and Drought Management Plan (WSDM Plan) uses the Stages and Actions Matrix (Figure 8) as a guide for the operation of storage and transfers for the next ten years, 1999-2008.
Metropolitan asserts that the investments that Metropolitan and its member agencies have made in water supply and storage, managed in a coordinated manner as presented in the WSDM Plan, will be sufficient to assure that retail firm water demands will be met 100% of the time through the year 2008.
Metropolitan performed an extensive analysis of projected water demands, current and expected water supplies, along with hydrologic variations to support this assertion. Appendix A presents a summary of this analysis which includes statistical probabilities of actions under the WSDM Plan and two illustrative examples of how supply resources may be used in the future under worst-case drought events. Although the WSDM Plan is intended to be in effect through 2008, for the purposes of analysis the planning horizon was extended through 2010.
The WSDM Plan seeks to define the operational envelope for the Metropolitan system into the near future. Although the WSDM Plan only looks out ten years, it nonetheless involves the operation of some storage and water transfer projects that have not yet become fully operational. This makes the estimation of storage and transfers operations difficult. Compounding this problem is the lack of certainty around future demands, economic conditions, or even the weather over the next ten years. To manage these uncertainties, Metropolitan has developed a computer based simulation model called the Integrated Resources Planning Simulation Model or IRPSIM.
IRPSIM uses a modeling method known as sequentially indexed monte-carlo simulation. Simply put, the model looks at projected regional retail demand and supplies of water over the next twelve years and adjusts each, up or down, based on an assumed pattern of future weather. For instance, if Metropolitan expected the weather over the next twelve years (1999-2010) to be the same as the last twelve years (1987-1998), then IRPSIM would adjust the projected 1999 demands and supplies based on the historical 1987 hydrology, and adjust the projected 2000 demands and supplies using the historical 1988 hydrology, and so on. One obvious drawback to this approach is that Metropolitan does not know what future weather will be. Therefore, Metropolitan runs the models over and over again until all recorded hydrologies, 70 in all, have been tried. In this way, Metropolitan can look at probabilistic results of being in shortage year by year through 2010.
Although the projections of water supplies used in this analysis required certain assumptions to be made, they were based on most likely or probable outcomes. In most cases, projected water supplies represented projects that are currently operational, under construction, or in the final stages of negotiations. The following represents a summary of these assumptions:
• Local recycling and groundwater recovery: assumes currently operational projects with expected increases in supply yield as demand increases
• Conjunctive use groundwater storage: assumes Las Posas (under final stages of construction) and implementation of similar programs which are under negotiation (such as Raymond, Orange, and Chino Basins)
• Semitropic and Arvin-Edison storage: assumes use of both programs which are operational with water already stored
• Eastside Reservoir Project: assumes use of non-emergency storage from the reservoir currently under construction and an initial fill projected to start in approximately one year • The Monterey Reservoirs: assumes use of State Water Project terminal reservoir supplies, Castaic and Perris Reservoirs, per the Monterey Amendment • Colorado River Aqueduct: assumes a full aqueduct through the implementation of the California Plan (including lining of All American and Coachella canals, SD/IID water transfer/exchange, conjunctive use off-aqueduct storage, and river re-operations) • State Water Project: assumes continuance of Bay-Delta Accord (with only current facilities) One way of viewing the result of Metropolitan's WSDM Plan analyses is by summary statistics. Table A- 1 gives the probabilities of shortage actions over the next twelve years.
Table A-1. Probability of Shortage Stage
1 by Forecast Year
1999 13% 13% 11% 7% 3% 0% O%
2000 13% 13% 11% 9% 3% O% 0%
2001 19% 17% 13% 10% 6% O% 0%
2002 19% 17% 13% 10% 4% 1% 0%
2003 19% 19% 14% 11% 4% 0% 0%
2004 20% 19% 16% 13% 4% 0% 0%
2005 21% 19% 17% 13% 6% O% O%
2006 21% 19% 19% 13% 6% 0% 0%
2007 23% 20% 19% 13% 4% 0% 0%
2008 26% 21% 19% 16% 6% 1% 0%
2009 26% 24% 19% 17% 6% 1% 0%
2010 26% 26% 19% 19% 6% 1% O%
Table A-1 can be read in one of two ways, by column or row. The Stage 7 column indicates that there are no historical weather conditions that require allocation over the next twelve years. This is the single most important conclusion of the WSDM Plan analysis. The Stage 6 column indicates that only in a few years--2002, and 2008 through 2010--would Metropolitan need have a need for option or spot transfer water. Read by row, Table A-1 indicates that in the year 2008 there is a 21% likelihood of taking some water from the Eastside Reservoir Project, a 19% likelihood of taking water from Semitropic or ArvinEdison storage programs, a 17% likelihood of interrupting long-term seasonal and replenishment deliveries for two years, and so on. It should be noted that these probabilities represent the best current estimates by Metropolitan, but are based entirely on historical weather conditions. Conditions that fall outside of historical ranges, either in duration or severity, are not represented by this data.
Another way to view the WSDM Plan analysis is by observing the operation of a single hydrology.
Table A-2 provides an example of resource operations for the period 1999 through 2010 assuming a repeat of the 1923 through 1934 hydrology. The table provides descriptions of hydrologic conditions to aid in understanding the example.
1 Stage 1 consists of withdrawal from the Eastside Reservoir Project. Stage 2 consists of the above plus withdrawals from the Semitropic and Arvin-Edison water storage and transfer projects. Stage 3 consists of the above plus an interruption of Long-Term Seasonal and Replenishment discount water.
Stage 4 consists of the above plus withdrawal from contractual groundwater programs and the Monterey Reservoirs. Stage 5 consists of the above plus a call for extraordinary drought conservation and interruption in agricultural discount water. Stage 6 consists of the above plus calls on option contract water and purchases of water on the open market. Stage 7 consists of the above plus allocation of remaining shortages. For a full description of stages and action, see Surplus and Shortage Resource Actions section and Figure 8 above.
For instance, 1923 was considered to be a dry year in southern California (defined as less than 9 inches of rain at the Los Angeles Civic Center) and is categorized by the California Department of Water Resources (DWR) as a below normal year for State Water Project deliveries. In this example, 1923 weather increases southern California's demand for water and decreases imported State Water Project supplies. The Colorado River Aqueduct supplies are influenced by yet another hydrologic indicator, but for the next ten year Metropolitan expects the Aqueduct to be full.
Table A-2 indicates that retail water demands in 1999, assuming a 1923 hydrology, will be 3.979 million acre-feet (maf). Adding expected long-term seasonal and replenishment demands of 0.165 maf gives a regional total water demand of 4.144 maf. After subtracting local supplies of 2.192 maf, which are also adjusted for 1923 weather, Metropolitan expects to see a demand of 1.952 maf. In 1999, under a 1923 hydrology, Metropolitan expects to see 2.954 maf of supply. This is enough to meet all expected demands and put over 1.0 maf into storage.
The 1923 through 1934 hydrology is significant because it starts and ends dry with little recovery in the middle. However, even in these most adverse conditions the actions proposed by the WSDM Plan provides the region with enough water to avoid shortage allocation. Again the most important result of this example is read from the last line, which indicates that there are no remaining shortages through 2008
Table A-3 provides a second example of using the 1980 through 1991 hydrology. This hydrology contains the most significant drought in recent record, ending with a critically dry year on the State Water Project that is expected to yield a mere 0.389 maf. However, even under these conditions the WSDM Plan provides a method to avoid firm water allocation.
The analyses performed using the prioritized action of the Stages and Actions Matrix support Metropolitan's assertion that water supply reliability can be attained through the use of regional storage, interruption of discounted water supplies, and transfers. And, through the implementation of the WSDM Plan, Metropolitan does not expect to allocate firm water deliveries for at least the next ten years.
Table A-2. A Simulation of Water Supplies and Demands 1923-1934 Hydrology Forecast Year 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 Hydrology Year 1923 1924 1925 1926 1927 1928 1929 1930 1931 1932 1933 1934 Hydrologic Conditions Southern California Year Type Dry Dry Dry Wet Wet Dry Dry Normal Wet
Normal Wet
Normal
Sacramento River Index D1630 Year Type Below
Normal
CriticallyDry
Dry Dry Wet Above
Normal
CriticallyDry
Dry Critically
Dry
Dry Critically
Dry
Critically Dry
Demands Retail Demand Long-term/Replenishment Demand
3.979 0.165
4.152 0.182
4.149 0.226
4,018 0.188
4.005 0.149
4.249 0.176
4.237 0,213
4.223 0.203
4.280 0.164
4.280 0.175
4.407 0.141
4.500 0.163
Total Demand 4.144 4.334 4.375 4.205 4.154 4.425 4.450 4.426 4,443 4.455 4.548 4,663 Local Supplies Groundwater Production L. A. Aqueduct Production Recycling Production Surface Production
1.529 0.383 0.152 0,128
1.545 0,287 0.162 0,089
1.537 0.304 0.174 0,076
1.288 0.316 0.186 0.116
1.299 0.392 0,197 0.154
1.575 0.302 0.207 0.147
1.568 0,245 0.217 0.108
1.434 0.235 0.230 0.094
1.307 0.174 0,242 0,133
1.439 0,324 0.254 0,136
1.318 0.251 0.266 0.151
1.454 0.220 0.277 0.145
Total Local Supply 2,192 2.084 2.091 1.905 2,043 2.231 2,139 1.993 1.856 2.153 1.986 2,097 Total MWD Demand 1.952 2.250 2,284 2,300 2.112 2.194 2.311 2.433 2.587 2.302 2.562 2.566 MWD Supply Sources Colorado River Aqueduct Supply State Water Project Supply MWD Cyclic Groundwater Deliveries Eastside Reservoir Arvin/Semitropic Groundwater Storage Longterm Seasonal Demand Cuts Cyclic Benefits Contractual Groundwater Storage DWR Reservoirs (Monterey Agreement) Voluntary Conservation MWD Ag Cuts Central Valley Transfers
1.200 1.754 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000
1.200 0.812 0.060 0.066 0.111 0,000 0.000 0.000 0.000 0.000 0.000 0.000
1.200 0.783 0.060 0.058 0.115 0,166 0.000 0.000 0,000 0.000 0.000 0,000
1.200 1.280 0.000 0.000 0,000 0.000 0.000 0,000 0.000 0.000 0.000 0.000
1.200 1.678 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000
1.200 1.438 0,000 0.000 0,000 0.000 0.000 0.000 0.000 0.000 0,000 0.000
1.200 0,764 0.060 0,060 0,119 0.153 0,000 0.000 0.000 0.000 0.000 0.000
1.200 1.163 0,060 0.010 0,000 0.000 0,000 0,000 0.000 0.000 0.000 0.000
1.200 0,589 0.060 0.425 0.115 0.104 0,000 0.095 0,000 0,000 0.000 0.000
1.200 0.843 0.059 0.023 0.117 0,116 0,000 0.000 0,000 0.000 0.000 0.000
1.200 0.559 0.000 0.219 0.059 0.000 0.060 0.095 0.131 0.206 0.033 0.000
1.200 0.620 0.000 0.041 0.041 0.000 0.060 0.084 0.088 0.210 0.031 0.193 Storage Puts 1.003 0.000 0.097 0.180 0.549 0.438 0.045 0.000 0,000 0.056 0.000 0.000 Remaining Shortage 0,000 0,000 0.000 0,000 0.000 0.000 0.000 0,000 0.000 0.000 0.000 0.000 Table A-3. A Simulation of Water Supplies and Demands 1980-1991 Hydrology Forecast Year 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 Hydrology Year 1923 1924 1925 1926 1927 1928 1929 1930 1931 1932 1933 1934 Hydrologic Conditions Southern California Year Type Wet Normal
Normal Wet Dry Dry Wet
Normal
Normal Dry Dry
Normal
Sacramento River Index D1630 Year Type Above
Normal
Dry Wet Wet Wet Dry Wet Dry Critically
Dry
Dry Critically
Dry
Critically Dry
Demands Retail Demand Lon£1-term/Replenishment Demand
3.781 0.105
4.170 0.141
3.930 0.171
3.647 0.101
4.308 0.136
4.250 0.187
4.151 0.183
4.281 0.201
4.380 0.191
4.550 0.219
4.663 0.224
4.497 0.214
Total Demand 3.886 4.311 4.101 3.748 4.444 4.437 4.334 4.483 4.572 4.769 4.887 4.712 Local Supplies Groundwater Production L. A. Aqueduct Production Recycling Production Surface Production
1.292 0.462 0.152 0.225
1.440 0.372 0.162 0.175
1.381 0.499 0.174 0.154
1.248 0.529 0.186 0.194
1.546 0.516 0.197 0.195
1.565 O.367 0.207 0.151
1.275 0.472 0.217 0.115
1.413 0.400 0.230 0.116
1.438 0.326 0.242 0.115
1.588 0.278 0.254 0.081
1.600 0.213 0.266 0.068
1.446 0.223 0.277 0.081
Total Local Supply 2.131 2.149 2.208 2.156 2.455 2.290 2.081 2.159 2.122 2.200 2,146 2.027 Total MWD Demand 1.755 2.162 1.894 1.591 1.989 2.147 2.253 2.324 2.450 2.569 2.741 2.684 MWD Supply Sources Colorado River Aqueduct Supply State Water Project Supply MWD Cyclic Groundwater Deliveries Eastside Reservoir Arvin/Semitropic Groundwater Storage Long-term Seasonal Demand Cuts Cyclic Benefits Contractual Groundwater Storage DWR Reservoirs (Monterey Agreement) Voluntary Conservation MWD Ag Cuts Central Valley Transfers
1.200 1.561 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000
1.200 1.441 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000
1.200 1.725 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 1,200 1.886 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000
1.200 1.643 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000
1.200 1.590 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000
1.200 1.441 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000
1.200 1.292 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000
1.200 0.611 0.060 0.199 0.115 0.131 0.000 0.133 0.000 0.000 0.000 0.000
1.200 1.285 0.060 0.024 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000
1.200 0.877 0.060 0.222 0.122 0.164 0.000 0.095 0.000 0.000 0.000 0.000
1.200 0.389 0.060 0.209 0.104 0.154 0.000 0.085 0.216 0.235 0.032 0.000 Storage Puts 1.006 0.260 0.344 0.240 0.200 0.200 0.388 0.168 0.000 0.000 0.000 0.000 Remaining Shortage 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 Metropolitan Water District of
Southern California
Water Supply Allocation Plan
December 2014 Revision
Attachment B
1 Inside cover: Photo courtesy of Cora Edmonds/ArtXchange for the Healing Planet Water Supply Allocation Plan
Table of Contents
List of Acronyms............................................................................................................................................ 3 Definitions ..................................................................................................................................................... 3 Section 1: Introduction ................................................................................................................................. 4 Section 2: Development Process .................................................................................................................. 4 Member Agency Input .............................................................................................................................. 4 Board of Directors Input ........................................................................................................................... 4 The 12-Month Review Process ................................................................................................................. 5 The Three-Year Review Process................................................................................................................ 5 2014 Review Process................................................................................................................................. 6 Section 3: Review of Historical Shortage Plans............................................................................................. 7 Interruptible Water Service Program........................................................................................................ 7 Incremental Interruption and Conservation Plan..................................................................................... 7 1995 Drought Management Plan.............................................................................................................. 7 1999 Water Surplus and Drought Management Plan............................................................................... 7 Section 4: Water Supply Allocation Formula ................................................................................................ 8 Base Period Calculations........................................................................................................................... 8 Allocation Year Calculations...................................................................................................................... 9 Water Supply Allocation Calculations..................................................................................................... 10 Section 5: WSAP Implementation............................................................................................................... 13 Allocation Period..................................................................................................................................... 13 Setting the Regional Shortage Level ....................................................................................................... 13 Exit Strategy ............................................................................................................................................ 14 Allocation Appeals Process..................................................................................................................... 14 Allocation Surcharge ............................................................................................................................... 14 Tracking and Reporting ........................................................................................................................... 16 Key Dates for Water Supply Allocation Implementation........................................................................ 16 Appendix A: Metropolitan Member Agencies............................................................................................ 18 Appendix B: Water Supply Allocation Plan Process Timeline ..................................................................... 19 Appendix C: 12-Month Review Process and Results .................................................................................. 21 Appendix D: Three-Year Review Process and Results................................................................................. 23 Appendix E: 2014 Review Process and Results........................................................................................... 25 Appendix F: Summary of Historical Shortage Plans.................................................................................... 27 Appendix G: Water Supply Allocation Formula Example............................................................................ 28 Appendix H: Board Policy Principles on Determining the Status of Extraordinary Supply.........................34 Appendix I: Base Period Mandatory Rationing Adjustment....................................................................... 35 2 Appendix J: Per-Capita Water Use Minimum Example............................................................................... 36 Appendix K: Qualifying Income-Based Rate Allocation Surcharge Adjustment Example...........................39 Appendix L: Groundwater Replenishment Allocation ................................................................................ 41 Appendix M: Water Rates, Charges, and Definitions.................................................................................. 42 Appendix N: Allocation Appeals Process .................................................................................................... 43 Appendix O: Appeals Submittal Checklist................................................................................................... 46 List of Tables and Figures
Table 1: Shortage Allocation Index ............................................................................................................. 10 Table 2: Allocation Surcharge ..................................................................................................................... 15 Table 3: Board Adopted Allocation Timeline .............................................................................................. 17 Table 4: Member Agencies ......................................................................................................................... 18 Table 5: Historical Shortage Plan Overview................................................................................................ 27 Figure 1: Base Period Retail Demand Calculation....................................................................................... 28 Figure 2: Allocation Year Retail Demand Calculation ................................................................................. 29 Figure 3: Allocation Year Wholesale Demand Calculation.......................................................................... 30 Figure 4: WSAP Allocation Regional Shortage Level 4 ................................................................................ 33 Table 6: Total Retail Level Allocation Year Supplies ................................................................................... 37 Table 7: Total Per-Capita Water Use Adjustment....................................................................................... 38 Table 8: Residential Per-Capita Water Use Adjustment............................................................................. 38 Table 9: Water Rates and Charges.............................................................................................................. 42 Figure 1: Base Period Retail Demand Calculation....................................................................................... 28 Figure 2: Allocation Year Retail Demand Calculation ................................................................................. 29 Figure 3: Allocation Year Wholesale Demand Calculation.......................................................................... 30 Figure 4: WSAP Allocation Regional Shortage Level 4 ................................................................................ 33 3 List of Acronyms
AF – Acre-feet
CUP – Groundwater Conjunctive Use Program
CWD – County Water District
DWP – Drought Management Plan
IAWP – Interim Agricultural Water Program Reductions and Rates IICP – Incremental Interruption and Conservation Plan
IRP – Integrated Resources Plan
GPCD – Gallons per Capita per Day
M&I – Municipal and Industrial
MWD – Municipal Water District
RUWMP – Regional Urban Water Management Plan
SWP – State Water Project
WSAP – Water Supply Allocation Plan
WSDM – Water Surplus and Drought Management
Definitions
Extraordinary Supplies- Deliberate actions taken by member agencies to augment the total regional water supply only when Metropolitan is allocating supplies through the WSAP.
Groundwater Recovery- The extraction and treatment of groundwater making it usable for a variety of applications by removing high levels of chemicals and/or salts.
In-lieu deliveries- Metropolitan-supplied water bought to replace water that would otherwise be pumped from the groundwater basins.
Seawater Barrier- The injection of fresh water into wells along the coast to protect coastal groundwater basins from seawater intrusion. The injected fresh water acts like a wall, blocking seawater that would otherwise seep into groundwater basins as a result of pumping. 4 Section 1: Introduction
Calendar Year 2007 introduced a number of water supply challenges for the Metropolitan Water District of Southern California (Metropolitan) and its service area. Critically dry conditions affected all of Metropolitan’s main supply sources. In addition, a ruling in the Federal Courts in August 2007 provided protective measures for the Delta Smelt in the Sacramento-San Joaquin River Delta which brought uncertainty about future pumping operations from the State Water Project. This uncertainty, along with the impacts of dry conditions, raised the possibility that Metropolitan would not have access to the supplies necessary to meet total firm demands1 and would have to allocate shortages in supplies to the member agencies.2
In preparing for this possibility, Metropolitan staff worked jointly with the member agency managers and staff to develop a Water Supply Allocation Plan (WSAP). The WSAP includes the specific formulas for calculating member agency supply allocations and the key implementation elements needed for administering an allocation should a shortage be declared. The WSAP became the foundation for the urban water shortage contingency analysis required under Water Code Section 10632 and was incorporated into Metropolitan’s 2010 Regional Urban Water Management Plan (RUWMP).
Section 2: Development Process
Member Agency Input
Between July 2007 and February 2008, Metropolitan staff worked cooperatively with the member agencies through a series of member agency manager meetings and workgroups to develop a formula and implementation plan to allocate supplies in case of shortage. These workgroups provided an arena for in-depth discussion of the objectives, mechanics, and policy aspects of the different parts of the WSAP. Metropolitan staff also met individually with fifteen member agencies for detailed discussions of the elements of the recommended proposal. Metropolitan introduced the elements of the proposal to many nonmember retail agencies in its service area by providing presentations and feedback to a number of member agency caucuses, working groups, and governing boards. The discussions, suggestions, and comments expressed by the member agencies during this process contributed significantly to the development of this WSAP.
Board of Directors Input
Throughout the development process Metropolitan’s Board of Directors was provided with regular progress reports on the status of this WSAP, with oral reports in September, October, and December 2007, an Information Board of Directors Letter with a draft of the WSAP in November 2007, and a Board of Directors Report with staff recommendations in January 2008. Based on Water Planning and Stewardship Committee discussion of the staff recommendations and further review of the report by
1 Firm demands are also referred to as uninterruptable demands; likewise non-firm demands are also called interruptible demands.
2 See Appendix A: Metropolitan Member Agencies.
5 the member agencies, refinements were incorporated into the WSAP for final consideration and action in February 2008. The WSAP was adopted at the February 12, 2008 Board of Directors meeting. 3 The 12-Month Review Process
When the Board adopted the WSAP in February 2008, the decision specified a formal revisit of the WSAP commencing in February 2010. The scheduled revisit was meant to ensure the opportunity for Metropolitan staff and the member agencies to re-evaluate the WSAP and recommend appropriate changes to the Board of Directors.
In April 2009, the Board voted to implement the WSAP for the first time. The WSAP was implemented at a Level 2 allocation level, and was in effect for the period of July 1, 2009, through June 30, 2010.
Since implementation of the 2009/10 WSAP began in July 2009, a number of practical issues relating to the WSAP were identified by staff and the member agencies for further consideration during the 12- Month Review Process. Metropolitan staff engaged with the member agencies in a formal review of the WSAP from January through May 2010. During the review process the member agency managers participated in a series of six workshops. The focus of these workshops was to facilitate in-depth discussion on WSAP-related issues and lessons learned since the WSAP was implemented in July 2009.
The proposed adjustments to the WSAP developed during the review process were adopted at the August 17, 2010 Board of Directors meeting4
.
The Three-Year Review Process
The Board action to adopt of the WSAP in February 2008 also directed staff to review the WSAP formula three years after the February 2008 adoption. February 2011 marked the three-year anniversary since the adoption of the WSAP. Similar to the 12-Month Review Process, the purpose of the Three-Year Review Process was to provide an opportunity for Metropolitan staff and the member agencies to reevaluate the plan and recommend appropriate changes for board consideration.
Metropolitan staff met with the member agencies in a formal review of the WSAP from February through August 2011. Staff and member agency managers participated in a series of eleven workshops.
Proposed adjustments to the WSAP developed during the process were adopted at the September 13, 2011 Board of Directors meeting.5
3 A complete listing of member agency meetings and Board of Directors reporting activities is contained in Appendix B: Water Supply Allocation Plan Process Timeline. 4 A complete listing of member agency meetings and Board of Directors reporting activities is contained in Appendix C: 12- Month Review Process and Results. 5 A complete listing of member agency meetings and Board of Directors reporting activities is contained in Appendix D: ThreeYear Review Process and Results. 6 2014 Review Process
In 2014, California was challenged with a third year of severe drought. 6 Metropolitan managed its
operations through significant use of regional storage reserves. It was anticipated that end of year total dry storage reserves would approach levels similar to those when the WSAP was last implemented in 2009.
Following discussion at the June 2014 Water Planning and Stewardship Committee, Metropolitan staff convened a member agency working group to revisit the WSAP. The purpose of the working group was to collaborate with member agencies to identify potential revisions to the WSAP in preparation for mandatory supply allocations in 2015. There were eight working group meetings and three discussions at the monthly Member Agency Managers’ Meetings.
The process focused on three areas of the WSAP: the Base Period, the Allocation Formula, and the Allocation enforcement mechanism. Proposed adjustments to the WSAP developed during the process were adopted at the December 9, 2014 Board of Directors meeting. 7
6 The Governor of California proclaimed a State of Emergency due to drought conditions on January 17, 2014 and, on April 24, 2014 issued an Executive Order proclaiming a continued State of Emergency noting drought conditions have persisted for the last three years and authorizing adoption and implementation of emergency regulations. 7 A complete listing of member agency meetings and Board of Directors reporting activities is contained in Appendix E: 2014 Review Process and Results.
7 Section 3: Review of Historical Shortage Plans8
The WSAP incorporates key features and principles from the following historical shortage allocation plans but will supersede them as the primary and overarching decision tool for water shortage allocation.
Interruptible Water Service Program
As part of the new rate structure implemented in 1981, Metropolitan’s Board of Directors adopted the Interruptible Water Service Program (Interruptible Program) which was designed to address short-term shortages of imported supplies. Under the Interruptible Program, Metropolitan delivered water for particular types of use to its member agencies at a discounted rate. In return for this discounted rate, Metropolitan reserved the right to interrupt delivery of this Interruptible Program water so that available supplies could be used to meet municipal and industrial demands.
Incremental Interruption and Conservation Plan
The ability to interrupt specific deliveries was an important element of Metropolitan’s strategy for addressing shortage conditions when it adopted the Incremental Interruption and Conservation Plan (IICP) in December 1990. Reductions in IICP deliveries were used in concert with specific objectives for conservation savings to meet needs during shortages. The IICP reduced Interruptible Service deliveries in stages and provided a pricing incentive program to insure that reasonable conservation measures were implemented.
1995 Drought Management Plan
The 1995 Drought Management Plan (DMP) was a water management and allocation strategy designed to match supply and demand in the event that available imported water supplies were less than projected demands. Adopted by the Metropolitan Board of Directors in November 1994, the 1995 DMP was a short-term plan designed to provide for the 1995 calendar year only. The primary objective of the 1995 DMP was to identify methods to avoid implementation of mandatory reductions. The 1995 DMP included various phases and a step-by-step strategy for evaluating supply and demand conditions and utilizing Metropolitan’s available options, with the final phase being implementation of the revised IICP. 1999 Water Surplus and Drought Management Plan
Metropolitan staff began work on the Water Surplus and Drought Management (WSDM) Plan in March 1997 as part of the Integrated Water Resources Plan (IRP), which was adopted by Metropolitan’s Board of Directors in January 1996. The IRP established regional water resource targets, identifying the need for developing resource management policy to guide annual operations. The WSDM Plan defined Metropolitan’s resource management policy by establishing priorities for the use of regional resources to achieve the region’s reliability goal identified in the IRP. In April 1999, Metropolitan’s Board of Directors adopted the WSDM Plan.
8 A summary of the key elements in the following allocation plan is found in Appendix F: Summary of Historical Shortage Plans. 8 The WSDM Plan also included a set of principles and considerations for staff to address when developing specific allocation methods. The WSDM Plan stated the following guiding principle to be followed in developing any future allocation scheme:
“Metropolitan will encourage storage of water during periods of surplus and work jointly with its member agencies to minimize the impacts of water shortages on the region’s retail consumers and economy during periods of shortage.”9
This principle reflects a central desire for allocation methods that are both equitable and minimize regional hardship to retail water consumers. The specific considerations postulated by the WSDM Plan to accomplish this principle include the following:10
• The impact on retail customers and the economy
• Allowance for population and growth
• Change and/or loss of local supply
• Reclamation/Recycling
• Conservation
• Investment in local resources
• Participation in Metropolitan’s interruptible programs • Investment in Metropolitan’s facilities.
Section 4: Water Supply Allocation Formula
Based on the guiding principle and considerations described in the WSDM Plan, Metropolitan staff and the member agencies developed a specific formula for allocating water supplies in times of shortage.
The formula seeks to balance the impacts of a shortage at the retail level while maintaining equity on the wholesale level, and takes into account growth, local investments, changes in supply conditions and the demand hardening11 aspects of non-potable recycled water use and the implementation of conservation savings programs. The formula, described below, is calculated in three steps: base period calculations, allocation year calculations, and supply allocation calculations.12 The first two steps involve standard computations, while the third section contains specific methodology developed for this WSAP.
Base Period Calculations
The first step in calculating a water supply allocation is to estimate water supply and demand using a historical base period with established water supply and delivery data. The base period for each of the different categories of demand and supply is calculated using data from the fiscal years (July through June) ending 2013 and 2014.
13 9 WSDM Plan, p. 1. Emphasis added.
10 WSDM Plan, p. 2. 11 Demand hardening is the effect that occurs when all low-cost methods of decreasing overall water demand have been applied (e.g., low-flow toilets, water recycling) and the remaining options to further decrease demand become increasingly expensive and difficult to implement. 12 Detailed operational elements of these objectives and a numerical example are discussed in Appendix G: Water Supply Allocation Formula Example. 13 Exceptions to this methodology are noted in the descriptions of base period calculations. 9 Base Period Local Supplies: Local supplies for the base period are calculated using a twoyear average of groundwater production, groundwater recovery, Los Angeles Aqueduct supply, surface water production, and other imported supplies. Non-potable recycling production is not included in this calculation due to its demand hardening effect.
Base Period Wholesale Demands: Demands on Metropolitan for the base period are calculated using a two-year average of firm purchases and in-lieu deliveries to long-term groundwater replenishment, conjunctive use, cyclic, and supplemental storage programs.
Base Period Retail Demands: Total retail-level municipal and industrial (M&I) demands for the base period are calculated by adding the Base Period Wholesale Demands and the Base Period Local Supplies. This estimates an average total demand for water from each agency.
Base Period Mandatory Conservation Credit: Metropolitan allows a consultation process that enables member agencies to describe mandatory water use restrictions and/or rationing restrictions that were in place within their service areas during the Base Period. Restrictions may vary among agencies but include restricted water uses, fines, and water budget or penalty based rate structures that are enacted by the governing body of the member agency or retail agency. Following the consultation process, Metropolitan staff will recommend adjustments based on evidence of reduced GPCD. To qualify for an adjustment, GPCD reductions would have to be observed that are beyond those expected from the agency’s ongoing conservation efforts and trends.
Allocation Year Calculations
The next step in calculating the water supply allocation is estimating water needs in the allocation year.
This is done by adjusting the base period estimates of retail demand for population or economic growth and changes in local supplies.
Allocation Year Retail Demands: Total retail M&I demands for the allocation year are calculated by adjusting the Base Period Retail Demands for baseline inflation and growth.
Baseline Inflation Adjustment: Baseline inflation occurs when non-potable recycling or conservation is developed after the Base Period. The development of these supplies reduces actual demands for water in the Allocation Year. Because non-potable-recycling and conservation are excluded from the WSAP formula, the actual need for water in the Allocation year is overestimated. The Baseline Inflation Adjustment removes increases in non-potable recycling and conservation annually from the Base Period forward to better reflect the true need for water in the Allocation Year.
Growth Adjustment: The growth adjustment is calculated using the estimated actual annual rate of population growth at the county level, as generated by the California Department of Finance, whenever possible. For years without complete data, the growth rate is calculated using an average of the three most recent years available.
Growth will be allocated based on historical per capita water use during the Base Period, with a cap equal to Metropolitan’s IRP Target for Water Use Efficiency. For 10 allocation years up to and including 2014, the cap will be 163 GPCD, and for allocation years 2015-2020 the cap will reduce linearly from 163 to 145 GPCD. On an appeals basis, member agencies may request that their adjustment be calculated using member agency level population growth. A weighted combination of actual population and actual employment growth rates may also be requested.
Allocation Year Local Supplies: Allocation Year Local Supplies include groundwater production, groundwater recovery, Los Angeles Aqueduct supply, surface water production, seawater desalination, and other imported supplies. Estimates of Allocation Year Local Supplies are provided by the member agencies upon implementation of a WSAP. If estimates are not provided, Metropolitan will use the sum of the Base Period Local Supplies and Base Period InLieu Deliveries as a default. Agencies may provide updated estimates at any time during the Allocation Year to more accurately reflect their demand for Metropolitan supplies.
Extraordinary Supplies: Under the WSAP formula, local supply production in the Allocation Year can either be designated as a “planned” supply, or as an “extraordinary” supply. 14 This is
an important designation for a member agency because the two types of supplies are accounted for differently in the WSAP formula. Local supplies classified at Extraordinary Supply are only partially included (scaled depending on the WSAP Level) as local supplies. This has the effect of providing significantly more benefit to the member agency in terms of total water supply that is available to the retail customer.
15 Allocation Year Wholesale Demands: Demands on Metropolitan for the allocation year are calculated by subtracting the Allocation Year Local Supplies from the Allocation Year Retail Demands.
Water Supply Allocation Calculations
The final step is calculating the water supply allocation for each member agency based on the allocation year water needs identified in Step 2. The following table displays the elements that form the basis for calculating the supply allocation. Each element and its application in the allocation formula are discussed below.
Table 1: Shortage Allocation Index
(a)
Regional Shortage
Level
(b)
Wholesale Minimum
Percentage
(c)
Maximum Retail Impact
Adjustment Percentage
1 92.5% 2.5%
2 85.0% 5.0%
3 77.5% 7.5%
4 70.0% 10.0%
14 Appendix H: Board Policy Principles on Determining the Status of Extraordinary Supply lists the key Board principles used in determining if a supply qualifies as an Extraordinary Supply. 15 See Appendix G: Water Supply Allocation Formula Example for specific allocation formulae. 11 5 62.5% 12.5%
6 55.0% 15.0%
7 47.5% 17.5%
8 40.0% 20.0%
9 32.5% 22.5%
10 25.0% 25.0%
Regional Shortage Level: The WSAP formula allocates shortages of Metropolitan supplies over ten levels.
Wholesale Minimum Allocation: The Wholesale Minimum Allocation ensures a minimum level of Metropolitan supplied wholesale water service to each member agency.
Maximum Retail Impact Adjustment: The purpose of this adjustment is to ensure that agencies with a high level of dependence on Metropolitan do not experience disparate shortages at the retail level compared to other agencies when faced with a reduction in wholesale water supplies. The Maximum Retail Impact Percentage is prorated on a linear scale based on each member agency’s dependence on Metropolitan at the retail level. This percentage is then multiplied by the agency’s Allocation Year Wholesale Demand to determine an additional allocation.
Conservation Demand Hardening Credit: The Conservation Demand Hardening Credit addresses the increased difficulty in achieving additional water savings at the retail level that comes as a result of successful implementation of water conserving devices and conservation savings programs. To estimate conservation savings, each member agency will establish a historical baseline Gallons Per Person Per Day (GPCD) calculated in a manner consistent with California Senate Bill SBx7-7.16 Reductions from the baseline GPCD to the Allocation Year are used to calculate the equivalent conservation savings in acre-feet. The Conservation Demand Hardening Credit is based on an initial 10 percent of the GPCD-based Conservation savings plus an additional 5 percent for each level of Regional Shortage set by the Board during implementation of the WSAP. The credit will also be adjusted for:
• The overall percentage reduction in retail water demand • The member agency’s dependence on Metropolitan
The credit is calculated using the following formula:
Conservation Demand Harding Credit = Conservation Savings x (10% + Regional Shortage Level Percentage) x (1 +((Baseline GPCD – Allocation Year GPCD)/Baseline GCPD)) x Dependence on MWD Percentage
16 California Department of Water Resources, February 2011, “Methodologies for Calculating Baseline and Compliance Urban Per Capita Water Use. Available at:
http://www.water.ca.gov/wateruseefficiency/sb7/docs/MethodologiesCalculatingBaseline_Final_03_01_2011.pdf 12 This provides a base demand hardening credit equal to 10 percent of conservation savings and increases the credit as deeper shortages occur, which is when conservation demand hardening has a bigger impact on the retail consumer. The credit also increases based on the percentage of an agency’s demand that was reduced through conservation. This accounts for increased hardening that occurs as increasing amounts of conservation are implemented. Lastly, the credit is scaled to the member agency’s dependence on Metropolitan to ensure that credits are being applied to the proportion of water demand that is being affected by reductions in Metropolitan supply.
Minimum Per-Capita Water Use Credit: This adjustment creates a minimum per capita water use threshold. Member agencies’ retail-level water use is compared to two different thresholds. The proposed minimum thresholds are based upon compliance guidelines established under Senate Bill X7-7.
• 100 GPCD total water use
• 55 GPCD residential water use
Agencies that fall below either threshold under the WSAP will receive additional allocation from Metropolitan to bring them up to the minimum GPCD water use level. If an agency qualifies under both thresholds, the one resulting in the maximum allocation adjustment will be given. 17 To qualify for this credit, member agencies must provide documentation of the total agency level population and the percent of retail level demands that are residential; no appeal is necessary.
Total WSAP Allocation: The allocation to an agency for its M&I retail demand is the sum of the Wholesale Minimum Allocation, the Retail Impact Adjustment, the Conservation Demand Hardening Credit, and the Minimum Per-Capita Water Use Credit. 18 Total Metropolitan Supply Allocations: In addition to the WSAP Allocation described above, agencies may also receive separate allocations of supplies for and seawater barrier and groundwater replenishment demands. Allocations of supplies to meet seawater barrier demands are to be determined by the Board of Directors independently but in conjunction with the WSAP. Separating the seawater barrier allocation from the WSAP allocation allows the Board to consider actual barrier requirements in the Allocation Year and address the demand hardening issues associated with cutting seawater barrier deliveries. According to the principles outlined for allocating seawater barrier demands, allocations should be no deeper than the WSAP Wholesale Minimum Percentage implemented at that time.
The WSAP also provides a limited allocation for drought-impacted groundwater basins based on the following framework:19
17 See Appendix J: Per Capita Water Use Minimum Example for specific minimum per-capita water use credit formulae and example.
18 See Appendix G: Water Supply Allocation Formula Example for specific allocation formulae. 19 See Appendix L: Groundwater Replenishment Allocation for more information. 13 1. Metropolitan staff will hold a consultation with the requesting member agency and the appropriate groundwater basin manager to document whether the basin is in one of the following conditions:
a. Groundwater basin overdraft conditions that will result in water levels being outside normal operating ranges during the WSAP allocation period; or b. Violations of groundwater basin water quality and/or regulatory parameters that would occur without imported deliveries
2. An allocation is provided based on the verified need for groundwater replenishment.
The allocation would start with a member agency’s ten-year average purchases of imported groundwater replenishment supplies (excluding years in which deliveries were curtailed). The amount would then be reduced by the declared WSAP Regional Shortage Level.
Section 5: WSAP Implementation
The WSAP will take effect if a regional shortage is declared by the Board of Directors. The following implementation elements are necessary for administering the WSAP during a time of shortage. These elements cover the processes needed to declare a regional shortage level as well as provide information pertaining to the allocation surcharge.
Allocation Period
The allocation period covers twelve consecutive months, from July of a given year through the following June. This period was selected to minimize the impacts of varying State Water Project (SWP) allocations and to provide member agencies with sufficient time to implement their outreach strategies and rate modifications.
Setting the Regional Shortage Level
Metropolitan staff is responsible for recommending a Regional Shortage Level for the Board of Directors’ consideration. The recommendation shall be based on water supply availability, and the implementation of Metropolitan’s water management actions as outlined in the WSDM Plan.
Metropolitan staff will keep the Board of Directors apprised to the status of water supply conditions and management actions through monthly reports to the Water Planning and Stewardship Committee. To further facilitate staff in the development of a recommended regional shortage level, member agency requests for local supply adjustments shall be submitted by April 1st.
Metropolitan’s Board of Directors, through the Water Planning and Stewardship Committee, is responsible for approving the final Regional Shortage Level at its April meeting. By the April meeting, the majority of the winter snowfall accumulation period will have passed and will allow staff to make an allocation based on more stable water supply estimates. Barring unforeseen large-scale circumstances, the Regional Shortage Level will be set for the entire allocation period, which will provide the member agencies an established water supply level for their planning. 14 Exit Strategy
While the Board ultimately has discretion to implement or lift and allocation at any point of time during the year; the WSAP includes a two-part exit strategy that is meant to streamline the WSAP implementation decision making process.
• If the Board decides to implement the WSAP, then any current WSAP allocation would remain in place until the end of the Allocation Year.
• If the Board decides not to implement the WSAP, then any current WSAP allocation would be terminated concurrent with the Board decision.
Allocation Appeals Process
An appeals process is necessary for the administration of any changes or corrections to an agency’s allocation. Metropolitan’s General Manager will designate, subsequent to a declaration of an allocation by the Board of Directors, an Appeals Liaison as the official point of contact for all information and inquiries regarding appeals. All member agency General Managers will be notified in writing of the name and contact information of the Appeals Liaison. Only appeals that are made through the Appeals Liaison and in accordance with the provisions outlined in Appendix N: Allocation Appeals Process will be evaluated. Basis for appeals claims can include but are not limited to:
• Adjusting erroneous historical data used in base period calculations • Adjusting for population growth rates
• Determining if a local supply qualifies as Extraordinary Supply Additional details and a checklist for the appeals process are available in Appendix N: Allocation Appeals Process and Appendix O: Appeals Submittal Checklist.
Allocation Surcharge
Member agency allocations are supported by an Allocation Surcharge. The Allocation Surcharge is charged to water use above the Member Agency allocation and is charged in addition to Metropolitan’s standard rates for water service. Allocation Surcharges will only be assessed to the extent that an agency’s total annual usage exceeds its total annual allocation. Any revenues collected through the Allocation Surcharge will be applied towards Metropolitan’s Water Management Fund, which is used to in part to fund expenditures in dry-year conservation. No billing or assessment of allocation surcharges rates will take place until the end of the twelve-month allocation period.
Allocation Surcharge: The application of the Allocation Surcharge structure is a two tier structure that provides a lower level of Allocation Surcharge for minor overuse of allocations and a higher level of Allocation Surcharge for major overuse of allocations. The structure and applicable Allocation Surcharges are listed in Table 2. 15 Qualifying Income-Based Rate Allocation Surcharge Adjustment:22 Any Allocation Surcharges incurred by a member agency under the WSAP will be adjusted to reflect the extent to which retail customers within a member agency’s service area are served under a “lifeline” or similar qualified discounted rate program based on income or ability to pay (“Income-Based Rate”).
Any member agency who is assessed Allocation Surcharges under the WSAP may submit an acre-foot equivalent of water used by retail customers served under a qualifying Income-Based Rate.
23 This amount of water use would be multiplied by the percentage of retail-level reduction in allocation year demand necessary for that member agency to avoid exceeding its WSAP allocation. The monetary amounts resulting from these acre feet are subtracted from the total monetary amounts incurred by an agency for exceeding its allocation. In the case that the monetary amounts associated with the Income-Based Rate are greater than the total Allocation Surcharges an agency incurs, no Allocation Surcharges will be incurred. The end result of this adjustment is that the member agency will not be subject to Allocation Surcharges for the use of water by their retail customers served under a qualifying Income-Based Rate.
Growth Rate Allocation Surcharge Adjustment”: In recognition of member agency differences in geography and climate, a Growth Rate Allocation Surcharge Adjustment will be given to any agency that exceeds its WSAP Allocation. The Allocation Surcharge reduction will be based on the difference in acre-feet between the Growth Adjustment applied at Metropolitan’s IRP planning goal rate, and the greater of the following:
• The IRP planning goal rate adjusted for the member agency’s ETo, or • The member agency’s certified and documented 20x2020 targeted GPCD If both of these alternatives result in a lower growth adjustment than the IRP planning goal, no Allocation Surcharge reduction will be made.
20 The base water rate shall be the applicable water rate for the water being purchased. In most cases, it will be the Tier 1 rate (plus Treatment Surcharge for treated water deliveries). However, it is possible that the water being purchased would be in the amount that would put an agency beyond its Tier 1 limit. In that case, the base water rate will be the Tier 2 rate (plus Treatment Surcharge for treated water deliveries).
21 Allocation Surcharge is applied to water use in excess of an agency’s WSAP allocation. 22 See Appendix K: Qualifying Income-Based Rate Allocation Surcharge Adjustment Example for specific penalty adjustment formulae and example. 23 Appropriate documentation and certification will be required.
Table 2: Allocation Surcharge
Water Use Base Water Rate20 Allocation
Surcharge21 Total Rate
100% of Allocation Tier 1 0 Tier 1
Between 100% and 115% Tier 1 $1,480 Tier 1 + ($1,480)
Greater than 115% Tier 1 $2,960 Tier 1 + ($2,960)
16 Tracking and Reporting
Subsequent to a declared regional shortage by the Board of Directors, Metropolitan staff will produce monthly reports of each member agency’s water use compared to its allocations based on monthly delivery patterns to be submitted by the member agency. In order to produce these reports, member agencies are requested to submit their local supply use on a monthly basis and certify end of allocation year local supply use. These reports and comparisons are to be used for the purposes of tracking and communicating potential underage/overage of an agency’s annual allocations.
Key Dates for Water Supply Allocation Implementation
The timeline for implementation of an allocation is shown in Table 3. A brief description of this timeline follows:
January to March: Water Surplus and Drought Management reporting occurs at Metropolitan’s Water Planning and Stewardship Committee meetings. These reports will provide updated information on storage reserve levels and projected supply and demand conditions.
April: Member agencies report their projected local supplies for the coming allocation year.
This information is incorporated in staff analysis of storage reserves and projected supply and demand conditions in order to provide an allocation recommendation to the Board.
Metropolitan’s Board will consider whether an allocation is needed. A declaration of an allocation will include the level of allocation to be in effect for the allocation year. Likewise, member agencies will report their projected demands and local supplies needed to meet seawater barrier and groundwater replenishment requirements for the allocation year.
Metropolitan’s Board will consider whether allocations for seawater barrier demands and groundwater replenishment demands are needed independently from the WSAP allocation decision.July 1st: If the Board declared an allocation in April, then it will be effective starting July 1st. The allocation level will be held through June 30th, barring unforeseen circumstances.
Member agencies will now be requested to submit their local supply use on a monthly basis and certify end of allocation year local supply use. Local production data must be reported to Metropolitan by the end of the month following the month of use (use in July must be reported by the end of August). This information will be combined with Metropolitan sales information in order to track retail water use throughout Metropolitan’s service area. Each month Metropolitan will report on member agency water sales compared to their allocation amounts.
June 30th: The allocation year is complete.
July: Member agency local supplies must be certified for the month of June, the last month of the previous allocation year.
August: Metropolitan will calculate each member agency’s total potable water use based on local supply certifications and actual sales data for the allocation year of July through June.
Allocation surcharges will be assessed for usage above a given member agency’s final adjusted allocation (reflecting the actual local supply and imported water use that occurred in the allocation year).
17 *Member agency projections of local supplies are due on April 1st to assist Metropolitan staff in determining the need for an allocation in the coming allocation year.
Table 3: Board Adopted Allocation Timeline
Year Month Year 1
Board Decision
Year 1
Allocation Year
Year 2
Board Decision
Year 2
Allocation Year
Year 1
January
February
March
April Declaration *
May
June
July
Effective Period
Continuous Tracking of Member Agency
Local Supply and Imported Water Use
August
September
October
November
December
Year 2
January
February
March
April Declaration *
May
June
July
Effective Period
Continuous Tracking of Member Agency
Local Supply and Imported Water Use
August Assess
September
October
November
December
Year 3
January
February
March
April
May
June
18 Appendix A: Metropolitan Member Agencies
Source: http://mwdh2o.com/WhoWeAre/Member-Agencies/
Table 4: Member Agencies
City of Anaheim City of Glendale City of San Marino
City of Beverly Hills Inland Empire Utilities Agency City of Santa Ana City of Burbank Las Virgenes MWD City of Santa Monica
Calleguas MWD City of Long Beach Three Valleys MWD
Central Basin MWD City of Los Angeles City of Torrance
City of Compton MWD of Orange County Upper San Gabriel MWD Eastern MWD City of Pasadena West Basin MWD
Foothill MWD San Diego CWA Western MWD
City of Fullerton City of San Fernando
19 Appendix B: Water Supply Allocation Plan Process Timeline July 2007
• City of Long Beach Water Department staff briefing
• Member Agency Managers/Member Agency Workgroup meeting • Northern Managers Group meeting
o Foothill MWD, City of Pasadena, City of Long Beach, Calleguas MWD, City of Los Angeles, West Basin MWD, City of Burbank, Three Valleys MWD, City of Glendale, Upper San Gabriel MWD
August 2007
• Central Basin MWD staff briefing
• Eastern MWD staff briefing
• San Diego CWA staff briefing
• Member Agency Managers/Member Agency Workgroup meeting • Western MWD staff briefing
• City of Beverly Hills staff briefing
September 2007
• Member Agency Subgroup meetings
o MWD of Orange County, San Diego CWA, West Basin MWD, Central Basin MWD • MWD of Orange County staff briefing
• Member Agency Workgroup meeting
• Member Agency Workgroup meeting
• MWD Board of Directors Oral Report
October 2007
• Inland Empire Utilities Agency staff briefing
• Central Basin MWD Caucus Meeting (included sub-agencies) • Three Valleys MWD staff briefing
• MWD of Orange County staff briefing
• West Basin MWD staff briefing
• MWD Board of Directors Oral Report
November 2007
• West Basin MWD Caucus Meeting (included sub-agencies) • West Basin Water Users Association presentation
• Walnut Valley MWD staff briefing (sub-agency of Three Valleys MWD) • Foothill MWD Managers Meeting (included sub-agencies) • Central Basin MWD staff briefing
• City of Claremont City Council (sub-agency of Three Valleys MWD) • MWD Board of Directors Information Letter with Draft Proposal 20 December 2007
• Northern Managers Group Meeting
• California Department of Public Health staff briefing • City of Long Beach Water Department staff briefing
• Santa Ana River Watershed Project Authority presentation • Foothill MWD Managers Meeting (included sub-agencies) • MWD Board of Directors Oral Report
January 2008
• Northern Managers Group Meeting
• Water Replenishment District Board of Directors presentation • Three Valleys MWD staff briefing
• Member Agency Conservation Coordinator’s Group presentation • Member Agency Managers/Member Agency Workgroup meeting • City of Chino Hills presentation (sub-agency of IEUA) • Member Agency Workgroup meeting
• Hemet/San Jacinto Exchange Club presentation
• MWD Board of Directors Report with Staff Recommended Water Supply Allocation Plan February 2008
• MWD of Orange County and Irvine Ranch WD staff briefing • MWD Board of Directors Action Item
• San Gabriel Valley Water Association Meeting
• Orange County Water Policy Meeting
• SCAG Water Policy Task Force Meeting
21 Appendix C: 12-Month Review Process and Results
January 2010
• WSAP 12-Month Review Process workshop #1
o Focused discussion of WSAP issues identified by Metropolitan staff and by member agencies since the July 2009 implementation began.
February 2010
• WSAP 12-Month Review Process workshop #2
o Continuation of focused discussion
• WSAP 12-Month Review Process workshop #3
o Continuation of focused discussion
March 2010
• WSAP 12-Month Review Process workshop #4
o Continuation of focused discussion
• MWD Board of Directors information item
o Review of potential modifications to the WSAP definition of Extraordinary Supply April 2010
• WSAP 12-Month Review Process workshop #5
o Recap of identified issues and discussion of Metropolitan staff proposals for adjustments to the WSAP
• Member Agency Managers Meeting
o Update on the 12-Month Review Process
• WSAP 12-Month Review Process workshop #6
o Discussion of WSAP issues related to groundwater replenishment • Member Agency Managers conference call
o Clarification of WSAP definition for Extraordinary Supply May 2010
• Member Agency Managers Meeting
o Discussion of proposed Extraordinary Supply policy principles and WSAP Local Supply certification process.
• Member Agency Managers conference call
o Discussion of proposed Extraordinary Supply policy principles June 2010
• MWD Board of Directors action item
July 2010
• MWD Board of Directors information item
o Review of proposed adjustments to the WSAP developed in the 12-Month Review Process
August 2010
• MWD Board of Directors action item
22 Resulting Changes
• Removed references to Gains and Losses of Local Supply o Removed references in the WSAP to “gains and losses of local supplies” in order to better facilitate the accounting of historical base year and allocation year local supplies.
This change did not affect the WSAP formula or allocations. • Removed references to the Regional Shortage Percentage o Removed references to the “Regional Shortage Percentage” in the WSAP to reduce unintended confusion between calculation factors and shortage amounts. This change did not affect the WSAP formula or allocations.
• Included the Retail Impact Adjustment in all shortage levels o Included the Retail Impact Adjustment for Regional Shortage Levels 1 and 2. This change results in additional allocations to Metropolitan-dependent agencies under Level 1 and Level 2 regional shortages.
• Revised the accounting of Extraordinary Supplies
o Revised the methodology for accounting of Extraordinary Supply in the WSAP formula by:
Removing the Base Period Local Supply threshold provision, Removing the sliding-scale sharing mechanism from the formula, and Including the full amount of the Extraordinary Supply in the calculation of the Retail Impact Adjustment.
• Included a Minimum Per Capita Water Use Threshold
o Developed a minimum water use credit based on two GPCD water use thresholds.
Member agencies would receive additional Metropolitan allocation for an acre-foot equivalent of GPCD below the minimum threshold. Member agency water use, on a gallon per capita per day (GPCD) basis, is compared to the following minimum thresholds established under Senate Bill X7-7 (Water Conservation Act of 2009) 100 GPCD total use or
55 GPCD residential indoor use
• Excluded Seawater Barrier from the WSAP Formula
o Excluded seawater barrier supplies from the WSAP Base Period and Allocation Year local supply calculations. This allows the Board to determine allocations for seawater barrier demands separately from the WSAP.
23 Appendix D: Three-Year Review Process and Results
February 2011
• WSAP 3-Year Review Process workshop #1
o Review of the existing WSAP policy formula; review of the process timeline; and focused discussion of WSAP issues identified by Metropolitan staff and by member agencies since the WSAP’s adoption in February 2008
March 2011
• WSAP 3-Year Review Process workshop #2
o Discussion of issues related to local supplies and baseline inflation due to adjustments for recycling in the WSAP formula
• WSAP 3-Year Review Process workshop #3
o Continuation of prior workshop
April 2011
• WSAP 3-Year Review Process workshop #4
o Discussion of issues and alternatives related to base period selection and baseline inflation in the WSAP formula
• WSAP 3-Year Review Process workshop #5
o Discussion of recommendations to address baseline inflation in the WSAP formula May 2011
• WSAP 3-Year Review Process workshop #6
o Discussion of issues and alternatives for the growth adjustment methodology in the WSAP formula
• WSAP 3-Year Review Process workshop #7
o Continuation of prior workshop
June 2011
• WSAP 3-Year Review Process workshop #8
o Continuation of prior workshop, discussion of WSAP implementation exit strategy • WSAP 3-Year Review Process workshop #9
o Continuation of exit strategy discussion, discussion of baseline inflation due to conservation and related conservation demand hardening issues July 2011
• WSAP 3-Year Review Process workshop #9
o Continued discussion of baseline inflation and conservation issues, and discussion of sharing allocations between agencies with common local resources August 2011
• WSAP 3-Year Review Process workshop #10
o Discussion of WSAP Allocation Year timing vs. Tier 1-Tier 2 rate cycle timing, discussion of approaches for encouraging completion of WSAP local supply certifications • Review WSAP at Member Agency Managers Meeting
o Discussion of proposed WSAP adjustments to address baseline inflation issues, revise the growth adjustment methodology, and establish a WSAP exit strategy 24 September 2011
• MWD Board of Directors action item
Resulting Changes
• Baseline Inflation Adjustment
o Removed non-potable recycling and conservation from the WSAP baseline Increases in recycling and conservation will be subtracted annually from the Base Period forward
The annual population growth rate will be applied after deducting the annual increases in recycling and conservation
If an agency ends up in allocation penalty, a penalty reduction will be applied in an amount equal to the Code-Based and rate Structure conservation savings that were removed from the WSAP baseline
• Changed the Growth Adjustment methodology
o Growth will be allocated at historical per capita rate capped at the 2010 Integrated Water Resource Plan (IRP) Target for Water Use Efficiency For years up to and including 2014, the cap will be 163 GPCD For years 2015-2020, the cap will reduce linearly from 163 to 145 GPCD o If an agency exceeds its allocation, a penalty reduction will be applied based on either:
The differential Evapotranspiration (ETo) of its service area compared to the MWD average, or
Certified and documented 20 x 2020 targeted GPCD
• Exit Strategy
o Clarified the course of action for an existing WSAP allocation when Metropolitan’s Board makes a declaration decision for the following WSAP year If there is an allocation for the next year, then the current allocation stays in place
If there is no allocation for the next year, then the current allocation is lifted concurrent with the April decision
25 Appendix E: 2014 Review Process and Results
July 2014
• WSAP Workgroup Meeting #1
o First meeting of the 2014 WSAP Review process; review of the existing WSAP policy and formula; review of the process timeline; began discussion of issues related to base period selection
• WSAP Workgroup Meeting #2
o Discussion of base period selection
August 2014
• WSAP Workgroup Meeting #3
o Continuation of prior workshop discussion; comparison of base period alternatives September 2014
• WSAP Workgroup Meeting #4
o Discussion of a base period proposal; discussion of replenishment issues in the WSAP; discussion of 2015 water supply scenarios
• Review WSAP at Member Agency Managers Meeting
o Review of WSAP workgroup process; discussion on issues related to base period, demand hardening, and local resources development
• WSAP Workgroup Meeting #5
o Review of base period recommendation; discussion of issues regarding agencies in mandatory conservation during a base period; discussion on replenishment in the WSAP October 2014
• WSAP Workgroup Meeting #6
o Continuation of prior workshop discussion; discussion of alternative methods for conservation demand hardening credit; discussion of new and existing local supplies • Review WSAP at Member Agency Managers Meeting
o Review of WSAP workgroup process; discussion of issues related to base period and demand hardening
November 2014
• WSAP Workgroup Meeting #7
o Review and discussion of issues and potential methods for base period selection and adjustment, replenishment allocation, and conservation demand hardening credit; review of estimated effects of potential WSAP changes at the regional level • WSAP Workgroup Meeting #8
o Review of proposed recommendations for the WSAP based on workgroup discussion • Review WSAP at Member Agency Managers Meeting
o Review of proposed recommendations for the WSAP based on workgroup discussion 26 Resulting Changes
• Base Period Update to FY2013 and FY2014
o Changed the WSAP Base Period from calendar years 2004-2006 to fiscal years ending July 2013 and 2014
o Mandatory Conservation Adjustment
Agencies with mandatory conservation in effect during the base period (FY 2013 and/or FY 2014) may qualify for a demand hardening adjustment, adjustment is subject to a consultation process that includes consideration historical demand and GPCD information
• Modify Conservation Demand Hardening Credit
o Replaced device calculation-based estimates of conservation savings with a GPCD-based method
Conservation savings are calculated by comparing GPCD from a historical baseline to the Allocation Year; the difference is converted to acre-feet using the Allocation Year population.
• Baseline GCPD is 10-year average ending between 2004 and 2010, with gross water, using gross water use minus non-potable recycled water production and documented historical population
o Replaced formula for calculating the credit for each Regional Shortage Level o Conservation Demand hardening credit will be based on an initial 10 percent of GPCDbased conservation savings plus an additional 5 percent for each level of Regional Shortage; the credit will also be adjusted for the overall percentage reduction in retail water demand and the member agency’s dependence on Metropolitan. • Allocation Surcharge
o Replaced the WSAP Penalty Rate with an Allocation Surcharge based on the estimated cost of Turf Replacement conservation programs
27 Appendix F: Summary of Historical Shortage Plans
These five elements incorporated into the WSAP have, in four out of five instances, been used in previous shortage plans. Both the IICP and the 1995 DMP used a historical base period calculation, adjusted for growth, made local supply adjustments, and used conservation hardening credits in their formulations. The retail impact adjustment is the only feature of the WSAP that has not been used historically.
Table 5: Historical Shortage Plan Overview
Plan Element 1991 IICP 1995 DMP WSAP
Historical Base Period √ √ √
Growth Adjustment √ √ √
Local Supply Adjustment √ √ √
Conservation Hardening Credit √ √ √
Retail Impact Adjustment √
28 Appendix G: Water Supply Allocation Formula Example
The following example gives a step-by-step description of how the formula would be used to calculate an allocation of Metropolitan supplies for a hypothetical member agency. All numbers are hypothetical for the purpose of the example and do not reflect any specific member agency.
Step 1: Calculate Base Period Retail Demand
Base Period Local Supplies: Calculated using a two-year average of groundwater (gw), groundwater recovery (gwr), Los Angeles Aqueduct supply (laa), surface water (sw), seawater desalination (sd), and other non-Metropolitan imported supplies (os). For the purpose of this example, assume that the two year average is 59,000 af. [(gw1+gwr1+laa1+sw1+sd1+os1) + (gw2+gwr2+laa2+sw2+sd2+os2)] ÷ 2 = 59,000 af Base Period Wholesale Demands: Calculated using the same two-year time period as the Base Period Local Supplies. The Base Period Wholesale Demands include firm purchases (fp) and in-lieu deliveries to long-term groundwater replenishment (il), conjunctive use (cup), cyclic (cyc), and supplemental storage programs (ss). For the purpose of this example, assume that the two year average is 69,000 af.
[(fp1
++il1+cup1+cyc1+ss1) + (fp2+il2+cup2+cyc2+ss2)] ÷ 2 = 69,000 af Base Period Retail Demands: Calculated as the sum of the Base Period Local Supplies and Base Period Wholesale Demand.
59,000 + 69,000 = 128,000 af
Figure 1: Base Period Retail Demand Calculation
59,000
128,000
69,000
0 20,000
40,000
60,000
80,000
100,000
120,000
140,000
160,000
Acre-Feet
Base Period Wholesale Demand Base Period Retail Demand
Base Period Local Supplies
□
□
□
29 Calculate Adjustment for Base Period Mandatory Rationing (if applicable): The hypothetical agency used in this example is assumed not to qualify for the Base Period Mandatory Rationing Adjustment. A detailed discussion of the adjustment methodology can be found in Appendix I: Base Period Rationing Adjustment Example.
Step 2: Calculate Allocation Year Retail Demand
Allocation Year Retail Demand: Calculated by adjusting the Base Period Retail Demand for any baseline inflation and growth that occurred since the Base Period. 128,000 af + 5,000 af (net adjustment to retail demand) = 133,000 af Figure 2: Allocation Year Retail Demand Calculation
Step 3: Calculate Allocation Year Wholesale Demand
Allocation Year Local Supplies: Estimates of Allocation Year Local Supplies are provided by the member agencies upon implementation of a WSAP. If estimates are not provided, Metropolitan will use the sum of the Base Period Local Supplies and Base Period In-Lieu Deliveries as a default. Agencies may provide updated estimates at any time during the Allocation Year to more accurately reflect their demand for Metropolitan supplies. For this example assume that the Allocation Year Local Supplies total 65,000 acre-feet.
Allocation Year Local Supplies = 65,000 af
For this example assume also that this agency has an additional 5,000 acre-feet of supplies that meet the determinations for Extraordinary Supply. These supplies are withheld from the allocation formula except for in calculating the Retail Impact Adjustment Allocation.
Extraordinary Local Supplies = 5,000 af
Allocation Year Wholesale Demands: Calculated by subtracting the Allocation Year Local Supplies (65,000 af) from the Allocation Year Retail Demands (133,000 af). 133,000 af - 65,000 af = 68,000 af
128,000 133,000
5,000
0 20,000
40,000
60,000
80,000
100,000
120,000
140,000
160,000
Acre-Feet
Growth Adjustment Allocation Year Retail Demand
Base Period Retail Demand
□
□
□
30 Figure 3: Allocation Year Wholesale Demand Calculation Step 4: Calculate the Wholesale Minimum Allocation
Wholesale Minimum Percentage: Calculate from Table 1 for Regional Shortage Level 4.
Table 1: Shortage Allocation Index
(a)
Regional Shortage
Level
(b)
Wholesale Minimum
Percentage
(c)
Maximum Retail Impact
Adjustment Percentage
4 70.0% 10.0%
Wholesale Minimum Allocation: Calculated by multiplying the agency’s Allocation Year Wholesale Demand (68,000 af) by the Wholesale Minimum Percentage (70%) from the Table 1 for Regional Shortage Level 4.
68,000 af * 70% = 47,600 af
Step 5: Calculate the Retail Impact Adjustment Allocation Maximum Retail Impact Adjustment Percentage: Calculate from Table 1 for Regional Shortage Level 4.
Retail Impact Adjustment Allocation: Calculated first by determining the agency’s dependence on Metropolitan by dividing the Allocation Year Wholesale Demand (68,000 af) minus the Extraordinary Supply (5,000 af) by the Allocation Year Retail Demand (133,000 af) and multiplying by 100.
[(68,000 af - 5,000 af)/ 133,000 af] * 100 = 47%
65,000
68,000
133,000
0 20,000
40,000
60,000
80,000
100,000
120,000
140,000
160,000
Acre-Feet
Allocation Year Retail Demand Allocation Year Wholesale Demand Allocation Year Local Supply
□
□
31 Next, this percentage dependence on Metropolitan (47%) is multiplied by the Maximum Retail Impact Percentage for Shortage Level 4 (10%).
47% * 10% = 4.7%
This percentage is now multiplied by the Allocation Year Wholesale Demand (68,000 af) for the Retail Impact Adjustment Allocation.
68,000 af * 4.7% = 3,221 af
Step 7: Calculate the Conservation Demand Hardening Adjustment Calculate Baseline GPCD: To estimate conservation savings, each member agency will establish a historical baseline GPCD calculated in a manner consistent with California Senate Bill SBx7-7, using a 10 or 15-year average ending between 2004 and 2010, using gross water use minus non-potable recycle water production and documented historical population. For this example assume that the Baseline GPCD is 154 GPCD
Baseline GPCD = 154 GPCD
Calculate Allocation Year GPCD: Next, calculate the allocation year GPCD by converting the Allocation Year Retail Demand to GPCD and dividing by the Allocation Year Population from the WSAP. For this example the Allocation Year Retail Demand is 133,000 AF (see Step 2 above) and assume the Allocation Year Population is 905,000 persons. The resulting GPCD is 131 GPCD.
Allocation Year GPCD = 133,000 af/year * 325,851 gallons/af ÷ 365 days/year ÷ 905,000 persons = 131 GPCD
Calculate Reduction in GPCD: Subtract Allocation Year GPCD from Baseline GPCD to determine the GPCD Reduction.
GPCD Reduction = 154 GPCD – 131 GPCD = 23 GPCD
Calculate Conservation Savings: Convert the GPCD Reduction to the equivalent annual conservation savings in acre-feet, using the Allocation Year Population.
Conservation Savings = ((GPCD Reduction) x 365 days/yr x Population) 325,851 gallons/af
Conservation Savings = 23 x 365 x 905,000 ÷ 325,851 = 23,316 af Multiply by Regional Shortage Level Percentage: Multiply the Conservation Savings by 10 percent plus an additional 5 percent for each level of Regional Shortage (see Step 4 above). This example assumes a Regional Shortage Level of 4. This scales the hardening credit by the level of regional shortage, thereby increasing the credit as deeper shortages occur when demand hardening has a larger impact on the retail consumer.
23,316 af x (10% + (4 x 5%) = 6,995 af
32 Multiply by Conservation Savings Percentage: Next, multiply by the percentage of an agency’s demand that was reduced through conservation. This scales the hardening by the total percentage reduction to recognize that increased hardening occurs as increasing amounts of conservation are implemented.
Conservation Savings Percentage = 1 + ((Baseline GPCD – Allocation Year GPCD)/Baseline GPCD) Conservation Savings Percentage = 1+ ((154 GPCD – 131 GPCD)/154 GPCD) = 115% 6,995 af x 115% = 8,044 af
Multiply by Dependence on MWD: Next, multiply by the agency’s percentage dependence on MWD as shown in Step 5 above. This scales the credit to the member agency’s dependence on MWD to ensure that credits are being applied to the proportion of water demand that is being affected by reductions in MWD’s supply. For this example, dependence on MWD is 47%.
8.044 af x 47% = 3,781 af
Summary: The Conservation Demand Hardening Adjustment calculation is summarized by the following formula:
Conservation Demand Hardening Adjustment = Conservation Savings x (10% + Regional Shortage Level %) x (1+Conservation%) x Dependence on MWD %
Conservation Demand Hardening Adjustment = 23,316 af x (10% + (4 x 5%)) x (115%) x (47%) = 3,781 af
Step 8: Calculate the Low Per-Capita Adjustment Allocation: The hypothetical agency used in this example is assumed not to qualify for the Low Per-Capita Adjustment. A detailed discussion and example of the Low Per-Capita Adjustment calculation can be found in Appendix J: Per Capita Water Use Minimum Example.
Step 9: Calculate the total WSAP Allocation
WSAP Allocation: Calculated by adding the Wholesale Minimum Allocation (47,600 af), the Maximum Retail Impact Adjustment (3,221 af), the Demand Hardening Adjustment (3,781 af), and the Low Per-Capita Adjustment (0 af).
47,600 af + 3,221 af + 3,781 af + 0 af = 54,602 af
33 Figure 4: WSAP Allocation Regional Shortage Level 4
Step 10: Calculate total retail level reliability
Retail level reliability: Calculated by adding the WSAP Allocation (54,602 af), the Allocation Year Local Supply (65,000 af) and the Extraordinary Local Supply (5,000 af) and dividing by the Allocation Year Retail Demand (133,000 af). (54,602 af + 65,000 af + 5,000 af) ÷ 133,000 af = 93.7% Total Metropolitan Supply Allocations: In addition to the WSAP Allocation described above, agencies may also receive separate allocations of supplies for groundwater replenishment and seawater barrier demands. More information on the groundwater replenishment allocation is located in Appendix L: Groundwater Replenishment Allocation. 47,600
3,221 3,781
68,000
0 10,000
20,000
30,000
40,000
50,000
60,000
70,000
80,000
Acre
-
Feet
Allocation Year Wholesale Demand Demand Hardening Adjustment Retail Impact Allocation Wholesale Minimum Allocation
□
D
D
D
D D
34 Appendix H: Board Policy Principles on Determining the Status of Extraordinary Supply
At the June 8, 2010 Water Planning and Stewardship Committee meeting Metropolitan’s Board of Directors adopted the following policy principles to guide staff in determining the Extraordinary Supply status of future member agency supply programs.
No Negative Impacts to Other Member Agencies
A potential Extraordinary Supply for a member agency should not decrease the amount of Metropolitan water supply that would be available to the other member agencies in a WSAP.
Programs that utilize Metropolitan supplies as a primary or in-lieu source or as a means of payback or future replenishment may have the effect of decreasing supplies, available to other agencies, if designated as Extraordinary Supply.
Provides Supply in Addition to Existing Regional Supplies A potential Extraordinary Supply should provide a water supply that increases the overall water supplies that are available to the region in a WSAP. A program that is designed to move existing regional supplies from year to year would not qualify.
Specifically Designed Program or Supply Action
A potential Extraordinary Supply must be intentionally created and operated to provide additional supply yield. Normal variations in existing and planned local supply programs would not qualify.
Intended for Consumptive Use in a WSAP
A potential Extraordinary Supply should be designed with the primary intention to deliver water supply to a member agency only at a time when Metropolitan is allocating supplies. Programs designed to deliver water on a regular basis would not qualify. Exceptions for reasonable use of a supply program for emergency or other extenuating local circumstances should be considered.
Fully Documented Resource Management Actions
A potential Extraordinary Supply should have a full description as to the source, transmission, distribution, storage, and delivery of the water supply.
These principles are intended to identify deliberate actions taken by member agencies to augment supplies only when Metropolitan is allocating supplies through the WSAP. Production from existing local supplies, programs that are operated on an ongoing basis, and incidental increases in water supply would not qualify as Extraordinary Supply. The intent of the Extraordinary Supply designation is to recognize programs and actions that are additive to the total regional water supply as the region continues to confront the water supply challenges from drought and regulatory conditions. To that end, any supply actions taken after the initial implementation of the WSAP in July 2009 that utilize Metropolitan supplies either as a primary source, or to refill or replenish an incurred obligation or deficit at a future date would not qualify as Extraordinary Supply. 35 Appendix I: Base Period Mandatory Rationing Adjustment Agencies that were under mandatory water use restrictions during the Base Period may have water use that is lower due to the mandatory actions already taken. Without adjusting for this, those agencies could be required to enforce even higher levels of restrictions under an allocation than those agencies that had not started mandatory restrictions.
To qualify for a Base Period Mandatory Rationing Adjustment, the member agency must provide Metropolitan staff with the following information:
• Time period when the mandatory conservation was in effect; it must be in effect during the Base Period
• A statement, with documentation, of how drought restrictions comply with the following Mandatory Conservation qualifications:
o Governing Body-authorized or enacted
o Includes mandatory demand reduction actions, restrictions or usage limitations including penalty-backed water budgets
o Enforced by assessing penalties, fines, or rates based upon violating restrictions or exceeding usage limitations
• If the agency in question is a retail subagency, then the retailer’s base period water demands during the Base Period in order to determine proportion to the member agency’s total demand • Historical data to construct GPCD base and trend for the consultation Calculating the Base Period Rationing Adjustment involves following steps:
• Use the Baseline GPCD 10 or 15-year period selected by member agency for the Conservation Demand Hardening Adjustment calculation.
• Interpolate from the GPCD value of the midpoint of the Baseline GPCD period to the average GPCD of the two years preceding the agency’s mandatory conservation • Extrapolate to the WSAP Base Period (FY2013 and FY2014) • Calculate the difference between estimated and observed GPCD for FY2013 and FY2014 • Convert to Acre-Feet and add to the member agency’s Base Period Retail Demands 36 Appendix J: Per-Capita Water Use Minimum Example
This adjustment creates a minimum per capita water use threshold. Member agencies’ retail-level water use under the WSAP is compared to two different thresholds. The minimum water use levels are based on compliance guidelines for total and residential water use established under Senate Bill X7-7.
Total Retail Level Use: 100 GPCD
Residential Retail Level Use: 55 GPCD
Agencies that fall below either threshold under the WSAP would receive additional allocation from Metropolitan to bring them up to the minimum GPCD water use level. To qualify for this credit, member agencies must provide documentation of the total agency level population and the percent of retail level demands that are residential; no appeal is necessary.
The following example gives a step-by-step description of how the Low Per-Capita Water Use Adjustment would be calculated for a hypothetical member agency. All numbers are hypothetical for the purpose of the example and do not reflect any specific member agency. This example was calculated using the following assumptions:
Allocation Year Retail Demand: 50,000 acre-feet
Allocation Year Local Supplies: 25,000 acre-feet;
Allocation Year Wholesale Demand: 25,000 acre-feet
Base Period Conservation: 5,000 acre-feet
Agency Population: 375,000
Percent of Retail Demands that are Residential: 60%
Step 1: Calculate Total Retail-Level Allocation Year Supplies Table 6 shows the Allocation Year Local Supply, WSAP Allocation, and the total Allocation Year Supplies for the example agency at each Regional Shortage Level. The WSAP Allocation was calculated using the methodology detailed in Appendix G: Water Supply Allocation Formula Example and the assumptions listed above.
37 Table 6: Total Retail Level Allocation Year Supplies Regional Shortage
Level
Allocation Year
Local Supply WSAP Allocation Total Allocation Year Supply 1 25,000 23,594 48,594
2 25,000 22,188 47,188
3 25,000 20,781 45,781
4 25,000 19,375 44,375
5 25,000 17,969 42,969
6 25,000 16,563 41,563
7 25,000 15,156 40,156
8 25,000 13,750 38,750
9 25,000 12,344 37,344
10 25,000 10,938 35,938
Step 2: Calculate the Equivalent Total and Residential GPCD The next step is to calculate the equivalent water use in gallons per capita per day (GPCD) for the Total Allocation Year Supply. The following equation shows the GPCD calculation under Regional Shortage Level 10.
35,938 af * 325,851 gallons ÷ 375,000 people ÷ 365 days = 85.6 GPCD The residential per-capita water use is calculated in the same manner. Based on the assumption that 60% of the agency demands are residential, the following equation shows the residential GPCD calculation under Regional Shortage Level 10.
35,938 af * 60% * 325,851 gallons ÷ 375,000 people ÷ 365 days = 51.3 GPCD Step 3: Compare the Total and Residential GPCD to the Minimum Water Use Thresholds The next step is to compare the total GPCD water use to the 100 GPCD total water use threshold. In a Regional Shortage Level 10, the WSAP results in an allocation that is 14.4 GPCD below the minimum threshold.
100 GPCD – 85.6 GPCD = 14.4 GPCD
Likewise the residential GPCD water use is compared to the 55 GPCD residential water use threshold.
55 GPCD – 51.3 GPCD = 3.7 GPCD
Step 4: Determine the Allocation Adjustment in Acre-Feet The final step is to calculate the acre-foot equivalent of the GPCD that fell below the minimum threshold. In a Regional Shortage Level 10, the adjustment provides 6,068 acre-feet of additional allocation to the agency; the results for Shortage Levels 1-10 are shown in Table 7.
14.4 GPCD ÷ 325,851 gallons * 375,000 people * 365 days = 6,068 acre-feet 38 Table 7: Total Per-Capita Water Use Adjustment
Regional
Shortage Level
Allocation Year
Supply
Equivalent
GPCD
GPCD Below
Threshold
Allocation
Adjustment
1 48,594 115.7 0 0
2 47,188 112.3 0 0
3 45,781 109.0 0 0
4 44,375 105.6 0 0
5 42,969 102.3 0 0
6 41,563 98.9 1.1 443
7 40,156 95.6 4.4 1,849
8 38,750 92.3 7.7 3,255
9 37,344 88.9 11.1 4,662
10 35,938 85.6 14.4 6,068
Again, this step is repeated for the residential water use. In a Regional Shortage Level 10, the adjustment provides 1,540 acre-feet of additional allocation to the agency; the residential water use results for Regional Shortage Levels 1-10 are shown in Table 8.
3.7 GPCD ÷ 325,851 gallons * 375,000 people * 365 days = 1,540 acre-feet Table 8: Residential Per-Capita Water Use Adjustment
Regional
Shortage Level
Allocation Year
Supply
Equivalent
GPCD
GPCD Below
Threshold
Allocation
Adjustment
1 29,156 69.4 0 0
2 28,313 67.4 0 0
3 27,469 65.4 0 0
4 26,625 63.4 0 0
5 25,781 61.4 0 0
6 24,938 59.4 0 0
7 24,094 57.4 0 0
8 23,250 55.4 0 0
9 22,406 53.3 1.7 697
10 21,563 51.3 3.7 1,540
Agencies that fall below either threshold under the WSAP would receive additional allocation from Metropolitan to bring them up to the minimum GPCD water use level. If an agency qualifies under both thresholds, the one resulting in the maximum allocation adjustment would be given. Under this example the agency would receive 6,068 acre-feet of additional allocation in a Regional Shortage Level 10.
39 Appendix K: Qualifying Income-Based Rate Allocation Surcharge Adjustment Example
The following example provides a step by step description of how the qualifying income-based rate allocation surcharge adjustment is calculated. To qualify for this adjustment, member agencies must provide documentation showing the amount of retail demands that are covered by a qualifying incomebased rate; no appeal is necessary.
The following list summarizes the allocation year demands, local supplies, and allocation as calculated in Appendix G: Water Supply Allocation Formula Example for a hypothetical agency under a Level 4 Regional Shortage. For detailed instructions on how to calculate these figures, reference Appendix G:
Water Supply Allocation Formula Example.
Allocation Year Retail Demand: 133,000 acre-feet
Allocation Year Local Supplies: 68,000 acre-feet;
Level 4 WSAP Allocation: 52,735 acre-feet
Step 1: Allocation Surcharge Calculation
(a) Water Use above Allocation: The first step in calculating the income-based rate Allocation Surcharge adjustment is to calculate the agency’s total Allocation Surcharge under the WSAP. If the agency did not incur any Allocation Surcharge from the allocation year, the income-based rate allocation surcharge adjustment would not apply. For the purpose of this example, the agency used 61,000 acre-feet of MWD supplies in the allocation year. This represents 8,265 acre-feet of use above the water supply allocation.
WSAP Allocation 52,735 af
Actual MWD Water Use 61,000 af
Use Above WSAP Allocation 8,265 af
(b) Total Allocation Surcharge: In this example the agency used 115.7% of its water supply allocation. 7,910 of the 8,265 acre-feet of use above the allocation would be assessed the Allocation Surcharge at an amount of $1,480 per acre-foot and 354 of the 8,265 acre-feet of use above the allocation would be assessed the Allocation Surcharge at an amount of $2,960.
Between 100% and 115%
of Allocation 7,910 af $1,480/af $11,706,800
Greater than 115% of
Allocation 354 af $2,960/af $1,047,840
Total 8,265 af $12,754,640
2 Step 2: Effective Income-Based Rate Cutback
(a) Calculate Retail Cutback: The second step in calculating the income-based rate allocation surcharge adjustment is to calculate the amount of supply cutback that would have been expected from qualifying income-based rate customers under the WSAP. Using the water supply allocation that was calculated above, the total retail level impact on the agency can be 40 determined. In this example the agency receives a retail level cutback of 15,265 acre-feet, or
11.5% of their retail level demand.
(b) Income-based Rate Customer Retail Cutback: To calculate the effective income-based rate cutback, the amount of demand covered by a qualifying income-based rate is multiplied by the effective retail level cutback. For this example assume that the agency has 10,000 acre-feet of qualifying demands.
(c) Income-based Rate Cutback Allocation Surcharge: Once the effective cutback has been calculated, the amount of Allocation Surcharge that is associated with qualifying income-based rate customers can be determined.
(d) Adjusted Allocation Surcharge Calculation: Finally, the Allocation Surcharge attributable to qualifying income-based rate customers is subtracted from the total Allocation Surcharge that was calculated above to determine the qualifying income-based rate adjusted allocation surcharge. In the case that the monetary amounts associated with the Income-Based Rate are greater than the total amounts an agency incurs, no Allocation Surcharge will be incurred.
Total Allocation Surcharge $12,754,640
Qualifying Income-Based Rate Allocation Surcharge $2,222,960 Qualifying Income-Based Rate Adjusted Allocation
Sh
$10,531,680
WSAP Allocation + Allocation Year Local Supplies 117,735 af Allocation Year Retail Demand 133,000 af
Effective Cutback 15,265 af (11.5%)
Qualifying Income-Based Rate Demand 10,000 af
Effective Cutback Percentage 11.5%
Effective Income-Based Rate Cutback 1,148 af
Between 100% and 115%
of Allocation 794 af $1,480/af $1,175,120
Greater than 115% of
Allocation 354 af $2,960/af $1,047,840
Total 1,148 af $2,222,960
2 41
Appendix L: Groundwater Replenishment Allocation
Groundwater basins help provide vital local supplies that can buffer the region from short-term drought impacts. Longer droughts can result in reductions to the many sources of water that replenish groundwater basins, resulting in lower basin levels and potential impacts to the overlying consumptive demands. Limited imported deliveries under these conditions may help avoid impacts to the basins that may be drawn out of their normal operating range or subject to water quality or regulatory impacts. To this end, Metropolitan provides a limited allocation for drought impacted groundwater basins based on the following framework:
a) Staff hold a consultation with qualifying member agencies who have taken groundwater replenishment deliveries since 2010 and the appropriate groundwater basin managers to document whether their basins are in one of the following conditions:
i. Groundwater basin overdraft conditions that will result in water levels being outside normal operating ranges during the WSAP allocation period; or ii. Violations of groundwater basin water quality and/or regulatory parameters that would occur without imported deliveries.
b) Provide an allocation based on the verified need for groundwater replenishment. The allocation would start with a member agency’s ten-year average purchases of imported groundwater replenishment supplies (excluding years in which deliveries were curtailed).
The amount would then be reduced by the declared WSAP Regional Shortage Level (5 percent for each Regional Shortage Level).
c) Any allocation provided under this provision for drought impacted groundwater basins is intended to help support and maintain groundwater production for consumptive use. As such, a member agency receiving an allocation under this provision will be expected to maintain groundwater production levels equivalent to the average pumping in the Base Period. Any adjustments to a member agency’s M&I allocation due to lower groundwater production would be reduced by deliveries made under this provision. d) Agencies for which this allocation does not provide sufficient supplies for the needs of the groundwater basin may use the WSAP Appeals Process to request additional supply (subject to Board approval). The appeal should include a Groundwater Management Plan that documents the need for additional supplies according to the following tenets:
i. Maintenance of groundwater production levels;
ii. Maintenance of, or reducing the further decline of, groundwater levels; iii. Maintenance of key water quality factors/indicators; iv. Avoidance of permanent impacts to groundwater infrastructure or geologic features; and
v. Consideration of severe and/or inequitable financial impacts.
Final amounts and allocations will be determined following the consultations with groundwater basin managers and member agencies.
42 Appendix M: Water Rates, Charges, and Definitions
Definitions:
(1) Tier 1 Supply Rate - recovers the cost of maintaining a reliable amount of supply. (2) Tier 2 Supply Rate - set at Metropolitan's cost of developing additional supply to encourage efficient use of local resources. (3) System Access Rate – recovers a portion of the costs associated with the delivery of supplies. (4) System Power Rate – recovers Metropolitan’s power costs for pumping supplies to Southern California. (5) Water Stewardship Rate – recovers the cost of Metropolitan’s financial commitment to conservation, water recycling, groundwater clean-up and other local resource management programs.
(6) Treatment Surcharge – recovers the costs of treating imported water. (7) Readiness-to-Serve Charge - a fixed charge that recovers the cost of the portion of system capacity that is on standby to provide emergency service and operational flexibility.
(8) Capacity Charge – the capacity charge recovers the cost of providing peak capacity within the distribution system.
Source: http://www.mwdh2o.com/WhoWeAre/Management/Financial-Information Table 9: Water Rates and Charges
Dollars per acre-foot (except where noted)
Rate Effective
1/1/2014
Effective
1/1/2015
Effective
1/1/2016
Tier 1 Supply Rate $148 $158 $156
Tier 2 Supply Rate $290 $290 $290
System Access Rate $243 $257 $259
Water Stewardship Rate $41 $41 $41
System Power Rate 161 $126 $138
Tier 1 $593 $582 $594
Tier 2 $735 $714 $728
Treatment Surcharge $297 $341 $348
Full Service Treated Volumetric Cost
Tier 1 $890 $923 $942
Tier 2 $1,032 $1,055 $1,076
Readiness-to-Serve Charge (millions of dollars) $166 $158 $153 Capacity Charge (dollars per cubic foot second) $8,600 $11,100 $10,900 43 Appendix N: Allocation Appeals Process
Step 1: Appeals Submittal
All appeals shall be submitted to the Appeals Liaison in the form of a written letter signed by the member agency General Manager. Each appeal must be submitted as a separate request, submittals with more than one appeal will not be considered. The appeal request is to include:
• A designated member agency staff person to serve as point of contact. • The type of appeal (erroneous baseline data, loss of local supply, etc.). • The quantity (in acre-feet) of the appeal.
• A justification for the appeal which includes supporting documentation.
A minimum of 60 days are required to coordinate the appeals process with Metropolitan’s Board process.
Step 2: Notification of Response and Start of Appeals Process The Appeals Liaison will phone the designated member agency staff contact within 3 business days of receiving the appeal to provide an initial receipt notification, and schedule an appeals conference.
Subsequent to the phone call, the Liaison will send an e-mail to the Agency General Manager and designated staff contact documenting the conversation. An official notification letter confirming both receipt of the appeal submittal, and the date of the appeals conference, will be mailed within 2 business days following the phone contact
Step 3: Appeals Conference
All practical efforts will be made to hold an appeals conference between Metropolitan staff and member agency staff at Metropolitan’s Union Station Headquarters within 15 business days of receiving the appeal submittal. The appeals conference will serve as a forum to review the submittal materials and ensure that there is consensus understanding as to the spirit of the appeal. Metropolitan staff will provide an initial determination of the size of the appeal (small or large) and review the corresponding steps and timeline for completing the appeals process.
Steps 4-7 of the appeals process differ depending upon the size of the appeal Small Appeals
Small appeals are defined as those that would change an agency’s allocation by less than 10 percent, or are less than 5,000 acre-feet in quantity. Small appeals are evaluated and approved or denied by Metropolitan staff.
Step 4: Preliminary Decision
Metropolitan staff will provide a preliminary notice of decision to the member agency within 10 business days of the appeals conference. The preliminary decision timeline may be extended to accommodate requests for additional information, data, and documentation. The Appeals Liaison will mail a written letter to the member agency staff contact and General Manager, stating the preliminary decision and the rationale for approving or denying the appeal. 44 Step 5: Clarification Conference
Following the preliminary decision the Appeals Liaison will schedule a clarification conference. The member agency may choose to decline the clarification conference if they are satisfied with the preliminary decision. Declining the clarification conference serves as acceptance of the preliminary decision, and the decision becomes final upon approval by Metropolitan’s executive staff.
Step 6: Final Decision
Metropolitan staff will provide a final notice of decision to the member agency within 10 business days of the clarification conference, pending review by Metropolitan’s executive staff. The Appeals Liaison will mail a written letter to the member agency staff contact and General Manager, stating the final decision and the rationale for the decision. A copy of the letter will also be provided to Metropolitan executive staff.
Step 6a: Board Resolution of Small Appeal Claims
Member agencies may request to forward appeals that are denied by Metropolitan staff to the Board of Directors through the Water Planning and Stewardship Committee for final resolution.
The request for Board resolution shall be submitted to the Appeals Liaison in the form of a written letter signed by the member agency General Manager. This request will be administered according to Steps 6 and 7 of the large appeals process.
Step 7: Board Notification
Metropolitan staff will provide a report to the Board of Directors, through the Water Planning and Stewardship Committee, on all submitted appeals including the basis for determination of the outcome of the appeal.
Large Appeals
Large appeals are defined as those that would change an agency’s allocation by more than 10 percent, and are larger than 5,000 acre-feet. Large appeals are evaluated and approved or denied by the Board of Directors.
Step 4: Preliminary Recommendation
Metropolitan staff will provide a preliminary notice of recommendation to the member agency within 10 business days of the appeals conference. The preliminary decision timeline may be extended to accommodate requests for additional information, data, and documentation. The Appeals Liaison will mail a written letter to the member agency staff contact and General Manager, stating the preliminary recommendation and the rationale for the recommendation. A copy of the draft recommendation will also be provided to Metropolitan executive staff.
Step 5: Clarification Conference
Following the preliminary recommendation the Appeals Liaison will schedule a clarification conference.
The member agency may choose to decline the clarification conference if the satisfied with preliminary recommendation. Declining the clarification conference signifies acceptance of the preliminary recommendation, and the recommendation becomes final upon approval by Metropolitan’s executive staff.
45 Step 6: Final recommendation
Metropolitan staff will provide a final notice of recommendation to the member agency within 10 business days of the clarification conference, pending review by Metropolitan executive staff. The Appeals Liaison will mail a written letter to the member agency staff contact and General Manager, stating the final recommendation and the rationale for the recommendation. A copy of the final recommendation will also be provided for Metropolitan executive review.
Step 7: Board Action
Metropolitan staff shall refer the appeal to the Board of Directors through the Water Planning and Stewardship Committee for approval.
46 Appendix O: Appeals Submittal Checklist
Appeal Submittal
Written letter (E-mail or other electronic formats will not be accepted) Signed by the Agency General Manager
Mailed to the appointed Metropolitan Appeals Liaison
Contact Information
Designated staff contact General Manager
o Name o Name
o Address o Address
o Phone Number o Phone Number
o E-mail Address o E-mail Address
Type of Appeal
State the type of appeal
o Erroneous historical data used in base period calculations • Metropolitan Deliveries
• Local Production
• Growth adjustment
• Conservation savings
o Exclusion of physically isolated areas
o Extraordinary supply designation
o Groundwater Replenishment Allocation
o Base Period Mandatory Rationing Adjustment
o Other
Quantity of Appeal
State the quantity in acre-feet of the appeal
Justification and Supporting Documentation
State the rationale for the appeal
Provide verifiable documentation to support the stated rationale o Examples of verifiable documentation Include, but are not limited to:
• Billing Statements
• Invoices for conservation device installations
• Basin Groundwater/Watermaster Reports
• California Department of Finance economic or population data • California Department of Public Health reports
Resolution Adopting the Water Shortage Contingency Plan Resolution 9281
RESOLUTION
OF THE BOARD OF DIRECTORS
OF THE METROPOLITAN WATER DISTRICT OF SOUTHERN CALIFORNIA
ADOPTING THE WATER SHORTAGE CONTINGENCY PLAN
WHEREAS, the Urban Water Management Planning Act requires urban water suppliers providing water for municipal purposes to more than 3,000 customers or supplying more than 3,000 acre-feet of water annually to prepare and adopt, in accordance with prescribed requirements, a water shortage contingency plan;
WHEREAS, the Urban Water Management Planning Act specifies the requirements and procedures for adopting such Water Shortage Contingency Plans;
WHEREAS, the Urban Water Management Planning Act requires urban water suppliers to conduct an annual water supply and demand assessment (Annual Assessment) each year and to include in their water shortage contingency plans the procedures they use to conduct the Annual Assessment; WHEREAS, the procedures used to conduct an Annual Assessment include, but are not limited to, the written decision-making process that an urban water supplier will use each year to determine its water supply reliability;
WHEREAS, The Metropolitan Water District of Southern California’s (Metropolitan’s) water shortage contingency plan provides that by June of each year, Metropolitan staff will present a completed Annual Assessment for approval by Metropolitan’s Board of Directors or by the Board’s authorized designee with expressly delegated authority for approval of Annual Assessment determinations; and
WHEREAS, the Board of Directors of The Metropolitan Water District of Southern California has duly reviewed, discussed, and considered such Water Shortage Contingency Plan and has determined the Water Shortage Contingency Plan to be consistent with the Urban Water Management Planning Act and to be an accurate representation of the planned actions during shortage conditions for The Metropolitan Water District of Southern California.
NOW, THEREFORE, BE IT RESOLVED by the Board of Directors of The Metropolitan Water District of Southern California that, on May 11, 2021, this District hereby adopts this Water Shortage Contingency Plan for submittal to the State of California and expressly authorizes the General Manager of The Metropolitan Water District of Southern California to approve the Annual Assessment each year.
I HEREBY CERTIFY that the foregoing is a full, true and correct copy of a resolution adopted by the Board of Directors of The Metropolitan Water District of Southern California, at its meeting held on May 11, 2021.
Secretary of the Board of Directors
of The Metropolitan Water District
of Southern California
Attachment C
I
Appendix 5
LOCAL PROJECTS
(From 2020 IRP local supply survey and Member Agency Coordination)
Local Projects A.5-1
Table A.5-1
Recycled Water Projects
Existing Projects
Ultimate
Yield/Capacity
(Acre-Feet) Online Date
City of Anaheim
Anaheim GWRS Purchases 120 2011
Anaheim Water Recycling Demonstration Project 110 2014
City of Burbank
Burbank Recycled Water System Project 1,300 1967
Burbank Recycled Water System Expansion Project - Phase I 850 1995 Burbank Recycled Water System Expansion Project - Phase II 960 2009 Calleguas Municipal Water District
Camrosa Water Reclamation Facility Project 1,600 1997
City of Camarillo Recycled Distribution System 1,502 1955 Conejo Creek Diversion Project 9,000 2003
Lake Sherwood Reclaimed Water System 420 1997
Oak Park/North Ranch Recycled Water Distribution System 1,300 1994 Oxnard Advanced Water Purification Facility Project Phase I 5,000 2015 Simi Valley Recycled Water Project 90 2001
VCWWD No. 1 WWTP Recycled Water Distribution System 1,100 2003 Central Basin Municipal Water District
Albert Robles Center for Water Recycling & Environmental Learning 10,000 2020 Century/Rio Hondo Reclamation Program 5,000 1992
Cerritos Reclaimed Water System 1,750 1978
Cerritos Reclamation Extension Project 260 1993
Lakewood Water Reclamation Project 500 1989
Montebello Forebay Groundwater Recharge Project 54,500 1962 Eastern Municipal Water District
Eastern Recycled Water System Expansion Project 5,000 2012 Original Customers, Reach 1 Phase I & Reach 2 28,950 1966 Rancho California Reclamation Expansion Project - Rancho Division 5,250 1993 Rancho California Reclamation Project - Rancho Division 225 1989 Reach 1 Phase II 1,700 2000
Reach 16 Phase I 707 2006
Reach 16 Phase II Not Provided Not Provided
Reach 3 & Reach 7 4,830 2012
Foothill Municipal Water District
La Cañada Flintridge Country Club Controlled Access Irrigation 90 1962 City of Glendale
Glendale Water Reclamation Project 400 1986
Glendale Water Reclamation Expansion Project 500 1992
Glendale Verdugo-Scholl and Brand Park Project 1,760 1995 A.5-2 Local Projects
Existing Projects
Ultimate
Yield/Capacity
(Acre-Feet) Online Date
Inland Empire Utilities Agency
Ely Basin Groundwater Recharge 14,000 1999
IEUA Regional Recycled Water Distribution System 13,500 1998 Regional Sewage Service Contract 3,500 1972
Las Virgenes Municipal Water District
Calabasas Project 900 Not Provided
Calabasas Reclaimed Water System Extension Project 700 1989 Las Virgenes Reclamation Project 2,700 1984
Las Virgenes Valley Project 500 Not Provided
City of Long Beach
Alamitos Barrier Reclaimed Water Project 3,025 2005
Leo J. Vander Lans Water Treatment Facility Expansion Project 3,475 2018 Long Beach Reclamation Project 1,700 1986
Long Beach Recycled Water System Expansion Phase I 2,750 2004 Original Customers 400 1980
THUMS 1,429 1981
City of Los Angeles
Burbank Deliveries to Los Angeles 9 2018
Central City/Elysian Park Project Phase I - Taylor Yard Park 150 2009 Downtown Water Recycling Project 2,116 2018
Griffith Park South Water Recycling Project 450 2019
Hansen Area Water Recycling - Hansen Dam Golf Course 500 2015 Hansen Area Water Recycling Phase I Project 2,115 2008
Harbor Water Recycling Project 5,000 2005
Los Angeles Greenbelt Project 1,766 1993
North Atwater Area Water Recycling Project 50 2015
Original Deliveries from West Basin Reclamation Program 740 1996 Sepulveda Basin Water Reclamation Project Phase IV 445 2010 Sepulveda Basin Water Reclamation Project Phases I - III 1,500 2007 South Gardena Lateral 95 2019
Van Nuys Area Water Recycling Project 150 2011
Municipal Water District of Orange County
Capistrano Valley Non-Domestic Water System 565 1989
Capistrano Valley Non-Domestic Water System Expansion Project 1,011 2006 El Toro Recycled Water System 260 1998
El Toro Recycled Water System Expansion Project - Phase I 1,050 2015 El Toro Recycled Water System Expansion Project - Phase II 350 2019 Green Acres Reclamation Project - Coastal MWD & Orange County 2,480 1991 GWRS Initial Expansion 30,000 2015
GWRS Phase I 74,880 2008
Local Projects A.5-3
Existing Projects
Ultimate
Yield/Capacity
(Acre-Feet) Online Date
Irvine Reclamation Expansion Project - Post 2003 Michelson & Los Alisos Dual Distribution System 8,500 2008
Irvine Reclamation Expansion Project - Pre 2003 Michelson & Los Alisos Dual Distribution System 1,500 Not Provided
Irvine Reclamation Project - Post 1983 Michelson System 10,000 1986 Irvine Reclamation Project - Pre 1983 Michelson System 6,000 1967 Moulton Niguel Reclamation Project - Phases I & II 470 1968 Moulton Niguel Reclamation Project - Phases III & IV 9,276 1993 San Clemente Recycled Water System Expansion Project 1,000 2015 San Clemente Water Reclamation Project 500 1990
San Clemente Water Reclamation Project - Municipal Golf Course 200 1957 Santa Margarita - Irvine Ranch Recycled Water Purchase Agreement 321 2001 Santa Margarita Advanced Purified Water Project 300 2018 Santa Margarita Chiquita Water Reclamation Project 2,772 2005 Santa Margarita Oso Water Reclamation Expansion Project 3,600 1988 Santa Margarita Oso Water Reclamation Project 1,200 1978 South Laguna Reclamation Expansion Project 0 1991
South Laguna Reclamation Project 860 1985
Trabuco Canyon Reclamation Expansion Project 800 1992
Trabuco Canyon Reclamation Project 280 1987
City of Santa Ana
Green Acres Reclamation Project - Santa Ana 320 2008
City of Santa Monica
Santa Monica Urban Runoff Recycling Facility 210 2005
San Diego County Water Authority
4S Ranch WRF/ Olivenhain MWD 1,145 2003
Camp Pendleton Marine Corps Base Recycled Water System 1,950 1997 Connection #1 - North City Water Reclamation Plant/City of San Diego 465 2003 Connection #2 - North City Water Reclamation Plant/City of San Diego 25 2003 Del Mar San Elijo WRF/ San Elijo JPA 130 2000
Del Mar San Elijo WRF/ San Elijo JPA additional verifiable expansions 20 2000 Encina Basin Phases I & II - Carlsbad WRF/ Carlsbad MWD 2,315 1993 Encina Basin Phases I & II - Carlsbad WRF/ Carlsbad MWD additional verifiable expansions 135 1993
Encina Basin Phases I & II - Gafner WRF/ Leucadia CWD 260 1993 Encina Basin Phases I & II - Gafner WRF/ Leucadia CWD additional verifiable expansions 15 1993
Encina Basin Phases I & II - Meadowlark WRF (via Mahr
Reservoir)/Vallecitos WD 2,425 1993
Encina Basin Phases I & II - Meadowlark WRF (via Mahr
Reservoir)/Vallecitos WD additional verifiable expansions 140 1993 A.5-4 Local Projects
Existing Projects
Ultimate
Yield/Capacity
(Acre-Feet) Online Date
Fallbrook Public Utility District Water Reclamation Project 1,200 1990 Fallbrook Public Utility District Water Reclamation Project Verifiable Expansions 500 Not Provided
Hale Avenue Resources Recovery Facility (HARRF)/City of Escondido 993 2004 Hale Avenue Resources Recovery Facility (HARRF)/City of Escondido additional verifiable expansions 127 2004
Hale Avenue RRF/City of Escondido HGWRP/Rincon MWD 648 2004 Hale Avenue RRF/City of Escondido HGWRP/Rincon MWD Verifiable Expansions 1,352 2004
Northwest Quadrant/Meadowlark WRF/Vallecitos WD 728 2009 Oceanside Water Reclamation Project 200 1992
Oceanside Water Reclamation Project Additional Verifiable Expansion 4,840 1992 Olivenhain SEJPA1-Quail Gardens 110 2000
Olivenhain SEJPA1-Quail Gardens additional verifiable expansions 13 2000 Olivenhain SEJPA2-Village Park, Manchester/Phase I 210 2000 Olivenhain SEJPA2-Village Park, Manchester/Phase I additional verifiable expansions 26 2000
Otay Recycled Water System Phases I & II 7,062 1991
Padre Dam Reclaimed Water System Phase I 850 1998
San Diego Northern Recycled Water Distribution System 12,619 1998 San Diego Northern Recycled Water Distribution System - deliveries to Poway 645 2009
San Diego Southern Recycled Water Distribution System 1,154 2006 San Dieguito San Elijo WRF/ San Elijo JPA 620 2000
San Dieguito San Elijo WRF/ San Elijo JPA additional verifiable expansions 80 2000
San Vicente Recycled Water System 230 1996
San Vicente Recycled Water Treatment Upgrades 340 2010
Santa Fe ID San Elijo WRF/ San Elijo JPA 530 2000
Santa Fe ID San Elijo WRF/ San Elijo JPA additional verifiable expansions 70 2000 Santa Maria Recycled Water System 400 1999
Santee Lakes Existing Project 65 1959
Santa Fe Valley WRF/Rancho Santa Fe CSD 153 2003
Woods Valley Ranch Water Reclamation Facility Phase I 47 2005 Three Valleys Municipal Water District
City Industry Regional Recycled Water Project - Rowland Portion 1,017 2008 City Industry Regional Recycled Water Project - Walnut Valley Portion 2,135 2008 Pomona Recycled Water Distribution System 1,500 1973
Rowland Non-Potable Water System 340 1985
Walnut Valley Recycled Water System 1,100 1986
Walnut Valley Recycled Water System Expansion Project 500 1993 Local Projects A.5-5
Existing Projects
Ultimate
Yield/Capacity
(Acre-Feet) Online Date
City of Torrance
Torrance Recycled Water Purchases 7,800 1995
Upper San Gabriel Valley Municipal Water District
City of Industry Recycled Water Distribution System 8,500 1983 County Sanitation Districts of Los Angeles County Deliveries 4,475 1978 Direct Reuse Project - Phase I 1,600 2003
Direct Reuse Project - Phase IIA Rosemead Extension 720 2011 Direct Reuse Project - Phase IIA Whittier Narrows Project 2,258 2006 Direct Reuse Project - Phase IIB Industry (Packages 1 - 4) 1,963 2011 Rose Hills Expansion 530 2015
South El Monte Recycled Water Expansion Project (Packages 1 - 5) 72 2019 West Basin Municipal Water District
West Basin Water Recycling Program Phase I - IV 29,460 1995 West Basin Water Recycling Program Phase V 8,000 2013
Western Municipal Water District of Riverside County
Corona Reclaimed Water Distribution System 4,750 2007
Elsinore Valley Horsethief Canyon Recycled Water System 400 1985 Elsinore Valley Railroad Canyon Recycled Water System 1,000 1984 Elsinore Valley Wildomar Recycled Water Project 300 2014 Jackson Street Recycled Water Pipeline Project - Phase 1 820 2018 Rancho California Reclamation Expansion Project - Rancho Division 750 1993 Rancho California Reclamation Project - Santa Rosa Division 225 1989 Riverside Recycled Water Program Phase 260 1997
Western Water Recycling Facility 900 1940
Western Water Recycling Facility Upgrade Project 1,300 2014 Under Construction Projects
Ultimate
Yield/Capacity
(Acre-Feet) Online Date
Central Basin Municipal Water District
CBMWD Recycled Water System Expansion Phase 1 (Gateway Cities) 500 2022 City of Los Angeles
Los Angeles Groundwater Replenishment Project Initial Phase 7,000 2024 Los Angeles Groundwater Replenishment Project Second Phase 4,000 2026 North Hollywood Area Water Recycling Project 300 2025
Pershing Drive Recycled Water Pipeline Project 750 2022 Sepulveda Basin Sports Complex Water Recycling Project Phases I & II 350 2021 Terminal Island Recycled Water Expansion Project 8,000 2025 Westside Area Water Recycling Project 150 2021
A.5-6 Local Projects
Under Construction Projects
Ultimate
Yield/Capacity
(Acre-Feet) Online Date
Municipal Water District of Orange County
GWRS Final Expansion 29,150 2023
Santa Margarita Water District Trampas Canyon RW Reservoir 5,000 2020 San Diego County Water Authority
East County Advanced Water Purification Program 12,882 2025 Escondido Membrane Filtration Reverse Osmosis Facility (Hale Avenue Resources Recovery Facility (HARRF)/City of Escondido) 3,280 2025 Oceanside Pure Water and Recycled Water Expansion Phase I Project 6,000 2025 Oceanside Pure Water and Recycled Water Expansion Phase I Project Additional Verifiable Yield 720 2025
San Diego Pure Water North City Phase I 33,600 2025
City of Santa Monica
Advanced Water Treatment 1,100 2021
Santa Monica Urban Runoff Recycling Facility Upgrades 350 2021 Upper San Gabriel Valley Municipal Water District
La Puente Valley County Water District Recycled Water Project 60 2024 CEQA Projects
Ultimate
Yield/Capacity
(Acre-Feet) Online Date
City of Anaheim
Anaheim South Recycled Water Project 850 2027
Central Basin Municipal Water District
West San Gabriel Recycled Water Expansion Project (Montebello Hills) 240 2020 Conceptual Projects
Ultimate
Yield/Capacity
(Acre-Feet) Online Date
Calleguas Municipal Water District
Camarillo Water Reclamation Plant Effluent Transfer Pipeline 1,120 2025 City of Camarillo Recycled Distribution System Expansion 2,583 2025 Oxnard Advanced Water Purification Facility Project - Phase II 5,000 2025 Oxnard Aquifer Storage and Recovery Completion Not Provided 2024 Oxnard Aquifer Storage and Recovery Wells #2 and #3 Not Provided 2024 VCWWD No. 1 WWTP Recycled Water Distribution System Expansion Phase I 500 2025
Central Basin Municipal Water District
City of Monterey Park Recycled Water Expansion Project 750 Not Provided East Los Angeles Recycled Water Expansion Project 500 Not Provided La Mirada Recycled Water Expansion Project 900 Not Provided Local Projects A.5-7
Conceptual Projects
Ultimate
Yield/Capacity
(Acre-Feet) Online Date
City of Compton
Recycled Water Feasibility Study 262 2025
Eastern Municipal Water District
Purified Water Replenishment, Phase I 4,000 2023
Purified Water Replenishment, Phase II 8,000 2035
Rancho Indirect Potable Reuse Project 4,000 2025
Foothill Municipal Water District
Descanso Gardens MBR Plant Not Provided Not Provided
City of Glendale
Public Works Yard Recycled Water Main Extension Project 80 Not Provided Inland Empire Utilities Agency
IEUA Regional Recycled Water Distribution System Expansion Ph I & II 33,000 Not Provided Las Virgenes Municipal Water District
Pure Water Project 3,100 2030
City of Los Angeles
Airport Police Facility Water Recycling Project 39 2024 Extension to ConRAC Water Recycling Project 10 2024
Forest Lawn Tank 450 2024
Harbor Connection to Joint Pollution Control Plant 3,500 2023 Harbor Extension On Gaffey 4,500 2023
Harbor Extension on Port of LA Right-of-Way 1,000 2022
Second Dominguez Gap Connection and Harbor Potable Backup 6,661 2021 Terminal Island Recycled Water Expansion Project 1,000 2021 Municipal Water District of Orange County
Moulton Niguel Reclamation Project - Phase V 2,000 2025 Santa Margarita Chiquita Water Reclamation Expansion Project 3,000 Not Provided Santa Margarita Recycled Water Conversion Projects 2,420 Not Provided City of Pasadena
Pasadena Non-Potable Water Project - Ph I 700 Not Provided Pasadena Non-Potable Water Project - Ph II: Southern Extension I 400 2023 Pasadena Non-Potable Water Project - Ph III: Southern Extension II 900 2027 Pasadena Non-Potable Water Project - Ph IV: Annandale Extension 280 2030 Pasadena Non-Potable Water Project - Ph V: Northwestern Extension 390 2033 Pasadena Non-Potable Water Project - Ph VI: Northeastern Extension 390 2036 San Diego County Water Authority
Additional Planned - Carlsbad WRF/ Carlsbad MWD 495 2025 Connection #1 - North City Water Reclamation Plant/City of San Diego (Extension 153) 489 2030
East County Advanced Water Purification Program Expansion 2,803 2045 Escondido Potable Reuse Project 5,000 2035
A.5-8 Local Projects
Conceptual Projects
Ultimate
Yield/Capacity
(Acre-Feet) Online Date
Hale Avenue Resources Recovery Facility (HARRF)/City of Escondido Additional Planned Expansions 6,800 2025
Indirect Potable Recharge 900 2020
Joint RW Transmission Project with SFID and OMWD/TBD (Bridges) 400 2030 Lilac Hills Ranch WRF/VCMWD 294 2035
Los Flores and Santa Margarita Basin Injection Project 1,320 2020 Lower Moosa Canyon Water Reclamation Facility Treatment Process Upgrade and Reclamation System 700 2020
Meadowlark Water Reclamation Facility Direct Potable Reuse 2,200 2030 Meadowood Water Reclamation Facility 143 2025
North County One Water Program - Carlsbad MWD 3,500 2035 North County One Water Program - Olivenhain MWD 2,500 2035 North County One Water Program - Poway 2,000 2035
North County One Water Program - San Dieguito WD 2,000 2035 North County One Water Program - Santa Fe ID 3,000 2035 North County One Water Program - Vallecitos WD 5,500 2030 North District Recycled Water Project Phase I 4,400 2030 North Village Water Reclamation Facility 105 2040
Olivenhain - SEJPA 1 (Gardenview Rd) 44 2030
Olivenhain SEJPA 3 (Manchester Avenue Phases I and II) 40 2025 Rancho Cielo Project 100 2030
Ray Stoyer Expansion 317 2025
San Diego Pure Water Phases II 59,360 2035
Welk Water Reclamation Facility 140 2025
Woods Valley Ranch Water Reclamation Facility Phase II 184 2020 Woods Valley Ranch Water Reclamation Facility Phase III 168 2030 City of Santa Monica
Santa Monica Connection 100 Not Provided
Three Valleys Municipal Water District
Los Angeles County Fairplex Recharge 1,000 2020
Pomona Recycled Water Distribution System Expansion 1,000 2020 Recharge in Chino Basin 2,405 2025
Western Municipal Water District of Riverside County
Corona Reclaimed Water Distribution System Expansion 1,760 2020 Demineralization of Recycled Water 550 2026
Elsinore Valley Horsethief Canyon Recycled Water System Expansion 500 2022 Indirect Potable Reuse Project 5,700 2035
Jackson Street Recycled Water Pipeline Project - Phase 2 2,550 Not Provided Riverside Habitat, Parks & Water Project (RHPWP) 10,000 2025 Local Projects A.5-9
Table A.5-2
Groundwater Recovery Projects
Existing Projects
Ultimate
Yield/Capacity
(Acre-Feet) Online Date
City of Beverly Hills
Beverly Hills Desalter Project 2,600 2003
Maple Wells (Shallow Wells) 350 2020
City of Burbank
Burbank Operable Unit/Lockheed Valley Plant 11,000 1996 Calleguas Municipal Water District
Round Mountain Water Treatment Plant 1,000 2014
Tapo Canyon Groundwater Treatment Plant 1,000 2010
Central Basin Municipal Water District
Juan Well Filter Facility 900 2001
Water Quality Protection Plan 5,807 2007
Eastern Municipal Water District
Menifee Basin Desalter Project 3,360 2002
Perris I Desalter 4,500 2006
Foothill Municipal Water District
Glenwood Nitrate Water Reclamation Project 1,600 1993
Olive Avenue IX GAC Groundwater Treatment Plant 2,000 2004 City of Glendale
Glendale Operable Unit 7,700 2001
Verdugo Park Water Treatment Plant 1,000 1997
Inland Empire Utilities Agency
Chino Basin Desalination Program Phase I 9,600 2000
Chino Basin Desalination Program Phase II & III 12,800 2006 Las Virgenes Municipal Water District
Westlake Wells-Tapia WRF Intertie Project 150 2000
Municipal Water District of Orange County
Capistrano Beach Desalter Project 1,300 2007
Deep Aquifer Treatment System 8,000 2002
El Toro Groundwater Remediation Project 4,000 2007
Garden Grove Nitrate Blending Project 4,000 1990
Irvine Desalter Project 6,700 2007
IRWD Wells 21 & 22 Desalter 6,400 2013
Mesa Water Reliability Facility 8,941 2001
San Juan Basin Desalter Project Phase I 4,800 2004
Tustin 17th Street Desalter 3,200 1996
Tustin Main St Treatment Plant 2,000 1989
San Diego County Water Authority
Mission Basin Desalter Facility Phases I & II 2,800 1994 A.5-10 Local Projects
Existing Projects
Ultimate
Yield/Capacity
(Acre-Feet) Online Date
Richard A. Reynolds Groundwater Desalination Facility 3,600 2000 Richard A. Reynolds Groundwater Desalination Facility Expansion 2,600 2017 Three Valleys Municipal Water District
Cal Poly Pomona Water Treatment Plant 250 2016
Harrison Groundwater Treatment Facility 981 2008
Towne Groundwater Treatment Plant & Well 3 Treatment Facility 4,678 1997 City of Torrance
Robert W. Goldsworthy Desalter 2,400 2002
Robert W. Goldsworthy Desalter Expansion 2,600 2019
West Basin Municipal Water District
C. Marvin Brewer Desalter 1,524 1993
Western Municipal Water District of Riverside County
Arlington Basin Groundwater Desalter Project 6,100 1990 Chino Basin Desalination Program Phases II & III 12,800 2006 Existing Groundwater Threshold 9,500 2001
Temescal Basin Desalting Facility Project 10,000 2001
Under Construction Projects
Ultimate
Yield/Capacity
(Acre-Feet) Online Date
Calleguas Municipal Water District
North Pleasant Valley Regional Desalter 3,800 2020
Eastern Municipal Water District
Perris II Desalter 5,400 2021
San Diego County Water Authority
Fallbrook Groundwater Desalter Project 3,100 2025
CEQA Projects
Ultimate
Yield/Capacity
(Acre-Feet) Online Date
Calleguas Municipal Water District
Los Robles Golf Course Groundwater Utilization Project 930 Not Provided Conceptual Projects
Ultimate
Yield/Capacity
(Acre-Feet) Online Date
City of Beverly Hills
La Brea Subbasin Groundwater Development 1,700 2023
City of Burbank
Deliveries from North Hollywood Operable Unit's offline wells Not Provided 2022 Local Projects A.5-11
Existing Projects
Ultimate
Yield/Capacity
(Acre-Feet) Online Date
Calleguas Municipal Water District
Moorpark Desalter Project 5,000 2030
Santa Rosa Basin Desalter 1,000 2025
Simi Groundwater Basin Reverse Osmosis Desalter 830 2025 Simi Valley Desalter Project 5,500 2025
Eastern Municipal Water District
Perris North Basin Groundwater Contamination Prevention and Remediation Program 6,750 2023
City of Los Angeles
West Coast Basin Brackish Water Reclamation 8,000 2024
San Diego County Water Authority
Middle Sweetwater River Basin Groundwater Well System 1,000 2035 Otay Mesa Lot 7 Groundwater Well System 400 2035
Rancho del Rey Brackish Groundwater Development 500 2035 San Dieguito River Basin Groundwater Recovery and Treatment Project 1,120 2025
San Marcos Groundwater Basin Supply Options 2,000 2030
A.5-12 Local Projects
Table A.5-3
Seawater Desalination Projects
Existing Projects
Ultimate
Yield/Capacity
(Acre-Feet) Online Date
San Diego County Water Authority
Claude "Bud" Lewis Carlsbad Desalination Plant - Carlsbad MWD 2,500 2015 Claude "Bud" Lewis Carlsbad Desalination Plant - SDCWA 50,000 2015 Claude "Bud" Lewis Carlsbad Desalination Plant - Vallecitos WD 3,500 2015 CEQA Projects
Ultimate
Yield/Capacity
(Acre-Feet) Online Date
Municipal Water District of Orange County
Doheny Ocean Desalination Project 16,800 2025
Huntington Beach Seawater Desalination Project 56,000 2027 West Basin Municipal Water District
West Basin Seawater Desalination Project 21,500 2030
Conceptual Projects
Ultimate
Yield/Capacity
(Acre-Feet) Online Date
San Diego County Water Authority
Otay Mesa Conveyance and Disinfection System Project (Purchase) 6,700 2030 Appendix 6
CONSERVATION ESTIMATES AND WATER SAVINGS FROM
CODES, STANDARDS, AND ORDINANCES
Conservation Estimates and Water Savings from Codes, Standards, and Ordinance A.6-1 Appendix 6
CONSERVATION ESTIMATES AND WATER SAVINGS FROM
CODES, STANDARDS, AND ORDINANCES
Background
Unlike traditional water supplies, which can be directly measured, conservation reduces water demand in ways that may only be indirectly quantified. Demand is reduced through changes in consumer behavior and savings from water-efficient fixtures. There are numerous approaches for estimating and projecting conservation savings, and many of them are utility-specific to meet the unique needs of different water agencies. Metropolitan estimates savings from the extensive existing conservation programs that it funds directly, as well as savings produced by plumbing codes. Metropolitan also incorporates the savings due to the impacts of price on consumers in its demand forecasts. These conservation savings estimates are incorporated into Metropolitan’s long-term planning documents such as the Integrated Water Resources Plan (IRP) and its Urban Water Management Plan (UWMP).
Conservation savings are commonly estimated from a base-year water-use profile. Beginning with the 1996 IRP, Metropolitan identified 1980 as the base year for estimating conservation because it marked the effective date of a new plumbing code in California. Among other changes, the new code required toilets in new construction to be rated at 3.5 gallons per flush or less. Between 1980 and 1990, Metropolitan’s service area saved an estimated 250 TAF per year as the result of this 1980 plumbing code and unrelated water rate increases. Within Metropolitan’s planning framework, these savings are referred to as “pre-1990 savings.” Metropolitan’s conservation accounting combines pre-1990 savings and estimates of more recently achieved savings from the following sources of conservation:
• Active Conservation – Water saved directly as a result of conservation programs by water agencies. Active conservation is unlikely to occur without agency action. • Code-Based Conservation – Water saved as a result of changes in water efficiency requirements for plumbing fixtures in plumbing codes. Sometimes referred to as “passive conservation,” this form of conservation would occur as a matter of course without any additional action from water agencies.
• Price-Effect Conservation – Water saved by retail customers attributable to the effect of changes in the real (inflation-adjusted) price of water. Because water has a positive price elasticity of demand, increases in water price will decrease the quantity of water demanded.
Metropolitan’s Conservation Estimate
In September 19, 2014, Governor Brown signed SB 1420 (Wolk, D-Davis), which added Section 10631(e)(4) to the Water Code. This Section provided that “water use projections may display and account for the water savings estimated to result from adopted codes, standards, ordinances, or transportation and land use plans” if that information is available and applicable to an urban water supplier. SB 606 (Hertzberg) amended Water Code Section 10631(e)(4), which is now Section 10631(d)(4) and applies only to retailers. This Section now requires that water use A.6-2 Conservation Estimates and Water Savings from Codes, Standards, and Ordinance projections, where available, must “display and account for the water savings estimated to result from adopted codes, standards, ordinances, or transportation and land use plans identified by the urban water supplier, as applicable to the service area.” Metropolitan’s conservation estimate is a comprehensive representation of Metropolitan’s active conservation activities. It includes a combination of: (1) fixture/program-related savings, and (2) an estimate of code-based plumbing code conservation savings from a 1990 base year. In addition, price-effect savings are calculated using Metropolitan’s MWD-EDM, a statistical model used to forecast retail water demands. Potential savings from public outreach and education programs are not included in Metropolitan’s conservation estimate.
Distinguishing between active, code-based, and price-effect conservation can be complex when, for example, active programs for fixtures are implemented concurrently with conservationrelated plumbing codes. Metropolitan’s conservation estimate combines active, code-based, and price-effect conservation savings using methods that avoid double counting. Currently, 96 devices and programs are accounted for in estimating active conservation. These devices are spread across residential, landscape, commercial, industrial, and institutional sectors. There are eight fixtures tied to Code-based conservation estimate.
Metropolitan’s conservation estimate is developed in cooperation with its 26 member agencies and falls into three general categories:
Single-family residential (SFR),
Multi-family residential (MFR), and
Commercial, industrial, and institutional (CII).
Active Conservation
Estimated savings for active conservation account for programs administered by Metropolitan and its member agencies since 1990. These savings are calculated by combining counts of active program activity – numbers of devices and/or program implementations – with devicerelated water savings factors. These factors include:
Savings per device/implementation
Device life expressed in years
Decay rate expressed as percent decay per year
Device savings estimates reflect the key assumptions outlined above. Devices may be represented more than once due to different implementation methods or savings factors.
Assumptions are periodically reviewed to ensure they represent the best available savings estimates. Device-specific savings are adjusted to account for performance decay rates, or device life, but not both. For example, a residential premium high-efficiency toilet (PHET) saves about 9.4 gallons per day when replacing a 1.6 gallons per flush toilet. Lifetime savings would assume a physical life of 20 years and no performance decay.
Code-Based Conservation
Code-Based conservation accounts for water saved as a result of changes in water efficiency requirements for plumbing fixtures in plumbing codes. Plumbing code conservation is the impact of plumbing codes and other ordinances on water demand. Metropolitan’s Code-Based conservation estimate represents plumbing code conservation with demographically-driven stock models. The stock models are device- or fixture- specific and are based on the same demographic data used in Metropolitan’s retail demand projection. Each stock model considers Conservation Estimates and Water Savings from Codes, Standards, and Ordinance A.6-3 the stocks and flows of conserving and non-conserving water devices, providing estimates of the impacts of plumbing codes on device saturation and overall savings.
Metropolitan’s Code-based conservation estimate accounts for the following:
• New Construction: Water fixtures installed due to new construction are assumed to be in compliance with the plumbing codes in effect when the new construction occurs. For instance, a house built in 1997 would meet the efficiency standards set by California’s 1992 plumbing code. Therefore, new construction is assumed to result in measurable savings from 1990, which is the baseline for conservation savings calculations. Estimates and projections of the number of fixtures added through new housing units and offices are based on growth in housing units or employment.
• Natural Replacement: Natural replacement accounts for the savings that accrue when fixtures are replaced with more efficient models due to remodeling, failure, or for other reasons. Metropolitan’s savings estimate represents this effect with a “natural replacement rate” that is expressed as a percentage of existing fixtures that are replaced in a given year.
Natural replacement rates vary by device and are linked to the expected life of the device.
Devices with short lifespans will be replaced more frequently and thus have higher natural replacement rates. A simple percentage is used to account for this natural turn-over in nonconserving fixtures because it is difficult to back-calculate the age of the fixtures in pre-1990 construction.
• Fixtures Up for Renewal: As water-conserving fixtures reach their useful lives and become defective or inefficient, they may be replaced with water conserving fixtures due to plumbing codes. The water savings from the device is then considered “renewed” savings, which is tracked in Metropolitan’s savings estimate. For example, a fixture that was installed through an active conservation program provides water savings that otherwise would not have been realized without plumbing codes. However, subsequent adoption of efficient plumbing codes means that when the fixture reaches the end of its life, it will be replaced by the same or more water-efficient model.
Stock Models
The number of efficient fixtures for each stock model is the sum of fixtures from active programs, new construction, natural replacement, and fixtures up for renewal. Table A.6-1 below shows the fixtures and devices that are assigned stock models based on existing plumbing codes.
Table A.6-1
Stock Models
Residential CII
Toilets Toilets
Showerheads Urinals
Faucet Aerators Pre-Rinse Spray Heads
Washing Machines Washing Machines
The Stock Models generate separate annual estimates of devices and fixtures for tracking active conservation savings, while also accounting for the impacts of active programs on the overall device saturation rate. As a result, increased levels of active conservation lead to lower levels of A.6-4 Conservation Estimates and Water Savings from Codes, Standards, and Ordinance plumbing code conservation. This helps avoid double counting in Metropolitan’s conservation savings estimate.
Plumbing Code Assumptions
Plumbing code savings are determined by the device-specific assumptions used in the stock models, presented in Table A.6-2. The stock models are driven by projections of housing and employment consistent with the demand projections. Initial device counts and growth in the number of devices are determined by the combination of demographic information and the following assumptions:
• Devices per Household or Per Employee: This factor represents the average number of devices per household or per employee and is multiplied by the demographic projections to develop estimates of total number of devices or “stock.” Devices per household and employee can vary by agency and change over time.
• Plumbing Code Compliance Rate: The plumbing code compliance rate is expressed as a percent and serves two purposes: (1) it indicates the presence of a plumbing code in a specific year, and (2) it determines the overall compliance rate with the plumbing code. This allows plumbing code effects to be phased in over several years. • Natural Replacement Rate: This represents the rate at which existing non-conserving devices are converted to conserving devices due to remodeling or device failure. It has a strong impact on the saturation rate of devices that existed prior to plumbing codes, such as pre1992 toilets. • Device Life: The stock models also account for device life for water-efficient devices installed after 1990. This allows the stock model to track devices installed through active conservation as they reach the end of their life and are replaced due to plumbing codes. The stock models use the same device life specified in the savings assumptions.
Table A.6-2
Plumbing Code Assumptions
Stock Model
Device per
Household/
Employee
Compliance
Rate
Natural
Replacement
Rate
Plumbing
Code Year
Res. Toilets 2 99% 2% 1994/2014
Res. Shower Heads 1.8 95% 10% 1994
Res. Aerators 3.5 90% 33% 1994
Res. Washing Machine 0.74 100% 6.7% 2018
CII Toilets 0.27* 100% 2% 1994/2014
CII Urinals 0.06 100% 4% 1994
CII Pre-Rinse Spray Heads 0.0055* 95% 16.7% 2006
CII Washing Machine 0.0073* 100% 5% 2007
* Varies over time and by agency (based on CUWCC BMPs savings factors) These assumptions are derived from California Urban Water Conservation Council (CUWCC) conservation reports, American Water Works Association Research Foundation’s 1999 end use study, Metropolitan’s Orange County Saturation Study, and other sources. In the residential sector, devices per household combine single family and multifamily trends.
Conservation Estimates and Water Savings from Codes, Standards, and Ordinance A.6-5 Model Water Efficient Landscape Ordinance
The California Water Commission adopted an updated Model Water Efficient Landscape Ordinance (MWELO) on July 15, 2015. The MWELO promotes efficient landscapes in new developments and retrofitted landscapes. The MWELO increases water efficiency standards for new and retrofitted landscapes through more efficient irrigation systems, greywater usage, onsite storm water capture, and by limiting the portion of landscapes that can be covered in turf. Local agencies had until December 1, 2015 to adopt the MWELO or to adopt a Local Ordinance which must be at least as effective in conserving water as MWELO. Local agencies working together to develop a Regional Ordinance had until February 1, 2016 to adopt, but they are still subject to the December 2015 reporting requirements. Local agencies were required to report on the implementation and enforcement of local ordinances by December 31, 2015.
Metropolitan’s modeling of Code-based conservation includes a calculation of savings that would result from 50 percent of new households having efficient outdoor water use consistent with MWELO. The 50 percent compliance rate for new households is a conservative estimate based on an assessment of the efficacy of the current MWELO ordinance.
Price Savings Assumptions
Price-effect savings are calculated by comparing MWD-EDM demand projections with price increases to demand projections with constant 1990 water rates. The difference is the priceeffect savings measured from a 1990 base. Price-effect savings increase as prices rise over time; they also increase as the household and employment base grow. A price increase applied to 1,000 households will generate more water savings than the same price increase applied to 500 households.
Un-metered Water Use Savings
A final category of savings tracked by Metropolitan is a product of other conservation efforts.
MWD-EDM projects un-metered water use as a fixed percentage of total retail M&I demand. As conservation savings lowers residential and CII demands, it lowers un-metered use by the same percent. For instance, if conservation reduces M&I demands by 10 percent in 2020 (compared to demands before conservation), un-metered water use is also reduced 10 percent. This reduction is based on the assumption that un-metered use varies according to overall demand and that reducing overall use also reduces un-metered use. The reduction in un-metered water use is captured in the MWD-EDM model and included as a conservation source.
The total conservation savings are shown in Table A.6-3.
A.6-6 Conservation Estimates and Water Savings from Codes, Standards, and Ordinance Table A. 6-3 Conservation Savings (acre-feet) Note: Metropolitan’s conservation savings projection includes savings from Metropolitan’s Conservation Credits Program, code-based conservation, price effect conservation, and pre-1990 device retrofits. The projection does not include savings from the implementation of future active conservation programs. 1990 1995 2000 2005 2010 2015 2020 2025 2030 2035 2040 2045 2050 0 26,000 59,000 94,000 133,000 152,000 144,000 93,000 55,000 35,000 25,000 17,000 0 0 83,000 177,000 244,000 291,000 370,000 472,000 560,000 623,000 665,000 701,000 731,000 757,000 0 31,000 62,000 94,000 125,000 156,000 187,000 205,000 229,000 258,000 293,000 333,000 379,000 0 9,000 18,000 26,000 35,000 44,000 52,000 53,000 54,000 55,000 56,000 57,000 58,000 Active Savings Code-Based Savings Price Savings Un-metered Water Savings Pre-1990 Savings 250,000 250,000 250,000 250,000 250,000 250,000 250,000 250,000 250,000 250,000 250,000 250,000 250,000 Total 250,000 399,000 566,000 708,000 834,000 972,000 1,105,000 1,161,000 1,211,000 1,263,000 1,325,000 1,388,000 1,444,000 Appendix 7
DISTRIBUTION SYSTEM WATER LOSSES
Distribution System Water Losses A.7-1
Appendix 7
DISTRIBUTION SYSTEM WATER LOSSES
California Water Code Section 10631(d)(3) requires urban retail suppliers to quantify distribution system water loss for each of the five years preceding the plan update, based on water system balance methodology developed by the American Water Works Association (AWWA). For the 2020 UWMP, Metropolitan is voluntarily reporting its distribution system water loss. Metropolitan followed the AWWA Water Audit methodology to track all sources of treated water and uses of treated water within its system. The AWWA Water Audit methodology quantifies real and apparent water system losses in an agency’s distribution system.
For its voluntary reporting of distribution system water losses, Metropolitan included its water balance audit for calendar years 2015 through 2019. The results of Metropolitan’s audit showed that the average water losses for its treated distribution system over the last five years from 2015 to 2019 is approximately 7.8 TAF. The water loss estimates are presented in Tables A.7-1 through A.7-5.
In addition to the distribution system losses described in the AWWA tables, Metropolitan estimates that 41.6 TAF was lost from reservoir evaporation occurring in Lake Mathews, Lake Skinner, and Diamond Valley Lake during calendar year 2019.
A.7-2 Distribution System Water Losses Table A.7-1 Metropolitan’s Distribution System Water Loss (AF) Calendar Year 2015 Own Sources (Adjusted for known errors) 791,352.381 Water Imported 0.000 System Input 791,352.381 AWWA Free Water Audit Software: Water Balance WASv5.0 ~mlNf1rn1 Water Audit Report for: Metropolitan Water District of Southern California Water Exported 0.000 Reporting Year: 2015 1/2015 - 1212015 Data Validity Score: ~9_5 __________ ----" Billed Water Exported Billed Metered Consumption (water Billed Authorized Consumption !exported is removed) 780,724.000 Authorized Consumption 781,504.700 780,724.000 Billed Unmetered Consumption 0.000 Revenue Water 0.000 Revenue Water 780,724.000 Unbilled Authorized Consumption Non-Revenue Water ,Unbilled Metered Consumption 0.000 I (NRW) Water Supplied 791,352.381 Water Losses 9,847.681 780.700 Apparent Losses 2,001.800 Real Losses 7,845.881 Unbilled Unmetered Consumption Unauthorized Consumption Customer Metering Inaccuracies Systematic Data Handling Errors Leakage on Transmission and/or Distribution Mains Not broken down 780.700 0.000 1,951.800 50.000 Leakage and Overflows at Utility's Storage Tanks Not broken down Leakage on Service Connections Not broken down 10,628.381 Distribution System Water Losses A.7-3 Table A.7-2 Metropolitan’s Distribution System Water Loss (AF) Calendar Year 2016 Own Sources (Adjusted for known errors) 754,436.090 Water Imported 0.000 System Input 754,436.090 AWWA Free Water Audit Software: Water Balance WASv5.0 tJjfijt!ffiB?iW1iS!I Water Audit Report for: Metropolitan Water District of Southern California Water Exported 0.000 Reporting Year: 2016 1/2016 • 12/2016 Data Validity Score: 95 Billed Water Exported Billed Metered Consumption (water Billed Authorized Consumption !exported is removed) 745,890.600 Authorized Consumption 746,636.500 745,890.600 Billed Unmetered Consumption 0.000 Revenue Water 0.000 Revenue Water 745,890.600 Unbilled Authorized Consumption Non-Revenue Water ,Unbilled Metered Consumption 0.000 I (NRW) Water Supplied 754,436.090 Water losses 7,799.590 745.900 Apparent losses 1,914.700 Real losses 5,884.890 Unbilled Unmetered Consumption Unauthorized Consumption Customer Metering Inaccuracies Systematic Data Handling Errors leakage on Transmission and/or Distribution Mains Not broken down 745.900 0.000 1,864.700 50.000 leakage and Overflows at Utility's Storage Tanks Not broken down leakage on Service Connections Not broken down 8,545.490 A.7-4 Distribution System Water Losses Table A.7-3 Metropolitan’s Distribution System Water Loss (AF) Calendar Year 2017 Own Sources (Adjusted for known errors) 850,417.043 Water Imported 0.000 System Input 850,417.043 AWWA Free Water Audit Software: Water Balance WASv5.0 HtrtliieGmw11J Water Audit Report for: Metropolitan Water District of Southern California Water Exported 0.000 Reporting Year: 2017 1/2017 - 1212017 Data Validity Score: ~9_5 __________ __, Billed Water Exported ------------ Billed Metered Consumption (water Authorized Consumption 843,331.300 Billed Authorized Consumption !exported is removed) 842,488.800 842,488.800 Billed Unmetered Consumption 0.000 Revenue Water 0.000 Revenue Water 842,488.800 Unbilled Authorized Consumption Non-Revenue Water ,Unbilled Metered Consumption 0.000 I (NRW) Water Supplied 850,417.043 Water Losses 7,085.743 842.500 Apparent Losses 2,156.200 Real Losses 4,929.543 Unbilled Unmetered Consumption Unauthorized Consumption Customer Metering Inaccuracies Systematic Data Handling Errors Leakage on Transmission and/or Distribution Mains Not broken down 842.500 0.000 2,106.200 50.000 Leakage and Overflows at Utility's Storage Tanks Not broken down Leakage on Service Connections Not broken down 7,928.243 Distribution System Water Losses A.7-5 Table A.7-4 Metropolitan’s Distribution System Water Loss (AF) Calendar Year 2018 Own Sources (Adjusted for known errors) 770,999.499 Water Imported 0.000 System Input 770,999.499 AWWA Free Water Audit Software: Water Balance WASv5.0 ei@~tlllNTiiH!I Water Audit Report for: Metropolitan Water District of Southern California Water Exported 0.000 Reporting Year: 2018 1/2018 - 12/2018 Data Validity Score: 95 Billed Water Exported Billed Metered Consumption (water Billed Authorized Consumption !exported is removed) 766,008.500 Authorized Consumption 766,774.500 766,008.500 Billed Unmetered Consumption 0.000 Revenue Water 0.000 Revenue Water 766,008.500 Unbilled Authorized Consumption Non-Revenue Water ,Unbilled Metered Consumption 0.000 I (NRW) Water Supplied 770,999.499 Water Losses 4,224.999 766.000 Apparent Losses 1,965.000 Real Losses 2,259.999 Unbilled Unmetered Consumption Unauthorized Consumption Customer Metering Inaccuracies Systematic Data Handling Errors Leakage on Transmission and/or Distribution Mains Not broken down 766.000 0.000 1,915.000 50.000 Leakage and Overflows at Utility's Storage Tanks Not broken down Leakage on Service Connections Not broken down 4,990.999 A.7-6 Distribution System Water Losses Table A.7-5 Metropolitan’s Distribution System Water Loss (AF) Calendar Year 2019 Own Sources (Adjusted for known errors) 706,766.917 Water Imported 0.000 System Input 706,766.917 AWWA Free Water Audit Software: Water Balance WASv5.0 ~MINtf1il!I Water Audit Report for: Metropolitan Water District of Southern California Water Exported 0.000 Reporting Year: 2019 1/2019 - 12/2019 Data Validity Score: 95 Authorized Consumption 700,559.700 Billed Water Exported Billed Metered Consumption (water Billed Authorized Consumption I exported is removed) 699,859.800 699,859.800 Billed Unmetered Consumption 0.000 Revenue Water 0.000 Revenue Water 699,859.800 Unbilled Authorized Consumption Non-Revenue Water ,Unbilled Metered Consumption 0.000 1 (NRW} Water Supplied 706,766.917 Water Losses 6,207.217 699.900 Apparent Losses 1,799.600 Real Losses 4,407.617 Unbilled Unmetered Consumption Unauthorized Consumption Customer Metering Inaccuracies Systematic Data Handling Errors Leakage on Transmission and/or Distribution Mains Not broken down 699.900 0.000 1,749.600 50.000 Leakage and Overflows at Utility's Storage Tanks Not broken down Leakage on Service Connections Not broken down 6,907.117 Appendix 8
METROPOLITAN’s EMERGENCY STORAGE OBJECTIVE
Metropolitan’s Emergency Storage Objective A.8-1
Appendix 8
METROPOLITAN’S EMERGENCY STORAGE OBJECTIVE
Metropolitan established its original criteria for determining emergency storage requirements in the October 1991 Final Environmental Impact Report for the Eastside Reservoir, which is now named Diamond Valley Lake. Emergency storage requirements are based on the potential of a major earthquake that would damage all supply aqueducts isolating Southern California from its imported water sources. The emergency storage criteria developed within the Eastside Reservoir EIR were again discussed in the 1996 Integrated Water Resources Plan. Metropolitan’s Board approved both of these documents.
In 2019, Metropolitan and its member agencies completed a process to update the emergency criteria and methodology for determining the regional planning estimate of emergency storage under Metropolitan’s Emergency Storage Objective. This planning estimate of emergency storage represents the amount of water that Metropolitan would store for the region to prepare for a catastrophic earthquake that would damage the aqueducts that transport imported water supplies to Southern California, including: the Colorado River Aqueduct, both the East and West branches of the California Aqueduct, and the Los Angeles Aqueduct. These emergency supplies, stored in Metropolitan and DWR existing surface reservoirs within the region, will allow Metropolitan to deliver reserve supplies to the member agencies to supplement their local production during a catastrophic earthquake or other disaster. This helps avoid severe water shortages during periods when the imported water aqueducts may be out of service.
The Emergency Storage Objective considers a six- and twelve-month outage period for the imported supply aqueducts, based on latest seismic information and estimates of repair duration for the different aqueducts. It also accounts for the operational flexibility of Metropolitan’s distribution system, a retail water demand cutback ranging from 25 to 35 percent considering the level of conservation that the region achieved during the recent drought, and an aggregated loss of 10 to 20 percent of local supplies accounting for factors that could affect local production during emergency conditions.
Under this update, Metropolitan’s Emergency Storage Objective was set to 750,000 acre-feet, as this level of storage would prevent severe water shortages to the region given new information on expected recovery durations. While the emergency storage would allow Metropolitan to deliver reserve supplies to the member agencies to meet their water needs during a catastrophic event, it is not intended to set a basis or a policy for allocating or apportioning storage for any individual member agency.
Included in this appendix is a copy of the Board Information Letter to Metropolitan’s Water Planning and Stewardship Committee dated May 14, 2019. This Board Information Letter and the attached draft white paper review the history, policy, and criteria for evaluating a regional planning estimate for emergency storage and describe the more than year-long coordination process between Metropolitan and its member agencies in developing the region’s estimate for Emergency Storage Objective.
Board of Directors
Water Planning and Stewardship Committee
5/14/2019 Board Meeting
9-3
Subject
Update of Metropolitan’s Emergency Storage Objective
Executive Summary
In February 2018, The Metropolitan Water District of Southern California (Metropolitan) and its member agencies embarked on a process to evaluate regional storage including how the storage programs performed during this post decade of drought and revisiting the size and management of Metropolitan’s emergency storage reserve. This process aims to maximize the potential for optimizing performance and operations of Metropolitan’s storage programs. As part of the process, a Workgroup comprised of Metropolitan staff and representatives from member agencies evaluated Metropolitan’s emergency storage objective.
Metropolitan, in coordination with the Workgroup, completed the attached draft White Paper on emergency storage, which summarizes the progress to date in estimating a planning objective for the region’s emergency storage.
Details
The White Paper reviews the history, policy, and criteria for evaluating a regional planning estimate for emergency storage. This evaluation prepares for major earthquake or other damage to the aqueducts that import water to Southern California. The emergency storage would allow Metropolitan to deliver reserve supplies to the member agencies to supplement local production. This would help avoid severe water shortages while one or more of the imported water aqueducts may be out of service.
The White Paper also describes the mechanisms the Workgroup employed, including: (1) updated emergency criteria, and (2) a revised methodology to evaluate emergency storage.
Updating emergency criteria involved revising the outage durations based on the latest seismic information, and revisiting retail water demands and locally available supplies within the service area. It also accounted for the member agencies’ unique situations in identifying practicable ranges of reduction of retail water demands through conservation and production levels of local water supplies during an imported supply emergency outage.
The proposed emergency storage volume considers various combinations of criteria to determine an envelope of acceptable scenarios designed to prevent severe shortages during the outage. Under this approach, the Workgroup focused on a range of values from 520,000 to 830,000 acre-feet (AF). With input from the Workgroup, staff recommends increasing the emergency storage objective to 750,000 AF. This recommended volume would be distributed amongst the available capacities of in-region Department of Water Resources and Metropolitan surface reservoirs.
The recommended emergency storage volume of 750,000 AF is an increase from the current planning target of 630,000 AF. A longer outage period based on damage restoration analysis and a consideration of lower local supply production attributed to this recommended increase in emergency storage.
The emergency storage volume presented in the White Paper represents a planning estimate for the amount of water that Metropolitan would store for the region in preparation for a catastrophic earthquake or other disaster. It 6~£s~EJ;HoEPRONLCITAN WATER DISTRICT ALIFORNIA
FORMATION
I
5/14/2019 Board Meeting 9-3 Page 2
is not intended to set a basis or a policy for allocating or apportioning storage for any individual member agency.
Staff will review and incorporate additional Board and Workgroup feedback in finalizing the White Paper. Staff will transmit the final White Paper to the Board and the member agencies.
Staff proposes to revisit the emergency storage periodically, and incorporate the analysis into the Integrated Water Resources Plan update process. In addition, a detailed review of the spatial distribution of storage and operation of the distribution system will be part of Metropolitan’s continued efforts to evaluate the storage portfolio. This next phase of evaluating Metropolitan’s regional storage portfolio is expected to be completed by spring of 2020.
Policy
By Minute Item 50358, dated January 12, 2016, the Board adopted the 2015 Integrated Water Resources Plan Update, as set forth in Agenda Item 8-3 board letter.
By Minute Item 50473, dated May 10, 2016, the Board adopted the 2015 Urban Water Management Plan, as set forth in Agenda Item 8-6 board letter.
Fiscal Impact
None
Brad Coffey
Manager, Water Resource Management
Date
Jeffrey Kightlinger
General Manager
Date
Attachment 1 – Draft White Paper on Metropolitan’s Emergency Storage Objective (May 2019)
Ref# wrm12661707
5/1/2019
5/1/2019
5/14/2019 Board Meeting 9-3 Attachment 1, Page 1 of 17
May 2019 Metropolitan Water District of Southern California 1 2018 Evaluation of Regional Storage Portfolio
DRAFT Evaluation of Metropolitan’s Emergency Storage Objective
SUMMARY
In February 2018, the Metropolitan Water District of Southern California (Metropolitan) and its member agencies embarked on a process for the Evaluation of Regional Storage Portfolio (ERSP) to maximize potential for performance and operations of Metropolitan’s storage programs. As part of the ERSP process, a Workgroup comprised of Metropolitan staff and representatives from member agencies evaluated Metropolitan’s Emergency Storage Objective (Emergency Storage).
This White Paper provides a summary of the history, policy, and criteria for evaluating a regional planning estimate for the Emergency Storage. This evaluation assumes major earthquake damage to the aqueducts that transport imported water supplies to Southern California. The Emergency Storage allows Metropolitan to deliver reserve supplies to the member agencies to supplement local production. This helps avoid severe water shortages during periods when the imported water aqueducts may be out of service.
This White Paper describes: (1) updating the emergency criteria, and (2) revising the methodology for calculating the Emergency Storage.
In the review and update of emergency criteria, the Workgroup considered the 2015 Integrated Water Resources Plan (IRP) and centered on the following:
A retail water demand cutback of 25 to 35 percent appears reasonable, based on the level of conservation that the region achieved during the recent drought; and A six‐and 12‐month aggregated loss of 10 to 20 percent of local production reported in the IRP seems reasonable. This allows a contingency for some damage to local facilities and accommodates variable durations of local repairs.
The Workgroup discussion also led to a new concept of an “envelope of solutions” to estimate an appropriate Emergency Storage for the region. The envelope concept shifts from a single equation and volume for determining emergency storage. Instead, it considers various combinations of criteria to determine a range of acceptable scenarios for Emergency Storage. The prior methodology assumed a single region‐wide scenario of conservation and local production loss. This envelope concept underscores member agencies’ unique situations while taking into account their inputs in identifying practicable ranges of decreases in retail water demands and local production. The Workgroup focused on an acceptable range of Emergency Storage values from 520,000 to 830,000 acre‐feet (AF).
Based on input from the process, staff recommends the following:
The Emergency Storage Objective should increase from 630,000 AF to 750,000 AF. This level of storage would prevent severe water shortages to the region given new information on expected recovery durations.
Metropolitan should revisit the Emergency Storage Objective periodically, possibly following the completion of any new IRP with the latest information on damage scenarios, local supplies, imported water demand, and attainable conservation.
5/14/2019 Board Meeting 9-3 Attachment 1, Page 2 of 17
May 2019 Metropolitan Water District of Southern California 2
DETAILED REPORT
Background
Metropolitan’s need for Emergency Storage is based on the potential for major earthquake damage to the Colorado River Aqueduct, California Aqueduct, and Los Angeles Aqueduct. Metropolitan coordinates with the member agencies in setting the emergency criteria, which forms the basis for establishing the Emergency Storage. These criteria assume that damage from such a catastrophic event could render the aqueducts that transport imported water supplies to Southern California out of service, isolating the region from its imported water supplies. Metropolitan’s objective is to provide regional emergency storage that could allow Metropolitan to deliver supplies to all its member agencies during this period of outage. The Emergency Storage allows Metropolitan to continue deliveries to its member agencies to supplement local water production and release from local storage. This helps avoid severe water shortages during periods when aqueducts are out of service. In addition to Emergency Storage, Metropolitan may draw from dry‐year storage during an emergency, if necessary and available.
Metropolitan’s emergency planning criteria were previously established and reported in the following documents:
1. Final Environmental Impact Report for the Eastside Reservoir (now named the Diamond Valley Lake) dated October 1991, which was adopted by the Board on September 24, 1991;
2. Southern California’s 1996 Integrated Water Resources Plan, which was adopted by the Board on January 9, 1996;
3. Reports on Metropolitan Water Supplies dated February 2002 and March 2003;
4. 2006 IRP Implementation Report, which was presented to the Board on September 11, 2006 and transmitted on October 9, 2006;
5. Metropolitan’s Emergency Storage Requirement, a written report presented to the Board on May 11, 2010; and
6. The 2015 Urban Water Management Plan dated June 2016, which was adopted by the Board on May 10, 2016.
Metropolitan’s Current Emergency Criteria
Metropolitan’s current emergency criteria provide for a six‐month water supply at 75 percent of member agencies’ retail demand under normal hydrologic conditions. Metropolitan’s emergency plan outlines that under catastrophic loss of water supply the following actions will be implemented, which serve as the criteria for determining Metropolitan’s Emergency Storage:
1. any existing interruptible water deliveries would be suspended;
2. firm supplies to member agencies would be restricted by a mandatory cutback of 25 percent from normal year retail demand levels;
3. water stored in the surface reservoirs and groundwater basins under Metropolitan’s interruptible program would be made available;
4. full local groundwater production, recycled water, and local surface emergency storage reserve production would be sustained; and
5. Metropolitan would draw on its emergency storage as well as other availablestorage.
These emergency planning criteria were the basis for the current Metropolitan’s Emergency Storage planning level of 630, 000 AF.
5/14/2019 Board Meeting 9-3 Attachment 1, Page 3 of 17
May 2019 Metropolitan Water District of Southern California 3 Review and Update of Metropolitan’s Emergency Criteria
The following sections detail the updated assumptions and changed conditions since the last evaluation of Emergency Storage in 2010. These include demand and supply forecasts developed for the 2015 IRP, updated studies on the potential for seismic damage and outage periods for the imported supply aqueducts, and flexibility improvements within Metropolitan’s distribution system implemented as a result of recent drought and supply challenges. This new information is critical to the review and update of the emergency criteria, which forms the basis for revising the Emergency Storage.
Outage Period Criteria
The outage period pertains to the amount of time the regional aqueducts that deliver imported water to Southern California may be out of service. This outage period is derived from the estimated restoration timelines based on the nature of potential damage to the aqueduct coupled with the operational ability to deliver supplies to the area served by that specific aqueduct. During an emergency outage period, Metropolitan’s member agencies will depend on previously stored imported and local supplies to supplement continued local production in meeting reduced levels of retail demands. It is acknowledged that some areas could be more impacted because they are primarily or exclusively fed by an imported aqueduct which is assumed to sustain damage. However, Metropolitan’s objective is to continue building and operating its system with flexibility to respond to various potential damage scenarios.
Recent Seismic Studies
In August 2015, Metropolitan, Los Angeles Department of Water and Power (LADWP), and California Department of Water Resources (DWR) formed the Seismic Resilience Water Supply Task Force (Task Force) for the purpose of collaborating on studies and mitigation measures to improve the reliability of imported water supplies to Southern California. The specific goals of the Task Force included:
Revisiting historical assumptions regarding potential aqueduct outages; Establishing a common understanding about individual agency aqueduct vulnerability assessments, projected damage scenarios, and planning assumptions; and Discussing ideas for improving the resilience of Southern California’s imported water supplies through multi‐agency cooperation.
Through exchange of information and ideas between the three agencies and experts from the industry and academia, the Task Force assessed potential aqueduct damage and restoration timeline for a M 7.8 earthquake on the San Andreas Fault. This scenario assumes severe damage to the Colorado River Aqueduct (CRA), the California Aqueduct, and the Los Angeles Aqueduct (LAA). A complete description of probable seismic damages and repair durations is presented in Metropolitan’s “Seismic Resilience Water Supply Task Force Report No. 1536” dated June 2017 (http://www.mwdh2o.com/PDF_About_Your_Water/Report1536_Final.pdf).
Table 1 presents a summary of the estimated outage duration under the earthquake scenario based on the nature of damage for each of the aqueducts.
5/14/2019 Board Meeting 9-3 Attachment 1, Page 4 of 17
May 2019 Metropolitan Water District of Southern California 4 Table 1
Estimated Outage Duration for Imported Supply Aqueducts (M 7.8 earthquake) Aqueduct Estimated Outage Duration
Colorado River Aqueduct 2 to 6 months (recovery of 80% CRA capacity) 3 to 5 years (recovery of 100% CRA capacity)
California Aqueduct: East Branch 12 to 24 months
California Aqueduct: West Branch 6 to 12 months
Los Angeles Aqueduct 18 months
Operational Flexibility
Metropolitan’s integrated system provides operational flexibility. The flexibility in Metropolitan’s distribution system was demonstrated during the unprecedented drought of 2014‐2016. Facing consecutive years of low SWP supplies, Metropolitan pushed CRA and Diamond Valley Lake (DVL) supplies to areas that Metropolitan normally serves only with SWP supplies or at higher blend of SWP. Figure 1 illustrates Metropolitan’s operations during that period of extraordinary drought when SWP supplies were at a historic low. Metropolitan can utilize much of the same operational flexibility in its distribution system to facilitate movement of stored supplies during a prolonged outage. This flexibility combined with retail demand reduction through additional conservation and local production at appropriate levels will allow the region to meet its demands in most areas during emergency outages. Although it is not possible for Metropolitan to predict the specific damage to the system in an event of a catastrophic emergency, it seeks to ensure the most flexibility possible throughout the system to respond to different damage scenarios.
Figure 1
Metropolitan Operations during Extraordinary Drought Actions (2014‐16) 5/14/2019 Board Meeting 9-3 Attachment 1, Page 5 of 17
May 2019 Metropolitan Water District of Southern California 5 During an emergency outage, previously stored imported supplies will be withdrawn to meet the region’s supplemental water needs. Emergency Storage is used first and dry‐year storage is then used, if necessary and available. Figure 2 shows the locations of existing DWR and Metropolitan surface reservoirs in various parts of the region.
Figure 2
Existing DWR and Metropolitan Surface Reservoirs
South of the San Andreas Fault
Metropolitan can draw from emergency supplies stored in Castaic Lake, Elderberry Forebay, and Pyramid Lake during an outage to serve the western areas that previously received SWP water. A limited quantity of CRA supplies could also be available to these areas when 80 percent of the CRA capacity is restored within six months to supplement emergency water needs in this area. Metropolitan can also supply up to 50 cfs of water from Greg Avenue Pump Station to the far western portion of its service area while repairs to the three aqueducts are being completed. This operational flexibility is also useful in the event that stored water was not adequate within the Castaic/Pyramid system.
Metropolitan can draw from emergency supplies stored in DVL, Lake Skinner, Lake Mathews, and Perris Lake during an outage to serve the eastern areas that previously received CRA and SWP water. When the CRA is restored to 80 percent of capacity within six months, it could provide up to 960,000 acre‐feet per year (AFY) of imported water to the region. This volume is more than the 15‐year historic average (2003 to 2017) CRA delivery of approximately 885,000 AFY and more than the 2015 IRP CRA delivery target of 900,000 AFY for a normal year. During outages, portions of the eastern area are expected to continue to receive treated CRA and/or stored emergency supplies through Weymouth. Some areas that normally receive SWP water from the East Branch may be served by delivering DVL water to Mills through the Inland Feeder/Lakeview Pipeline intertie. Metropolitan recognizes that there are currently no options to supply Existing Reservoirs
DWR
Pyramid
Elderberry
Castaic
Perris
Metropolitan
Mathews
Skinner
DVL
Conveyance Systems
Metropolitan
State of Calif.
Los Angeles
5/14/2019 Board Meeting 9-3 Attachment 1, Page 6 of 17
May 2019 Metropolitan Water District of Southern California 6 the Rialto Pipeline from emergency storage reservoirs during an outage of the East Branch of the California Aqueduct. However, water stored in Silverwood Lake (which is not included in Metropolitan’s Emergency Storage portfolio) could be available to supply the Rialto Area as soon as repairs to damaged penstocks and pipelines downstream of Silverwood Lake are completed. This could likely require less time than repairs to the East Branch north of Silverwood Lake. In addition, other potential options to supply the Rialto region include several conceptual pump back operations and increased groundwater storage and extraction capacity for emergencies.
Metropolitan will continue to deliver treated water from stored emergency supplies during an outage and from imported supplies upon service restoration. Four of Metropolitan’s five water treatment plants have redundant power feeds from the power provider. A project is currently underway to also equip the fifth plant with a redundant power feed. All five water treatment plants have backup emergency generators that support all treatment processes with the exception of ozone. Disinfection using chlorine would occur when the plants are reliant on generator power for treatment operations during a loss of utility power.
Metropolitan maintains a minimum 30 day supply of chlorine in the region.
Updated Outage Criteria
In updating the emergency outage criteria, the Workgroup considered both the duration of aqueduct repair based on the nature of potential seismic damage and recently demonstrated operational flexibilities of Metropolitan’s distribution system.
Figure 3 shows the range of outage durations for the CRA, California Aqueduct East and West Branches, and the LAA. The effective outage period is then derived by accounting for the estimated durations of repair for each regional aqueduct coupled with the operational ability to deliver supplies to the area served by that specific aqueduct. In updating the outage period, the Workgroup considered the following operational assumptions:
The estimated outage duration and repair of LAA under the earthquake scenario is 18 months.
However, when the West Branch comes back in service within 12 months, it can supply water to LADWP through LA‐35 while the LAA repairs continue.
Assumed outage period: 12 months for member agencies receiving supplies from West Branch and LAA.
The estimated outage duration and repair time of East Branch is 12 to 24 months. However, when 80 percent of the CRA capacity comes back in service within 6 months, CRA supplies would be available to many Metropolitan member agencies that normally receive SWP supplies. Thus, some areas that are normally served with water imported through the East Branch may be served with water imported through the CRA, using delivery of DVL water to Mills and several other options that should be evaluated in the Rialto area discussed above. Assumed outage period: 6 months for member agencies receiving supplies from CRA and East Branch (with the exception of Rialto agencies).
Using these assumptions, the effective new outage criteria presented in Figure 3 calls for storing supplemental supplies for 12 months in the West Branch and LAA areas (supplied by emergency storage in Castaic, Pyramid, and Elderberry) and 6 months in the CRA and East Branch areas (supplied by emergency storage in Perris, Skinner, Mathews, and DVL). In addition to the 12‐month stored emergency supplies, West Branch areas could also be served with limited amounts of CRA supplies within 6 months to help meet demands in areas normally served with SWP supplies and higher blend areas. It is not possible to predict the specific damage to the system as a result of a catastrophic event. Therefore, system flexibility is important to ensure all supplies may be moved, if necessary and possible. 5/14/2019 Board Meeting 9-3 Attachment 1, Page 7 of 17
May 2019 Metropolitan Water District of Southern California 7 Figure 3
Updated Emergency Outage Criteria
Retail Demand Cut Back Criteria
Demand Projection
The first step in calculating the Emergency Storage is to determine the total amount of emergency retail water demand at the member agency level. The Emergency Storage is intended to reflect estimated supplemental water demands on Metropolitan during an emergency outage now updated to a period of 6 or 12 months. Thus, the aggregate of emergency retail demand is used to determine the aggregate supplemental demands on Metropolitan during such emergency, which excludes non‐firm deliveries. Those deliveries are assumed to be suspended during an outage, as shown in Table 2.
Calculations of the emergency retail demand are provided for the year 2018 based on forecasts reported in the 2015 IRP. The retail demands in Table 2 were calculated at the member agency level. The numbers shown in this table represent the aggregate total retail demand (M&I and agricultural), replenishment, and seawater barrier demands over the emergency outage period considered. The total retail demands are based on forecasts from the Southern California Association of Government’s (SCAG) 2012 Regional Transportation Plan/Sustainable Community Strategy and from the San Diego County Association of Government’s (SANDAG) Series 13: 2050 Regional Growth Forecast (October 2013) forecast. The SCAG and SANDAG regional growth forecasts are the core assumptions in the econometric demand modeling for Metropolitan’s 2015 IRP.
Table 2
Firm Retail Demands (Average Year)
(Acre‐Feet)
2018
Demands for 6‐months and 12‐months(1)
Total Retail Demand 2,735,617
Replenishment (197,103)
Seawater Barrier (52,000)
Firm Retail Demand 2,486,514
Note: (1) Retail demands are assessed for the 6‐month outage period for member agencies receiving supplies from CRA and East Branch, and 12‐months for member agencies receiving supplies from West Branch and LAA (see Attachment A).
CRA
East Branch
West Brach
LA Aqueduct
2 months
12 months
6 months
18 months
0 Minimum Outage
Months
12 18
I
I
24 6 months
24 months
12 months
18 months
0 Maximum Outage
Months
12 18
I I I
I I
I
24 0
=
Effective Outage
Months
12 18
OuttageJ
Outtagej
Outt11ge
Outt11ge
24 5/14/2019 Board Meeting 9-3 Attachment 1, Page 8 of 17 May 2019 Metropolitan Water District of Southern California 8 Reduced Retail Demands during Emergency Outage
The next step in calculating the emergency storage demand on Metropolitan is to subtract a percentage reduction, or cutback, in water use from the retail demands. For illustrative purposes, Table 3 below shows the resulting reduction in retail demands during emergency outage after a cutback of 25 percent is imposed on the 2018 average condition retail demands. The retail demands in Table 3 are calculated at the member agency level. The numbers represent the aggregated total over the emergency outage period considered.
The assumption of a 25 percent retail demand cutback is a planning criterion that is consistent with previous Metropolitan studies that showed overall outdoor water use at approximately 30 percent. That cutback criterion is also consistent with the Public Policy Institute of California (PPIC) report (Building Drought Resilience in California’s Cities and Suburbs, June 2017) based on lessons learned during drought.
A higher level of austerity, public awareness, and a likely emergency declaration during an outage may support a higher cut back through additional conservation actions.
Table 3
Retail Level Emergency Demands (Average Year)
(Acre‐Feet)
2018
Demands for 6‐months and 12‐months(1)
Firm Retail Demand 2,486,514
25% Reduction (Cutback) (621,629)
100% IAWP Reduction N/A
Retail Demand during Emergency 1,864,885
Note: (1) Retail demands are assessed for the 6‐month outage period for member agencies receiving supplies from CRA and East Branch, and 12‐months for member agencies receiving supplies from West Branch and LAA (see Attachment A).
Local Production Level Criteria
The next step in calculating the Emergency Storage is to determine the amount of local supplies (local production of in‐region supplies and release from local storage) available to meet retail demands at the member agency level. The local production represents the member agencies’ highest potential production from the various types of supplies available within their service areas with consideration to each member agency’s supply, capacity, and demand limitations. For this evaluation, the year 2018 forecast from the 2015 IRP is initially used to estimate the local production for the 6‐month and 12‐month emergency outage periods. In addition, Metropolitan also considered the factors that could limit each member agency’s local supplies production. These include:
Supply limitation – Considers all supplies available during an emergency outage (including additional groundwater rights, allowable over pumping in the basin, or similar mechanism if available and needed)
Capacity limitation – Considers all available local production capacity (including extra well capacities to produce the any additional groundwater supplies if available and needed) Demand limitation – Considers the projected demand during the outage period (to determine the needed supplies from local and supplemental sources)
5/14/2019 Board Meeting 9-3 Attachment 1, Page 9 of 17
May 2019 Metropolitan Water District of Southern California 9 The Unused Local Production represents the aggregated production of individual member agencies above what is needed to meet their demands. In contrast, the Effective Local Production is the aggregated amount of locally available supplies that are produced to meet the reduced retail demands during an emergency outage. The Effective Local Production is derived by subtracting Unused Local Production from the aggregate total local production. For planning purposes in determining the Emergency Storage for the region, the Effective Local Production is calculated with the assumption that locally available supplies will be used only within the producing member agency’s service areas and not be used or exported to meet the demands of other agencies. However, in real emergency outages, it is likely that member agencies would implement region‐wide and inter‐agency coordination for the most efficient operation and use of available supplies.
As part of evaluating the Effective Local Production, Metropolitan also assessed the additional local groundwater that could be theoretically produced and local surface storage that could be reasonably available during an emergency outage. This evaluation revealed that additional groundwater supplies, while theoretically available, could not be produced due to one or a combination of limiting factors. The local surface storage, on the other hand, includes all reasonably available surface water storage that the member agency could produce and use within its service area during extended shortages. The Local Surface Storage in Table 4 includes SDCWA’s calculated Emergency Storage Requirement of 20,000 AF (as reported to their Water Planning Committee in July 18, 2018) and a portion of its carryover storage. Under the Carryover Storage Policy Guidelines, included in SDCWA’s Water Shortage Contingency Plan Appendix A dated August 2017, SDCWA will maintain a carryover target volume of 70,000 AF and a maximum of 100,000 AF to be utilized over five consecutive dry‐years. During an emergency outage, the region will most likely draw supplies from all reasonably available storage to meet demands. This evaluation reasonably assumes that in addition to its emergency storage, one‐fifth of SDCWA’s 70,000 AF target carryover storage, amounting to 14,000 AF, would be available for a catastrophic emergency outage based on the low likelihood that that all carryover supplies would have been withdrawn over multiple dry‐years.
Table 4 shows the aggregate total for each type of locally available supplies over the emergency outage period considered. For illustrative purposes for 2018, Table 4 also presents the local production at 100 percent, 90 percent, and 80 percent. The LAA production is excluded from this calculation because the Emergency Storage assumes the loss of all imported water supplies. The member agency local production data is included as Attachment A.
5/14/2019 Board Meeting 9-3 Attachment 1, Page 10 of 17 May 2019 Metropolitan Water District of Southern California 10 Table 4
Effective Local Production
(Acre‐Feet)
2018
Local Production for 6‐months and 12‐months(1)
At 100% At 90% At 80%
Groundwater 832,000 748,800 665,600
Surface Water 54,935 49,442 43,948
Local Surface Storage(2) 34,000 30,600 27,200
Recycling and GW Recovery 353,797 318,417 283,038
Seawater Desalination 25,319 22,787 20,255
Los Angeles Aqueduct 0 0 0
Other 13,100 11,790 10,480
IRP Targets(3) 18,087 18,087 18,087
Subtotal Local Production 1,331,238 1,199,923 1,068,608 Unused Local Production (152,021) (86,449) (31,056)
Effective Local Production 1,179,216 1,113,474 1,037,551 Note: (1) Local production are assessed for the 6‐month outage period for member agencies receiving supplies from CRA and East Branch, and 12‐months for member agencies receiving supplies from West Branch and LAA 9 (see Attachment A).
(2) Local Surface Storage is comprised of emergency storage plus reasonably available storage above emergency.
(3) Conservation and locally available supply targets from the 2015 IRP for Year 2018.
Emergency Demands on Metropolitan
The final step in calculating the Emergency Storage is to subtract the Effective Local Production from the retail demands during an emergency outage for each member agency. The resulting difference represents the supplemental water demands on Metropolitan during an outage period This is the Emergency Storage planning level for the region. Table 5 shows the aggregated totals at varying local production levels for 2018. The table below illustrates that the emergency demand on Metropolitan, and in effect the Emergency Storage, increases as Effective Local Production decreases under the 90 percent and 80 percent scenarios.
Table 5
Emergency Demands on Metropolitan
(Acre‐Feet)
Local Production
At 100% At 90% At 80%
Retail Demand during Emergency 1,864,885 1,864,885 1,864,885 Effective Local Production (1,179,216) (1,113,474) (1,037,551) Metropolitan Emergency Demand 685,666 751,411 827,334
5/14/2019 Board Meeting 9-3 Attachment 1, Page 11 of 17 May 2019 Metropolitan Water District of Southern California 11 Sensitivity Analysis
A sensitivity analysis of retail cutback and loss of local supplies were conducted. To explore the sensitivities of the Emergency Storage from these two criteria, Metropolitan evaluated various percentages of demand cut backs and levels of local production. Table 6 shows the resulting Emergency Storage at various combinations of retail demand cutback and local production levels. This matrix of emergency storage values presents retail demand cut backs of 0 percent, 25 percent, 35 percent, and 50 percent and local production levels of 100 percent, 90 percent, and 80 percent.
Table 6
Range of Potential Emergency Storage Objectives for Year 2018 (Acre‐Feet)
Local Production Level Retail Demand Cutback
0% 25% 35% 50%
100% 1,176,600 685,700 513,300 294,000
90% 1,286,600 751,400 570,700 332,300
80% 1,417,900 827,300 636,300 377,300
Envelope Concept for Metropolitan’s Emergency Storage Objective Rather than considering a specific region‐wide scenario of conservation and local production loss, the Workgroup discussion led to the development of a range of emergency storage values that could provide reliability during the outage period. The concept of an envelope of solutions emerged, with the idea that an envelope of solutions will yield an appropriate Emergency Storage for the region. The Emergency Storage, in turn, could be achieved through various combinations of (1) retail demand cutback from achievable conservation and (2) local production level taking into account potential damages to local facilities. This envelope concept underscores member agencies’ individual and unique situations while taking into account their inputs in identifying practicable ranges of decreases in retail demand and local production.
For the retail demand cut back, most member agencies considered the 25 to 35 percent range to be reasonable. This range is based on the level of conservation that the region was able to achieve during the recent drought. For the local production, several member agencies expected some damage to local facilities during the earthquake. In addition, Metropolitan acknowledges that retail demand cutback may also lead to reduction of non‐potable recycled water use. Thus, for local production, the Workgroup focused on a range from 80 percent to 100 percent of the member agencies’ reported local production in the 2015 IRP. This would allow contingency planning for uncertainties in damage to local facilities and accommodate different durations of local repairs. This is a modification from the previous assumption of full local production at the IRP level during an outage period.
As indicated in Table 6, a scenario using the criteria of 25 percent retail demand cut back and 100 percent local production level yield an estimated Emergency Storage of 686,000 AF for year 2018. However, the Workgroup focused on an envelope of alternatives for Emergency Storage that could provide reliability during the outage period. The same table matrix of values above highlights the range from 520,000 to 830,000 AF. Within this range, an Emergency Storage of 750,000 AF is recommended. This level of storage would prevent severe water shortages in the region with practicable ranges of reduced demands through conservation and plausible levels of local production during an emergency outage. Figure 4 shows that the 5/14/2019 Board Meeting 9-3 Attachment 1, Page 12 of 17 May 2019 Metropolitan Water District of Southern California 12 Emergency Storage would be sufficient to cover various combinations of practicable ranges of decreases in retail demand and local production.
Figure 4
Emergency Storage Objective derived from the Envelope Concept Allocation of Emergency Storage in Regional Reservoirs
Once the Emergency Storage is determined, it can then be allocated to the various surface reservoirs within the region, previously illustrated in Figure 2, south of the San Andreas Fault. The total storage capacity of existing DWR and Metropolitan surface reservoirs and the allocation to emergency storage, seasonal, regulatory, and drought carryover needs are shown in Table 7 through 11. For the DWR reservoirs, the values in the tables reflect the normal maximum operating and dead pool storages indicated in the DWR report “California State Water Project, Volume III, Storage Facilities, Bulletin 200” dated November 1974.
For this evaluation, recreational waters in DWR reservoirs are assumed to be available for emergency use during outage periods. On a short‐term basis for operational purposes, storage at any specific reservoir may be below these planning levels. When this happens, the emergency storage is shifted temporarily to any of the other existing reservoirs.
Department of Water Resources Surface Reservoirs
Table 7 below shows the five major reservoirs owned and operated by DWR in or near Metropolitan’s service area. Castaic Lake, Elderberry Forebay, and Pyramid Lake are located on the West Branch of the California Aqueduct. Silverwood Lake and Lake Perris are on the East Branch of the California Aqueduct.
The total storage capacity of these five reservoirs is approximately 721,600 AF. When cost allocation factors from DWR Bulletin 132 Appendix B, Table B‐2 are applied to the operational storage capacities, Metropolitan’s share of storage in the reservoirs is equivalent to 644,400 AF. 0 10
20 30
40 %
0 10 20 30 40 50
Decrease in Local Production
% Decrease in Retail Demand (Cut Back)
Through Additional Conservation
750,000 AF
Scenarios where
750,000 TAF of
storage is sufficient -
5/14/2019 Board Meeting 9-3 Attachment 1, Page 13 of 17 May 2019 Metropolitan Water District of Southern California 13 Table 7
Allocation of Storage Capacities in DWR Reservoirs
(Acre‐Feet)
Reservoir Total Storage
Capacity Dead Storage Storage Paidby Others
Storage Paid by
Metropolitan
Pyramid Lake 169,900 4,800 7,000 158,100
Castaic Lake 323,700 18,600 12,500 292,600
Elderberry Forebay 28,200 800 1,100 26,300
Silverwood Lake 73,000 4,000 24,300 44,700
Lake Perris 126,800 4,100 0 122,700
Total 721,600 32,300 44,900 644,400
Source: California Department of Water Resources (1974). California State Water Project, Volume III, Storage Facilities, Bulletin 200, pages 294, 340, 367, 407, and 408.
From 2005 to 2017, DWR temporarily lowered the maximum storage elevation in Lake Perris because of seismic safety issues. This elevation change resulted in reduction of storage available to Metropolitan in Lake Perris, which was taken into account in past emergency storage evaluations. In 2018, the seismic retrofit of Lake Perris was completed, which restored storage to its full capacity. For purposes of the emergency storage analysis provided herein, it is assumed that 122,700 AF could be available to Metropolitan from Lake Perris. Furthermore, the Monterey Amendment, executed by the DWR and most of the State Water Contractors in 1995 and 1996, addresses the allocation of SWP water in times of shortage and deals with a number of other issues that facilitate more water management flexibility for Contractors.
Table 8 shows the distribution of Metropolitan’s emergency storage in DWR reservoirs. Of the total 644,400 AF of storage in DWR Reservoirs that is for Metropolitan use, almost 381,000 AF of this amount is allocated to emergency storage and the remaining 263,600 AF is for seasonal, regulatory, and dry‐year storage.
Silverwood Lake capacity does not add to the total Emergency Storage Capacity because of its location outside of major earthquake faults assumed for the emergency storage calculation methodology. However, Silverwood Lake could be available after a seismic event upon restoration of any damaged distribution system components downstream of the lake. It is expected that the portion of the distribution system downstream of the lake could be restored more expeditiously after an event due to its relatively short length, accessibility of the pipelines, and redundancies in the system. 5/14/2019 Board Meeting 9-3 Attachment 1, Page 14 of 17 May 2019 Metropolitan Water District of Southern California 14 Table 8
Allocation of Emergency Storage in DWR Reservoirs
(Acre‐Feet)
Reservoir Metropolitan Storage
Capacity
Seasonal, Regulatory
and Dry‐Year Storage
Emergency Storage
Capacity
Pyramid Lake 158,100 0 158,100
Castaic Lake 292,600 153,900 138,700
Elderberry Forebay 26,300 0 26,300
Silverwood Lake 44,700 44,700 0
Lake Perris 122,700 65,000 57,700
Total 644,400 263,600 380,800
Metropolitan Surface Reservoirs
Table 9 shows the allocation of storage resources in Metropolitan’s three major surface reservoirs, Lake Mathews, Lake Skinner, and DVL. These three reservoirs provide approximately 1,036,000 AF of total storage capacity to Metropolitan’s service area.
Lake Mathews has available storage of approximately 178,500 AF and distributes CRA water to Riverside, Orange, Los Angeles, and San Bernardino counties. Lake Skinner has approximately 43,800 AF of available storage and receives CRA and SWP water for distribution to Riverside and San Diego counties. DVL is Southern California’s largest reservoir with approximately 810,000 AF of total capacity, with 798,500 AF of available capacity to meet demands and provide emergency water supplies.
Table 9
Allocation of Storage Capacities in Metropolitan Reservoirs (Acre‐Feet)
Reservoir Total Storage Capacity Dead Storage Available Capacity Lake Mathews 182,000 3,500 178,500
Lake Skinner 44,000 200 43,800
Diamond Valley Lake 810,000 11,500 798,500
Total 1,036,000 15,200 1,020,800
Table 10 shows the components of storage, including emergency, seasonal, regulatory, and dry‐year storages, for all of Metropolitan’s reservoirs. Under the recommended Emergency Storage of 750,000 AF, out of the roughly 1,021,000 AF of available Metropolitan storage capacity, approximately 369,200 AF are reserved for emergency storage, with the remaining storage capacity available for seasonal, regulatory, and dry‐year storage.
5/14/2019 Board Meeting 9-3 Attachment 1, Page 15 of 17 May 2019 Metropolitan Water District of Southern California 15 Table 10
Allocation of Emergency Storage in Metropolitan Reservoirs (Acre‐Feet)
Reservoir Available
Capacity
Emergency Storage Objective
at 750 TAF
Seasonal, Regulatory
and Drought Storage
Emergency
Storage
Lake Mathews 178,500 100,000 78,500
Lake Skinner 43,800 10,000 33,800
Diamond Valley Lake 798,500 541,600 256,900
Total 1,020,800 651,600 369,200
Emergency Storage Capacities in DWR and Metropolitan Reservoirs The Emergency Storage presented in this white paper is evaluated based on regional aggregation of retail demands and locally available supplies within the service area. The resulting Emergency Storage is assumed to be distributed amongst the available capacities within the existing DWR and Metropolitan surface reservoirs. During an outage, Metropolitan delivers supplement water to member agencies from previously stored emergency supplies, and dry‐year supplies if necessary and available, based on the most effective operation of the distribution system under emergency conditions.
Table 11 presents the storage of emergency supplies in DWR Reservoirs, Lake Mathews, and Lake Skinner to be fixed quantities, with any remaining need reflected as changes in DVL’s emergency storage allocation under the recommended 750,000 AF of Emergency Storage.
Table 11
Allocation of Emergency Storage in Existing Reservoirs(1) (Acre‐Feet)
Reservoir Emergency Storage Objective
at 750 TAF
Pyramid Lake 158,100
Castaic Lake 138,700
Elderberry Forebay 26,300
Lake Perris 57,700
Lake Mathews 78,500
Lake Skinner 33,800
Diamond Valley Lake 256,900
Total 750,000
Note: (1) This allocation provides operational guidance but does not create a minimum emergency storage volume in any single reservoir.
5/14/2019 Board Meeting 9-3 Attachment 1, Page 16 of 17 May 2019 Metropolitan Water District of Southern California 16 Conclusion
This white paper summarizes the progress to date of the Workgroup coordination process to estimate a planning objective for the region’s emergency storage, as part of Metropolitan’s ERSP. Evaluating the Emergency Storage involves the regional aggregation of retail water demands and locally available supplies within the service area. It also accounts for the member agencies’ unique situations in identifying practicable ranges of additional conservation actions that could yield decreases in retail demand and levels of local production that could be accomplished during emergency outage.
Under the new envelope concept, the Workgroup focused on an acceptable range of regional emergency storage values from 520,000 to 830,000 AF. Based on feedback to date, staff recommends an Emergency Storage of 750,000 AF. This level of storage would prevent severe water shortages for the region with practicable ranges of water demand reduction achievable conservation actions and plausible levels of local production. This recommended regional emergency storage is assumed to be distributed amongst the available capacities within the existing DWR and Metropolitan surface reservoirs, as shown in Table 11.
The Emergency Storage presented in this white paper is a regional planning objective. It is an estimate for the amount of Metropolitan water that the region targets to store in preparation for a catastrophic earthquake event. This evaluation of Emergency Storage is not intended to set a basis or a policy for allocating or apportioning storage for each individual member agency.
The Workgroup proposes that this storage objective be revisited periodically, possibly following the completion of a new IRP. Metropolitan also considers spatial distribution for the purpose of determining generally where to store its emergency water. However, specific operations during an emergency will depend on the actual conditions at that time. Since member agency demands for supplemental water will be met through deliveries of supplies from storage, evaluation of spatial distribution of storage and most effective operation of the distribution system will be accomplished as part of Metropolitan’s continued efforts and coordination within the ERSP’s storage portfolio evaluation or other regional planning processes.
5/14/2019 Board Meeting 9-3 Attachment 1, Page 17 of 17 May 2019 Metropolitan Water District of Southern California 17 Total Retail Demand Aqencies al 6 month Outaqe Foothill MWO 9,204 Pasadena 16,217 San Marino 2,700 Three Valleys MWD 63,226 Upper San Gabriel MWO 106.945 Anaheim 34 253 Fullerton 14 315 MWDOC 310,510 Santa Ana 19,074 Eastern MWO 126,051
Western MWD 147,318
IEUA 143.302
San Dieoo Countv
Water Authoritv 315.373
Aaencies at 12 month Outaae
Central Basin MWD 296,066
Compton 7,766
Long Beach 68,633
Torrance 28,420
West Basin MWD 179,750
Santa Monica 13,732
Burbank 27,819
Glendale 30 319
Los Angeles 566,486
San Fernando 3,150
Calleguas MWO 164,638
Beverl y Hills 11,938
Las Viraenes MWD 28,413
MWDTOTAL 2,735,617
Attachment A
2018 Member Agency Total Retail Demand and Local Production (Source data for Tables 2, 3, and 4)
Recycling + GW Recovery
Groundwater Surface Production Reclamation Other lmpons 3,970 200 120 0
6,000 0 0 0
2,250 0 0 0
21 ,650 3,100 4,384 0
74,163 4500 4.354 0
23,932 0 39 0
10,376 0 0 0
107,945 2,000 93,163 0
13,478 0 160 0
40,400 1,550 25,112 0
73,700 2,750 21,295 0 74,800 16.240 28 573 0
5,900 24,595 19 956 0
182,300 0 55,972 0
6,400 0 0 0
28,700 0 10,118 0
2,700 0 9,150 0
34,600 0 33,621 0
8,200 0 145 0
300 0 13,985 0
1,500 0 8,984 0
77,794 0 11,681 0
3,143 0 0 0
27,700 0 7,483 13,100
0 0 700 0
100 0 4,804 0
832,000 54,935 353,797 13,100
Note: Member agency local production are approximation for year 2018 based on 2015 IRP and are estimated for the outage periods indicated.
This table shows individual member agency estimates used to develop Metropol~an's Emergency Storage Objective for the region .
For agencies along the Rialto Pipeline. see discussion on pages 5-6 related to system limitations for receiving CRA supplies.
Local Surface
Seawater Desai Storage IRP Target
0 0 67
0 0 118 0 0 20 0 0 447 0 0 625 0 0 249 0 0 104 0 0 1,651 0 0 139
0 0 890 0 0 1,064 0 0 969
25.319 34,000 2 204
0 0 1,590 0 0 56 0 0 452 0 0 207 0 0 1,173 0 0 100 0 0 159 0 0 221 0 0 4,070 0 0 23 0 0 1,198 0 0 87 0 0 207 25,319 34,000 18,087 1,331 ,238
Local suiface storage includes all reasonably available surafce storage that the member agency could produce and use within its seivice area. Includes SDCWA's calculated ESP storage requirement reported to their Water Planning Committee in July 2018 and a portion of their target carryover storage as discussed in page 9.
I
Appendix 9
SEISMIC RISK ASSESSMENT AND MITIGATION PLAN
Seismic Risk Assessment and Mitigation Plan A.9-1
Appendix 9
SEISMIC RISK ASSESSMENT AND MITIGATION PLAN
Beginning January 2020, CWC Section 10632.5 mandates UWMPs to include a seismic risk assessment and mitigation plan to assess the vulnerability of each of the various facilities of a water system and mitigate those vulnerabilities. For Metropolitan, this required assessment and plan are accomplished as part of developing its resilience strategy and are presented in detail in Metropolitan’s seismic resiliency reports attached to this appendix.
Over its nearly 90-year history, Metropolitan has been proactive in mitigating seismic risks posed to its expansive infrastructure, as well as improving its ability to maintain (or quickly restore) water deliveries following a major earthquake. This ability to mitigate seismic risks and maintain (or quickly restore) water deliveries following a seismic event is referred to as “seismic resilience.” Metropolitan’s holistic strategy for seismic resilience follows a “defense in depth” multi-layered approach for managing risk. Metropolitan’s Seismic Resilience Strategy has three primary objectives:
1. Provide a diversified water supply portfolio, system flexibility, and emergency storage
2. Prevent damage to water delivery infrastructure in probable seismic events and limit damage in extreme events
3. Minimize water delivery interruptions through a dedicated emergency response and recovery organization
Metropolitan’s Seismic Resilience Strategy is implemented through four components that encompass the various internal functions that promote the organization’s seismic resilience objectives. These components are supplemented by Metropolitan’s commitment to interagency coordination when preparing and responding to a seismic event and other emergencies. The strategy is shown below in Figure A.9-1.
Figure A.9-1
Seismic Resiliency Strategy
• •
SEISMIC RESILIENCE
STRATEGY
ENGINEERING OPERATIONS
INTER-AGENCY
COORDINATION
A.9-2 Seismic Risk Assessment and Mitigation Plan
A brief description of the components of Metropolitan’s Seismic Resilience Strategy and examples of their implementation are provided below.
Planning
The goals of the planning component are to develop and maintain a diversified water resource portfolio; provide a flexible system that allows for operational changes to handle variations in water supply, planned or unplanned system outages; and to maintain adequate emergency storage supplies. Metropolitan has developed a diverse water resource portfolio through the enactment of various exchange and water banking programs. These water supply programs are described in detail in Section 3 and Appendix 3. In addition to existing supply programs, development of the Regional Recycled Water Program would provide Metropolitan with an additional water resource and would be strategically located on the coastal side of the San Andreas Fault. Metropolitan also strives for regional seismic resilience by incentivizing local agencies to develop increased conservation, recycling, storage, and other water management programs.
As Metropolitan expanded its system over the years, it has continually improved the flexibility of the system to handle changes in water supply or pipeline or facility outages. One example of Metropolitan’s system flexibility is the Common Pool service area, which can be supplied by the Jensen, Weymouth, or Diemer water treatment plants. Additionally, Metropolitan has constructed its system such that most of the service area can be supplied by either Colorado River or State Water Project supplies.
Metropolitan’s imported water supplies from the CRA and SWP East and West Branches cross the San Andreas Fault (SAF) Zone prior to reaching Metropolitan’s service area. A major earthquake on the SAF has the potential of damaging all three aqueducts and disrupting imported supplies for up to six months. Metropolitan constructed Diamond Valley Lake (DVL) on the coastal side of the fault to mitigate the potential impacts of a major SAF earthquake to its service area.
Completion of DVL nearly doubled Metropolitan’s available surface water storage in the region and, along with other local reservoirs, is used to maintain 6 to 12 months of emergency water storage supply. Water from DVL can supply four of Metropolitan’s five regional water treatment plants.
Engineering
The goal of the engineering component is to assess and mitigate seismic risk to individual facilities, and the system. This is accomplished through Metropolitan’s Seismic Resilience of Structures Program, the Seismic Resilience of Pipelines Program, the Dam Safety Program, and special seismic assessments.
Seismic Resilience of Structures
Metropolitan’s program to increase the seismic resilience of structures is an ongoing program with the goal of protecting life safety and critical infrastructure to minimize water delivery interruptions following a seismic event. The initial program focused on evaluating the seismic risk of above ground structures (e.g., water treatment plants) constructed prior to 1990 and upgrading structures to mitigate the risk when found to be seismically deficient. The program has recently expanded to include post-1990 structures due to the progress made on the initial list of structures. Examples of seismically upgraded facilities include the Colorado River Aqueduct pump plant buildings, the Weymouth East and West Wash Water Tanks, and the Diemer and Jensen Administration Buildings.
Seismic Risk Assessment and Mitigation Plan A.9-3
Seismic Resilience of Pipelines
Metropolitan’s conveyance and distribution system has been built in conformance with standards and practice at the time of design. In keeping with the goals of the Seismic Resilience Strategy, Metropolitan is developing seismic design criteria for new pipelines based on current state of practice, geotechnical and seismicity criteria, operating conditions, and asset management strategies. The planned design approach for new pipelines will be to establish performance criteria, identify seismicity and ground conditions along the alignment, and design the pipeline to resist damage from ground shaking and deformation. Specialized pipe joints and sections can be designed to accommodate ground deformation from fault displacement or liquefaction. For existing pipelines, seismic resilience will be incorporated as a component of pipeline rehabilitation projects. Metropolitan will evaluate each upgrade individually to balance risk, performance, and cost. Metropolitan’s Casa Loma Siphon Barrel No. 1 Seismic Upgrade Project is an example of the organization incorporating seismic design in the rehabilitation of existing pipelines. The existing siphon, which crosses a segment of the San Jacinto Fault Zone and is subject to long-term subsidence, will be replaced with earthquake-resistant ductile iron pipe.
The pipe joints are designed to accommodate ground displacement without failure to allow for continued service following an earthquake.
Dam Safety Program
Metropolitan has an ongoing Dam Safety Initiatives Program that has initiated several plans to improve Metropolitan's dam seismic safety and earthquake readiness. These initiatives are being coordinated with the California Division of Safety of Dams (DSOD) and Office of Emergency Services and include the following:
Ongoing preparation of Emergency Action Plans, including inundation maps Performing training exercises at the dam site to test processes during a seismic event Providing training and guidance on overall dam safety Reviewing operation and maintenance methods for reservoir drawdown and operations after a seismic event
Updating guidelines and procedures on protection against seismic risk Establishing a strong communications system on seismic information Performing structural strengthening of dams, including rehabilitation and improvement of spillways and inlet/outlet towers such as Lake Skinner Outlet Tower Improving dam safety instrumentation, monitoring, and reporting capabilities Special Seismic Assessments
Metropolitan conducts special seismic assessments to increase understanding of the vulnerability of the organization’s assets and operations to various seismic hazards. The studies focus on hazards specific to individual facilities or the system as a whole and identify options to mitigate the risks posed by the hazards. In addition, the studies support emergency response training and planning for future earthquake events by estimating the magnitude of damage that may occur from various seismic events. The following is a list of some of the reports that Metropolitan has completed:
Liquefaction Susceptibility Mapping for the Metropolitan Water District of Southern California’s Feeder System (Report No. 1625), Carollo Engineers, Inc., 2019.
A.9-4 Seismic Risk Assessment and Mitigation Plan
Colorado River Aqueduct – San Gorgonio Pass Seismic Event Vulnerability Study (Report No. 1484), GeoPentech, July 2014.
Potential Effects of Southern California Seismic Events on Metropolitan Water Deliveries (Report No. 1335), Metropolitan Facility Planning staff, January 2009.
Operations
The goal of the operations component is to maintain effective emergency planning and response capabilities. This is accomplished through maintaining an effective Emergency Response Organization, conducting routine emergency response training exercises, and maintaining emergency construction capabilities.
Metropolitan’s Emergency Response Organization (ERO) is comprised of over 200 predesignated employees who work in the Emergency Operations Center (EOC), the Incident Command Posts, or the field during emergencies. ERO staff has completed specialized training that meets State and Federal requirements. Metropolitan's emergency response structure follows the National Incident Management System (NIMS) and the State of California's Standardized Emergency Management System (SEMS).
In addition to specialized NIMS training, Metropolitan staff routinely participate in emergency response training exercises that are often based on a postulated seismic event. In 2019, Metropolitan started a new five-year emergency exercise plan that will allow all member agencies to participate in at least one of Metropolitan’s annual emergency exercises. The first of these exercises was a tabletop exercise for the Orange County member agencies on August 29, 2019, which focused on a hypothetical incident at the Diemer Water Treatment Plant.
Metropolitan has conducted over 100 exercises since February 2018. This included two large functional emergency exercises for the EOC and multiple tabletop exercises, workshops, and seminars for the 12 Incident Command Posts located at the water treatment plants, conveyance and distribution facilities, and other strategic locations in Metropolitan’s service area.
Metropolitan maintains the necessary staffing, materials, and equipment to respond to two simultaneous pipeline breaks. The Machine Shop and Coating Shop at La Verne are available to fabricate pipe sizes up to 12 feet in diameter, and Metropolitan’s construction forces have the necessary equipment and expertise to make the repairs in-house. In addition, Metropolitan has upgraded its satellite phones to ensure communication ability following a seismic event and is in the process of installing high frequency radios at all Incident Command Posts and the Emergency Operations Center.
Reporting
Metropolitan has committed to providing annual updates to its Board of Directors on the organization’s Seismic Resilience Strategy and its progress toward identified short-term and longterm goals. The organization has also committed to providing a formal report on a five-year interval summarizing accomplishments related to seismic resilience and changes in directives to the Seismic Resilience Strategy.
Inter-Agency Coordination
Improving the region’s seismic resilience requires that member agencies understand the seismic risks to the imported water supplies so that they may appropriately plan on the local level.
Opportunities for inter-agency coordination are provided through the Local Resources Program where Metropolitan incentivizes the development of local groundwater, recycling, and other supply resources to offset imported demands. As stated previously, Metropolitan provides Seismic Risk Assessment and Mitigation Plan A.9-5
member agencies the opportunity to participate in emergency response exercises. As part of a recent study, Metropolitan developed maps that define the relative liquefaction susceptibility of the region inclusive of the conveyance and distribution system and has made these maps available to member agencies. Recently, the organization updated the emergency storage goals through several workshops in coordination with member agencies.
Metropolitan is also a member of the Seismic Resilience Water Supply Task Force, along with the California Department of Water Resources (DWR) and the Los Angeles Department of Water and Power (LADWP). As the owners of the three conveyance facilities that provide imported water to the region, Metropolitan, DWR, and LADWP have recognized the importance of coordinating responses following a major seismic event that disrupts the imported water supplies. Each agency has provided an overview of the seismic risk to their respective systems and are in the process of developing a Water Mutual Assistance Agreement to formalize the coordination efforts following a major earthquake that disrupts service to the imported water supplies.
Metropolitan’s Seismic Resilience Reports
The various components of Metropolitan’s resilience strategy summarized above are described in detail in Metropolitan’s Seismic Resilience Report First Biennial Report (February 2018) and Seismic Resilience Report 2020 Update (February 2020) presented as part of this appendix. These reports are also available on Metropolitan’s website:
http://mwdh2o.com/AboutYourWater/Planning/Seismic-Resilience-Report/ A.9-6 Seismic Risk Assessment and Mitigation Plan
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Report No. 1551
February 2018
REPORT
SEISMIC RESILIENCE
FIRST BIENNIAL REPORT
The Metropolitan Water District of Southern California
700 N. Alameda Street, Los Angeles, California 90012
The Metropolitan Water District of Southern California Seismic Resilience First Biennial Report Report No. 1551 – February 2018 iii
SEISMIC RESILIENCE
FIRST BIENNIAL REPORT
Prepared By:
The Metropolitan Water District of Southern California
700 North Alameda Street
Los Angeles, California 90012
Report Number 1551
February 2018
The Metropolitan Water District of Southern California Seismic Resilience First Biennial Report Report No. 1551 – February 2018 Page iv
Copyright © 2018 by The Metropolitan Water District of Southern California.
The information provided herein is for the convenience and use of employees of The Metropolitan Water District of Southern California (MWD) and its member agencies. All publication and reproduction rights are reserved. No part of this publication may be reproduced or used in any form or by any means without written permission from The Metropolitan Water District of Southern California. Any use of the information by any entity other than Metropolitan is at such entity's own risk, and Metropolitan assumes no liability for such use.
Prepared under the direction of:
Gordon Johnson Chief Engineer
Prepared by:
Robb Bell Engineering Services
Don Bentley Water Resource Management
Winston Chai Engineering Services
David Clark Engineering Services
Greg de Lamare Engineering Services
Ray DeWinter Administrative Services
Edgar Fandialan Water Resource Management
Ricardo Hernandez Engineering Services
Rosa Lau Engineering Services
Silvia Perez Water System Operations
Ian Whyte Water System Operations
Reviewed by:
Grace Chan Water Resource Management
Heather Collins Water System Operations
Kevin Donhoff Water Resource Management
Jim Green Water System Operations
Bob Harding Water Resource Management
Mike Rojas Engineering Services
Jack Safely Water Resource Management
Deven Upadhyay Assistant General Manager/Chief Operating Officer Brent Yamasaki Water System Operations
Additional copies: The Seismic Resilience Report is located on the Seismic Resilience SharePoint site. To obtain a copy of this document, please contact the Engineering Services Group.
Disclaimer
Extensive efforts have been made to ensure that the material contained in this document is accurate as of the date of publication. There are many factors, however, related to the content and applicability of this document which are beyond the control of MWD. In addition, the contents of this publication will be periodically updated, so the reader should inquire about any such changes in addition to reading this document. Finally, the reader is encouraged to seek appropriate technical and/or legal advice when specific facts or circumstances arise that raise questions concerning the applicability or interpretation of the policies and procedures discussed herein.
PUBLICATION HISTORY:
Initial Release (First Biennial Report) February 2018
The Metropolitan Water District of Southern California Seismic Resilience First Biennial Report Report No. 1551 – February 2018 Page v
TABLE OF CONTENTS
EXECUTIVE SUMMARY ............................................................................................................................VII SECTION 1 INTRODUCTION.................................................................................................................. 1‐1 Purpose ......................................................................................................................................................1‐1 Seismic Resilience Strategy Structure........................................................................................................1‐2 Report Organization...................................................................................................................................1‐3 List of Abbreviations and Acronyms ..........................................................................................................1‐3 SECTION 2 BACKGROUND.................................................................................................................... 2‐1 Seismic Risk ................................................................................................................................................2‐1 Seismic Resilience ......................................................................................................................................2‐4 Metropolitan’s Historical Approach to Seismic Resilience ........................................................................2‐5 Metropolitan’s Comprehensive, Integrated Seismic Resilience Strategy................................................2‐11 SECTION 3 PLANNING COMPONENT .................................................................................................... 3‐1 Diversified Water Supply Portfolio ............................................................................................................3‐1 System Flexibility........................................................................................................................................3‐3 Emergency Storage ....................................................................................................................................3‐4 SECTION 4 ENGINEERING COMPONENT............................................................................................... 4‐1 Seismic Resilience of Structures.................................................................................................................4‐1 Special Seismic Assessments......................................................................................................................4‐4 Seismic Resilience of Dams and Reservoirs ...............................................................................................4‐7 Pipeline Seismic Resilience.......................................................................................................................4‐10 SECTION 5 OPERATIONS COMPONENT ................................................................................................ 5‐1 SECTION 6 REPORTING COMPONENT .................................................................................................. 6‐1 Record Keeping ..........................................................................................................................................6‐1 Annual Updates..........................................................................................................................................6‐1 Formal Reporting .......................................................................................................................................6‐1 SECTION 7 SEISMIC RESILIENCE WATER SUPPLY TASK FORCE............................................................... 7‐1 2016 Aqueduct Workshop .........................................................................................................................7‐2 Future Task Force Activities.......................................................................................................................7‐4 SECTION 8 SEISMIC RESILIENCE PERFORMANCE OBJECTIVES AND NEAR‐TERM GOALS........................ 8‐1 Established Performance Objectives and Near‐Term Goals......................................................................8‐1 Other Near‐Term Goals..............................................................................................................................8‐6 The Metropolitan Water District of Southern California Seismic Resilience First Biennial Report Report No. 1551 – February 2018 Page vi
TABLE OF CONTENTS (cont’d)
Table 4‐1: Current Metropolitan Jurisdictional Dam and Reservoir Facilities.............................................. 4‐8 Figure 1‐1: Seismic Resilience Strategy Structure and High Level Goals...................................................... 1‐2 Figure 2‐1: Likelihood of M6.7 or greater earthquake in the next 30 years (Source: UCERF3) .................. 2‐1 Figure 2‐2: Major Earthquake Faults in Southern California ........................................................................ 2‐2 Figure 2‐3: Resilience ‐‐ the ability to reduce the magnitude and/or duration of disruptive events.......... 2‐4 Figure 2‐4: Detailed Breakdown of Metropolitan’s Seismic Resilience Strategy ....................................... 2‐11 Figure 3‐1: Integrated Resource Plan, Metropolitan’s Service Area Supplies.............................................. 3‐2 Figure 4‐1: Status of Seismic Assessments and Upgrades of Pre‐1990 Structures...................................... 4‐3 Figure 4‐2: Example of Seismic Resistant Pipe (courtesy of Kubota Corp. and JFE)................................... 4‐11 Figure 5‐1: Metropolitan’s Emergency Response Organization................................................................... 5‐1 Figure 7‐1: Seismic Resilience Water Supply Task Force .............................................................................. 7‐2 List of Appendices
Appendix 1 Key Seismic Resilience Achievements
Appendix 2 Modern Era Earthquakes over M6.3 Within or Near Metropolitan’s Primary Service Area Appendix 3 Provision for CRA Uplift
Appendix 4 Summary of Damage to Metropolitan Infrastructure from Past Earthquakes Appendix 5 Metropolitan Water Storage Capacity
Appendix 6 Seismic Design Frequently Asked Questions (FAQs) Appendix 7 Summary of Previous Metropolitan Seismically Induced Damage Studies Appendix 8 Administrative Code Section 4503 “Suspension of Deliveries” and 9/21/06 IAS Clarification The Metropolitan Water District of Southern California Seismic Resilience First Biennial Report Report No. 1551 – February 2018 Page vii
EXECUTIVE SUMMARY
The ability to maintain, or quickly restore, water deliveries after a seismic event. ‐‐Definition of “Seismic Resilience” for a water agency An interruption in a key lifeline service such as water delivery can be devastating to a community’s recovery after an earthquake. As the agency responsible for delivering imported water to over 19 million people in one of the world’s most seismically active regions, The Metropolitan Water District of Southern California (Metropolitan) has made substantial
efforts to minimize the impact of a major
earthquake on the people and businesses within
its service area. In 2017, Metropolitan refined and
formalized its approach for addressing seismic
resilience by fully integrating its planning,
engineering, operations, and reporting functions.
This report documents Metropolitan’s integrated
Seismic Resilience Strategy, reports on key historic
achievements, and communicates near‐term goals
aimed at further enhancing the seismic resilience
of Metropolitan’s infrastructure and water
deliveries.
Seismic Resilience
“Resilience” is broadly defined as the ability of a system to absorb and rebound from shocks. The more resilient a system is, the smaller the impact will be that any given shock will have on the system, and the shorter the duration of recovery will be. Using the broad definition of resilience as a baseline, Metropolitan defines “seismic resilience” as the ability to maintain (or quickly restore) water deliveries following a seismic event. The more prepared a water agency is for earthquakes, and the more effective its emergency response capabilities are, the less impact the event will have on water deliveries to its customers.
Metropolitan’s Seismic Resilience Strategy
Metropolitan’s Seismic Resilience Strategy is a multi‐faceted approach to prepare for and respond to seismic events. It involves close, formal coordination within the Metropolitan organization and with other owners of imported water conveyance systems that cross the Southern San Andreas Fault.
Coordination within Metropolitan and its member agencies focuses on diversifying water resources; enhancing operational flexibility; providing adequate emergency water supplies; and identifying and addressing infrastructure and system vulnerabilities. This coordination also involves development of effective emergency response capabilities.
The coordination with other owners of imported water conveyance systems is through a multi‐agency task force. The members of this task force, which includes the California Department of Water Resources Capacity/
Performance
measure
Resilience
Period of disruption
Tlme
Loss in
capacity
The Metropolitan Water District of Southern California Seismic Resilience First Biennial Report Report No. 1551 – February 2018 Page viii
(DWR) and the Los Angeles Department of Water and Power (LADWP) as well as other State and water industry organizations, work together to evaluate the unique seismic vulnerabilities of Southern California’s imported water systems.
In addition to the coordination elements, Metropolitan’s Seismic Resilience Strategy includes a reporting component to increase transparency and accountability. Each year, Metropolitan staff will update its Board of Directors on recent achievements and near‐term goals. Every two years, a written report will be prepared to document these items.
Water is recognized as a critical resource, but having sufficient water available following an earthquake is essential. Seismic resilience has a goal that in most scenarios, water will be available for the vast majority of people and business affected by the event and for essential post‐earthquake activities such as fire suppression.
Conclusion
Metropolitan’s strategy for seismic resilience has evolved over time and has benefited from the lessons learned from major seismic events around the world. Because of this strategy, significant improvements in the overall seismic resilience of Metropolitan’s water system have been made in each of the following key areas: water resource diversity, operational flexibility, emergency water storage capacity, resilience of existing infrastructure, and emergency response capabilities.
Metropolitan has also established a number of near‐term goals within each of the planning, engineering, and operations components of seismic resilience that will further enhance this multi‐layered approach.
Metropolitan’s refined Seismic Resilience Strategy approach will maintain a clear and effective focus on long‐term efforts, clearly communicate program achievements and goals to the Board, and provide member agencies with more clarity regarding projected seismic performance of Metropolitan’s infrastructure.
The Metropolitan Water District of Southern California Seismic Resilience First Biennial Report Report No. 1551 – February 2018 Page 1‐1
SECTION 1 INTRODUCTION
Purpose
The Metropolitan Water District of Southern California (Metropolitan) owns and operates a complex conveyance, treatment, and distribution system that serves a 5,200‐square‐mile service area within an active seismic region. Over its nearly 90‐year history, Metropolitan has been proactive in mitigating seismic risks posed to this expansive infrastructure, as well as improving its ability to maintain (or quickly restore) water deliveries following a major earthquake. This ability to mitigate seismic risks and maintain (or quickly restore) water deliveries following a seismic event is referred to as “seismic resilience.” Metropolitan’s strategy for seismic resilience follows a “defense in depth” multi‐layered approach for managing risk:
providing a diversified water resource portfolio, system flexibility, emergency water storage, robust emergency response capabilities and performing cyclical assessments of facilities and addressing identified vulnerabilities.
Over the last 20 years, Metropolitan has made significant progress in a number of key areas related to seismic resilience (see Appendix 1):
1. Increasing water supply resilience, flexibility, and emergency storage
2. Addressing the susceptibility of above‐ground structures to damage from seismic events
3. Developing effective and robust emergency response capabilities Recognizing the need for continuous improvement, Metropolitan recently re‐assessed the various activities that enhance seismic resilience to refine, expand, and formalize its overall approach. The resulting Seismic Resilience Strategy is a fully integrated approach toward minimizing regional water delivery interruptions and restoring interrupted regional deliveries quickly after an earthquake.
The specific goals of the refined Seismic Resilience Strategy are to:
Improve the integration of planning, engineering and operations activities focused on seismic resilience through regular collaborative meetings and integrated reporting Expand current programs to identify and address any additional seismic vulnerabilities Re‐visit existing seismic performance objectives in light of advancements in the knowledge of earthquake hazards, earthquake engineering, and mitigation capabilities Document Metropolitan’s seismic resilience activities to facilitate knowledge transfer and coordination
Improve accountability by communicating seismic resilience goals and accomplishments to Metropolitan’s Board of Directors and member agencies on an annual basis Enhance member agency planning efforts for emergency response and facility improvements by providing more clarity regarding the projected seismic performance of Metropolitan’s infrastructure
This document describes Metropolitan’s Seismic Resilience Strategy, summarizes key historical achievements, and communicates near‐term goals that will further increase the seismic resilience of Metropolitan’s system.
The Metropolitan Water District of Southern California Seismic Resilience First Biennial Report Report No. 1551 – February 2018 Page 1‐2
Seismic Resilience Strategy Structure
Metropolitan’s Seismic Resilience Strategy (see Figure 1‐1) is a multi‐faceted approach that involves coordination among key functions within Metropolitan as well as formal coordination with other owners of imported water conveyance systems that cross the Southern San Andreas Fault.
Figure 1‐1: Seismic Resilience Strategy Structure and High Level Goals As shown in the figure, the coordination within Metropolitan and its member agencies focuses on the activities of planning, engineering/design, operations/emergency response, and reporting. These efforts are complemented by the efforts of the multi‐agency Seismic Resilience Water Supply Task Force (Task Force). This Task Force includes the California Department of Water Resources (DWR) and the Los Angeles Department of Water and Power (LADWP) as well as other State and water industry organizations and focuses on the unique seismic vulnerabilities of Southern California’s imported water supplies.
The purpose of Metropolitan’s Seismic Resilience Strategy is to enable Metropolitan to restore water deliveries to its member agencies promptly after seismic events by maintaining a diversified supply portfolio, system flexibility, and emergency storage; minimizing damage to infrastructure; and supporting a robust emergency response and recovery capability. This integrated, comprehensive approach will maintain focus on effective long‐term efforts, clearly communicate program achievements and goals to the Board, and provide more clarity to member agencies regarding projected regional seismic performance to enhance local facility and emergency response planning efforts.
The Metropolitan Water District of Southern California Seismic Resilience First Biennial Report Report No. 1551 – February 2018 Page 1‐3
Report Organization
This report is organized as follows:
Section 2 – Background. Provides context regarding inherent seismic risks within Southern California, a definition of seismic resilience, and a summary of how Metropolitan’s seismic resilience strategy developed over time.
Section 3 – Planning Component. Describes planning activities that address seismic resilience through Metropolitan’s diverse water supply portfolio and adaptive management approach to managing resources, including establishing emergency storage. Section 4 – Engineering Component. Describes technical programs that identify and mitigate the seismic vulnerability of Metropolitan’s infrastructure and systems. Section 5 – Operations Component. Describes the emergency response organization, training exercises, and post‐event capabilities that serve to minimize the disruption of water deliveries following earthquakes.
Section 6 – Reporting Component. Explains the purpose and timing of the integrated reporting component.
Section 7 – Seismic Resilience Water Supply Task Force Component. Describes the purpose of the collaborative task force, recent progress, and planned activities. Section 8 – Seismic Resilience Performance Objectives and Near‐Term Goals. Summarizes existing objectives of the various components of seismic resilience, describes areas where new objectives are being considered, and provides high‐level goals planned to be achieved by December 2019.
List of Abbreviations and Acronyms
BCP Business Continuity Plan
CIP Capital Investment Plan
CRA Colorado River Aqueduct
DATs Damage Assessment Teams
DSOD Division of Safety of Dams
DVL Diamond Valley Lake
DWR California Department of Water Resources
EAP Emergency Action Plan
EOC Emergency Operations Center
ERO Emergency Response Organization
FEMA Federal Emergency Management Agency
ICCs Incident Command Centers
IRP Integrated Water Resources Plan
The Metropolitan Water District of Southern California Seismic Resilience First Biennial Report Report No. 1551 – February 2018 Page 1‐4
IT Information Technology
ITP IT Continuity Plan
LAA Los Angeles Aqueduct
LADWP Los Angeles Department of Water and Power
LRP Local Resources Program
M Magnitude
MARS Member Agency Response System
MCE Maximum Considered Earthquake
Metropolitan The Metropolitan Water District of Southern California MOU Memorandum of Understanding
MW Moment Magnitude
MWD The Metropolitan Water District of Southern California NIAC National Infrastructure Advisory Council
NIMs National Incident Management System
O&M Operation and Maintenance
OCC Operations Control Center
PCCP Prestressed Concrete Cylinder Pipe
PGA Peak Ground Acceleration
SCE Southern California Edison
SEMS Standardized Emergency Management System
ShakeOut Great Southern California ShakeOut Scenario
SWC Security Water Center
SWP State Water Project
Task Force Seismic Resilience Water Supply Task Force
UBC Uniform Building Code
UCERF3 Uniform California Rupture Forecast Version 3
USGS United States Geological Survey
WSAP Water Supply Allocation Plan
WSDM Water Surplus Drought Management
The Metropolitan Water District of Southern California Seismic Resilience First Biennial Report Report No. 1551 – February 2018 Page 2‐1
SECTION 2 BACKGROUND
Seismic Risk
Within Southern California, there are a number of known active faults with varying levels of activity that are capable of generating significant earthquakes and causing widespread damage to infrastructure.
Modern era earthquakes that occurred within or close to Metropolitan’s primary service area with a magnitude above 6.3 (M6.3) are listed in Appendix 2. In 2015, the United States Geologic Survey (USGS) released the Uniform California Earthquake Rupture Forecast Version 3 (UCERF3), which provides a forecast for the likelihood of rupture for particular earthquake faults within California. UCERF3’s forecast of the likelihood of a M6.7 earthquake or greater in the next 30 years on each active fault in Southern California is shown in Figure 2‐1. As indicated in the figure, the Southern San Andreas Fault was identified as having the highest likelihood (19%) of a M6.7 earthquake or greater in the next 30 years. UCERF3 further states that the there is a 93% chance of a M6.7 or greater earthquake occurring on one of the faults within Southern California within the next 30 years, and a 36% chance of a M7.5 or greater earthquake occurring within the next 30 years.
Figure 2‐1: Likelihood of M6.7 or greater earthquake in the next 30 years (Source: UCERF3) As shown in Figure 2‐2, a significant portion of Metropolitan’s infrastructure, including the Colorado River Aqueduct (CRA) and several treated water pipelines, is located near or crosses active faults.
Tabulated values repre sent the likelihood of having one or more earthquakes in the next 30 years I starting from 2014). [At the points on the fuult indicated by Mlitecin:les. ~ .7means magnitude greater than or equal to 6.7, and likewise for the other two magnitude thresholds.%, pem'DI.
Values listed in parentheses indicate the factor by which the likelihoods have increased, or decreased, relative to the prn,ious model (UCERF2), where "- " means the previous value was zero. "Readine,s" indicares the facto, by which probabilities are currently elevated, or lower, because ofihe length of time since the previous wge earthquake] Map data: Google™ Earth
19.0%
17.3%
6.8%
Data SID. NOM, U.S. N,,... NGA. GEBCO
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Data LDEO-Columbia. NSF. NOAA
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10.9)
11 .01
12.5)
1/100 1/10 10
30-year M~6.7 likel ihood (percoot]
100
5.0%
4.9%
(0.4)
(1.3)
(56.7)
The Metropolitan Water District of Southern California Seismic Resilience First Biennial Report Report No. 1551 – February 2018 Page 2‐2
Figure 2‐2: Major Earthquake Faults in Southern California The risk of earthquake damage to Metropolitan’s infrastructure from these active faults is manifested through different seismic hazards, including seismically induced ground shaking, seismically induced ground failure, and surface fault displacement.
Seismically induced ground shaking can damage buildings, structures, aqueducts, pipelines, and tunnels. The intensity and duration of shaking at a particular location is dependent on a number of factors, including the earthquake magnitude, the distance from the earthquake epicenter, and local soil conditions.
Examples of typical effects of seismically induced ground shaking. The photograph on the left shows a damaged building from the 1994 M6.7 Northridge Earthquake. The building has essentially fallen backwards, and what was once a straight wall now appears curved. The photograph on the right shows the collapsed portion of a freeway overpass from the same earthquake.
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• MWD Treatment Plants
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0 The Metropolitan Water District of Southern California Seismic Resilience First Biennial Report Report No. 1551 – February 2018 Page 2‐3
Seismically induced ground failure includes liquefaction, landslide, and seismic settlement.
Liquefaction occurs when prolonged shaking causes saturated (water‐bearing) soils to consolidate and lose their bearing capacity. This can compromise the support of structures that are constructed in these zones, including buildings and pipelines. Prolonged shaking can also lead to displacement of large areas of soil or rock, resulting in hazardous landslides and rock falls. The integrity of buildings and pipelines constructed in landslide zones can be compromised if the supporting ground experiences seismically induced failure; rockfalls can also result in structural damage due to the impacts of large boulders on structures. Seismic settlement is similar to liquefaction, except that the soil is not saturated.
Examples of seismically induced ground failures include liquefaction (left photo) and landslides (right photo) from the 2011 M6.3 Christchurch, New Zealand Earthquake and the 2016 M7.8 Kaikoura, New Zealand Earthquake, respectively. Surface fault displacement is usually only observed in large magnitude earthquakes but can result in devastating structural damage. The 1972 Alquist‐Priolo Earthquake Fault Zoning Act prohibits construction of buildings in California within 50 feet of a known active fault trace. Therefore, surface fault displacement is generally not an issue for Metropolitan’s buildings constructed after the early 1970s. However, several components of Metropolitan’s conveyance and distribution infrastructure cross known active faults, including the CRA, various pipelines, and power transmission lines. These facilities are subject to damage from surface fault displacement.
Examples of surface fault displacement. The photograph on the left shows railroad tracks displaced as a result of the 1952 M7.5 Kern County Earthquake. The photograph on the right shows a field that shifted as a result of the 2010 M7.1 earthquake in Canterbury, New Zealand.
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Seismic Resilience
General
According to the National Infrastructure Advisory Council (NIAC), infrastructure resilience is “the ability to reduce the magnitude and/or duration of disruptive events.” The effectiveness of a resilient infrastructure or enterprise depends upon its ability to “anticipate, absorb, adapt to, and rapidly recover from a potentially disruptive event.” [ref. “Critical Infrastructure Resilience Final Report and Recommendations,” September 8, 2009]. This event may be man‐made, such as a cyber‐attack, or a natural disaster, such as a drought, flood, or earthquake.
“Seismic resilience” (see Figure 2‐3) narrows the focus of infrastructure resilience to only earthquakes.
Using the definition of “infrastructure resilience” presented above, Metropolitan has defined seismic resilience for water agencies as the ability to reduce the magnitude and/or duration of water delivery interruptions resulting from seismic events. Rather than striving to make an entire water system “earthquake‐proof,” seismic resilience involves setting reasonable performance goals that provide sufficient benefits that justify the corresponding investments required by both an agency and its ratepayers. Metropolitan’s seismic resilience performance objectives are summarized in Section 8 of this report.
Figure 2‐3: Resilience ‐‐ the ability to reduce the magnitude and/or duration of disruptive events Applicability to Metropolitan
For over a decade, Metropolitan has had a well‐defined approach to system reliability that addressed overall system resilience in five key areas: Water Supply Reliability, System Capacity, Infrastructure Reliability, System Flexibility and Emergency Response.
Seismic resilience is an essential aspect of Metropolitan’s overall reliability strategy. Water deliveries are extremely crucial following earthquakes for fire suppression, for the general welfare of local residents, and for the regional economy that relies on imported water. Metropolitan’s approach to seismic resilience has evolved over time to become one that is highly effective and recognized within the water industry [ref. “Water Supply in Regard to Fire Following Earthquake,” Charles Scawthorn, Pacific Earthquake Engineering Research Center, November 2011].
Source: http://www.iparametrics.com/solutions/infrastructure‐resilience.html Capacity/
Performance
measure
Resilience
Period of disruption
Time
Lon In
capacity
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Metropolitan’s Historical Approach to Seismic Resilience “The aqueduct is being built for the future as well as the present, and must stand and give adequate service for an indefinitely long time.”
From the “Design” Chapter of “The Great Aqueduct” book by Julian Hinds, 1938. “It was desirable that faults be crossed at right angles, to minimize damage in the event of movement, and that some flexible type of conduit on or near the surface be used so that if repairs become necessary they will be as simple as may be…”
From “Major Problems of Aqueduct Location” by Julian Hinds, Nov. 24, 1938 Engineering News‐Record.
Since its inception, and particularly during the design and construction of the CRA, Metropolitan has
recognized the potential vulnerability of water
infrastructure to disruptions by earthquakes. This
section provides a brief overview of Metropolitan’s
historical approach to seismic resilience, focusing on
major earthquake events in the past and lessons
learned from these events.
Post‐1906 San Francisco and 1933 Long Beach
Earthquakes (1930‐1970)
Conveyance and Distribution System: The majority of
Metropolitan’s conveyance and distribution system
was constructed between the 1930s and the 1970s.
Historical documents regarding the planning and
design of this infrastructure describe a philosophy of
“permanence,” which may be considered as a
forerunner to “resilience.” This philosophy not only
took into account decades of wear and tear, routine
hazards, and large storms, but also provided for seismic resilience.
Despite having no provisions within design codes,
Metropolitan took proactive measures to address
seismic resilience while designing the CRA.
Metropolitan geologists and engineers took into
account the ground shaking and deformation that had
occurred along the San Andreas Fault system during
the 1857 Fort Tejon earthquake and lessons learned
from 1906 San Francisco earthquakes, and
supplemented their understanding of regional active faults through geologic mapping and analysis of stereo aerial photographs. This led to the aqueduct being designed to cross active faults near the ground The 1906 M7.8 San Francisco earthquake struck the
coast of Northern California at 5:12 a.m. on April 18.
Severe shaking was felt from Eureka on the North
Coast to the Salinas Valley. Broken gas lines resulted
in fires that lasted for several days due to a lack of
fire supply. As a result, about 3,000 people died and
over 80% of the city of San Francisco was destroyed.
The 1933 M6.7 Long Beach earthquake took place on
March 10 at 5:54 P.M. Damage to buildings was
widespread and between 115 and 120 people died.
The earthquake highlighted the need for earthquake‐
resistant design for structures in California.
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surface in inverted siphons and cross fault traces at
right angles. The designers also opted for a more
flexible siphon design in fault regions than the rigid
monolithic concrete construction used elsewhere on
the CRA, and provided extra hydraulic grade at three
siphons crossing active faults (Appendix 3). These
provisions were intended to minimize the adverse
effects of seismically induced ground movement and
to simplify access for repairs.
Water Treatment Plants: Metropolitan’s water
treatment plants were also designed with features
that enhance seismic resilience, beginning with the
F. E. Weymouth Water Treatment Plant in 1940, and
followed by the Robert B. Diemer Water Treatment
Plant in 1963. The plants are modular in design and
incorporate redundancy of key components. They are
also situated strategically to maximize gravity flow to a majority of the distribution system.
Dams and Reservoirs: Metropolitan began a Safety of
Dams program many years before formal reporting
was required by the California Division of Safety of
Dams (DSOD). Staff regularly inspects Metropolitan’s
dams for vulnerabilities, documents their findings,
and reports these findings to DSOD.
La Verne Shops and Construction Equipment: The La
Verne Shops were built in the 1940s to support the
construction and maintenance of Metropolitan’s
initial infrastructure. The shops were expanded in the
1960s as Metropolitan’s system grew along with its
service area. These specialized shops provide support
for routine maintenance activities and are also vital
for responding to emergency events impacting
Metropolitan and member agency facilities. The
stockpiling of key materials and the ability to roll pipe and fabricate or repair specialty equipment greatly
enhances seismic resilience. Many of Metropolitan’s pumps, piping, valves, and related equipment are too large to be routinely stocked by vendors.
Metropolitan’s dams are inspected on a regular basis.
Photo of the 120‐inch Froriep Vertical Turning Lathe
(above) and the 5‐inch G&L Horizontal Boring Mill
(below) in the La Verne Machine shop.
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Post‐1971 San Fernando Earthquake (1971‐1990)
Earthquake Committee: Following the San Fernando
Earthquake in 1971, Metropolitan formed an
Earthquake Committee to investigate damaged
structures at the Joseph Jensen Water Treatment Plant
and to recommend enhanced seismic design criteria
and site improvements to mitigate the seismic risk
from potential future events.
The recommended modifications, such as the addition
of stone columns to prevent liquefaction, are believed
to have contributed to improved seismic performance
of the Jensen plant in the 1994 Northridge Earthquake
(see Section 4 of this report).
The Earthquake Committee also evaluated other
facilities and recommended additional improvements
that resulted in the upgrade of several key structures
throughout Metropolitan’s system. The Committee’s
efforts evolved over time into the current formal
approach, with its emphasis on improving the seismic
resilience of structures.
Emergency Response Plan: This period also saw
Metropolitan adopt its Emergency Response Plan and
establish a formal Emergency Response Organization
(ERO). These steps led to regular emergency response
training for staff, and eventually to staging formal
emergency response exercises. As part of this effort,
Metropolitan coordinated with its member agencies to
establish the Member Agency Response System
(MARS). Engineering Damage Assessment Teams
(DATs) were also created to rapidly assess damage and
help prioritize and initiate repair efforts.
La Verne Shops and Construction Equipment: The La
Verne Shops were further expanded in the 1980s to
support a major rehabilitation of the main pumps on the Colorado River Aqueduct. The additional fabrication capacity increased Metropolitan’s ability to respond to emergency events.
Local Projects Program: To decrease reliance upon imported water, Metropolitan established the Local Projects Program in 1982 to provide financial incentives to member agencies for the development of recycled water projects throughout the region. A more diversified water portfolio helps the region’s overall water supply reliability, which improves seismic resilience for the entire service area.
The San Fernando earthquake struck the greater Los
Angeles region in the early morning of February 9,
1971. The M6.5 earthquake caused severe property
damage over $500 million and the loss of life directly
attributable to the earthquake reached 58.
There were over 145 post‐earthquake ignitions,
typically caused by severed gas lines. Metropolitan
experienced widespread damage at the Jensen plant,
including a severe break to a 72” influent conduit and
damage to the new finished water reservoir (shown
below).
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Post‐1989 Loma Prieta and 1994 Northridge Earthquake (1990‐2010) During this period, Metropolitan greatly enhanced
seismic resilience by performing seismic risk
assessments, updating seismic design criteria,
strengthening dozens of at‐risk structures,
encouraging development of local water resources,
increasing emergency storage supplies, and
enhancing emergency response capabilities.
Seismic Design Criteria: During the Inland Feeder
Project, criteria were developed for new pipelines
that cross seismic faults. The refined fault‐crossing
strategy includes using steel pipelines with welded
joints; crossing fault‐zones at right angles, and
burying the pipes at relatively shallow depth to
enable easy access for repair; and locating the
pipelines where they can drain into channels or
streams if damaged at fault crossings. Metropolitan
also began considering the benefits of exceeding
minimum code requirements for essential structures.
Seismic Upgrade Program: Dozens of pre‐1990
structures were upgraded during this period. The
benefit of upgrading seismically vulnerable facilities
was demonstrated during the Northridge Earthquake
in 1994. Structures that were upgraded at the Jensen
plant, which was near the earthquake’s epicenter,
experienced only minor damage. The only significant damage consisted of rupture of an inlet 84‐inch steel pipeline. The Jensen plant was off‐line for less than 72 hours while the broken pipeline was repaired, and limited water deliveries were maintained during the repairs. Appendix 4 summarizes damage to Metropolitan infrastructure from the 1971 San Fernando and 1994 Northridge earthquakes.
Local Resources Program: In 1995, Metropolitan established the Local Resources Program (LRP). The LRP combined the Local Projects Program, which provided financial incentives for recycled water projects, with the Groundwater Recovery Program, which provided financial incentives to encourage the development of local groundwater recovery projects. The present LRP has been highly successful in reducing the region’s dependence upon imported water.
Diamond Valley Lake (DVL): DVL was completed in 1999 to increase operational flexibility and reliability by providing seasonal storage, drought protection, and dedicated emergency supplies. Seismic resilience was a major factor in both the siting and design of the reservoir. DVL was specifically constructed south and west of the San Andreas Fault, and it was designed to withstand a major event on that fault in order to mitigate for the potential interruption of Southern California’s imported water supplies. This 810,000 acre‐ The M6.9 Loma Prieta earthquake occurred in
Northern California on October 17, 1989, at 5:04 p.m. .
The shock was centered approximately 10 miles
(16 km) northeast of Santa Cruz on a section of the
San Andreas Fault System.
The earthquake was responsible for 63 deaths and
over 3,750 injuries. The Loma Prieta segment of the
San Andreas Fault System had been relatively inactive
since the 1906 San Francisco earthquake until two
moderate foreshocks occurred in June 1988 and again
in August 1989.
As a result of this event, there were more 916
documented water system pipe breaks. This resulted
in the loss of water pressure in the Marina District of San Francisco and difficulty in fighting fires.
The Metropolitan Water District of Southern California Seismic Resilience First Biennial Report Report No. 1551 – February 2018 Page 2‐9
foot reservoir, combined with other storage programs, provides a 6‐month emergency water supply for Metropolitan’s service area.
Special Seismic Risk Assessments: During this period,
Metropolitan broadened the scope of seismic risk assessments, from focusing on isolated structures to assessing entire facilities, such as the Diemer plant, and overall systems, such as the CRA. These efforts included seismic vulnerability
assessments, facility reliability assessments, and system flexibility studies. These special seismic risk assessments led to several capital projects to structurally upgrade facilities, provided input into Metropolitan’s emergency response
planning to reduce the time to restore service, and identified options to improve system flexibility to help maintain water deliveries during planned and unplanned outages.
Emergency Response Planning: Following the Northridge
Earthquake, Metropolitan revised its Emergency Response Plan and associated programs and established a Member Agency Coordinator function. Metropolitan also began conducting training exercises in coordination with member agencies and other external agencies and three functional exercises based on postulated seismic events were conducted during this period. In addition, the EOC was relocated from the Sunset Headquarters Building to Eagle Rock, and Incident Command Centers (ICCs) were established at each of the water treatment plants. Recognizing that seismic events can impact business functions as well as infrastructure, staff developed a formal Business Resumption Plan. Over time, this evolved into the present Business Continuity Plan (BCP) and IT Continuity Plan (ITP).
Emergency Response Construction Capabilities: In 2008,
Metropolitan enhanced its ability to respond to emergency events by initiating a long‐term project to refurbish and upgrade the La Verne Shops. Metropolitan can roll pipe and conduct simultaneous repairs on two large‐diameter pipelines.
Retaining in‐house fabrication functions is important, as there are few firms in the western U.S. with similar capabilities. In recent years, private firms with machine shop and fabrication capabilities have tended to increase the amount of work outsourced to offshore facilities, instead of retaining it locally. These firms have little ability to respond expeditiously to emergency needs.
The M6.7 Northridge earthquake occurred
on January 17, 1994, at 4:31 a.m. and had a
duration of approximately 10‐20 seconds.
The death toll was 57, with more than 8,700
injured. Property damage was estimated to
be between $13 and $50 billion. LADWP
reported a total of 1,405 pipe repairs and
that water pressure had dropped to zero in
some areas.
Metropolitan experienced damage at the
Jensen Plant including a rupture of an 84”
diameter pipeline. Crews worked around the
clock and restored service within 72 hours.
The ability to roll pipe in the La Verne shops
expedited these emergency repairs.
Although Metropolitan’s response was very
good, a task force was formed to develop
recommendations for further improvement
(Ref. Report 1087, “Northridge Earthquake
Assessment Report”).
The Metropolitan Water District of Southern California Seismic Resilience First Biennial Report Report No. 1551 – February 2018 Page 2‐10
Post‐2010 Chile, 2011 Christchurch and 2011 Great East Japan Earthquakes (2010‐Present) Seismic Resilience Strategy Defined: The recent earthquakes in Chile, New Zealand, and Japan demonstrated the
importance of seismic resilience, and have resulted in
extensive discussions among industry experts and public agencies on strategies to achieve greater levels of seismic resilience beyond the conventional measures of prevention and protection. This was particularly true for the 2011 Christchurch, New Zealand Earthquake, although it was the smallest of the three. The reason was the widespread damage that occurred in the downtown section of Christchurch,
despite the fact that the infrastructure was designed and constructed in accordance with modern building codes. While the majority of buildings did not fall, and most people were able to exit safely, many of the downtown structures were unsuitable for occupation and had to be demolished. In
addition, many of the buried utilities were damaged and had to be abandoned in place. The combined loss of structures and utilities resulted in a long‐term reduction to the
population within the city.
Concurrent with the infrastructure industry’s focus on
resilience, Metropolitan re‐assessed its existing programs and developed a more integrated, comprehensive approach to
seismic resilience. One improvement was to incorporate the concept of performance‐based design during seismic
evaluations. In addition to the evaluation of structures based on design‐level earthquakes to prevent damage,
performance‐based design evaluates the effects of more
extreme events to anticipate structural damage. Another improvement was to embrace the significant technological advancements that can improve seismic resilience, including computer modeling techniques, seismic resistant products, and recent industry research. These improvements have
allowed Metropolitan to develop an enhanced strategy for seismic resilience moving forward.
During this period, Metropolitan also formed a collaborative Task Force to address the unique vulnerabilities of the major aqueducts that cross the San Andreas Fault. In 2017, Metropolitan fully integrated the various seismic resilience efforts currently underway throughout the organization. The resulting Seismic Resilience Strategy is described in detail in Sections 3 through 7 of this report.
A M6.3 earthquake occurred in Christchurch,
New Zealand on 22 February 2011 at
12:51 p.m. The earthquake was centered
6 miles south‐east of the center of
Christchurch, which at the time was New
Zealand's second‐most populous city. The
earthquake caused widespread damage across
Christchurch, killing 185 people in the nation's
fifth‐deadliest disaster.
In December 2014, Los Angeles Mayor Eric
Garcetti released Resilience by Design which
provided recommendations to addresses Los
Angeles’ greatest earthquake vulnerabilities,
including taking steps to secure imported
water supplies.
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Metropolitan’s Comprehensive, Integrated Seismic Resilience Strategy The enhanced Seismic Resilience Strategy has the following objectives for Metropolitan and for the entire southern California region:
Provide a diversified water supply portfolio, system flexibility, and emergency storage Prevent damage to water delivery infrastructure in probable seismic events and limit damage in extreme events
Minimize water delivery interruptions through a dedicated emergency response and recovery organization
This strategy is built upon improved collaboration within Metropolitan and formal collaboration with LADWP and DWR, which also import water to Southern California.
Figure 2‐4: Detailed Breakdown of Metropolitan’s Seismic Resilience Strategy As shown in Figure 2‐4, Metropolitan’s enhanced Seismic Resilience Strategy includes four components within Metropolitan and a fifth component that involves formal coordination between Metropolitan, LADWP, and DWR.
System Flexibility
Special Seismic
Assessments
Seismic Resilience of
Dams and Reservoirs
Pipeline Seismic
Emergency Response
Train ing Exerci ses
Emergency Response
Metropolitan's Board
Formal Biennial Report
Summary of Projected
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1. The Planning component develops diversified water resources, system flexibility, and emergency water storage through Metropolitan’s Integrated Water Resources Plan (IRP) and System Overview Studies. The goal of Metropolitan’s IRP is to develop a diverse water supply portfolio that will be able to maintain a reliable water supply under any conditions, including a major seismic event.
2. The Engineering component addresses design concepts, vulnerability studies, and seismic resilience projects executed under Metropolitan’s Capital Investment Plan (CIP). The Engineering component includes evaluating the seismic resilience of structures, monitoring dams, special seismic assessments, and enhancing pipeline seismic resilience. These efforts are all aimed at improving the seismic resilience of the treatment plants and distribution system through facility upgrades and operational flexibility improvements.
3. The Operations component involves Metropolitan’s emergency response organization, training exercises, and construction capabilities. Their objectives are to effectively prepare for and respond to emergency events so that impacts to water deliveries are minimized and interrupted deliveries are restored quickly.
4. The Reporting component involves documenting the Seismic Resilience Strategy, tracking progress of seismic resilience activities, and annual reporting of near‐term goals and recent accomplishments to Metropolitan’s Board. This component is aimed at facilitating knowledge transfer, increasing accountability, and improving the transparency of seismic resilience goals and achievements to the Board and member agencies. The reporting component also supports the planning efforts of member agencies by communicating potential outage durations of Metropolitan facilities during emergency events.
5. The Seismic Resilience Water Supply Task Force component involves Metropolitan’s formal collaboration with DWR, LADWP, the State of California, and other water industry organizations to address the unique seismic vulnerabilities of Southern California’s imported water supplies. The two primary objectives of this task force are to 1) enable the agencies to coordinate emergency response efforts, and 2) identify practical mitigation options for reducing the magnitude and duration of disruptions to the region’s imported water supplies following a large earthquake on the San Andreas Fault.
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SECTION 3 PLANNING COMPONENT
As a supplemental supplier to the Southern California water community, Metropolitan faces many challenges in meeting the region’s needs for water supply reliability and quality. One of the challenges is the ability to maintain water deliveries within the region following a major seismic event. In general, Metropolitan’s planning efforts focus on meeting demands during dry and critical periods. However, during the original planning for Diamond Valley Lake (DVL), Metropolitan considered a scenario and a plan to meet demands if imported supplies were interrupted due to a seismic event, including development of a significant increase in storage dedicated to meeting emergencies.
Historically, Metropolitan has provided 50 to 60 percent of the water used in its service area from the Colorado River (via the Colorado River Aqueduct) and from the Sacramento‐San Joaquin River Watershed (via the State Water Project). In addition to relying on imported supplies, Metropolitan and its member agencies have developed other sources, including groundwater, surface water, recycled water, desalination of seawater, and an aggressive water conservation and water use efficiency program. These investments, and Metropolitan’s ongoing efforts in several different areas, coalesce toward the goal of long‐term regional water supply reliability.
Metropolitan’s Integrated Water Resources Plan (IRP) is the foundation for planning and developing a diverse water supply and emergency storage. The fundamental goal of the IRP is for Southern California to develop a water supply portfolio that will be able to maintain a reliable water supply. Maintaining this reliability includes investments prior to major seismic events, when there could be extended outages of imported water conveyance systems. To meet this fundamental IRP goal of a diversified water portfolio, Metropolitan believes in investing in the reliability of imported supplies, incentivizing its member agencies to develop increased water conservation, recycling, storage, and other resource‐management programs. A significant part of imported water supply reliability is preparing for recovery periods following seismic events. With the commencement of the IRP process in 1993, Metropolitan formalized this process as a long‐term strategy and official policy.
Metropolitan’s success in improving water supply reliability by diversifying its water resource portfolio, and by the application of adaptive resource management approaches has also increased seismic resilience.
At a system level, the Planning component of seismic resilience has several facets:
Diversified water supply portfolio
System flexibility
Emergency storage
Diversified Water Supply Portfolio
Metropolitan has undertaken a number of planning initiatives over the years in order to maintain a diversified water portfolio. These initiatives include the IRP, periodic IRP updates, the Water Surplus and Drought Management (WSDM) Plan, and the Water Supply Allocation Plan (WSAP). Collectively, these initiatives provide policy framework guidelines and resource targets for Metropolitan to ensure regional water supply reliability, along with additional resilience for seismic events. In addition to Metropolitan’s efforts to coordinate regional supply planning through its inclusive IRP process, Metropolitan’s member The Metropolitan Water District of Southern California Seismic Resilience First Biennial Report Report No. 1551 – February 2018 Page 3‐2
agencies also conduct their own planning analyses and may develop projects independently of Metropolitan.
2015 IRP Update
The 2015 IRP Update was a refinement of Southern California’s water management strategy, with seismic resilience continuing to be a key component. The 2015 IRP Update called for increasing the targets for conservation and local supply development and an emphasis on the importance of protecting and maintaining existing local supplies. The more that conservation and local supplies can contribute to the baseline each year, the more imported water Metropolitan can divert into storage to prepare for droughts of unknown duration or potential seismic events. Further developing a diverse water supply portfolio also contributes to increased seismic resilience.
Figure 3‐1: Integrated Resource Plan, Metropolitan’s Service Area Supplies Metropolitan’s Service Area Supplies under the IRP
In 1990, about 41 percent of regional water demands were met with local resources and conservation. By 2040, about two‐thirds will be met by local resources and increased conservation and recycling, as shown in Figure 3‐1. Metropolitan’s strategy is to maintain rather than increase traditional levels of imported supplies. The long‐term portfolio approach looks to local solutions to sustain the region’s continued growth. Increased flexibility to draw upon a wide range of sources from an ever more diverse water supply portfolio results in greater resilience to the potential impacts of seismic events on Southern California’s water supply infrastructure.
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Water Surplus and Drought Management (WSDM) Plan
Diversifying the region’s water supplies and developing adequate and healthy water storage reserves have proven to be the backstop for water supply reliability. These actions have also contributed to improved seismic resilience for the region. Stored water reserves provide certainty for meeting the needs of the region’s vast service area when traditional sources of supply are challenged by drought, climate change, seismic events, and other risks. It is critical that these storage resources be developed, managed and enhanced.
Metropolitan’s WSDM Plan, which defines a regional water management strategy for Metropolitan and its member agencies, has focused on using storage to manage water supplies and enhance reliability since 1999. The WSDM Plan includes the following guiding principle: Metropolitan will encourage storage of water during periods of surplus and work jointly with its member agencies to minimize the impacts of water shortages on the region’s retail consumers and economy during periods of shortage.
Water Supply Allocation Plan
When continued drought, earthquakes, or other natural disasters lead to shortages of supplies, Metropolitan distributes a limited amount of water through its Water Supply Allocation Plan (WSAP). First developed in 2008, Metropolitan’s WSAP takes a basic premise ‐‐to fairly distribute a limited amount of water supply‐‐ and applies it through a detailed methodology to reflect a range of local conditions and needs of the region’s retail water consumers. In particular, under severe drought conditions or a potential seismic event that impacts imported conveyance systems, it may be necessary and prudent to call for greater reductions in the use of limited water supplies and to reduce reliance on storage reserves. The WSAP has 10 levels of water supply allocations, each corresponding to a five percent reduction of supply. A Level 2 allocation, for example, represents a reduction of approximately 10 percent in overall water supply available to each member agency. The level of WSAP reduction implemented would correlate to the severity of the seismic event.
System Flexibility
Metropolitan develops its facilities to meet demands; however, in the course of developing a reliable system to meet demands, some flexibility has been incorporated into the system. This flexibility helps Metropolitan accommodate changes in water supply, demands, and water quality. System flexibility also helps mitigate the impacts of planned and unplanned outages. Metropolitan’s system flexibility has two key components:
Operational flexibility: the ability to respond to changes in regional supply, water quality, or member agency demands
Delivery flexibility: the ability to maintain partial to full deliveries during planned and unplanned single‐facility outages
Metropolitan has found that for planned and unplanned outages of Metropolitan facilities, system flexibility at the regional and local levels is key to minimizing the effects of these outages. Water supply reliability and water demand‐driven projects increase Metropolitan’s system flexibility, which in turn can The Metropolitan Water District of Southern California Seismic Resilience First Biennial Report Report No. 1551 – February 2018 Page 3‐4
also increase seismic resilience. For example, the construction of DVL and the Inland Feeder provided significantly increased water supply reliability through the potential for dramatically increased storage of imported supplies within the service area. These projects increased water supply reliability and system flexibility, and also greatly improved seismic resilience as the storage was purposely located on the coastal side of major faults that are crossed by the SWP, CRA, and Los Angeles Aqueduct (LAA). A significant amount of storage in DVL is dedicated to emergency storage. This water is not used except in emergency conditions such as following a major seismic event. Additionally, the Diemer and Jensen plants (and associated feeders) were constructed as water demand‐driven projects that also significantly improved delivery flexibility and seismic resilience within Metropolitan’s distribution system.
Emergency Storage
Over the past two decades, Metropolitan has developed a large regional storage portfolio that includes both dry year and emergency storage capacity (summarized in Appendix 5). Storage generally takes two forms: surface reservoirs and groundwater basin storage. In late 2011, heading into the most recent drought cycle, Metropolitan had developed over 5.5 million acre‐feet of storage capacity and had successfully stored over 2.7 million acre‐feet.
Additionally, Metropolitan has long discussed and executed plans to maintain a reliable supply of water in the face of any type of water supply condition, including following major seismic events that could impact imported water conveyance systems. The development of its diverse resource mix has enhanced the flexibility of Metropolitan’s conveyance and distribution system. Metropolitan established criteria for determining emergency storage requirements in the October 1991 Final Environmental Impact Report for the Eastside Reservoir, which is now DVL. These criteria were again discussed in the 1996 IRP. Both of these documents were approved by Metropolitan’s Board. Additionally, Metropolitan’s emergency storage requirements were summarized in a 2008 Board Report entitled “Water Surplus and Drought Management Plan on water supply and demand as of October 30, 2008.” Emergency storage requirements are based on the potential of a major earthquake causing damage to one or more of the aqueducts that convey Southern California’s imported supplies (SWP, CRA, and LAA) into the region. The adopted criteria assume that damage from such an event could render the aqueducts out of service for six months. As a result, Metropolitan has based its planning on a 100 percent reduction in these imported supplies for a period of six months.
Metropolitan’s WSDM Plan shortage stages guide Metropolitan’s management of available supplies and resources during an emergency to minimize impacts of the catastrophe. This emergency plan outlines that under catastrophic loss of water supply the following actions will be taken:
1. Interruptible water deliveries would be suspended
2. Firm supplies to member agencies would be restricted by a mandatory cutback of 25 percent from normal year retail demand levels
3. Water stored in surface reservoirs and groundwater basins under Metropolitan’s program would be made available
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4. Full local groundwater production, recycled water, and local surface emergency storage reserve production would be sustained
5. Metropolitan would draw on its emergency storage as well as other available storage Under the emergency criteria, retail demands would be met through existing surface storage, local production, and storage in surface reservoirs owned and operated by Metropolitan and by DWR. The total amount of storage available for emergency needs in Metropolitan’s storage facilities, including DVL, Lake Mathews, and Lake Skinner, is currently 292,100 acre‐feet (February 2018). The amount of emergency storage available to Metropolitan in DWR’s reservoirs, including Lake Perris, Castaic Lake, Silverwood Lake, and Pyramid Lake, is an additional 334,300 acre‐feet (February 2018).
SUMMARY
Through its IRP, Metropolitan has established a fundamental goal that Southern California will have a reliable water supply system for present and future generations, even if imported water supplies are disrupted due to a major seismic event. This reliability is achieved through Metropolitan’s development of local water supplies, emphasis on water conservation, and establishment of emergency storage on the coastal side of major earthquake faults that are crossed by the SWP, CRA, and LAA. These reliability actions enable Southern California to continue water deliveries during the period when imported supply aqueducts are out of service due to damage from a major seismic event. In addition, Metropolitan’s planning efforts to diversify the water supply and increase overall system flexibility over time have also contributed to providing resilience against potential in‐basin earthquakes.
Metropolitan will continue to evaluate its water resource planning programs in terms of how they may further enhance seismic resilience and coordinate these efforts with the Engineering and Operations functions that are described in Sections 4 and 5 of this report.
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SECTION 4 ENGINEERING COMPONENT
Metropolitan manages a number of strategies and component studies that evaluate facilities and systems against earthquake hazards. Mitigation options are then developed and executed when practical. These strategies include evaluating the seismic resilience of structures; special seismic assessments that address multiple facilities and systems; and other specialized efforts that address the seismic resilience of dams and reservoirs and the mitigation of geotechnical hazards.
Seismic Resilience of Structures
The purpose of evaluating the seismic resilience of structures is to prevent seismic damage to water delivery infrastructure from probable events and to limit damage due to extreme events in order to minimize water delivery interruptions. For occupied structures, the goal is to protect life safety and critical functions. Metropolitan applies a systematic approach to evaluate older structures that were constructed in accordance with earlier codes, and where necessary, to upgrade structures with seismic deficiencies.
The criteria applied to the seismic evaluations incorporate current code provisions and up‐to‐date industry standards. In general, structures are upgraded to maintain seismic performance levels that are comparable to the levels of a new facility. Additional details are provided in Appendix 6, “Seismic Design Frequently Asked Questions.”
Over the past two decades, this effort was primarily aimed at improving the seismic resilience of above‐ ground facilities and structures constructed prior to 1990. For example, the original pump houses at the five CRA pumping plants were determined to be vulnerable to significant damage in a design‐level earthquake. A design‐level earthquake is a probable event that is defined by the Building Code as the basis for seismic design of structures. To address this vulnerability, which could have impacted deliveries from the CRA over an extended period, new buttress walls were constructed in 1996.
Construction of new buttress walls at Hinds Pumping Plant The Metropolitan Water District of Southern California Seismic Resilience First Biennial Report Report No. 1551 – February 2018 Page 4‐2
Procedure for Seismic Evaluation of Structures
A seismic risk‐reduction program identifies seismic deficiencies of structures and quantifies the associated risks through an effective evaluation process, enabling limited resources to be allocated strategically to projects that address key vulnerabilities and to maximize improvements in seismic resilience of the water delivery system.
Metropolitan’s procedure for the seismic evaluation of structures includes the following steps:
1. Preliminary evaluation of all high‐risk structures
The preliminary evaluation of existing structures is a high‐level assessment to quickly determine if a structure is seismically deficient. Typically, this evaluation involves drawing review, visual inspection, and simplified calculations. If a potential seismic deficiency is identified, the structure is categorized as seismically deficient and the preliminary evaluation is complete.
2. Prioritization of structures with seismic deficiencies Structures identified as seismically deficient are then prioritized in preparation for a detailed evaluation. Structures built after 1990 were designed and constructed in accordance with the 1988 or later versions of the Uniform Building Code (UBC), which provides reasonable assurance of withstanding a design‐level earthquake without catastrophic structural failure. Therefore, structures built before the early 1990’s are given priority for the detailed evaluations, with consideration of life safety and the importance of the facility in water deliveries.
3. Detailed evaluation to develop retrofit options
Structures identified with at least one potential seismic deficiency via the preliminary evaluation are thoroughly assessed to confirm any deficiencies. Feasible retrofit options are developed during this step to mitigate the identified deficiencies, and more advanced procedures such as finite element modeling and comprehensive structural calculations may also be applied. The analysis methodology, its results, findings, and recommendations are then summarized in a report that includes rough order‐of‐magnitude construction costs.
4. Final retrofit design to strengthen deficient structures The recommendations from the detailed evaluation form the basis for requesting approval from the Board of Directors to proceed with a seismic upgrade project. A project team consisting of design engineers and a project manager considers all feasible retrofit options developed during the detailed evaluation and recommends one option for the final retrofit design. In this process, the project team considers adequacy for seismic resistance, cost, constructability, operational impacts, and environmental impacts to select the preferred option. The selected option is then developed into bidding documents that include detailed design drawings and specifications for the retrofit work.
The Metropolitan Water District of Southern California Seismic Resilience First Biennial Report Report No. 1551 – February 2018 Page 4‐3
5. Periodic reevaluation of strengthened structures
The seismic design provisions in building codes are constantly evolving, which reflects lessons learned from recent earthquakes and new findings in regional seismicity. Metropolitan periodically re‐evaluates its facilities to ensure that system reliability is not compromised due to newly discovered vulnerabilities. Factors that may trigger a re‐evaluation of a previously upgraded structure include:
Substantial increase of seismic hazard level at the site New discovery of site seismicity
New discovery of potential seismic deficiencies in the structure Significant deterioration of existing materials in the structure Progress to date
A comprehensive inventory list of Metropolitan’s above‐ground structures is used to track the progress of the evaluation and seismic upgrades of structures. To date, Metropolitan has completed preliminary evaluations of all 311 pre‐1990 above‐ground structures (see Figure 4‐1). Upgrades of many critical structures have also been completed, including the five pumping plants along the Colorado River Aqueduct, the Jensen Administration Building, and the Lake Mathews Outlet Tower.
Figure 4‐1: Status of Seismic Assessments and Upgrades of Pre‐1990 Structures
Status as of January 2018
.. .. u
~E t: .l!! C
~~i 311 i "C ;;;
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.... ' .,. ~"' C i i i
::, Completed: Remaining: l
... 311 0 ~ Q.
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.2 ~ Acceptable: Potentially Deficient: .. ::, > .. 195 116 ... .. .., "' "ii. .. "' .. + + + + ..,
l! In various phases of Authorized for Authorization Planned I!: Upgraded: ;;;, design or construction: deta lied evaluation: for detailed evaluation: u 56 e 30 2 28 .. ~ I
.. .. C Related to water Not related to iif delivery: water delivery: ~ ftJ-= -~ !l! ... 4 24 ...
The Metropolitan Water District of Southern California Seismic Resilience First Biennial Report Report No. 1551 – February 2018 Page 4‐4
As shown in the figure, of the 116 structures identified as potentially deficient, 56 have been upgraded and 32 are authorized for study, design or construction. The remaining 28 structures will proceed through Metropolitan’s CIP evaluation process to obtain authorization for the detailed evaluations. Since 1998, Metropolitan has invested over $200M in seismic upgrades of its key structures.
Expanded Approach for Achieving Seismic Resilience of Structures In 2017, the strategy for achieving the seismic resilience of structures was modified to further enhance the seismic resilience of the delivery system. The refined strategy moved beyond assessing only Pre‐1990 above‐ground structures to include the following:
Fully and partially buried structures
Seismic anchorage and bracing of non‐structural components such as equipment, pipes, and ducts. Structures constructed between 1990 and 2000 (prior to the adoption of UBC1997) For the first two items, it was recognized that fully and partially buried structures, while less vulnerable to seismic hazards than above‐ground structures, are nevertheless important to maintaining system reliability. Similarly, the seismic resilience of non‐structural components, such as equipment and piping, is also important for minimizing operational downtime after an earthquake.
The third item, relating to UBC1997, is included in the expanded effort since seismic design codes have been modified such that some structures designed and constructed after 1990 also warrant an assessment. Recorded ground motions in the 1994 Northridge Earthquake, for example, revealed that the design seismic force specified in building codes at the time were underestimated for sites located close to faults. This near‐fault effect was incorporated into the subsequent code (UBC 1997). As a result, certain structures designed between 1990‐2000 prior to the adoption of UBC 1997 may be vulnerable to a major earthquake.
Moving forward, the near‐term focus is to complete the detailed evaluations and seismic retrofit projects that have been authorized to date. Long‐term goals include:
Continue assessment of seismic design criteria to incorporate updated seismic resilience strategy Document a systematic approach to improve seismic resilience of non‐structural components Conduct preliminary evaluations for critical fully or partially buried structures Conduct preliminary evaluation of post‐1990 structures.
Special Seismic Assessments
Special seismic assessments are performed to complement the original seismic resilience of structures evaluations. These special assessments include seismic vulnerability evaluations, general reliability assessments, and system flexibility studies.
Seismic Vulnerability Evaluations. Seismic vulnerability evaluations identify potential impacts of credible earthquake scenarios on individual facilities and the system as a whole. For these studies, staff review current and readily available seismic hazard data from public, academic, state, and federal sources, as well as input from geotechnical consultants, to screen each facility or system (e.g., the CRA) for its level of exposure to seismic hazards (i.e., surface displacement, ground shaking, liquefaction, and landslides) The Metropolitan Water District of Southern California Seismic Resilience First Biennial Report Report No. 1551 – February 2018 Page 4‐5
during a major seismic event. Based on the potential level of exposure and the resulting damage to Metropolitan facilities, the time to restore service are estimated. These studies then evaluate the impact of the damage on Metropolitan’s water delivery capability and identify areas with limited backup capability to provide water while the facility is out of service. Improvements that could reduce the loss of service, and/or reduce the time to restore service, are then identified and prioritized.
Findings from these evaluations can lead to capital
improvements to strengthen facilities, improve system
flexibility, and/or provide input into Metropolitan’s
emergency response planning to improve the seismic
resilience of the distribution system.
To date, Metropolitan has completed over ten seismic
vulnerability studies. A few examples are listed below, while a complete list with a brief summary of each study is included in Appendix 7.
Seismic Risk Assessment of Local Water Production
Facilities in the Service Area of Metropolitan Water
District of Southern California, January 14, 1991,
Dames & Moore
Probable Maximum Loss Analysis for Metropolitan Water District of Southern California, September 1998, EQE International
2009 Report No. 1335: Effects of Southern California Seismic Events on Metropolitan Water District Deliveries
2014 Report No. 1490: Colorado River Aqueduct Seismic Vulnerability Investigations – Summary Report
2017 Report No. 1533: Seismic Risk Assessment – Conveyance and Distribution System Tunnels General Reliability Assessments. The vulnerability of Metropolitan’s facilities to damage from major seismic events is also evaluated through general reliability assessments. The objective of these assessments is to examine the vulnerability of facilities to unplanned service interruptions from the following hazards and events:
Seismic activity Fire
Hydraulic surge Corrosion
Vehicle impact Wind‐blown projectiles
Equipment malfunction Third‐party construction
Erosion/Scour/Flooding Vandalism
The assessments are based on compiling data collected from several sources and evaluating the information to identify vulnerabilities that may damage a facility and impact water deliveries. The sources of information include prior reliability studies conducted for the facility; the facility’s piping and The 2014 Potential Impact of a Seismic Event
on the CRA Tunnels validated historic
assumptions regarding potential outage
durations for the CRA tunnels.
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instrumentation diagrams, electrical single‐line drawings and plant layout drawings; interviews with Water System Operations and Engineering Services staff; reviews of corrective maintenance reports, reviews of CIP projects; and field inspections of the facilities.
The general reliability assessments focus on the following when relating to seismic activities:
Assessing the ability of individual equipment and piping within the facilities to withstand an earthquake
Reviewing potential soil stability issues that might affect earthquake vulnerability with Metropolitan’s geotechnical staff
Reviewing the ability of existing critical structures (i.e., tanks, treatment basins and pump house buildings) to withstand a seismic event
After identifying potential vulnerabilities to specific hazards and events, staff categorize the vulnerabilities based on the potential service impacts and identify options to mitigate the vulnerability and improve reliability. Mitigation steps include conducting capital projects to rehabilitate, replace, or upgrade equipment and facilities; performing operation and maintenance (O&M) activities for minor equipment modifications; creating procedures for designing, operating or maintaining the facility; and refining Metropolitan’s emergency response plan. These options are prioritized based on their potential impact on the operation of the facility and are considered for evaluation and action. The cost and benefit of options that involve capital projects are evaluated through the normal CIP evaluation process.
Metropolitan has completed a total of eight general reliability assessments to date, including assessments of the CRA, all five water treatment plants, the conveyance system, and portions of the distribution system. A few examples are listed below, while a complete list with a brief summary of each study is presented in Appendix 7. As the understanding of earthquake probability and seismic forces continues to increase, these studies will be periodically updated.
2006 Report No. 1227: Distribution System Reliability Assessment 2006 Report No. 1255: Weymouth Water Treatment Plant Reliability Assessment 2006 Report No. 1297: Colorado River Aqueduct Reliability Assessment System Flexibility Studies. System flexibility studies identify:
1. The impacts of regional facility outages on water deliveries to member agencies
2. Areas with limited flexibility to serve water, which may impact deliveries during an outage
3. Options to improve system flexibility (e.g., interconnections with other agencies, local resource development, or isolation valves).
These studies postulate outages to Metropolitan and DWR facilities, assign a reasonable duration to the outage based on past experience, and then evaluate the impact of the assumed outage on water deliveries through the following steps:
1. Identify service connections affected by an outage
2. Evaluate Metropolitan options to deliver water to the affected service connections The Metropolitan Water District of Southern California Seismic Resilience First Biennial Report Report No. 1551 – February 2018 Page 4‐7
3. Evaluate member agency backup options (e.g., wells, treatment plants, surface storage, interconnections with other agencies) to deliver water to affected service connections
4. Quantify the impact of each outage in terms of loss of retail service to affected service connections, and identify service connections and/or regions with limited or no backup capability
5. Identify options to mitigate the impact of the outage and improve system flexibility to respond to planned and unplanned outages
The results of these studies support member agencies’ efforts to improve local system reliability in the event of a planned or unplanned outage of a Metropolitan facility; support joint efforts of Metropolitan and its member agencies in evaluating the reliability benefits of potential projects; and support Metropolitan’s efforts to identify options to improve operational flexibility.
Two significant system flexibility studies have been completed to date:
System Reliability Study (2006). This study evaluated the flexibility of Metropolitan’s overall distribution system. The study examined the impact of single failures in the system to the ability to deliver water to member agencies and identified existing backup options to deliver water during the outage. Specific types of failures considered in the study included individual facility failures (e.g., the CRA, a treatment plant, a reservoir) and failures in each isolatable segment of the distribution system (e.g., pipelines). Over 250 different postulated events were considered, and the impact on delivery to each service connection was evaluated for each event. The study considered the capabilities both within Metropolitan’s system as well as the member agencies’ to mitigate impacts of an outage. The study did not, however, consider multiple failures that might be associated with an earthquake, due to the almost unlimited number of combinations of failures that would have to be considered. Metropolitan and member agency discussions regarding this study and local and regional obligations led to a clarification about Administrative Code 4503 “Suspension of Deliveries” that is included in Appendix 8. Mills Water Supply Reliability Study (Report No. 1337). One of the findings of the 2007 Integrated Area Study was that the supply of raw water to the Mills plant had a lesser degree of redundancy than Metropolitan’s other water treatment plants. The Mills Water Supply Reliability Study was undertaken to evaluate conditions that could interrupt the normal raw water supply to the Mills plant, such as earthquakes, and develop options to improve the redundancy and flexibility of supply to the plant.
Seismic Resilience of Dams and Reservoirs
The seismic stability of Metropolitan’s dams is safeguarded by a robust and proactive comprehensive dam safety strategy managed by the Safety of Dams Team. The core responsibilities of the Safety of Dams Team are to perform inspections, interpret and analyze collected surveillance and monitoring data, evaluate dam structures and appurtenant works, report the findings, and serve as Metropolitan’s liaison with the California Department of Water Resources, Division of Safety of Dams (DSOD).
Metropolitan owns and operates 20 facilities that are under the jurisdiction of DSOD, as listed in Table 4‐1.
There are a total of 24 individual dams/reservoirs, as some of these facilities have multiple dams.
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Table 4‐1: Current Metropolitan Jurisdictional Dam and Reservoir Facilities Dam/Reservoir Name Dam Type
Cajalco Creek Detention Basin Flood Control
Copper Basin Reservoir Surface Water Reservoir
Diamond Valley Forebay Hydraulic Structure
Diamond Valley Lake Surface Water Reservoir
Diemer Mixing & Settling Basin No. 8 Hydraulic Structure Diemer Ozone Contactor Basins Hydraulic Structure
Diemer Treated Water Reservoir Hydraulic Structure
Garvey Reservoir Surface Water Reservoir
Gene Wash Reservoir Surface Water Reservoir
Goodhart Canyon Detention Basin Flood Control
Lake Mathews Surface Water Reservoir
Lake Skinner Surface Water Reservoir
Live Oak Reservoir Surface Water Reservoir
Mills Reclamation Basin No. 14 Hydraulic Structure
Mills Treated Water Reservoir No. 1 Hydraulic Structure Mills Treated Water Reservoir No. 2 Hydraulic Structure Orange County Reservoir Surface Water Reservoir
Palos Verdes Reservoir Surface Water Reservoir
Skinner Treated Water Reservoir Hydraulic Structure
Weymouth Treated Water Reservoir Hydraulic Structure
Metropolitan’s Comprehensive Dam Safety Management Program Metropolitan’s comprehensive dam safety strategy is comprised of six key elements:
1. Regular detailed inspections
2. Surveillance monitoring and performance reporting
3. Cyclical facility assessments
4. Emergency preparedness
5. Inundation map preparation
6. Execution of capital projects
Regular Detailed Inspections
Regular detailed inspections are essential to preserve the integrity of a dam and are necessary for early problem detection and remediation. All Metropolitan dams are regularly inspected by Metropolitan staff at specific intervals using a formal, multilayered process:
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New and Old Outlet Towers at Lake Mathews (2008)
Daily or weekly observations
Monthly inspections of dam and reservoir facilities with the highest DSOD designated hazard classification, with at least semi‐annual inspections of all other facilities Detailed mandatory annual inspections conducted in the presence of DSOD staff Upon completion of the annual DSOD inspections, DSOD prepares and provides a summary inspection report that summarizes their findings and may identify recommended remedial work, which is cataloged as action items that are corrected promptly.
Surveillance Monitoring and Performance Reporting
All Metropolitan dams and reservoirs incorporate instrumentation that measures specific performance parameters such as dam or structural movement, water levels, and seepage, as well as other parameters such as shaking due to earthquakes. Collected data are retained as part of the required annual DSOD inspection report.
In terms of seismic resilience, data from surveillance monitoring and performance reporting contribute to the Cyclic Facility Assessments described below by identifying changes in specific parameters, such as dam or reservoir movement or increased seepage, that may indicate a condition that could affect the ability of the dam or reservoir to withstand an earthquake.
Cyclical Facility Assessments
Cyclic facility assessments were initiated at Metropolitan in 2004 and are generally repeated about every 10 years. These assessments use the most up‐to‐date data and evaluation criteria to identify potential vulnerabilities in dam embankments, dam structures, foundations, outlet facilities and spillways and develop mitigation options, if necessary. If a potential vulnerability or deficiency is identified, a rehabilitation or remediation project may be included in Metropolitan’s CIP.
An example of a facility assessment that evolved
into a project under Metropolitan’s CIP is the Lake
Mathews Outlet Tower. The outlet tower, which is
critical for water deliveries to a large portion of
Metropolitan’s service area, was constructed in
1938 and modified in 1961 to increase its height by
30 feet. A facility assessment conducted in 1994
determined that the modified tower was vulnerable
to significant damage from ground shaking. A
project was authorized to evaluate and address this
vulnerability, resulting in a new seismically resilient Outlet Tower being constructed in 2005.
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Emergency Preparedness
Metropolitan has a comprehensive Emergency Action Plan (EAP) for each of its dam and reservoir facilities.
The EAP identifies potential emergency conditions that could occur at a dam or reservoir facility and describes procedures to be implemented to minimize loss of life and property damage. EAPs serve to provide guidance to responders, local agencies, and stakeholders in evaluating potential hazards, determining the severity of the emergency, and establishing communication protocols. Required content of dam EAPs are provided in the Federal Emergency Management Agency’s (FEMA) Federal Guidelines for Dam Safety, Emergency Action Planning for Dams (FEMA 64, July 2013).
Inundation Map Preparation
Inundation maps illustrate worst‐case flooding that would result in the complete draining of a full reservoir. Inundation maps show lateral and longitudinal extent of flooding, flood wave arrival times, maximum flood wave depths, total flooding duration, and peak flood flow rates. Inundation maps are a required component of dam and reservoir EAPs and are used by local emergency response agencies for emergency planning purposes.
Metropolitan’s current cycle of inundation mapping updates is planned to be completed by 2018 for all dam and reservoir facilities.
Execution of Capital Projects
Dam and reservoir facility vulnerabilities or deficiencies that are identified during detailed inspections or from cyclical assessments are proposed for rehabilitation or remediation through Metropolitan’s CIP. Past examples of facility rehabilitation or remediation projects include the Lake Mathews Outlet Facilities, described earlier, and the Seismic Upgrade of the Diemer Finished Water Reservoir.
Currently, several dam and reservoir related capital projects are in progress, including the final design of the outlet valve replacements at Copper Basin and Gene Wash Reservoirs and the construction of the Palos Verdes Reservoir floating cover replacement and tower seismic upgrades. Planned future projects include floating cover replacements and facility upgrades for the Mills Finished Water Reservoir Nos. 1 and 2 and Garvey Reservoir.
Pipeline Seismic Resilience
Metropolitan’s pipelines are exposed to a number of geohazards of varying risk, including fault zone crossings, permanent ground deformation from causes such as liquefaction or landslides, and ground shaking during seismic events. While Metropolitan’s pipelines have always been constructed in conformance with standards of practice at the time of design, there haven’t been code requirements to address seismic risk. In addition, until recently, there have not been mitigation options for large diameter pipelines.
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The photograph on the left shows a pipe joint pullout due to liquefaction from 1995 in Kobe, Japan. (photo courtesy of D. Ballantyne, Understanding the Seismic Vulnerability of Water Systems, Regional Water Providers Consortium Board, October 2013) The photograph on the right shows pipe damage at a fault crossing (photo courtesy of D.
Ballantyne, Understanding the Seismic Vulnerability of Water Systems, Regional Water Providers Consortium Board, October 2013)
There are currently several seismic resistant pipeline options, such as earthquake resistant ductile iron pipelines with special seismic resistant joints (see Figure 4‐2), that are becoming available in diameters suitable for use by Metropolitan.
Figure 4‐2: Example of Seismic Resistant Pipe (courtesy of Kubota Corp. and JFE) As mentioned previously, Metropolitan is now formalizing a strategy to achieve significant improvements in seismic resistance of the distribution system over time. This approach takes advantage of up‐to‐date seismicity data, modern computer modeling techniques, recently developed seismic resistant products, extensive industry research, and updated codes.
The Metropolitan Water District of Southern California Seismic Resilience First Biennial Report Report No. 1551 – February 2018 Page 4‐12
The seismic resilience strategy for pipelines has three components:
1. Part 1 – Conducting vulnerability assessments of the existing distribution system
2. Part 2 – Identifying potential mitigation measures for existing pipelines
3. Part 3 – Establishing design and performance criteria for new pipelines and rehabilitation projects Parts 1 and 2 are described below in more detail. Part 3 for new pipelines will be developed in conjunction with several new large‐diameter pipeline projects that are planned over the next 5 to 10 years.
Part 1 –Vulnerability Assessment of Existing Pipelines: Due to the relatively good performance of large‐ diameter pipelines within Metropolitan’s distribution system during previous earthquakes, Metropolitan is focusing on the most vulnerable existing pipelines to establish the need and priority of future mitigation work as well as integrating seismic mitigation into planned rehabilitation programs for aging pipelines. This approach is currently being followed for the PCCP Rehabilitation Program. It is anticipated that there will be relatively few cases where it would be considered cost‐effective to upgrade a pipeline solely to enhance seismic resilience.
Vulnerability assessments of pipelines within the distribution system follow the same multi‐step approach used for traditional risk assessments. The initial steps entail gathering available geologic, seismologic, and geodetic data, and then identifying seismic hazards along a pipeline route, such as fault zone crossings, liquefaction zones, and landslide hazards. Three simulated earthquake scenarios are considered in the evaluation: a frequent seismic event, moderate event, and a severe event. The hazard assessment provides a bounded solution that includes the expected probable and maximum probable damage for each earthquake scenario.
The resulting damage to the pipeline due to the three design seismic scenarios provides an insight into the corresponding consequences of disruption. These consequences include life‐safety impacts, delivery impacts, and societal/environmental impacts.
Preliminary screening is then performed to identify the most vulnerable pipelines that warrant further analysis. Depending on the nature of the seismic hazard, Metropolitan may perform a preliminary assessment using a simplified analysis based on probable ground strain and pipeline material properties.
However, in some cases, a more detailed finite element model is required to fully determine the behavior of the pipe and the surrounding support strata under seismic shaking. This comprehensive analysis includes soil‐structure interaction, rupture modeling, and permanent pipeline deformation.
For any pipelines that do not meet the performance objectives, mitigation measures are considered. The order and timing of projects to mitigate risks as part of the overall rehabilitation strategy are evaluated and prioritized for inclusion in Metropolitan’s CIP.
Part 2 – Mitigation Measures for Existing Pipelines: Where mitigation is recommended to minimize the consequences of service disruption, the general design goals are to design pipe segments and joints that can withstand projected vertical and horizontal movement. In most cases, a simplified analysis will provide sufficient insight into seismic performance; however, in some cases, it may be necessary to analyze the pipeline and connecting structures using a more comprehensive computer model.
The Metropolitan Water District of Southern California Seismic Resilience First Biennial Report Report No. 1551 – February 2018 Page 4‐13
Existing continuous welded steel pipe with adequate wall thickness and joint welds typically perform well under significant ground shaking. Where mitigation of existing pipelines is required to achieve acceptable seismic performance, Metropolitan may use specialized earthquake resistant joints as an option. Where these joints cannot achieve acceptable seismic performance, other options may include stiffening of the joints and pipe section; and enlarged vault sections to isolate the pipe from maximum ground deformation. Metropolitan may also evaluate alternate alignment options to relocate existing pipes, if feasible, to avoid areas of known fault crossings or expected permanent ground deformation that may result in significant disruption. Where these options are not feasible and seismic risk is not within acceptable limits, Metropolitan may consider installation of isolation valves or addition of a vault with a removable pipe spool to allow quick insertion of a bulkhead to facilitate shutdown and repair of the damaged section of pipe
Part 3 – Design Guidelines for New Pipelines: The guidelines for new pipelines will be similar in concept to existing pipelines and will be developed in conjunction with several new large‐diameter pipeline projects that are planned over the next 5 to 10 years.
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SECTION 5 OPERATIONS COMPONENT
Metropolitan is prepared to respond to all types of emergencies through its Emergency Management and Business Continuity Operating Policy A‐06. Key elements of this policy include IT Disaster Recovery, Business Continuity and Emergency Response functions. This section focuses on the Emergency Response functions due to specific steps in this area that pertain to seismic resilience.
Emergency Response Organization
Metropolitan maintains a dedicated Emergency Operations Center (EOC) that can be activated at any time to manage Metropolitan's response to a large disaster, including seismic events. The EOC is equipped with multiple modes of communication and coordinates directly with Metropolitan’s Operations Control Center (OCC) and Security Watch Center (SWC), as well as with numerous external agencies. For example, the EOC would coordinate with DWR and LADWP, as well as other related agencies, in the event of one or more aqueducts being damaged by an earthquake on the San Andreas Fault, as further explained in the next section.
Metropolitan also has Incident Command Centers (ICCs) located at various facilities. These ICCs can also be activated at any time to manage localized emergencies, and will coordinate directly with the EOC during a major disaster. Metropolitan also has Damage Assessment Teams (DATs) that that can be called upon by the ICCs to conduct investigations at incident sites. The DATs consist of engineers who can assess damage and initiate engineering responses, including recommendations for short‐term repairs or work‐arounds and potential designs for permanent, long‐term repairs.
The Emergency Response Organization (ERO), illustrated in Figure 5‐1, is comprised of over 200 pre‐ designated employees who work in the EOC, the ICCs, or in the field during emergencies. ERO staff has completed specialized training that meets State and Federal requirements.
Metropolitan's emergency response structure follows the National Incident Management System (NIMS) and the State of California's Standardized Emergency Management System (SEMS).
Figure 5‐1: Metropolitan’s Emergency Response Organization • Legal Officer
• Public Information Officer
EOC Director • Liaison Officer
• Safety Officer
• EOC Support
Planning/Intel Logistics Finance &
Section Chief Section Chief Admin
Section Chief
• Conveyance & • GIS/ Mapping • Resource Tracking
Distribution . Planning/ • IT (Troubleshooting)
. Water Quality Documentation . Communications
. Water Treatment . Engineering . Personnel Support
• Headquarters ICC . Advanced Planning/ • Logistics
• Security Officer Demobilization Implementation
. Ops Support/Radios • Situation Status • Supply and
Procurement
. Warehouse
The Metropolitan Water District of Southern California Seismic Resilience First Biennial Report Report No. 1551 – February 2018 Page 5‐2
Photographs from recent emergency exercises at the EOC
Emergency Response Training Exercises
In addition to training emergency response staff on NIMS procedures, Metropolitan regularly conducts emergency response training exercises which have often been based upon a postulated seismic event.
Examples include:
“Resilient Grid“ Functional Exercise, 19 Oct 2017
“Can you hear me now?” Full Scale Communications Exercise, 08 Apr 2017 “Desert Shake” Functional Exercise – 04 Nov 2015 (Metropolitan and seven other agencies) “Oh Susana!” Functional Exercise – 05 Nov, 2013 (Metropolitan and four other agencies) “Golden Guardian” Functional Exercise – 20 Jun 2012
“California Rolling” Mini Functional Exercise – 08 Oct 2008 “Hollywood Havoc” Functional Exercise – 04 April 2007 “Mayhem at Mathews” Tabletop Exercise – 15 Mar 2006 (Metropolitan and four other agencies) In 2017, Metropolitan completed a five‐year exercise plan that allowed all of its member agencies to participate in at least one of Metropolitan’s annual emergency exercises during that period. Metropolitan also conducts approximately 50 tabletop and functional exercises each year. This includes three large‐scale emergency exercises per year for the EOC and for each of the 12 ICCs. There are also monthly communication drills (includes Member Agency Response System (MARS) two‐way radio, internal Metropolitan radio system, WebEOC updates, mass notification system, and satellite phones) with member agencies, ICCs, Treatment Plant Control Centers, and DWR facilities. These regular exercises, as well as monthly radio and communications tests with member agencies and other outside agencies, help Metropolitan to continually improve its readiness.
Emergency Response Construction Capabilities
Metropolitan maintains the capability to perform rapid repair of damaged facilities such as large pipelines for up to two simultaneous repairs. The machine, fabrication, coating, and valve shops at the La Verne The Metropolitan Water District of Southern California Seismic Resilience First Biennial Report Report No. 1551 – February 2018 Page 5‐3
Shops are used extensively to support system‐wide maintenance; to provide emergency services within Metropolitan, for member agencies, and for DWR; and to perform fee‐for‐service work that supports member agencies and the State Water Project. The fabrication shop can roll pipe on a 24‐hour‐per‐day basis. In 2015, Metropolitan expanded the La Verne Shops to enable the fabrication of two pipe sections up to 12 feet (3.7 meters) in diameter simultaneously, and has been developing standardized pipeline repair drawings and shoring drawings to expedite repair operations.
Metropolitan also maintains stockpiles and materials on hand, and has its own construction equipment and crews ready to mobilize if necessary. Pre‐selected urgent repair contractors can also provide additional construction support in case of an emergency. Maintaining these manufacturing and construction capabilities supports Metropolitan’s efforts to efficiently operate and maintain its infrastructure and to quickly repair components or systems that may be damaged.
Pipe being rolled at Metropolitan’s La Verne Shops Metropolitan construction crews 42” x 30” adapter flange being drilled at Metropolitan’s La Verne Shops
Stocks of steel plate allow Metropolitan to roll pipe of various diameters and wall thicknesses
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SECTION 6 REPORTING COMPONENT
The reporting component of Metropolitan’s seismic resilience strategy focuses on the following areas:
1. Record Keeping: Tracking progress and maintaining a record of expenditures
2. Annual Updates: Providing annual updates to Metropolitan’s Board of Directors
3. Formal Reporting: Preparing a formal Seismic Resilience Biennial Report Record Keeping
The Record Keeping component involves tracking progress on key seismic activities and maintaining a detailed record of all investments and expenditures related to seismic upgrade projects.
Key seismic resilience activities include the planning, engineering, operations, and Task Force component near‐term goals identified in Section 8. Specific activities include:
Special planning studies related to seismic resilience Seismic evaluations of structures, facilities, and regions Designs for seismically upgrading structures/systems and related construction activities Emergency response training exercises
Development of new seismic performance objectives
Joint efforts with external agencies through the Task Force For each of these activities, progress will be tracked and reported on at regular intervals. In addition, the cumulative cost of capital investments in seismic upgrade projects will be tracked and reported on annually.
Annual Updates
Staff will update Metropolitan’s Board of Directors on an annual basis. The annual update will focus on current seismic resilience issues, recent Metropolitan and Task Force accomplishments, and near‐term goals.
Formal Reporting
The biennial report will summarize seismic resilience objectives, goals, and accomplishments; consolidate key reference material; and provide a high‐level summary of the various activities related to seismic resilience throughout Metropolitan. Specific areas of emphasis will include:
Knowledge Transfer: The biennial report will provide a convenient, comprehensive source for seismic resilience information. The report will contain key information for all seismic resilience efforts throughout Metropolitan, and will include a list of all formal Metropolitan reports on seismic issues. Individuals can use this information to familiarize themselves with Metropolitan’s seismic resilience history, issues, and goals, which will make them more effective in supporting seismic resilience efforts.
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Accountability: Through annual reporting to the Board, seismic resilience programs will maintain a higher degree of visibility, focus and momentum on projects and studies that will help Metropolitan meet target goals.
Transparency: The sharing of seismic resilience studies, projects, and performance objectives will benefit the facility planning efforts of member agencies. Seismic risk, mitigation, and projected duration of outages are complex issues that deserve adequate discussions between Metropolitan and member agencies to facilitate decisions and investments that best serve the public.
This summary report will be updated every two years.
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SECTION 7 SEISMIC RESILIENCE WATER SUPPLY TASK FORCE
The City of Los Angeles has recently increased its focus on seismic risks and public safety. In December 2014, the city released the report, “Resilience by Design,” which highlighted Los Angeles’ earthquake vulnerabilities and laid out strategies to protect lives; improve the capacity of the city to respond to earthquakes; prepare the city to recover quickly from earthquakes; and protect the economy of Los Angeles and all of Southern California.
A concern noted in “Resilience by Design” is the importance of water infrastructure and the unique dependence of the region upon imported water supplies, all of which cross the San Andreas Fault. The report included a recommendation to fortify the imported water aqueducts by creating a Seismic Resilience Water Supply Task Force (Task Force) with the LADWP, Metropolitan, and DWR.
In August 2015, the three agencies formed the Task Force for the purpose of collaborating on studies and mitigation measures to improve the seismic resilience of imported water supplies to Southern California.
The Task Force is comprised of managers and staff from the planning, engineering, and operations functional groups of each agency, and includes executive management on a steering committee. The Task Force also coordinates with other agencies and utilities.
The Task Force created a structure (Figure 7‐1) that includes functional sub‐teams that will focus on aqueduct assessments and mitigation, emergency response, and public relations in the near‐term. The Task Force also recognized the benefit of long‐term collaboration regarding ‘non‐aqueduct’ assessments and mitigation, and agreed to discuss such issues as they arise.
The initial Task Force goals include:
Establishing a common understanding about individual agency aqueduct seismic vulnerability assessments, projected damage scenarios, and planning assumptions Revisiting historical assumptions regarding potential aqueduct outages due to seismic events Discussing opportunities for improving the seismic resiliency of Southern California’s imported water supplies through multi‐agency cooperation
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Figure 7‐1: Seismic Resilience Water Supply Task Force One of the initial activities for the Task Force was to conduct a workshop that would allow the three agencies to establish a common understanding about each agency's seismic vulnerabilities; revisit historical planning assumptions; and identify action items that would lead to increased seismic resilience moving forward. The workshop is summarized below.
2016 Aqueduct Workshop
On March 30, 2016, the Task Force held an Aqueduct Workshop at Metropolitan’s Headquarters Building in Los Angeles. The purpose of this workshop was to discuss potential damage to Southern California’s imported water aqueducts from a major seismic event on the San Andreas Fault. The discussion focused specifically on the Great Southern California ShakeOut Scenario (ShakeOut) of a M7.8 earthquake, developed by the U.S. Geological Survey (USGS) and many partners. The workshop format allowed for a candid exchange of information and ideas between staff from the three agencies, along with LADWP’s Seismic Resilience and Sustainability Program’s Expert Panel that included experts from industry and academia.
Participants were asked to consider preparations for, and response to, the ShakeOut Scenario from a regional perspective. Specifically, participants were asked, “If all aqueducts were owned and operated by a single agency, then what steps should be taken now to mitigate potential damage, and what would the priority of repairs be following a major seismic event to most rapidly restore imported water deliveries to the region?” This focus on actions that would best serve the region led to productive discussions and practical recommendations for the three agencies to improve the resilience of imported water supplies.
Seismic Resilience Water Supply Task Force
Working Groups (WG's)
Assessments and Mitigation of Aqueducu
Scope.i Assess vulnerabllitfes of aqueducts ar,.d
identify poten1lal sy;stem fmprovements with
reglonal sers m1c reislllency ~ nerlts. ldenrifv p,oactrve mea.s.1.ues to reduce infrasu1Jcture repa[r durations. Recommendadom should com.ider
MCE and other moril! probab!@ scenarios,
Members:
0WR: Dall@ Reonle, Phil ~ocq
M WO: Greg de lamare, R. Hernandez
DWP: Cra ig Davls
Functions and Responsibilities
Members:
Management
Ovenfght Committee
DWR~ Jeanne Kuttel, David Duval
MWO: Gorden Johnson, Jim Green
DWP: Jeme5 Yennotta, Susan Rowghani
Seismic Resflience T ioam
Members:
DWR: Dave Renal•. Phil~~
MWD: David Clark, Mike Roj ..
DWP: Craig Davis, MlkeGrahek
Non-aqueduct l\s.sessment:s .. nd Mitigation
scope-; Assess water sys tem components
Impacting overall selsmrc resiliency of rmported
water supplles and lnve-.stlgatt! emergrng
technology to improve ~,~mic resillency.
MiPmbus.:
0WR: Dase Rennie, Phil t.eeocq
MWO; Greg de Lamare, R. Hernandez
DWP! Craig Davis, Mike Grahek
--- - - - - -- ~-
Public R~lotlom
Scope: Cocrdioale multl-agency Pfess
rele,a-s.e jas--r-e~ed)
Member-5:
DWR, Doug Carlson
MWD: BobMulr
DWP: JOE! Rarna llo1 Amanda Parsons
Mayor's 0fftcer: Vicki Currv
Emergency Response
Scope: Prepare for a coordinaled multH,sericv
response to emergency events rnvoli'ing one or
more aci:ueducts. Conduc.t OCC-.!islonal tabll!' top and funct.fonal Joint agency emergency e:icercf.s.es.
Perform perrodic operatfonal rnrert:ie exercrses.
MiPmbers:
DWR: Chrl!!itV Jon~
MWD: Ian Whyte
DWP: Patrlc.k Horton, Mike Grah@lc
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The assembled team concluded that for a M7.8 ShakeOut Scenario event on the southern portion of the San Andreas Fault, the recovery times would exceed historic planning assumptions:
Restoration of full aqueduct capacities could take more than six months Restoration of partial aqueduct flows could take at least two months The March 30, 2016 Task Force Workshop at Metropolitan’s Headquarters Building When considering this specific scenario from a regional perspective, the participants concluded that residents within Metropolitan’s service area would be best served if the three agencies:
Implement recently identified mitigation projects on the Colorado River Aqueduct and Los Angeles Aqueduct
Prioritize known vulnerabilities on the Colorado River Aqueduct, Los Angeles Aqueduct, and the State Water Project
Execute an agreement to allow for a coordinated response to emergency events Share resources when responding to emergency events
Focus initial repair efforts on the State Water Project’s West Branch and the Colorado River Aqueduct*
(*This is based on a ShakeOut‐type event; it is recognized DWR will also have a priority to serve other customers on the East Branch)
LADWP’s Seismic Resilience and Sustainability Program’s Expert Panel noted the significance of the nation’s largest municipal utility, largest water wholesaler, and largest state‐owned water agency joining together to address a major hazard for the first time, and encouraged the Task Force to continue working together long into the future. The assembled team agreed that Southern California could become better prepared for seismic events and that the Task Force should continue to facilitate coordinated vulnerability The Metropolitan Water District of Southern California Seismic Resilience First Biennial Report Report No. 1551 – February 2018 Page 7‐4
assessments, evaluate mitigation options, and develop agreements that allow coordinated emergency responses to major seismic events. It was clear that common issues could be studied more efficiently together and there was a consensus for the Task Force to continue to maintain the momentum achieved through this workshop. Although the regional challenge of achieving a greater level of seismic resiliency is significant, the consensus was that it would be achievable through the continued, dedicated efforts of the Task Force.
Future Task Force Activities
To continue the momentum built during the collaborative workshop, the Task Force agreed to conduct conference calls every two months and to initiate a repeating 5‐year cycle of planning, executing, and reporting on collaborative goals, activities and accomplishments. This approach is aimed at providing effective management of long‐range actions and ensuring task force stability.
The first cycle has included preparation of a detailed report that summarized the 2016 Workshop and identified goals for the period between April 2017 and March 2022. The second cycle will report on progress achieved between 2017 and 2022, and will identify goals for the period between 2022 to 2027.
The high‐level goals for 2018 to 2019 are included in Section 8 of this report.
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SECTION 8 SEISMIC RESILIENCE PERFORMANCE OBJECTIVES AND NEAR‐TERM GOALS
This section summarizes Metropolitan’s established performance objectives for the various components of seismic resilience, along with corresponding near‐term goals. The goals listed are those that are anticipated to be completed in calendar years 2018 and 2019.
Established Performance Objectives and Near‐Term Goals:
System Level
Facility Level
Emergency Response
Task Force
Other Near‐term Goals:
Establish Additional Performance Objectives
Develop a Standard Approach for Evaluating Non‐Structural Elements Enhance Member Agency Planning Efforts
Seek Funding for Identified Projects
Support California WaterFix
Established Performance Objectives and Near‐Term Goals
Seismic resilience performance objectives are summarized in this section along with the corresponding near‐term goals.
System Level
System‐level seismic resilience performance objectives and near‐term goals focus on two areas: System Flexibility and Regional Supply Interruption/Emergency Storage.
System Flexibility
There are two primary components of system flexibility that contribute to seismic resilience:
1. Operational flexibility ‐ the ability to accommodate short‐term changes in regional supply, water quality, or member agency demands, and
2. Delivery flexibility ‐ the ability to maintain deliveries to member agencies during single regional facility planned or unplanned outages.
Metropolitan will continue to develop a demand‐driven, flexible regional system aimed at meeting demands, while reducing the impacts of regional infrastructure outages. Regional delivery flexibility improvements will be achieved through demand‐driven projects.
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System Flexibility Goal
2019 Goal: Conduct Rialto Pipeline Alternative Supply Needs study This study will identify potential near‐term and long‐term options to meet municipal and industrial (M&I) demands supplied exclusively from the Rialto Pipeline system in the event of a disruption of supplies from the California Aqueduct, East Branch.
Emergency Storage
Performance Objectives: Metropolitan’s objectives for emergency storage include maintaining a six‐ month supply of water to account for interruption of imported water supplies (assuming a 25% reduction at the retail level).
Emergency Storage Goals
2019 Goal: Complete a re‐evaluation of Metropolitan’s emergency storage needs This study will re‐evaluate Metropolitan’s emergency storage requirement based on updated assumptions on potential outage durations for the State Water Project and the Los Angeles Aqueduct.
The latest projections for the worst case scenario are that Metropolitan’s Colorado River Aqueduct can be repaired within 6 months, LADWP’s Los Angeles Aqueduct within about 18 months, the West Branch of the SWP within 6‐12 months and the East Branch of the SWP within 12‐24 months. 2019 Goal: Complete a comprehensive evaluation of Metropolitan’s storage programs This comprehensive evaluation will review all existing storage programs within Metropolitan Facility Level
Facility‐level seismic resilience performance objectives and near‐term goals are categorized based on functionality of facilities: essential facilities related to water delivery; supporting facilities with permanent staff, such as administration buildings; and supporting facilities without permanent staff, such as warehouse facilities.
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Essential Facilities (related to water delivery)
Performance Objectives: Performance objectives for essential facilities include maintaining operation with minimum interruption after design‐level events and controlling structural damage to facilitate recovery after extreme events.
Essential Facility Goals
Goal 1: Complete construction of approved seismic upgrade projects Carbon Creek Pressure Control Structure (2018)
Ten Control Structures along the Allen McColloch Pipeline (2018) Diemer Administration (Control) Building (2019)
Five CRA Pumping Plant Switch Houses (2019)
Goal 2: Conduct studies, and complete design of approved upgrade projects Define the scope and approach for assessing potential seismic‐induced damage to Metropolitan’s water conveyance and distribution pipelines (2018) - The purpose of the damage assessment is to estimate the number and severity of pipeline breaks and leaks during major earthquakes, and identify pipelines with the greatest risk for seismic damage. The results of the study will provide input into Metropolitan’s emergency response planning activities, and will help prioritize future pipeline seismic resilience enhancements.
Design of seismic upgrade for Weymouth West Wash Water Tank (2018) Design of seismic upgrade for Diemer West Filter Building (2018) Complete evaluation of options, design, and award of construction contract to strengthen the CRA Whitewater Tunnel No. 2 (2019)
- This work will include strengthening shallow tunnel sections near the portals, improving tunnel access at the west portal, prequalifying tunnel repair contractors, stockpiling steel sets, and pre‐designing tunnel repair elements.
Investigate options to improve emergency raw water bypass capabilities at Skinner, Weymouth, Jensen and Mills Water Treatment plants (2019)
Vulnerability study of CRA electric transmission and distribution systems (2019) Design of seismic upgrade for the original portion of the Water Quality Lab in La Verne and the Weymouth Administration Building (2019)
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Supporting Facilities with Permanent Staff
Performance Objectives: Performance objectives for support facilities with permanently assigned staff include controlling structural damage to prevent casualties and severe injuries under design‐level events and maintaining structural stability to prevent catastrophic collapse under extreme events.
Supporting Facilities (with permanent staff) Goals
Goal 1: Expedite construction of approved seismic upgrade projects Headquarters Building seismic upgrades (award construction contract in 2018) Goal 2: Complete approved studies and seismic upgrade designs Seismic upgrade to Field Engineering Building at La Verne (2019) Supporting Facilities without Permanent Staff
Objectives: Performance objectives for support facilities without permanently assigned staff include controlling structural damage to facilitate recovery after design‐level events and maintaining structural stability to prevent catastrophic collapse under extreme events.
Goals: Metropolitan’s near‐term goal for improving the seismic resilience of support facilities without permanently assigned staff is to continue exploring opportunities of integrating seismic upgrade work of these relatively minor structures with future capital projects at the facility. At this time, no specific goals have been identified in this area.
Emergency Response
Objectives: Metropolitan’s objective is to maintain an effective emergency response organization and support facilities to ensure Metropolitan is prepared to respond to significant earthquakes. Regular training is conducted to ensure staff is prepared for actual events. Metropolitan maintains shop and construction crew capabilities to complete the repair of two simultaneous large diameter pipeline breaks within seven days. This capability is augmented by Metropolitan’s ability to re‐deploy its contractors and to call upon other agreements to repair four additional large diameter pipe breaks simultaneously within seven days (as well as repair other facility damages). These capabilities ensure Metropolitan is prepared to respond to significant earthquakes.
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Emergency Response Goals
Goal 1: Prepare and conduct emergency exercises
Conduct a joint agency workshop to prepare a draft Joint Agency Response Plan (2018) Conduct high‐level training for DWR, LADWP, and MWD staff on the Joint Agency Response Plan (2019)
Run a functional exercise on the Joint Agency Response Plan (2019) Goal 2: Execute a MOU to allow for a coordinated emergency response Prepare draft MOU and submit for review (2018)
Secure LADWP, Metropolitan, and DWR approval for the MOU (2019) Task Force
Task Force Goals
2018 Goals: Collaborative LADWP, Metropolitan, and DWR Goals Discuss the applicability of lessons learned from seismic events in Japan, Chile, New Zealand, and Mexico
Compare each agency’s approach to conducting seismic assessments Meet with Southern California Edison (SCE) and Southern California Gas Co. to discuss the potential vulnerabilities of aqueduct power systems
Conduct workshop to explore potential aqueduct interties 2019 Goals: Collaborative LADWP, Metropolitan, and DWR Goals Establish a leadership structure for a coordinated response to major events Finalize a three‐agency database of available emergency response resources Conduct a three‐agency table top emergency exercise
Develop a ShakeOut Scenario Response and Restoration Plan Conduct a second three‐agency functional emergency exercise that includes energy utilities I
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Other Near‐Term Goals
Additional seismic resilience goals Metropolitan plans on achieving during 2018 and 2019 include:
1. Develop a Standard Approach for Evaluating Non‐Structural Elements (2019) The Seismic Upgrade Program was expanded from its focus on pre‐1990 above‐ground structures to include post‐1990 structures, partially buried structures, and non‐structural components in essential facilities. The existing approach to evaluating pre‐1990 structures is also applicable to the post‐1990 and partially buried structures. However, a standard approach needs to be developed for evaluating the non‐structural components within existing facilities, which involves equipment anchorages and bracing for piping, ducts, and cable trays.
2. Establish Additional Performance Objectives (2019)
Metropolitan intends to establish seismic resilience performance objectives in the following areas:
a) New pipelines
b) Retrofit of existing Metropolitan pipelines, typically concurrent with rehabilitation projects c) New and existing tunnels
Metropolitan is now in the process of developing a more comprehensive strategy for incorporating seismic mitigation into the design of its pipelines and tunnels. Although it is possible to clearly define performance objectives for above‐ground structures, this process is more complicated for pipelines and tunnels for two reasons: 1) The performance of a pipeline or tunnel subjected to seismic forces is less well‐defined than with structures, and 2) The performance needs of specific pipelines, pipeline segments, or tunnels vary widely due to Metropolitan’s supply flexibility and the varied reliance on imported water by member agencies. Metropolitan will explore these issues in greater detail as it moves ahead with major capital programs, including the PCCP Rehabilitation Program. It is expected that by December 2019, Metropolitan will have established an approach for addressing seismic vulnerabilities during pipeline and tunnel rehabilitation projects, and for new pipeline and tunnel design efforts.
3. Investigate the Potential for Developing a Model to Prioritize Pipeline Rehabilitation (2019) The prioritization model will seek to optimize the sequence of pipeline repairs to achieve the greatest risk reduction for every dollar invested. The prioritization model would take into account multiple risk factors including seismic risk exposure, pipeline condition, consequence of failure in terms of damage to key facilities (e.g., hospital), difficulty of repairs, system flexibility, and cost of repairs.
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4. Enhance Member Agency Planning Efforts (2019)
Development of the following documents will support member agency planning efforts regarding new facilities and emergency response programs:
a) Summary of seismic performance objectives by facility class; examples of recent seismic upgrade projects; and identification of open items
b) Summary of projected outage durations for Metropolitan facilities under “Operational”, “Design”, and “MCE” earthquake scenarios
5. Seek Approval for Detailed Seismic Studies (Ongoing) Under the ongoing Seismic Upgrade Program, Metropolitan will assess the options for seismic upgrades to 28 structures identified as seismically deficient. These projects will be considered for inclusion in Metropolitan’s Capital Investment Plan.
6. Support California Water Fix (Ongoing)
Metropolitan will continue supporting the California WaterFix to increase seismic resilience of the Bay‐Delta portion of the State Water Project.
The Metropolitan Water District of Southern California Seismic Resilience First Biennial Report Report No. 1551 – February 2018 Appendix Page 1‐1
Appendix 1
Key Seismic Resilience Achievements
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Metropolitan has made significant improvements in the overall seismic resilience of its water system over the past few decades. These achievements include:
1971 Earthquake Committee formed to assess damage and recommend improvements 1976 Metropolitan’s Emergency Response Plan formally adopted 1983 Member Agency Response System (MARS) established 1993 Incident Command Centers (ICCs) established at each treatment plant and a formal engineering response chart adopted for the Damage Assessment Teams (DATs) 1995 Formal Business Resumption Plan developed
1996 Seismic upgrade of CRA Pump Houses completed
1999 Construction of Diamond Valley Lake completed
2004 South slope stability improvements completed at Diemer 2005 Construction of new Lake Mathews Tower completed 2010 Jensen Administration Building seismic upgrade completed 2010 Construction of the Inland Feeder completed
2011 Seismic upgrade of Mills Electrical Buildings 1 & 2 completed 2013 Seismic upgrade of Diemer Finish Water Reservoir completed 2013 Diemer East Wash Water Tank seismic upgrade completed 2014 Seismic upgrade of Weymouth Filter Buildings 1 and 2 completed 2014 CRA seismic assessment confirmed historical assumptions for duration of worst‐case outage of the CRA
2015 Seismic upgrade of Jensen Washwater Tanks 1 & 2 completed 2015 Seismic upgrade of Weymouth East Wash Water Tank completed 2015 Task Force formed to enhance seismic resilience of imported water supplies 2017 Seismic upgrade of Diemer East Filter Building completed Note: Metropolitan has invested over $250M in seismic upgrade projects since 1998.
The California Department of Water Resources has also taken steps to improve the seismic resilience of Southern California’s imported water systems, including:
1997 Construction of new Outlet Tower at Silverwood Lake completed 2018 Lake Perris Dam improvements completed
The Metropolitan Water District of Southern California Seismic Resilience First Biennial Report Report No. 1551 – February 2018 Appendix Page 1‐4
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The Metropolitan Water District of Southern California Seismic Resilience First Biennial Report Report No. 1551 – February 2018 Appendix Page 2‐1
Appendix 2
Modern Era Earthquakes over M6.3
Within or Near Metropolitan’s Primary
Service Area
The Metropolitan Water District of Southern California Seismic Resilience First Biennial Report Report No. 1551 – February 2018 Appendix Page 2‐2
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The Metropolitan Water District of Southern California Seismic Resilience First Biennial Report Report No. 1551 – February 2018 Appendix Page 2‐3
Southern California has experienced at least six earthquakes within or near Metropolitan’s service area and with magnitudes greater than M6.3 during the past hundred years.
Date Event Location Fault Magnitude
April 21, 1918 San Jacinto San Jacinto 6.7
Mar. 10, 1933 Long Beach Newport‐Inglewood 6.4
Feb. 9, 1971 San Fernando Sierra Madre 6.5
June 28, 1992 Landers San Andreas 7.3
Jan. 17, 1994 Northridge Northridge Thrust 6.7
Oct, 16, 1999 Hector Mine Lavic Lake Fault 7.1
The Metropolitan Water District of Southern California Seismic Resilience First Biennial Report Report No. 1551 – February 2018 Appendix Page 2‐4
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The Metropolitan Water District of Southern California Seismic Resilience First Biennial Report Report No. 1551 – February 2018 Appendix Page 3‐1
Appendix 3
Provision for CRA Uplift
The Metropolitan Water District of Southern California Seismic Resilience First Biennial Report Report No. 1551 – February 2018 Appendix Page 3‐2
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The Metropolitan Water District of Southern California Seismic Resilience First Biennial Report Report No. 1551 – February 2018 Appendix Page 3‐3
MWD
METROPOLITAN WATER DISTRICT OF SOUTHERN CALIFORNIA
COLORADO RIVER AQUEDUCT
TECTONIC ALLOWANCE ORIGINAL INTENTION
INVESTIGATION
1 March 2016
The Metropolitan Water District of Southern California Seismic Resilience First Biennial Report Report No. 1551 – February 2018 Appendix Page 3‐4
Purpose and Objective
Historic documents have mentioned that the d(lsigners of the Colorado River Aqueduct (CRA) incorporated "measures in their engineering designs to minimize the impacts on the flow through the CRA due to future vertical displacements across the key fault traces mapped at that time. The measures included an additional 0.8 m (2.5 ft) of drop beyond that required by siphon losses at ... three fault crossings" (Report 1484). "In each
siphon [Big Morongo and San Andreas]
approximately 2.5 feet of additional grade
was allowed to provide for adjustment in
slope if future movement should occur"
(Contract Number 149).
Figure 1 shows the location of each of the
siphons in question.
The question was raised regarding the
specifics of how this was accomplished.
This document will describe investigation
into whether this allowance was
incorporated, the mechanism by which
this allowance was included, summarize
historical records suggesting such an
1.o ..
~
Figure 1
Overview Map
...,
nt.nd,
allowance, and recommend field investigations which can confirm this analysis.
Observances of Tectonic Allowance
Record drawings for the Colorado River Aqueduct were explored to identify any occurrences or explanation for design Hydraulic Grade Line (HGL) at the Big Morongo Siphon, San Andreas Siphon and Casa Loma Siphon. The first observance of the allowance is found in the hydraulic profiles prepared as a part of the original record
drawings of the Colorado
River Aqueduct in 1935.
Selected copies are
included at the end of this
document.
A discontinuity is
observed in the HGL,
dropping by a notated
2.5 feet at the beginning of
the Big Morongo Siphon,
San Andreas Siphon, and
Casa Loma Siphon. The
HGL is highlighted in red
on Figure 1, with the 2.5-
foot drop circled.
j]
Figure 1
Original 1935 San Andreas Siphon Plan and Profile
A second observance of the allowance is found in the record drawings associated with the late 1950's construction of the second barrel for the CRA siphons (Specification Numbers 504 and 509). As before, selected copies are included at the end of this document. The plan and profiles found in the second barrel siphon record drawings show two parameters corresponding to hydraulic grade at the downstream transition structures, as follows:
March 2016 CRA Tectonic Uplift Allowance
The Metropolitan Water District of Southern California Seismic Resilience First Biennial Report Report No. 1551 – February 2018 Appendix Page 3‐5
• ''.HG. El.", assumed to be an acronym for .Hydraulic Grade Elevation, and assumed to refer to the pressure head at design flow
• "WS El.", assumed to be an acronym for Water Surface Elevation, and assumed to refer to the water surface under free-surface .. , ! 1
flow conditions at design flow
In the siphon, the HGL -is observed to be
above the soffit of the pipeline,
indicating the pipeline is designed to be
under pressurized flow. Upon entering
the transition structure, the HGL is
below the top of the transition structure
walls as free surface flow is designed for.
As shown on Figure 2, the Water Surface
Elevation line in the outlet transition
structure is depicted 2.5 feet below the
Hydraulic Grade Elevation line, as
I - • I
/600,
Figure 2
' .. f - 1
circled in red. For other transition
structures, the Hydraulic Grade Big Morongo Siphon Second Barrel Plan and Profile Elevation line meets the Water Surface
Elevation line, as shown on Figure 3 for Thousand Palms Siphon.
A second barrel was not constructed at Casa Loma Siphon according to the original plans, so no corresponding record drawing was identified.
Staff from the Hydraulics team confirmed via calculation that the headloss depicted by the HGL is consistent with the major and minor losses shown in the record drawings for the design flows.
A third observation of the allowance is found in the hydraulic profiles. While not called out numerically as on the previous two sources, the hydraulic profiles depict a slope offset at the Big Morongo and San Andreas Siphons of a much greater magnitude than those
observed for other siphons. This is depicted in two figures on the following page.
It is understood that the design philosophy for each siphon was to size the losses across each siphon to maintain the free surface flow HGL across the siphon. This can be graphically observed in Figure 4 as shown by the red dashed line
highlighting the HGL matching the canal or conduit slope upstream and downstream of the siphon.
At Big Morongo and San Andreas siphons, an offset of
2.5 feet is observed between the slope upstream of the
siphon and the slope downstream of the siphon. Figure 5 highlights this in blue for Big Morongo Siphon.
CRA Tectonic Uplift Allowance 2
0 Figure 3
Thousand .Palms Siphon Second Barrel Plan
and Profile
March2016
The Metropolitan Water District of Southern California Seismic Resilience First Biennial Report Report No. 1551 – February 2018 Appendix Page 3‐6
_--· ,offG,.,ao
"~ , o•ll'I' '
"
,·~ • I 5i~ Ii &tlf l-1
• ,,,.
March 2016
J,
Figure 4
Siphon HGL Slope Consistent with Aqueduct Slope
Slope Offset ,, • I m~ "": I,, II I )j
I
ll : I ,., , ..t ~;;-ll
Figure 5
Siphon HGL Slope at Big Morongo Siphon
Q:lp<'.f';O~,f..1,.-vt'L,ff
#t'CH.1/VCP~
111., c1J.. ro :q
trilfl{)ltlR • 1• 1'1:1 N.V,-Ji1
•=-3< ·-
,.,.
~.lt)l;/1'.,,, ~ ~
,r,n,tftlC ,..,nu #i. E IU ,;:, -,.,~··
STC>IW 1'll"tJtJ,. f'O ~•JO
""'!"~ .... ~ .... ,,__._._ -
......... -...,-;,..
3 CRA Tectonic Uplift Allowance
The Metropolitan Water District of Southern California Seismic Resilience First Biennial Report Report No. 1551 – February 2018 Appendix Page 3‐7
1nis last set of oliservanoe • of the 2.5-foot allowance may provide n suggestion of the designer's thoughts on the effect of the aJJowancc. The H_ draulic Grade Line obseived on the pmfileii grad11a1Jy <lI'ops relative to the in cit elevation though tho Moro11go Number 1 Tunnel and the Morongo Number 2 TUIIIld, an<l in the conduit immediately upstream of the San Andrens Siphon. While dimensions nor elevation.- 11rc ca lled out on thi profile, the depth at the outlet to the lorongo umber 2 Tunnel can b .. measured on the drawing as 8.9 feet, and the depth at the entrance to the San ndreas Siphon can he m asured on the drawing as 7.8 feet.
Previous Surveys
Dased on the contract document, construction on Big Morongo Siphon and San Andreas Siphon was tarted on 5 Feb 1935 and concluded on 16 Sep 19%, l ith work activities compktcd by fay 1936. ln Februazy and March 1935, a construction staking survey \ as comlucted. Included in Lhe survey notes arc an adjustment to the slopes consistent with the marki.1ps includ d 111 the con tract· documcnrs (Contt'act 149). Thi liming is consis1eal with U1e start of construction.
In August 1937, ailer conslruction of the 'R/\, 1he as-buil1 urvey wa conducted lo set brass cap on th transition structure as pennancnt benchmark . Bcncl1marks established include:
• a manhole at Station 93 16+46
• the outlet transition structur for Rig lorongo Siphon at Station 9353+ 15 • the outlet transition trucnu·e fol' Ea ·t San Andr a Siphon at Station 9581 125 (refem~d to as "Oullt:l Siphon ' in survey notes)
• the inlet l'r:insicion sr,ucnire for San Andrea· Siphon at Station 9591 175 • ii manhol e at 'talion 9595+00
• the outlet transition structure for San Andreas Siphon at Station 9625+ 75 • the outlet tnmsilion !$h.11cture for' West S.m Andrea · Siphon at Station 9651 1 75 (rcfetTed to as .. sma ll siphon'' in smvey notes)
These are recorded in field Dool 2740. u me.nlion is made~ ilhin the survey nores of any measurement ofinvc1t elevations ofthc pipeline or transition structure, so any in.forenccs mad to !ho invert elevation require the assumption that the transition structure dimensions are con ·istent ,, ith th-: pl.mnecl dimensions apperuing on the constrnelion plans ( 19.17 foet for tlic Big fomngo Sipl1on outlet transition structure
18.96 feel for the Dig forongo Siphon inlet transition structure and both San Andreas Siphon transition slrnclurcs).
In 1998, the asa oma Siphon first harrel was surveyod as a part of an as-built survey prepared for construction of concrete nc:t ·emenl between Stations 11073+45 and 11073+93 related to work on the Inland Feeder. The su1vey note mention replacement of the pipeline, but do nol appear to includ an survey ofinverl tilil ations.
hi 2008, the Si:ln Jacirtt:o Diversion SITUcture, which 01iginattid as the in!llf tnmsitfon str.11cture to tl1e Casa Loma Siphon first barrel was su1veyed as a pa11' of establishing NA VI) 1988 elevation$ in the area. While the survey notes do not incJ ude invert ehlvations, they do include the weir elevation,~ hicb can be used lo estimate th invert elevation based on the r cord drawing .
In 2014, a sdtfornent stud was conducted by Surve at San Andreas Siphon and Big Morongo Siphon lo (letcn.ninc the difference ilt elevation b.;tw.;cn the i.alot and outlet trnnsition st1uch1res. Th urvoy onl CRA Tectonic Upliil Allowance 4 March 2016
The Metropolitan Water District of Southern California Seismic Resilience First Biennial Report Report No. 1551 – February 2018 Appendix Page 3‐8
measured !he relati e di1Terence betwt:en lh e benchmark set on the inlet and ouUt:t l:nm.si lioo s1ructurt:s of each siphon in the ug-w 1 193 7 SUJ ey. TI1e difference in elevntion between Ute inlet and outlc1 trnctuto benchmarks is presontecl in the table below, suggesting 110 changes in relati o ground movement in lhe in1ervening eight de a<les.
Table I 1934 and 2014 Survey Comparison
May 2014 'urvey ugust 1935 Survey Difference
Siphon (feet) (feet) (feet)
Ilig Morongo 7.90 7.90 0.00
San Andreas 6.64 6.68 -0.04
~~ SU rt<')' f !OW l,,:,ok 2740 "1d SU"'CY Noto IOl)t .)' 1)4:
As witl1 the previous suiveys no measurement was made of the invert elevations so it is not pos ible to veru)' !hat !he slope of the canal includes 1J1e 2.5-foot slope offset upstre,1m of the siphon directly from su1vey measurements.
However, using the deri ed measun:ments developed as a parl of! me (ultimah,ly from the design dmwing~)1 f'11e slope off.<Jel can be calculatccl. Lf1ho difforen1;e in elevation between the invc1i elevations a1' the inlet and outlet tran~ition tructures is '2 .5 ti e1 greater than that calculated ba ed on the design slope for ihe siphon, lfo:n lhll survlly data~ ould confirm the leCloni(; all.uwancllis inclmfodin the slope offstil.
Based n lh notes included in 1he cort1n1 t documen1 and the slope · appearing on the hydrauli profile . a . lope of0.00077 was used fo r design of the lengths o:f'tl1e CR siphons. ·111e table below presents the cakulatiun, including several other siphons for comparison.
Table 2 Slope onslll Cakulalion
Transition Structure Invert ~:levation Drop per D.-op p r 'lope Upstream Downstream Survey Slope Offset
Siphon Name (fl.-msl ' 88) (ft-msl ' 88) (feet) (feet) (feet) Cottonwood Spri ng Siphon l, 759_2 l 1,758.60 0.61 0.46 0.)5 Encl Wash Siplion 1,740 .23 1,740.12 0,11 0.45 ·0.34
Iron Ledge Siphon l , 729 .36 1,728.93 0.43 0.23 0.20
East Thcmrnl Siphon 1,728.27 1. ,727.90 0.37 0.14 0.23
West Fan Hill Siphon l,657.67 1,657.03 0.64 0.42 0.Z2
Thousand Palms Siphon 1,645.53 1,643.93 1..60 1.46 0 14 Whitehouse anyon 1,593.82 1,593.27 lL55 0.40 0.15
Siphon
Big Morongo Siphon 1 591.85 1,584.31 7.54 4.94 2.60
E,ast San Andreas Siphon 1,574. 16 L,573.69 0.47 0.27 0.20 San Andreas Siphon 1,573.22 1,566.84 6.38 2.62 3.76
War"'
1J10..:1~ ~'9• ofQ Ct.077 &...sod. "l'P..,. o)f! _.oph<n: q, """' hydroui,~p><(II••. b .. was th .... oa tt>• ,.,;.,,..,,1 pl"" ,l\d [")fJo, f<r ,!l.(<[tl,es,phm, h<t<:d "'thcrt!M• farch 2016 5 CRA Tectoni Uplift Allowance
The Metropolitan Water District of Southern California Seismic Resilience First Biennial Report Report No. 1551 – February 2018 Appendix Page 3‐9
As shown in Table 2, most of the siphons exhibit a deviation in surveyed slope from the design slope of between 0.1 and 0. 2 feet. Big .Morongo Siphon and San Andreas Siphon slope offsets of more than 2.5 feet each, showing that the slope across each of these siphons is greater than that required to meet the design slope for the siphon of 0.00077. It should be noted that the slope offset for San Andreas Siphon is calculated as 3. 76 feet, 1.26 feet greater than the 2.5 feet suggested by the allowance. This may suggest the suggested mechanism for accomplishing the allowance is incorrect, or there may be other factors at play here.
While survey data has not explicitly measured the invert elevations at any point following the construction of these siphons, this calculation is based on the assumption that the siphon transition structures were constructed consistent with the construction plans. If the internal height of the transition structures is in doubt, survey of the invert elevations of the transition structures could be of value.
Field Observations
Given the lack oflevel sensors along the CRA, Water Supply Operations (WSO) staff have conducted several field investigations of depths along the CRA during periods of constant flow. These field investigations generally consist of one or two staff recording single measurements of depth at several manholes and transition structures between Hinds Pumping Plant and San Jacinto Tunnel.
Under the design flow of 1,605 cfs, the normal depth is designed as 12.96 feet in the most frequently used cut and cover conduit cross-sections, and 13.17 feet in the most frequently used tunnel sections. Figure 1 presents results from the field investigation conducted on 20 March 2013, with flow conditions near design flows.
Conduit Soffit = 16'
16 15
14 13
12 '- .A t1.
'r . . .. ·--
.£: 11
ii.
Q> 10 0
.. 9
-
~
Hinds
pp
CD
ia 8
s: 7
6 5 ~ 4
3 ~
2 1
0 our esv ot SO
Lo
r.~nvon San Andreas
Coachella Siphon Siphon Outlet
Tunnel ~ l L ____. l -J---..... ... , __ f
. ' '\ V
,
Big Morongo~
Siphon
Inlet
..,<J<
Mile Marker
Figure 1
~
Bia Moronao
Siohon
Outlet
"'-. C::~n
Aodrea s
<::jpbo n
1-Alet.
Observed Water Depths
20 Mar 2013
1,609 cfs
Observed Water Depths at Design Flow
CRA Tectonic Uplift Allowance 6 March2016
The Metropolitan Water District of Southern California Seismic Resilience First Biennial Report Report No. 1551 – February 2018 Appendix Page 3‐10
The depth at the San Andreas Siphon and Big Morongo Siphon transition structures consistently stand out with observed water depth lower than the other siphons, dropping to less than 7 feet and less than 9 feet, respectively. These depths are fairly consistent with the depths of 7. 8 feet and 8.9 feet observed in the design hydraulic profile discussed at the end of Section 0.
Mechanism
Some possible ideas that could have been incorporated include sizing the diameter of these siphons larger (reducing the headloss across the siphon) or including some type of weir structure.
It is surmised that the mechanism used for incorporating the additional head was to build the inlet transition structure 2.5 feet above the elevation at which the structure would have been constructed without the slope offset. Given that the pressurized pipeline within the siphon can change slope without impacting the hydraulics beyond minor losses, the slope of one of the stretches of pipeline could be raised to achieve a 2.5-foot elevation increase. The contract document suggests this -"The slope given in the hydraulic properties [0.00077] does not include the additional grade allowed to provide for adjustmertt if future earth movement should take place. " (Contract 149)
An exaggerated demonstration of this mechanism is shown in Figure 1. The existing profile of the aqueduct, including the 2.5 foot allowance, is shown in black. A red line, lower at the upstream end of the siphon has been added to shown the 2.5-foot lower starting invert without the allowance. The blue line shows what the initial slope in the siphon would have been in the first pipeline segment without the allowance.
Further, exploring the different versions of the drawings prepared prior to construction suggests the addition of the grade as a slope change. Eight different record drawings are present in EDMS between August and December 1934 (the notice for bids was released 5 December 1934.) These partially correspond to four different Figure 1
Surmised Design Mechanism
construction methodologies and material choices prepared prior to the bid notice (jointed cast-in-place concrete, pre-cast concrete, above ground steel pipe, and buried steel pipe). Ultimately, jointed cast-inplace concrete was selected at the time of the bid notice. The upstream invert elevations of the transition structure in some of the drawings prepared in November l 93411ave been raised by 2.5 feet from the August 1934 drawings, with differing slopes (however, each of the differing construction methodologies uses different slopes), with the height of the transition structures maintained between the different drawings. It should also be noted that the 2.5 foot allowance is observed on drawings dating back to 1933, so the allowance was likely planned for prior to 1934.
Assuming the head constraints on the design of the CRA would have been established first at the downstream end (either at the tumlels or of the elevation of Lake Mathews), this would suggest that if the allowance had not been included at each siphon, the CRA upstream of all three upstream siphons could have been designed ? .5 feet lower in elevation, with the lift at Hinds Pumping Plant reduced by 7 .5 feet.
Conclusions
In review of record drawings and contract documents associated with the CRA, a tectonic allowance of
2.5 feet of HGL has been included in the design of Big Morongo Siphon, San Andreas Siphon, and the Casa Loma Siphon. Based on the above investigation into this allowance, it is believed that the mechanism for accomplishing the allowance is a slope offset in the invert elevation slope, accomplished by an increased slope in the pressurized pipeline segments within these siphons.
March 2016 7 CRA Tectonic Uplift Allowance
The Metropolitan Water District of Southern California Seismic Resilience First Biennial Report Report No. 1551 – February 2018 Appendix Page 3‐11
Ba ·ed on available records, inwrt elevations have rn:ver been surveyed at Big Morongo Siphon, San Andr a!; Siphon, nnd 1he first bnmel of the Ca a Loma Siphon. Having inve11 li::vation s111vey data will not pro e tltc mechanism an fuJ1her ·than cun·enf\y shown on 1-ccord drawiJ1gs. However, i:fthe internal height of the transi lion st.rm:1ure is io doubt, survey of the invert ele at ions of the transition structures ould be of val ue,
In addition, internal ,n.spection of the cast-in-place concrete pipeline and associatedjofnts, as well as internal survey to lk,tennine any localized movement, may be desired for non-hydrnulic rea ·ons.
DiJforcnlial smvcy be1ween lhc inl et· and outl et transition structures would Likcl. be ofli1tle value be 'ond l11at already provided in 2014. Two additional levels of survey could be conduc ted- a survey of j ust the in ert elevations oflhc transition tructure , requi1ing minimal de-watering, and a su1vey and i.ru pc tion of the entirety ofthe si phons, requiring full dewate1ing.
Estimates ofefforl for survey oflhe in ert elevations in just the lransition structure· would be 24 stalf how. plus minimal dcwatcri ng, and cff011 for the full siphon survey of tho cnt:irc Ionglh of the two siphons would be 200 slalfhours, plus slalf for foU de1 alering.
Reference and List of Record Drawing
ll1e following table list~ record drawings and documents used in preparation oflhis analysis.
Table3 Record Drawing · and Documents onsulted
Record or ID
1umber
Net'!!::
B-36]-26
8 -363-23
B-363-12
B-1197S
B-11979
B-20749
B-20748
llR-149
FB 740
100129042
2037 01 037
2039 02 008
B-1660
B-1663
Record Drawing Type
Plan and Profile
Plan and Profile
Plan and Profil e
Plau and Pl'otile
Plan arid Profile
Hydraulic Profile
Hydraulic Profile
Conlracl
Su1vey Field Book
Survey otcs
SUJ cy Note$
Su1vey otes
Transitions & Sections
Tran itions & Sections
\\) l::i'.3'1C9tht::it'1.--mdbffl WUJ1Y.:'l,l'rudalh1~J IILC:1 J..aJ..i.~:phr.111 U.~oc:tlt-v"!ti CRA Tectonic Uplifl Allowance 8
Siphon
Big Morongo
San Andreas
asa Loma Siphon
Big Morongo
SanAndrear;;
Multipl e in cluding Big
Moror1go and San Andrea
Multiple
13ig Morongo and San Andreas
Big Morongo and San Andrea
Big Morongo and San Andreas
Casa Loma Siphon 1umbcr l
San Jacinto l)iversion Structure
San ndreas
BigMorongo
Revision Date
22 Nov 1934
30 Nov 193 5
15 June 1934
30 Oct 1997
1 Nov 1956
1 Aug 1965
I ug 1965
S Feb 1937
12 Jul 1938
19 May 2014
24 August 1998
5 May 2008
21 _ ov 1934
22 ov 1934
March 2016
The Metropolitan Water District of Southern California Seismic Resilience First Biennial Report Report No. 1551 – February 2018 Appendix Page 3‐12
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The Metropolitan Water District of Southern California Seismic Resilience First Biennial Report Report No. 1551 – February 2018 Appendix Page 4‐1
Appendix 4
Summary of Damage to Metropolitan
Infrastructure from Past Earthquakes
The Metropolitan Water District of Southern California Seismic Resilience First Biennial Report Report No. 1551 – February 2018 Appendix Page 4‐2
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The Metropolitan Water District of Southern California Seismic Resilience First Biennial Report Report No. 1551 – February 2018 Appendix Page 4‐3
Metropolitan experienced a significant amount of damage to its infrastructure during both the 1971 San Fernando and 1994 Northridge earthquakes. Both of these seismic events primarily impacted the Jensen Water Treatment Plant. Engineering prepared summary reports for both events. The information below represents a convenient summary of what may be found in “Report of Structural Damage to Joseph Jensen Filtration Plant, Earthquake of February 9, 1971” (Report No. 891C), “Historical Documentation of the Jensen Plant Earthquake Disaster of February 9, 1971” (Report No. 909), and “Damage and Repair Report for Joseph Jensen Filtration Plant, Northridge Earthquake of January 17, 1994 (October 1994). 1971 SAN FERNANDO EARTHQUAKE
The San Fernando earthquake struck the greater Los Angeles region in the early morning of February 9, 1971. The thrust earthquake, which had a moment magnitude between 6.5 and 6.7, caused severe damage in the northern San Fernando Valley, with extensive surface faulting to the south of the epicenter.
The epicenter was approximately 6.8 miles from the Jensen Plant.
Metropolitan experienced widespread damage at the Jensen Plant. This included a severe break to a 72” Influent Conduit and damage to various structures including the Administration Building, Finished Water Reservoir, Access Tunnel, Mixing and Settling Basins, and Filters.
Following is a summary of the damage to these facilities.
INFLUENT CONDUIT
Transverse cracks up to ½‐in on concrete encasement
Three joints in the ¼‐inch thick steel cylinder separated Joint failed and opened up to ¾‐inch at the soffit
Fracture continued thru the top half of the joint
Much spalling of the mortar lining about 8‐inches on each side of the joint About 113‐feet south of the 72‐inch outlet, 75% of the joint failed Joint opened up about ¾‐inch near the invert and the lining was damaged for about thirty inches each side of the joint
Entire joint was pulled apart
Mortar lining was damaged for about 24‐inches on each side of the joint Considerable spalling and cracking of the lining was evident around the 72‐inch outlet Lining suffered spalling and cracking approximately 15‐feet downstream of the tunnel portal Several additional cracks, up to 1/16‐inch wide, were observed in the lining Two 84‐inch and 72‐inch welded steel pipelines suffered only minor damage and consisted of cracking of the lining
Minor cracking at the junction of the 72‐inch pipelines and the 12‐foot, 6‐inch square reinforced concrete box conduit
The Metropolitan Water District of Southern California Seismic Resilience First Biennial Report Report No. 1551 – February 2018 Appendix Page 4‐4
The 12‐foot wide by 12‐foot high reinforced concrete box extending northerly from the main control building had three transverse cracks in the walls and slabs located between Station 5+60 and 6+00;
Cracks varied in width from 1/32‐inch to 1/16 inch;
5 Transverse expansion joints in this portion of the influent conduit had separations varying from ½ ‐inch to 2‐inches horizontally, and from ¼‐inch to 1‐inch vertically.
EFFLUENT CONDUIT
Severe damage toward the southerly end;
Differential displacement;
Complete fracture or shearing.
MAIN CONTROL BUILDING
Considerable horizontal and vertical displacement throughout; led to multiple non‐structural damaged areas throughout building
Building moved approximately 5‐inches to the south and approximately 6‐3/4‐inches to the east There was settlement of 2‐inches on the south side of the building causing a slight southeasterly tilt.
BALBOA INLET TUNNEL
Concrete tunnel lining badly spalled and cracked at a distance approximately 100 feet near the Olive View Fault crossing;
CONNECTING CONDUITS
Significant damage occurred at expansion joints, intersection of east‐west and north‐south galleries, and by punching of an embedded pipe into a wall Several portions of the structure between expansion joints moved as separated structures, on the three axes of movement, and also moved with twisting (torsional) action on each of the three planes
In some cases, the joint filler and sealant was compressed and squeezed out of the joint Individual working of the structurally separated portions of the structure caused them to pound against each other, thereby resulting in spalling of concrete adjacent to the edges of the expansion joints
Considerable cracking and some spalling occurred at the intersection of the east‐west and north‐ south 25‐foot wide influent conduit and pipe gallery, all were repairable Cracks in slabs and walls occurred at the intersection of pipe galleries Nos. 1 and 2 in the north‐ south influent conduit and pipe gallery, but all were repairable The Metropolitan Water District of Southern California Seismic Resilience First Biennial Report Report No. 1551 – February 2018 Appendix Page 4‐5
The southern end of the east‐west pipe that was cast into the west wall of the north‐south influent conduit pipe gallery pounded and caused the wall to shatter Large amount of movement took place in the overhead piping at the intersection of the east‐west and north‐south influent conduit pipe galleries
Movement was in several directions, with pipe having been displaced.
MIXING AND SETTLING BASINS
Significant damage occurred at expansion joints, and the intersection of the east‐west and north‐ south galleries
Several portions of the structure between expansion joints moved as separate structures on the three axes of movement
Some cases, the joint filler and sealant was compressed and squeezed out of the joint; The individual working of the structurally separated portions of the structure caused them to pound against each other, thereby resulting in spalling of concrete adjacent to the edges of the expansion joint
Cracking and some spalling occurred at the intersection of the east‐west and north‐south influent conduit and pipe gallery
Cracks in slabs and walls occurred at the intersection of pipe galleries Nos. 1 and 2 in the north‐ south influent conduit and pipe gallery
FILTERS
Some vertical and lateral displacement occurred between adjacent beds at some expansion joint locations
Compressive loads forced expansion joint material out of some joints Minor spalling occurred adjacent to some expansion joints An apparent lateral thrust from the west caused the wash troughs to pull partly out of the insets Wash troughs acting as struts transferred the thrust to the gullet wall, which had not been completely poured, causing the wall to split at the east line of reinforcing bars Cracking and spalling in other filter beds occurred at the wash troughs but were minor in nature Minor spalling occurred where 16‐inch spray header line passes through the wall filter beds The west end of the conduit was damaged
Connection between the used washwater conduit and the 48‐inch diameter conduit pulled apart Top walkway grid slab cracked diagonally across the northeast corner of filter bed Filter control building No. 2 separated from the walkway at the top of the filter beds expansion joint
Separation varied from ½‐inch to 1 ¼‐inch at the expansion joint between Filter Control Building No. 2 and the valve and meter structure
The Metropolitan Water District of Southern California Seismic Resilience First Biennial Report Report No. 1551 – February 2018 Appendix Page 4‐6
Valve and meter structure settled 1” lower than Filter Control Building No. 2 Lining on north side of the return washwater line had a spalled area.
CHEMICAL BUILDING
Severe lateral and vertical motion
Column anchor bolts either stretched or pulled out of the footing concrete at all six columns Column in south wall buckled
Column at northeast corner bowed out of line
Diagonal bracing system in exterior walls failed
Diagonals failed in tension or damaged in compression Upper concrete floors and roof were pierced by the diagonal bracing and columns Considerable cracking or spalling of slab concrete
Building frame racked out of plumb, being tilted toward the east Metal door and window frames in north wall were racked out of square Several siding panels on the north wall broke loose from the framing Siding fasteners snapped off or pulled out
All anchor bolts for the four chemical tanks failed by being sheared, bent or pulled out Tanks were not damaged by second floor slab; although marks on tank indicate that 6 to 8 inches of vertical movement took place
Columns supporting exterior stairway were bent.
BRIDGE AND BOX CULVERT FOR RAILROAD SPUR TRACK
Vertical crack at the juncture between the north abutment and the wing wall on the west side Wall and abutment became offset.
WASHWATER TANK
Vertical movement of the tank
Movement caused anchor bolts to either pull out or fail in tension Tank slammed down upon the ring wall, resulting in buckling in the upper courses of the tank skin Damage to stairway.
FINISHED WATER RESERVOIR
North Wall:
- Did not rupture but had 3 continuous horizontal cracks - Cracks varied in width from hairline to 1/32 inch and were spaced - There were many random vertical and diagonal hairline or large cracks.
The Metropolitan Water District of Southern California Seismic Resilience First Biennial Report Report No. 1551 – February 2018 Appendix Page 4‐7
South Wall:
- Easterly half of the south wall had several vertical and diagonal random cracks - Wall between column lines ‘B’ and ‘C’ was severely shattered - Some earth backfill entered the reservoir thru the wall and roof rupture - Random vertical and diagonal wall cracks occurred in the westerly half of the south wall - Fracturing and spalling occurred at other locations along the south wall on both the interior and exterior surfaces
- Lateral offset at crack, particularly where it crossed the wall corbels. East Wall:
- Portion of east wall, north of outlet received extensive damage - Bowed inward between the floor and roof slabs
- Series of continuous horizontal cracks
- Extensive lengths of spalls and cracks with some fractures occurred at the base of the wall - Large vertical crack occurred in the east wall
- Overflow weir wall was also damaged and laterally offset at a vertical construction joint in the same area
- East wall, south of the outlet structure, showed some offset and spalling at the floor line - Random and vertical cracks occurred at about mid‐height - East wall of the finished water reservoir was severely fractured and spalled. West Wall:
- Fractured and shattered above the floor slab line;
- Horizontal displacement of the bottom of this wall occurred at the fracture; - Wall shattered for its full height between column 24 and 25. Roof
- Failure plane occurred in the roof slab between column lines B and C - Extensive damage to the roof slab occurred adjacent to the drop panel connections; - Fracture at the drop panel line was apparent only in the north half of the reservoir - Continuous east‐west failure occurred in line with the south edge of the roof slab drop panels - Roof slab south of this line had a vertical offset approximately 12 inches lower than the roof slab on the north side
- From column line “0”, east to column line “V”, spalling was evident only at the west faces of the drop panels
- Roof slab fractured between column lines “B” and “C”
- Continuous east‐west lines of failure occurred between column lines 3 and 4, 7 and 8, and 24 and 25. These breaks or spalls exposed the reinforcement for the full length of the reservoir roof slab.
The Metropolitan Water District of Southern California Seismic Resilience First Biennial Report Report No. 1551 – February 2018 Appendix Page 4‐8
- The width of spalling at the construction joint between column lines 24 and 25 varied between 4 feet and 6 feet. During the quake, this joint opened up, allowing for considerable quantities of gravel backfill to fall through from above. - The roof slab was also severely spalled, shattered and offset vertically at the west edge of the drop panel line adjacent to the east wall
- Spalling also occurred at the west face of the drop panels at line “B” from column line 22, to a point midway between column lines 24 and 25.
RESERVOIR FLOOR
While floor slab damage was general throughout the structure it was most apparent in the southeast quadrant
Spalled strip running east‐west between column 2 and 3, from a point midway between lines B and C to the east wall
Spalled strip at the center of the structure, between lines 13 and 14. These spalled strips averaged about 2 feet wide and many of them had vertical offsets upward from the general floor level. There were additional spalled construction joints in the north‐south direction; however, none of these were as long as the two east‐west spalls previously described Spalling occurred at the drainage gutters for almost the entire length in both the north‐south and east‐west directions
Continuous spalls occurred throughout and between various lines Floor cracking occurred midway between lines 14 and 15 in the east‐west direction; the south exterior wall drop panels at M‐1, N‐1 and U‐1 spalled in the east‐west direction; Floor slab cracks located were located as follows:
- North‐south between lines Y and Z; from midway between lines 5 and 6 to a point midway between lines 17 and 18
- North‐south between lines between Z and AA, from a point midway between lines 2 and 3 to a point midway between lines 19 and 20; diagonally across the southeast corner of drop panel W‐18
- North‐south between lines P and Q; from a point midway between lines 13 and 14; to column line 15
- East‐west between lines 14 and 15, from a point midway between lines D and E, to a point midway between lines E and F.
The Metropolitan Water District of Southern California Seismic Resilience First Biennial Report Report No. 1551 – February 2018 Appendix Page 4‐9
BAFFLE WALLS AND COLUMNS
Damage to the baffle walls consisted of two principal types; cracking or fracturing of the vertical beams and dislodgement and fracturing of the corrugated asbestos cement panels, only one vertical concrete beam collapsed
The other beams remained standing but were tilted out of plumb Many of the other vertical beams were fractured or cracked near the base or in the region slightly above the base
There were a number of spalls in the cast‐in‐place concrete projections forming the panel slots on the sides of the circular roof columns
A large number of the corrugated asbestos cement panels were damaged or completely destroyed. Some of them fell to the floor and were shattered, while others that remained in place were damaged less severely.
Approximately 73 baffle walls vertical beams sustained cracks, fractures, spilling, etc. Damage to the reservoir roof columns varied widely, from hairline cracks to complete fractures The damage to any individual column appeared generally to be the same at the top as at the bottom
The majority of columns were spalled, or otherwise damaged on the east and west sides There were two notable exceptions: The first row of columns south of the north wall and the first row of columns north of the south. In these two rows, major damage occurred on the north and south sides
In all cases, damage to the circular columns appeared to be primarily due to flexure and not to vertical load
A number of the columns, notably those in the first row east of the west wall, were visibly out of plumb
The tops of these columns were displaced east. Damage to drop panels and column capitals were generally limited to minor spalls and some cracks, except for several bottom capitals located in the northeasterly quadrant of the reservoir that were fractured or shattered.
RESERVOIR OUTLET STRUCTURE
Severe and extensive damage;
Fractures throughout the entire structure.
RESERVOIR INLET STRUCTURE
Moderate damage;
Spalled concrete exposing reinforcement.
The Metropolitan Water District of Southern California Seismic Resilience First Biennial Report Report No. 1551 – February 2018 Appendix Page 4‐10
1994 NORTHRIDGE EARTHQUAKE
In 1994, the Northridge earthquake occurred on January 17, at 4:30 a.m. It had a duration of approximately 10–20 seconds. The blind thrust earthquake had a moment magnitude (Mw) of 6.7. The death toll was 57, with more than 8,700 injured. In addition, property damage was estimated to be between $13 and $50 billion, making it one of the costliest natural disasters in U.S. history. LADWP reported a total of 1,405 pipe repairs and that water pressure had dropped to zero in some areas. The epicenter was approximately 7.3 miles from the Jensen Plant.
Metropolitan had damage at the Jensen Plant and adjacent facilities. Following is a summary of the damage to these facilities:
MAJOR DAMAGE
Jensen Plant Balboa Influent Conduit
- 84‐in influent pipeline severed approximately 3‐in horizontally and 1‐in vertically near venturi structure
East Valley Feeder
- Pipeline breaks occurred between Odessa and Rinaldi Streets (976+86.70) and Woodley Avenue and Rinaldi Street (957+66.50)
- Sectionalizing valve damage caused damage to all electrical equipment - Street asphalt damage as result of pipe breaks/leaks
West Valley Feeder No. 1
- Crack at cut‐off wall at Station 1219+10
- Sectionalizing valve structure damaged, causing damage to all electrical equipment Main Electrical Center
Service Connection CLWA‐1T
- Service connection structure settled and drifted laterally - Misalignment of valve assemblies
Service Connection LA‐25
- Extensive damage at ten pipe joints in the 97‐in diameter pipeline and 60‐in diameter overflow pipeline; pipe joints spread 1/8” to 3/4”
- Reinforced box conduit suffered a break and 2” separation; a 6‐1/2” separation occurred at the joint where the double box conduit meets the discharge structure - Turnout structure moved 6 to 8 inches east
- Double box conduit moved 3 inches to the east
The Metropolitan Water District of Southern California Seismic Resilience First Biennial Report Report No. 1551 – February 2018 Appendix Page 4‐11
Service Connection LA‐35T
- Damage to valve structure and pipe bridge due to differential displacement Newhall Tunnel
- Buckling of steel liner
- Concrete construction joints opened and closed resulting in sand and water infiltration - Bulge on steel liner split at circumferential joint resulting in oil and water infiltration
The Metropolitan Water District of Southern California Seismic Resilience First Biennial Report Report No. 1551 – February 2018 Appendix Page 4‐12
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The Metropolitan Water District of Southern California Seismic Resilience First Biennial Report Report No. 1551 – February 2018 Appendix Page 5‐1
Appendix 5
Metropolitan Water Storage Capacity
The Metropolitan Water District of Southern California Seismic Resilience First Biennial Report Report No. 1551 – February 2018 Appendix Page 5‐2
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The Metropolitan Water District of Southern California Seismic Resilience First Biennial Report Report No. 1551 – February 2018 Appendix Page 5‐3
Over the past two decades, Metropolitan has developed a large regional storage portfolio that includes both dry year and emergency storage capacity. Storage generally takes two forms: surface reservoirs and groundwater basin storage. Heading into the most recent drought cycle, Metropolitan had developed over
5.5 million acre‐feet of storage capacity and had successfully stored over 2.7 million acre‐feet. This is a more than 13 times the storage capacity compared to the 1980s, with record quantities of water in reserve. This increase in storage capacity is shown in Figure 5‐1.
Figure 5‐1. Summary of Metropolitan’s Storage Capacity Over Time Some examples of storage resources that have been developed since 1990 include:
Surface Water Reservoirs:
- Diamond Valley Lake (810,000 acre‐feet)
- SWP Article 56 Carryover Storage (up to 200,000 acre‐feet) - Flexible Storage in Castaic Lake and Lake Perris (219,000 acre‐feet) - Intentionally Created Surplus in Lake Mead (1.5 million acre‐feet) Groundwater Storage:
- Member Agency Conjunctive Use Programs (210,000 acre‐feet) - Semitropic Storage Program (350,000 acre‐feet)
- Arvin‐Edison Storage Program (350,000 acre‐feet)
- San Bernardino Municipal Water District Storage Program (50,000 acre‐feet) - Kern Delta Water District Storage Program (250,000 acre‐feet) - Mojave Storage Program (390,000 acre‐feet)
The Metropolitan Water District of Southern California Seismic Resilience First Biennial Report Report No. 1551 – February 2018 Appendix Page 5‐4
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The Metropolitan Water District of Southern California Seismic Resilience First Biennial Report Report No. 1551 – February 2018 Appendix Page 6‐1
Appendix 6
Seismic Design Frequently Asked
Questions
The Metropolitan Water District of Southern California Seismic Resilience First Biennial Report Report No. 1551 – February 2018 Appendix Page 6‐2
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The Metropolitan Water District of Southern California Seismic Resilience First Biennial Report Report No. 1551 – February 2018 Appendix Page 6‐3
What are the effects of earthquakes?
! Ground shaking
! Ground rupture
! Liquefaction
! Landslides and avalanches
• Tsunamis
The Metropolitan Water District of Southern California Seismic Resilience First Biennial Report Report No. 1551 – February 2018 Appendix Page 6‐4
What causes earthquakes?
"' Slips or rupture of faults
! Movements of tectonic plates
! Volcanic or magmatic activity
! Sudden changes in earth's crust
What is a fault?
• Faults are fractures or discontinuities in large
masses of rock, where the rocks on either side
have undergone relative displacement
• Faults are planar surfaces, not lines
! Faults can be vertical, horizontal, or at some
angle in between
! Faults can be divided into three basic types
• Strike-slip
• Thrust
• Normal
! Strike-slip and thrust most common in So. Cal.
The Metropolitan Water District of Southern California Seismic Resilience First Biennial Report Report No. 1551 – February 2018 Appendix Page 6‐5
The Metropolitan Water District of Southern California Seismic Resilience First Biennial Report Report No. 1551 – February 2018 Appendix Page 6‐6
Oia,mond Valley Lale• ....
San Andreas Fault
/",.,- 1&.;otF_..
Q MWJ Tre.tmont P1ants
S uw:, PUf"l'tllrla P\anQ
* IMOS-
.....................
----- = .. .. Aqurduct
' ',
! Fault with the highest probability of
generating a major earthquake in So. Cal.
! Potential impact on MWD operation
' CRA
• Hinds and Eagle Mountain Pumping Plants
• Rialto and Inland Feeders
• East Branch of State Water Project
• DWR's Santa Ana Pipeline
The Metropolitan Water District of Southern California Seismic Resilience First Biennial Report Report No. 1551 – February 2018 Appendix Page 6‐7
Liquefaction
! What is liquefaction?
• A process by which water-saturated soils
temporarily lose strength and act like liquid
• Factors needed for liquefaction
• Loose or low density sandy soils
• Shallow ground water
• Strong ground shaking
0 ·+
The Metropolitan Water District of Southern California Seismic Resilience First Biennial Report Report No. 1551 – February 2018 Appendix Page 6‐8
How to measure earthquakes?
• Earthquake Magnitude
• Describes size of earthquake
• Unique value for each earthquake
• Quantitative value based upon amount of released
energy
! Earthquake Intensity
• Describes effect of earthquake
• Multiple number of values for every earthquake
• Qualitative description or quantitative
measurement of ground or structural response to
earthquake
Definitions
! Maximum Credible Earthquake
• Largest earthquake that is physically capable of occurring on a fault
• Peak Ground Acceleration (PGA}
• Maximum acceleration measured at ground surface during the course of earthquake motion
• %g
! Acceleration expressed as a percentage of the force of gravity ! Maximum Considered Earthquake Ground
Motion
• Smaller of the probabilistic ground motion (2% probability of exceedance in 50 years), and the deterministic ground
motion (Maximum Credible Earthquake occurring on the
controlling fault)
The Metropolitan Water District of Southern California Seismic Resilience First Biennial Report Report No. 1551 – February 2018 Appendix Page 6‐9
Earthquake Magnitude
! One unique value for each earthquake
depending upon amount of energy released
! Earlier version - Richter or Local Magnitude
• Current version - Moment Magnitude
• Logarithmic-based measurement scale
'" A magnitude 6 earthquake releases 32 times
more energy than a magnitude 5 and 1,024
times more energy than a magnitude 4
earthquake (based on Moment Magnitude)
• Reported to the nearest 0.1, e.g., M7.1
What affects earthquake magnitude?
! Fault rupture length - Longer rupture length
releases more energy
! Length of fault - Longer faults have the
potential to release more energy than shorter
faults
• San Andreas is longest fault in So. Cal. and has
the largest potential to generate a Magnitude
8+ earthquake.
The Metropolitan Water District of Southern California Seismic Resilience First Biennial Report Report No. 1551 – February 2018 Appendix Page 6‐10
Earthquake Intensity
! Multiple values for each earthquake depending
on location relative to earthquake epicenter
! Described qualitatively using a system such as
the Modified Mercalli Scale (roman numerals
between I: not felt and XII: total damage) based
upon visual perception of earthquake severity in
terms of effects on humans and structures
• Reported quantitatively using seismographs to
measure ground motion
What affects earthquake intensity?
• Magnitude of earthquake - increased
magnitudes tend to increase intensity
• Distance from earthquake - increased distance
from an earthquake tends to lessen intensity
! Fault type - thrust faults tend to increase
intensity of vertical ground motions
! Site soil conditions - rock sites tend to lessen
intensity compared to soil sites
! All factors interact to yield unique site-specific
intensity
The Metropolitan Water District of Southern California Seismic Resilience First Biennial Report Report No. 1551 – February 2018 Appendix Page 6‐11
3 Il l Felt indoors
4 IV-V Felt by most people; slight damage
5 VI-VII Felt by all; damage minor to moderate
6 VII-VIII Everyone runs outdoors; damage
moderate to major
7 IX-X Major damage
8+ X-XII
How are earthquake magnitude and
intensity used in design?
! Earthquake magnitudes are not specifically used
in design
• Designs are based upon resisting predicted
earthquake intensities (quantified by peak
ground accelerations stated to nearest 0.01 or
%g)
• Earthquake magnitudes and several other
factors are used to estimate earthquake
intensities for design
The Metropolitan Water District of Southern California Seismic Resilience First Biennial Report Report No. 1551 – February 2018 Appendix Page 6‐12
Deterministic Seismic Hazard Assessment
! Determines the largest Peak Ground Acceleration that
can occur on a site for a single magnitude earthquake at a single distance from the site, regardless of the
likelihood that an earthquake event with the selected
magnitude and distance will occur.
! Induced Peak Ground Accelerations at a site are
evaluated assuming that the specific Maximum Credible
Earthquake occurs on each of the nearby faults at the
closest approach to that site.
! The fault that generates the largest Peak Ground
Acceleration at a site is called the "controlling fault." ! The Peak Ground Acceleration generated by the
controlling fault is the controlling ground motion.
Probabilistic Seismic Hazard Assessment
! Considers all possible magnitude earthquakes (up to the Maximum Credible Earthquake) on all faults identified
within 100km at all possible distances from a site, and the likelihood of the occurrence of each combination.
! Each identified fault is evaluated separately with regard to activity rates, the relative number of earthquakes at different magnitudes, expected earthquake magnitude
range, and its location relative to the site.
! The individual fault contributions are combined to
develop total probabilities for any specified Peak Ground Acceleration at a site. As a result, Peak Ground
Accelerations for a site can be determined with a
specified probability of exceedance.
The Metropolitan Water District of Southern California Seismic Resilience First Biennial Report Report No. 1551 – February 2018 Appendix Page 6‐13
Current Building Code Seismic Design
Requirements
'! Maximum Considered Earthquake (MCE) Ground Motion
• Probabilistic: Ground motion with 2% probability of
exceedance in 50 years
• Deterministic: Ground motion generated by Maximum
Credible Earthquake occurring on the controlling fault(s) • Smaller ground motion determined by these two methods governs aesign
Deterministic approach usually governs in So. Cal.
'! A Regular Facility is designed for 2/3 of MCE Ground Motion to achieve Life Safety performance
'! An Essential Facility is design for a higher performance • Building codes establish the minimum seismic design
criteria, and building owners can choose to design for a higher performance
'! Building codes do not apply to facilities under Cal.
Division of Safety of Dams (DSOD) jurisdiction
Regular
Essential
Normal occupancy
High occupancy/Special
occupancy
•Manufacturing facilities
•Schools
•Hospitals
•Jails, detention facilities
•Public utility facilities
•Hazardous material storage facilities
• Fire and police stations
• Emergency shelters
• Aviation facilities
The Metropolitan Water District of Southern California Seismic Resilience First Biennial Report Report No. 1551 – February 2018 Appendix Page 6‐14
.. ' 0.4g 0.4g
1994 Northridge Earthquake - Resulted in codification of the near-source effect• USC 1997 1998 0.52g 0.4g 0.4g
Seismic hazard map updated to reflect the adoption of Maximum Considered Earthquake Ground Motion as the basis of structural design I I• I I I • • I ., !
+The listed PGA values are based on generic seismic hazard maps included in the codes. A site-specific analysis may result in different values. *Other factors such as frequency contents and shaking duration will result in adverse effect on structures that cannot be captured by PGA along. The effect is more pronounced when the site is close to earthquake epicenter, and accounted for by amplifying PGA .
• Limited structural damage . . . • Safe to occupy immediately after earthquake with minor repair • • •
Life Safety
. . .
• Significant structural damage; no imminent risk of
collapse
• Occupants would safely evacuate from the building
• Not safe to occupy w/o major repair. Repair may be
economically impractical.
• Extensive structural damage and on verge of partial or Green
Yellow
or Red
total collapse Red
• Building is likely damaged beyond repair both
technically and economically
*As defined in ASCE 41-06 Seismic Rehabilitation of Existing Buildings The Metropolitan Water District of Southern California Seismic Resilience First Biennial Report Report No. 1551 – February 2018 Appendix Page 6‐15
The Metropolitan Water District of Southern California Seismic Resilience First Biennial Report Report No. 1551 – February 2018 Appendix Page 6‐16
What's the expected seismic
performance of a structure meeting
current code requirements?
• Regular Facilities
• The objective is to allow safe evacuation of
occupants (Life Safety), instead of focusing on
prevention of structural damage
• Essential Facilities
• The objective is to allow continuous operation of
the building (Immediate Occupancy) with limited
structural damage
• The expected performances are for the design
earthquake (2/3 of MCE Ground Motion)
Does the building code require existing
structures to be upgraded to the current
code requirements?
! No, but there are a few exceptions
! Exceptions
• Type of structural system known to have significant
inherent deficiencies: unreinforced masonry or block
wall structures
Structures required for post-earthquake disaster
response: hospitals and emergency response centers
• Extensive addition/alternation
! Owners can reduce seismic risk with voluntary
upgrades
The Metropolitan Water District of Southern California Seismic Resilience First Biennial Report Report No. 1551 – February 2018 Appendix Page 6‐17
What's the acceptable seismic performance
level for an existing structure, as it may not
meet the current code requirements?
! Depending on post-earthquake functions of the
building, the owner may choose the desired
performance level
• Immediate Occupancy
• Life Safety
• Collapse Prevention
! Non-building structures (reservoirs, tanks ... ) are
designed based on consensus standards and
guidelines (e.g. ASCE, ASME, AWWA ... )
• Operational
• Prevention of uncontrolled release of contents
What seismic performance are specified in MWD's
seismic design criteria?
Importance
Designation
Bui lding Code
and Industry
Sta ndards
Design Intent
Per Code/
Standard
Language
Met ropolitan
Seismic Design
Objective
Building Type Structures
Essential Facilities
CBC
ASCE 7
New
Provide a larger margin
against collapse in MCE
and remain operational
in Design Earthquake
(2/3 MCE)
To remain operational
following a major
seismic event
Exi sting
CBC
ASCE 41
Enhanced performance
against life safety in
Design Earthquake
Intended to maintain
occupancy
immediately following
a major seismic event
Regular Facilities
CBC
ASCE 7
New
Collapse prevention in
MCE and prevent life
threatening damage in
Design Earthquake
May experience
significant damage, but
would prevent life
threatening injury or
casualty following a
major seismic event
Existing
CBC
ASCE 41
To achieve life safety in
Design Earthquake
May experience
significant damage, but
would prevent life
threatening injury or
casualty following a
major seismic event
The Metropolitan Water District of Southern California Seismic Resilience First Biennial Report Report No. 1551 – February 2018 Appendix Page 6‐18
What seismic performance are specified in MWD's seismic design criteria? (Cont.)
Importance
Designation
Building Code
and Industry
Standards
Design Intent
Per Code/
Standard
Language
Metropolitan
Seismic Design
Objective
••••. 1a11 ■ :
Essential Facilities (Related to Water
Delivery)
New Existing
CBC CBC
ASCE 7 ASCE 41
ACl350 ACl3S0
AWWAD100 AWWAD100
API 650 API 650
Provide a larger margin Not differentiated.
against failure in MCE
and require a higher
level of liquid tightness
to maintain
serviceability in Design
Earthquake (2/3 MCE)
To remain operational To remain
following a major operational or can
seismic event be restored quickly
following a major
seismic event
Regular Facilities (Not Related to Water
Delivery)
New Existing
CBC CBC
ASCE 7 ASCE 41
ACl3S0 ACl3S0
AWWAD100 AWWA Dl00
API 650 API 650
Prevent catastrophic Not differentiated.
failure in MCE and
prevent uncontrolled
release of liquid in
Design Earthquake
May experience May experience
significant leak and significant leak and
require dewatering to require dewatering to
repair, but would repair, but would
prevent uncontrolled prevent uncontrolled
release of liquid release of liquid
following a major seismic following a major seismic
event event
The Metropolitan Water District of Southern California Seismic Resilience First Biennial Report Report No. 1551 – February 2018 Appendix Page 7‐1
Appendix 7
Summary of Previous Metropolitan
Seismically Induced Damage Studies
The Metropolitan Water District of Southern California Seismic Resilience First Biennial Report Report No. 1551 – February 2018 Appendix Page 7‐2
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The Metropolitan Water District of Southern California Seismic Resilience First Biennial Report Report No. 1551 – February 2018 Appendix Page 7‐3
The impact of earthquakes on Southern California and on Metropolitan’s system has been the subject of several previous internal and external assessments:
Seismic Risk Assessment of Local Water Production Facilities in the Service Area of Metropolitan Water District of Southern California, January 14, 1991, Dames & Moore. This is a comprehensive report on the effects of a major earthquake on the Southern San Andreas Fault. The report has various models for estimating damage and concludes that there could be hundreds of local water pipelines damaged, loss of power, etc. Metropolitan feeders that are vulnerable to damage were identified, and the report estimates that Metropolitan service will be lost for 6 months or less. The report also predicts significant damage to ground water wells.
Probable Maximum Loss Analysis for Metropolitan Water District of Southern California. September 1998, EQE International. This report was prepared to assess the potential monetary loss associated with several earthquake scenarios. This report highlighted the potential for widespread damage resulting from an earthquake. The study did not address the impact on deliveries or system recovery.
Assessment of Frequency of Recovery Plan and Extreme Events within the Metropolitan Water District Service Area, December 2001, Geomatrix Consultants. This report was prepared to aid in the evaluation of hazards under the System Reliability Plan (see next report). This report evaluated the probability of earthquakes of two levels of severity within Metropolitan’s service area. The first was a moderate (strong) earthquake similar to the Northridge earthquake (M6.7) and the second was an extreme event, on the order of M7.5. The report provided information on the probability of these earthquakes both within each of Metropolitan’s operating regions and within the service area as a whole. The scope of the report did not include evaluating the impact on service or time for recovery.
Distribution System Reliability Assessment, (Report No. 1227), December 2006, Metropolitan Facility Planning staff. This report evaluated the reliability of the distribution system. In addition, a separate section of the report dealt with the vulnerability of Metropolitan’s facilities to various initiating events. The report addressed the probability of failures in the system due to various random causes including earthquakes. It utilized information from the Geomatrix study to estimate the probability of seismically induced failures. Estimates for the recovery time from the various events were provided.
Facility Reliability Assessments, 2006, Metropolitan Facility Planning staff. Reliability assessments were conducted by Metropolitan of the five treatment plants and the Colorado River Aqueduct. These assessments evaluated the susceptibility of individual facilities to a series of hazards such as fire, flooding, and earthquakes. Earthquakes were identified as one of the highest risk hazards because of the potential to cause numerous simultaneous failures. The reliability assessments identified structures that had not been updated to the latest seismic criteria. As part of the Seismic Upgrade Program, these structures have been evaluated. Where necessary, capital projects were initiated to upgrade the facilities to the most recent building codes. Completed Facility Reliability Assessments are listed below:
Diemer Water Treatment Plant Reliability Assessment, (Report No. 1225), 2006 Skinner Water Treatment Plant Reliability Assessment, (Report No. 1246), 2006 Weymouth Water Treatment Plant Reliability Assessment, (Report No. 1255), 2006 The Metropolitan Water District of Southern California Seismic Resilience First Biennial Report Report No. 1551 – February 2018 Appendix Page 7‐4
Mills Water Treatment Plant Reliability Assessment, Report No. 1269, 2006 Jensen Water Treatment Plant Reliability Assessment, Report No. 1280, 2006 Colorado River Aqueduct Reliability Assessment, Report No. 1297, 2006 System Reliability Study, 2007, Metropolitan Facility Planning staff. This study evaluated the reliability of the entire system. This study examined the impact of single failures within the system on the ability to deliver water to member agencies and identified existing backup options. The failures considered included individual facilities as a unit (e.g., a treatment plant or a reservoir). For pipelines, the study considered a failure in each isolatable segment of the line. The impact on deliveries to each service connection was identified and over 250 different events were studied. The study considered capabilities within Metropolitan’s system, as well as the member agencies’, to mitigate the failures. This study did not consider multiple failures that might be associated with an earthquake due to the almost unlimited number of combinations of failures that would have to be considered.
Golden Guardian 2008. In November 2008, under the auspices of the USGS, Caltech and Earthquake Research Associates, a major disaster drill was conducted in Southern California. The drill was based on a magnitude 7.8 earthquake on the San Andreas Fault (Golden Guardian Exercise). The preliminary studies conducted as part of the exercise indicated that major damage is expected. The impact on water systems was one of the areas of focus for the drill and the related studies. The studies concluded that in areas impacted heavily, water service could be lost for six months.
Potential Effects of Southern California Seismic Events on Metropolitan Water Deliveries (Report No. 1335), January 2009, Metropolitan Facility Planning staff. This report provided a perspective on the magnitude of damage that could result from moderate and extreme earthquakes, the corresponding potential impacts on Metropolitan water deliveries, and estimated time frames for restoring service. The report also offered recommendations for reducing the potential impacts of certain significant seismic events.
Mills Water Supply Reliability Study (Report No. 1337), Metropolitan Facility Planning staff. The Mills study was prepared in response to findings of the Integrated Area Study, which identified risks to the raw water supply to the Mills plant. The study evaluated alternatives to improve the reliability and redundancy of the raw water supply to Mills. A capital project has been initiated to implement one of the options.
Potential Impact of a Seismic Event on the CRA Tunnels (Report No. 1478), August 2014, Metropolitan Facility Planning staff. This is the first report of a comprehensive study of the seismic vulnerability of the CRA. Five companion reports (Metropolitan Report Numbers 1470, 1484, 1485, 1490 1558) are described below. This study evaluated the vulnerability of CRA tunnels to damage from a major seismic event, provided a perspective of the level, extent and type of seismic damage that could be imposed on CRA tunnels, and estimated the time frame to restore service. The results of the study showed that most of the CRA tunnels are expected to perform well following a large seismic event. Of all the CRA tunnels, only the area near the west portal of the San Jacinto tunnel would be subject to liquefaction, but this area would be easily accessible. The area above the west portal of the San Jacinto tunnel could also be subject to seismically induced landslides, but a project was completed in 1998 to mitigate the potential damage from The Metropolitan Water District of Southern California Seismic Resilience First Biennial Report Report No. 1551 – February 2018 Appendix Page 7‐5
a landslide at the portal. For the remainder of the tunnels, the potential to experience heavy damage from landslide or rockfalls is negligible. Despite traversing a highly seismic area, there are only three instances of the CRA tunnels crossing a known active fault: Whitewater Tunnel No. 2, Thousand Palms Tunnel No. 2, and Wide Canyon Tunnel No. 2. Of these three tunnels, Whitewater Tunnel No. 2 would likely experience the most significant displacement from a fault rupture.
For ground shaking, while a number of the tunnels could experience high levels of shaking based on estimated Peak Ground Acceleration (PGA), most of these tunnels are deep and constructed in hard rock, which is beneficial for their performance during an earthquake. However, approximately 4.2 miles of tunnel were identified as having a high potential of experiencing heavy damage from the Maximum Considered Earthquake (MCE). These are areas that have shallow cover (e.g. near portals) and experience high PGA values. It should be noted that the entire 4.2 miles would not be expected to be damaged from a single earthquake, but rather there would be isolated areas of damage with those identified tunnel sections. A CIP has been submitted to further investigate the vulnerability of these tunnel sections and to identify options to mitigate the risk.
The Whitewater Tunnel No. 2 was identified as having the greatest cumulative seismic risk. The tunnel is crossed by the Garnett Hills segment of the San Andreas Fault which, from the San Gorgonio Pass Seismic Event Vulnerability Study (Report No. 1484; 2014), could experience up to a 12 foot horizontal and 3 foot vertical offset from a rupture of the San Andreas Fault approximating the MCE. The tunnel could also experience very high levels of shaking from the MCE, and was constructed in compacted sands and gravels, which could negatively impact the performance against the shaking.
For the purpose of estimating repair times, a worst‐case damage scenario was developed for the Whitewater Tunnel No. 2, and a tunnel repair workshop was conducted to get a realistic understanding of repair methods and repair times (reference Report No. 1485).
Colorado River Aqueduct – San Gorgonio Pass Seismic Event Vulnerability Study (Report No. 1484), July 2014, GeoPentech. This study evaluated the potential for horizontal and vertical deformation following a large seismic event within the San Gorgonio Pass area. To assist in the study, a team of geoscientists experienced in assessing the potential for fault displacements along the southern San Andreas Fault System in the area of the San Gorgonio Pass was assembled under GeoPentech, Inc. The study incorporated the most recent information available regarding the seismicity of the area including: geology, geodesy, seismicity, paleoseismology, and tectonics.
The information gathered during the course of the study was used to develop a 3‐dimensional deformation model of the San Gorgonio Pass area using Coulomb 3.3 (San Gorgonio Pass Model). The model was developed to estimate the surface fault displacement and deformation that would occur along and near the CRA within the San Gorgonio Pass as a result of future seismic events. The results of the San Gorgonio Pass Model were compared to current geologic and geomorphic data, which showed a reasonable reflection of the natural conditions of the area, validating the results of the model.
The MCE for the southern San Andreas Fault would be a rupture originating near the Salton Sea around Bombay Beach and extending through the San Gorgonio Pass up to between Wrightwood and Three The Metropolitan Water District of Southern California Seismic Resilience First Biennial Report Report No. 1551 – February 2018 Appendix Page 7‐6
Points. Based on available geologic data, the most likely event on the San Andreas Fault to rupture in on the Garnett Hills Fault, which is a strand of the San Andreas Fault system located in the San Gorgonio Pass.
Results from the San Gorgonio Pass Model indicate that an earthquake approximating the MCE for the Southern San Andreas Fault System could result in a horizontal offset of approximately 12 feet and a vertical deformation of approximately 3 feet at the Garnett Hills Fault crossing of the CRA. The vertical deformation would extend over the CRA for approximately 60 miles.
The seismic event would result in uplift along the longitudinal profile of the CRA with three separate peaks, with the last peak occurring at or near the Whitewater Tunnel No. 2 and resulting in a cumulative upward deformation of approximately 3 feet. This upward deformation of the CRA would reduce the flow carrying capacity of the aqueduct. An accompanying probabilistic rupture hazard analysis of the San Gorgonio Pass (Report No. 1470) showed that the above deformation occurring at the CRA crossing has a return period of approximately 750 years.
The Colorado River Aqueduct San Gorgonio Pass Seismic Event Vulnerability Study – Hydraulic Analysis, (Report No. 1558), September 2014, Metropolitan Facility Planning and Hydraulics staff. This study documents a detailed hydraulics analysis that evaluated the impact of a seismically induced vertical uplift of the CRA alignment over a length of approximately 60 miles, based on the uplift profile from the San Gorgonio Pass Seismic Event Vulnerability Study (Report No. 1484). The analysis showed that despite the uplift, Metropolitan would be able to continue flowing approximately 1300 cubic feet per second, approximately 80 percent of design flow, through the aqueduct after initial rapid repairs are completed.
The analysis assumed free surface flow with a 3‐foot minimum freeboard, the same as the current aqueduct design. Minor pressurization of the system could allow for some additional flow if required. The analysis also assumed that repairs to the CRA following the earthquake maintained the design cross sections and friction of the non‐damaged CRA sections, and that no repairs were done to reestablish the grade.
Probabilistic Rupture Hazard Analysis of CRA at San Gorgonio Pass (Report No. 1470), October 2014, Metropolitan staff. This report is a supplemental report to Report No. 1484, “Colorado River Aqueduct – San Gorgonio Pass Seismic Event Vulnerability Study.” The report documents the results of a probabilistic rupture hazard analysis of the CRA where it crosses the Garnett Hills segment of the Southern San Andreas Fault in the San Gorgonio Pass. The analysis showed that the projected 3‐foot vertical and 12‐foot horizontal surface deformation at the CRA crossing in the San Gorgonio Pass has a return period of approximately 750 years.
Colorado River Aqueduct Seismic Vulnerability Investigations – Summary Report (Report No. 1490), December 2014, Metropolitan Facility Planning staff. This report briefly summarizes the results of the CRA seismic vulnerability studies (Reports 1478, 1484, 1485 and 1558).
Seismic Risk Assessment – Conveyance and Distribution System Tunnels (Report No. 1533), March 2016, GeoPentech and Metropolitan Facility Planning staff. This study evaluated the seismic risk of the 41 tunnels within Metropolitan’s Conveyance and Distribution System to heavy damage during a future maximum considered earthquake (MCE) event that would adversely impact water deliveries to member agencies while the tunnel is out of service for repairs. The study was completed through a two part The Metropolitan Water District of Southern California Seismic Resilience First Biennial Report Report No. 1551 – February 2018 Appendix Page 7‐7
process. Part 1 screened each of the 41 tunnels and identified tunnels that were vulnerable to one or more seismic hazard, and could result in a loss of service to the member agencies (i.e., no backup capability) if flow through the tunnel is disrupted. Tunnels that met both criteria in Part 1 were deemed a potential seismic risk to Metropolitan’s water delivery reliability and were pushed through to Part 2 of the process. Part 2 further evaluated each of the potential high‐risk tunnels identified in Part 1 and numerically ranked each tunnels degree of seismic risk in order to identify which tunnel(s) may pose the greatest risk to Metropolitan’s water delivery capability.
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Appendix 8
Administrative Code Section 4503
“Suspension of Deliveries” and
9/21/06 IAS Clarification
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§ 4503. Suspension of Deliveries.
(a) Whenever repairs or maintenance of the District's system, in the opinion of the Chief Executive Officer of the District, shall require suspension of delivery of water at any point or points, such delivery may be suspended without liability on the part of the District; provided, that except in cases of emergency, as determined by the Chief Executive Officer, notice of such suspension of service shall be given to the affected member public agency in advance of such suspension. Metropolitan will make a concerted effort to notify and work with member public agencies regarding all scheduled interruptions. The District will schedule non‐emergency interruptions for the low demand months of the year, typically October through April, in coordination with the member public agencies. (b) Each member agency shall have sufficient resources such as local reservoir storage, groundwater production capacity, system interconnections or alternate supply source to sustain a seven‐ day interruption in Metropolitan deliveries based on annual average demands. If a member public agency has been provided with a sixty (60) day notice of when an interruption in service is to occur, the member public agency shall be responsible for and reimburse direct costs, excluding labor costs, incurred by Metropolitan in the event that a scheduled non‐emergency interruption of up to seven days is postponed or cancelled at the request of the member public agency as a result of insufficient local resources, and the District agrees to such cancellation or postponement. Direct costs shall be determined by Metropolitan’s Chief Executive Officer, in consultation with the affected member agency. These direct costs shall be applied to the member public agency’s water invoice following cancellation or postponement of the shutdown.
(c) Except in cases of emergency, the District, working with the member agencies, will produce a shutdown schedule each September for the annual shutdown season from October through April. The District will also develop a three‐year shutdown schedule, which will give notice of the proposed shutdowns greater than seven days at least one‐year in advance. (d) Replenishment Service certifications will be adjusted for the reduction of credits that are accrued due to shutdowns that are greater than seven days. No adjustments will be made for shutdowns seven days or less unless the member agency provides a service to the District by serving another member agency in‐lieu of District deliveries during a shutdown even if the shutdown is seven days or less.
Section 322.4 based on Res. 7260 – May 12, 1970, amending Res. 3896 – August 18, 1950; amended by M.I. 33642 – March 10, 1981. Section 322.4 repealed and Section 4503 adopted by M.I. 36464 – January 13, 1987, effective April 1, 1987; amended by M.I. 42278 ‐ February 11, 1997; paragraph amended by M. I. 44812 ‐ March 12, 2002; paragraph amended by M. I. 45943 – October 12, 2004; paragraphs assigned (a), (b), (c), & (d) designations and amended by M. I. 45988 – November 9, 2004.
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2007 Integrated Area Study (IAS) Clarification
1. Original intent
a. Communicated that MWD’s system is interruptible
b. Protected MWD from liability claims for required shutdowns c. Illustrated commitment to minimizing impacts
i. Advanced notice & coordination
ii. Non‐emergency outages only during low flow months
d. Required member agencies to make provisions for outages i. 7‐day supply of average annual demands
ii. No enforcement – no penalty
2. Updated text & interpretation
a. Recognized changing conditions
i. Increased member agency dependence upon MWD
ii. Many agencies in non‐compliance
iii. Increased difficulty in storing treated water
b. Revised requirement for member agency outage provisions i. Capability to sustain 7‐day interruption (not limited to supply) ii. Penalty added for cancellation or postponement of outage
3. IAS clarification
a. MWD planned outages are required to maintain long‐term reliability b. Unplanned MWD outages may also occur
c. Intent of 4503 was to encourage agency provisions for planned and unplanned outages d. Compliance not enforced (beyond interference with planned outages) e. Member agencies responsible for decisions regarding provisions for unplanned outages f. Regional flexibility improvements achieved through demand‐driven LRP & IAS projects REPORT
SEISMIC RESILIENCE REPORT
2020 UPDATE
The Metropolitan Water District of Southern California
700 N. Alameda Street, Los Angeles, California 90012
Report No. 1551-1
February 2020
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Seismic Resilience Report
2020 Update
Prepared By:
The Metropolitan Water District of Southern California
700 North Alameda Street
Los Angeles, California 90012
Report Number 1551-1
February 2020
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Copyright © 2020 by The Metropolitan Water District of Southern California.
The information provided herein is for the convenience and use of employees of The Metropolitan Water District of Southern California (MWD) and its member agencies. All publication and reproduction rights are reserved. No part of this publication may be reproduced or used in any form or by any means without written permission from The Metropolitan Water District of Southern California. Any use of the information by any entity other than Metropolitan is at such entity's own risk, and Metropolitan assumes no liability for such use.
Prepared under the direction of:
John Bednarski Chief Engineer
Prepared by:
Albert Rodriguez Engineering Services
Reviewed by:
Deven Upadhyay Assistant General Manager/Chief Operating Officer Brent Yamasaki Water System Operations
Catherine Stites General Counsel
Tobin Tellers Engineering Services
Cash Spradling Engineering Services
David Clark Engineering Services
Arlene Arita Engineering Services
John Shamma Engineering Services
Howard Lum Engineering Services
Grace Chan Water Resources Management
Kevin Donhoff Water Resources Management
Jack Safely Water Resources Management
Ian Whyte Water System Operations
Greg de Lamare Engineering Services
Additional copies: The Seismic Resilience Report is located on the Seismic Resilience SharePoint site. To obtain a copy of this document, please contact the Engineering Services Group.
Disclaimer
Extensive efforts have been made to ensure that the material contained in this document is accurate as of the date of publication. There are many factors, however, related to the content and applicability of this document which are beyond the control of MWD. In addition, the contents of this publication will be periodically updated, so the reader should inquire about any such changes in addition to reading this document. Finally, the reader is encouraged to seek appropriate technical and/or legal advice when specific facts or circumstances arise that raise questions concerning the applicability or interpretation of the policies and procedures discussed herein.
PUBLICATION HISTORY:
Initial Release (First Biennial Report No. 1551) February 2018 2020 Update (Report No. 1551-1) February 2020
Cover Photo: Test setup for large diameter seismic-resilient ductile-iron pipe to be used on Metropolitan’s Casa Loma Siphon The Metropolitan Water District of Southern California Seismic Resilience Report 2020 Update Report No. 1551-1 v | P a g e
CONTENTS
EXECUTIVE SUMMARY .......................................................................................................................1 SECTION 1 PURPOSE .....................................................................................................................3 SECTION 2 BACKGROUND .............................................................................................................5 Seismic Risk ...............................................................................................................................................5 Seismic Resilience Strategy .......................................................................................................................5 SECTION 3 SEISMIC RESILIENCE STRATEGY UPDATES/REVISIONS....................................................7 Planning Component.................................................................................................................................7 Engineering Component ...........................................................................................................................8 Operations Component ..........................................................................................................................14 Reporting Component.............................................................................................................................15 Seismic Resilience Water Supply Task Force...........................................................................................15 SECTION 4 SEISMIC RESILIENCE NEAR-TERM GOALS.....................................................................17 Status of 2018 Listed Goals.....................................................................................................................17 2020 Update Near-Term Goals...............................................................................................................22 Figure 2-1: Detailed Breakdown of Metropolitan’s Seismic Resilience Strategy....................................6 Figure 3-1: Status of Seismic Assessment and Upgrades of Pre-1990 Structures ..................................9 Appendix A: M6.3 or Greater Earthquakes in Southern California Region - 1900 to Present Appendix B: List of Metropolitan Staff Seismic Conference Papers The Metropolitan Water District of Southern California Seismic Resilience Report 2020 Update Report No. 1551-1 vi | P a g e
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EXECUTIVE SUMMARY
In February 2018, the Metropolitan Water District of Southern California (Metropolitan) published Report No. 1551, Seismic Resilience First Biennial Report, which defined Metropolitan’s Seismic Resilience Strategy and identified a number of near-term goals to improve Metropolitan’s seismic resilience. The 2020 Seismic Resilience Report Update is a supplement to the Seismic Resilience First Biennial Report (2018 Report). The purpose of the update is to document revisions to Metropolitan’s Seismic Resilience Strategy, document seismic-resilience-related studies completed since publication of the 2018 Report, list the achievements related to the seismic performance objectives and near-term goals identified in the 2018 Report, and communicate new performance objectives and goals that will further increase the seismic resilience of Metropolitan’s system.
Since the publication of the 2018 Report, Metropolitan has initiated multiple studies that will improve planning for earthquake response. Completed studies include an evaluation of Metropolitan’s emergency storage requirements and an evaluation of the susceptibility of the conveyance and distribution pipelines to liquefaction. Staff is also nearing completion of an assessment of the potential damage to the conveyance and distribution pipelines from different earthquake events.
In the last two years, Metropolitan has also completed construction for seismic upgrades to 17 structures.
Additionally, Metropolitan substantially completed the initial round of seismic evaluations for aboveground structures constructed pre-1990, which in general pose an elevated seismic risk. Evaluation of above-ground structures built post-1990 has been initiated as well as evaluation of hydraulic structures (e.g., reservoir outlet towers) to assess their seismic risk when compared to current design practices.
Finally, Metropolitan conducted over 100 emergency response exercises, workshops, and seminars since February 2018, including two large functional exercises. These exercises help to ensure that Metropolitan staff is prepared for when an eventual earthquake occurs. Metropolitan also started a new five‐year exercise plan in 2019 that will allow all of its member agencies to participate in at least one of Metropolitan’s annual emergency exercises during the next five years.
Overall, Metropolitan has achieved many of the near-term goals that were proposed in the 2018 Report and is continuing the efforts to complete the few items that are still outstanding. The strategy outlined in the 2018 Report to develop the seismic resilience of the system is an ongoing process that will continue to evolve and adapt as new information becomes available.
Staff recommends changing the frequency of written update reports from its current two-year cycle to a frequency of a written report every five years, with the next written report to the Board in 2025. Staff will continue to provide annual oral updates on Metropolitan’s Seismic Resiliency Strategy to the Board.
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SECTION 1 PURPOSE
The Metropolitan Water District of Southern California (Metropolitan) owns and operates a complex conveyance, storage, treatment, and distribution system that serves a 5,200-square-mile service area within an active seismic region. Over its approximate 90-year history, Metropolitan has been proactive in mitigating seismic risk posed to the system, as well as improving its ability to maintain or quickly restore water deliveries following a major earthquake.
In February 2018, Metropolitan published Report No. 1551, Seismic Resilience First Biennial Report (2018 Report), which summarized Metropolitan’s historical approach to mitigating seismic risk and defined the organization’s current Seismic Resilience Strategy and the core components of that strategy. The report also identified performance objectives and near-term goals of the Seismic Resiliency Strategy. The 2018 Report is available on Metropolitan’s website using the link below:
http://mwdh2o.com/PDF_About_Your_Water/SRS%20Report%201551_Final_030518A_Submit_Reduce d.pdf
The 2020 Seismic Resilience Report Update is a supplement to the 2018 Seismic Resilience First Biennial Report. The purpose of the update is to document recent revisions to Metropolitan’s Seismic Resilience Strategy regarding emergency storage requirements, document seismic-resilience-related studies completed since publication of the 2018 Report, and list the achievements related to Metropolitan’s Seismic Resilience of Structures Program, emergency response planning, and the seismic performance objectives and near-term goals identified in the 2018 Report. The report also identifies new performance objectives and goals that will further increase the seismic resilience of Metropolitan’s system.
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SECTION 2 BACKGROUND
Seismic Risk
Southern California is crossed by numerous faults of varying levels of activity that are capable of generating large earthquakes and causing widespread damage. The 2018 Report listed six earthquakes that occurred within or near Metropolitan’s service area in southern California since 1900 - four strong earthquake events (M6.0 – 6.9) and two major earthquake events (M7.0 to M7.9).
In 2019, two significant earthquakes events occurred in the region. On July 4, 2019, a M6.4 earthquake occurred near Ridgecrest, approximately 122 miles north/northeast of Los Angeles. Then on July 5th, a M7.1 earthquake occurred in the same vicinity. While the earthquakes caused major damage to Ridgecrest and the surrounding communities, the earthquakes only caused mild shaking in the Los Angeles region due to the distance from the epicenter. However, these earthquakes are a reminder that earthquake risk is always present and that the region must take steps to prepare and respond.
A map showing significant (M6.3 and greater) earthquakes that have occurred in the southern California region since 1900 is provided in Appendix A.
Seismic Resilience Strategy
Metropolitan’s Seismic Resilience Strategy is comprised of four components that encompass the various functions that promote the organization’s seismic resilience objectives.
Planning – Developing and maintaining a diversified water portfolio, system flexibility, and emergency storage supplies
Engineering – Evaluation and mitigation of seismic risks of infrastructure and the water system as a whole
Operations – Maintain effective emergency planning and response capabilities Reporting – Increase accountability and transparency of seismic resilience programs Metropolitan’s Seismic Resilience Strategy was described in detail in the 2018 Report, and the overall structure of the strategy is unchanged. A detailed breakdown of Metropolitan’s Seismic Resilience Strategy is provided in Figure 2-1. The figure provides an overview of the comprehensive actions taken to mitigate impacts from large earthquakes, to quickly respond following an earthquake event, and to provide transparency regarding seismic risk and preparedness.
As shown in Figure 2-1, in addition to the activities conducted under the Planning, Engineering, Operations, and Reporting components of the Seismic Resilience Strategy, Metropolitan has continued its involvement with the Seismic Resilient Water Supply Task Force. The Seismic Resilient Water Supply Task Force is a collaboration between Metropolitan, the Department of Water Resources (DWR), and the Los Angeles Department of Water and Power (LADWP) to improve the seismic resilience of the imported water supply aqueducts.
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Figure 2-1: Detailed Breakdown of Metropolitan’s Seismic Resilience Strategy The Metropolitan Water District of Southern California Seismic Resilience Report 2020 Update Report No. 1551-1 7 | P a g e
SECTION 3 SEISMIC RESILIENCE STRATEGY UPDATES/REVISIONS Planning Component
Emergency Storage
Beginning in February 2018, Metropolitan and its member agencies convened a workgroup to evaluate regional storage, including the size and management of Metropolitan’s emergency storage program. The goal of the emergency storage program evaluation was to update the emergency criteria and develop a revised methodology to determine emergency storage needs. The methodology and recommendation of the workgroup were described in a draft white paper, “2018 Evaluation of Regional Storage Portfolio:
Draft Evaluation of Metropolitan’s Emergency Storage Objective,” and presented to Metropolitan’s Board in May 20191.
The update of the emergency criteria was based on 1) newly revised potential outage durations for the region’s imported water supplies – the Colorado River Aqueduct (CRA), the Los Angeles Aqueduct, and the State Water Project east and west
branches – following a seismic event, and 2) a
revisit of retail water demand and locally
available supplies within the service area. The
revised outages were developed as part of the
Seismic Resilience Water Supply Task Force.
The workgroup took into account the
capabilities of member agencies when
identifying reduction of retail water demand
and local production during an emergency
outage of imported supplies. This is a critical
change in that the previous storage calculation
assumed 100 percent local production during
the outage period.
The new emergency storage criteria considered various combinations of local demand reduction and supply production to develop an envelope of scenarios designed to prevent a shortage during an outage.
Based on the range of potential scenarios, the workgroup recommended 750,000 acre-feet for the emergency storage program target, an increase from the previous planning target of 630,000 acre-feet.
The emergency storage is assumed to be distributed among the available capacities of existing Department of Water Resources and Metropolitan surface reservoirs located on the coastal side of the San Andreas Fault. Since member agency demands for supplemental water will be met through deliveries of supplies from storage, evaluation of spatial distribution of storage and most effective operation of the
1 The Metropolitan Water District of Southern California, Water Planning and Stewardship Committee, Board Item 9-3, “Update of Metropolitan’s Emergency Storage Objective,” May 2019. http://www.mwdh2o.com/WhoWeAre/Board/Board-Meeting/Board%20Archives/2019/05- May/Letters/064883968.pdf
Diamond Valley Lake
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distribution system will be accomplished as part of Metropolitan’s continued efforts and coordination within Metropolitan’s storage portfolio evaluation or other regional planning processes.
System Flexibility
In July 2019, Metropolitan’s Board of Directors authorized an amendment to the Administrative Code to enable delivery of member agency water supplies in Metropolitan’s system in an emergency subject to the General Manager’s approval2. The amendment is an effort to enhance water delivery reliability after a serious emergency in which 1) Metropolitan is unable to make deliveries to a member agency due to physical damage to Metropolitan’s system resulting from a natural disaster or other emergency and 2) there are no alternate means for Metropolitan or the member agency to provide service to an area without the use of a portion of Metropolitan’s system. The Administrative Code change clarifies the conditions of these emergency deliveries in a proactive way, instead of a reactive way in response to damaged infrastructure following a natural disaster or serious emergency.
Engineering Component
Seismic Resilience of Structures
Metropolitan has developed an ongoing program for evaluating and upgrading its above-ground facilities with the goal of protecting life safety and critical infrastructure to minimize water delivery interruptions following a seismic event. The initial round of evaluations focused on structures that were deemed likely to be more susceptible to damage from earthquakes – buildings constructed prior to 1990. Structures built after 1990 were constructed in accordance with the 1988 or later versions of the Uniform Building Code, which provides reasonable assurance of withstanding a design-level earthquake without catastrophic failure. The program procedure for the seismic resilience of Metropolitan’s above-ground structures was described in the Seismic Resilience First Biennial Report and the program status as of January 2018 was provided. Since publication of that report, an additional 17 seismic upgrades have been completed. Figure 3-1 provides the overall status for the pre-1990 structures as of November 2019. Of the 311 pre-1990 structures identified, 63 percent were found to be acceptable and 37 percent (116 structures) potentially deficient following the rapid evaluation process. Of the 116 structures, 85 have either been seismically upgraded or are in design or construction. The remaining are largely structures that are not related to water delivery.
The program for seismically upgrading the above-ground structures is meant to be a continuous program, with the intent of reevaluating structures periodically. Structures found to be acceptable during the initial evaluation round may undergo a reevaluation, if warranted by new information such as a significant increase in seismic design force or displacement due to code revisions or newly discovered ground conditions, damage of structural components, severe material deterioration, and/or changes of occupancy.
2 The Metropolitan Water District of Southern California, Engineering and Operations Committee, Board Item 8-4 “Authorize Amendments to the Administrative Code Regarding Deliveries of Member Agency Supplies in Metropolitan’s System in an Emergency; the General Manager has determined that the Proposed Action is Exempt or Otherwise Not Subject to CEQA”, July 2019. http://www.mwdh2o.com/WhoWeAre/Board/BoardMeeting/Board%20Archives/2019/07-July/Letters/07092019%20BOD%208-4%20B-L.pdf The Metropolitan Water District of Southern California Seismic Resilience Report 2020 Update Report No. 1551-1 9 | P a g e
As shown in Figure 3-1, evaluation of the pre-1990 structures related to water delivery has been substantially complete and the deficient structures are being addressed. Following the 1994 Northridge earthquake, and subsequent earthquakes in Taiwan, Japan, and New Zealand, substantial research in seismic design and code revisions has taken place. Post-1990 structures may or may not meet the current seismic performance standards, which has prompted Metropolitan to expand the seismic evaluation to post-1990 structures, a process which was initiated in early 2019 to further improve its seismic resilience.
Twenty-six structures have been identified as part of the post-1990 structure list. Rapid evaluations have been completed on six structures, and none have been identified as seismically deficient.
As Metropolitan begins its evaluation of the post-1990 above-grade structures, staff is also initiating a process to identify and systematically evaluate below-ground structures such as vaults and manholes.
Similar to the evaluation of above-ground structures, the prioritization of these facilities will consider potential impacts to water delivery and potential for loss of life.
Status as of November 2019 Pre-1990 Structures Requiring Seismic Evaluation Rapid Evaluation Rapid Evaluation Results Seismic Upgrade Detailed Evaluation Priority 311 Completed: 311 Remaining: 0 Acceptable:
195 Potentially
Deficient:
116 Upgraded:
73 In Various Phases of
Design or Construction: 12 Authorized for Detailed Evaluation: 3 Authorization Planned for Detailed Evaluation: 28 Related to Water Delivery:
4 Not Related to
Water Delivery: 24 Figure 3-1: Status of Seismic Assessment and Upgrades of Pre-1990 Structures Seismic Resilience of Pipelines
Metropolitan’s pipelines have been constructed in conformance with standards of practice at the time of design. Historically, there have been very few prescriptive code requirements for seismic design of pipelines. Only recently have there been developments in mitigation options for large diameter pipelines, including improved techniques to analyze the response of structures and pipelines within the ground from I
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shaking, increased post-earthquake data collection of ground motions and damage observations, and demonstrated performance of earthquake-resistant pipeline products.
In keeping with the goals of the Seismic Resilience Strategy, Metropolitan is developing seismic design criteria for new pipelines based on current state of practice, geotechnical and seismicity criteria, operating conditions, and asset management strategies. The planned design approach for new pipelines will be to establish performance criteria, identify seismicity and ground conditions along the alignment, and design the pipeline to resist damage from ground shaking and deformation. Specialized pipe joints and sections can be designed to accommodate ground deformation from fault displacement or liquefaction. For existing pipelines, seismic resilience will be incorporated as a component of pipeline rehabilitation projects. Metropolitan will evaluate each upgrade individually to balance risk, performance, and cost. See the Seismic Performance Objectives in this section for more information on the pipeline seismic design.
Metropolitan is in the early years of a 20-year program to rehabilitate its prestressed concrete cylinder pipelines (PCCP), which, at 163 miles, makes up approximately 20 percent of Metropolitan’s conveyance and distribution system. The initial phase of the program will focus on the Second Lower Feeder, which will be upgraded with an interior steel liner. The new steel lining and the welded joints are designed to improve the seismic performance of the pipeline. For Reach 9 of the Second Lower Feeder, Metropolitan is investigating alternatives for realigning the portion of the pipeline that crosses the Newport-Inglewood Fault. One alternative being evaluated is to use specialized large-diameter earthquake-resistant steel pipe to accommodate fault displacement while maintaining structural integrity of the pipe for water conveyance.
Following this strategy, Metropolitan is completing the final design for rehabilitation of the Casa Loma Siphon Barrel No. 1 on the CRA in 2020. The Casa Loma Siphon Barrel No. 1 crosses the San Jacinto Fault Zone and is subject to long-term subsidenceinduced deformation from groundwater pumping. The project will replace 800 feet of
the existing 148-inch diameter concrete
pipeline with two parallel barrels of 104-inch
diameter earthquake resistant ductile iron
pipe (ERDIP). The ERDIP joints are designed
to accommodate ground displacements
without failure, which will allow for
uninterrupted service following a major
earthquake.
Seismic Resilience of Dams and Reservoirs
Metropolitan's ongoing strategy for managing the safety of its 24 dams includes five major components:
(1) Detailed Inspections; (2) Monitoring & Reporting; (3) Facility Assessments; (4) Emergency Action Plans, including Inundation Maps; and (5) Capital Projects for dam improvements and upgrades.
Consistent with the goals of the Seismic Resilience Strategy, Metropolitan performs cyclical assessments of its facilities that include: 1) developing dam seismic performance criteria based on current state of practice, geotechnical and seismicity criteria, and operating conditions, 2) selecting design or safety evaluation earthquakes, 3) characterizing ground motions, 4) analyzing seismic performance of the dams Earthquake-Resistant Pipe
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and foundations, and 5) evaluating structural adequacy of dam appurtenant structures for earthquake loading.
Finally, Metropolitan has an ongoing Dam Safety Initiatives Program that has initiated several plans to improve Metropolitan's dam seismic safety and earthquake readiness. These initiatives are being coordinated with the California Division of Safety of Dams (DSOD) and Office of Emergency Services and include the following:
Ongoing preparation of Emergency Action Plans, including inundation maps Performing training exercises at the dam site to test processes during a seismic event Providing training and guidance on overall dam safety Reviewing operation and maintenance methods for reservoir drawdown and operations after a seismic event
Updating guidelines and procedures on protection against seismic risk Establishing a strong communications system on seismic information Performing structural strengthening of dams, including rehabilitation and improvement of spillways and inlet/outlet towers such as Lake Skinner Outlet Tower Improving dam safety instrumentation, monitoring, and reporting capabilities Special Seismic Assessments
Metropolitan conducts studies to further the organization’s understanding of the vulnerability of the system to seismic hazards. The studies support emergency response training and planning for future earthquake events by estimating the magnitude of damage that may occur from various seismic events.
Recently completed and ongoing studies are described below.
Completed Study:
Report 1625 - Liquefaction Susceptibility Mapping for the Metropolitan Water District of Southern California’s Feeder System (Carollo Engineers, Inc., 2019). The liquefaction susceptibility mapping study provides a relative scale of liquefaction susceptibility of deposits along Metropolitan’s conveyance and distribution system, given sufficient earthquake ground motions. Existing liquefaction maps available from the California Geological Survey provide a conservative overview of potentially liquefiable areas without any delineation for relative susceptibility. Areas are marked as either liquefiable or not liquefiable. The study utilized available geologic mapping data as well as publicly available groundwater data to map the relative liquefaction susceptibility of Metropolitan’s conveyance and distribution pipelines for historical high and modern (1999 to 2019) groundwater depths providing five levels of relative scaling of susceptibility from very high to very low. The results of the study will be used to identify specific locations that may be targeted for future site-specific detailed liquefaction analyses, help prioritize pipeline replacement projects, and assess alternative pipeline alignments.
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Studies currently underway:
Earthquake Damage Assessment of Metropolitan Water District Conveyance and Distribution Feeder System (ABS Consulting, Inc.). The study utilizes proprietary modeling software to estimate the potential number of pipeline breaks that may occur from various extreme earthquakes such as a Magnitude 7.8 earthquake on the South San Andreas Fault. The damage assessment model takes into account pipeline material and joint type, distance from earthquake source, and regional geologic conditions when developing the damage estimate. The results of the study will provide input into Metropolitan’s earthquake emergency response planning and training activities, and help prioritize future pipeline seismic resilience enhancements. Anticipated completion is March 2020.
Seminars and Workshops
Metropolitan has recognized the importance of providing awareness of the seismic hazards and risks to Metropolitan, its member agencies, and sub-agencies and encouraging a transfer of knowledge of assessment and mitigation strategiesto reduce seismic risk. Metropolitan ensures that risk awareness and knowledge transfer are promoted through active participation at various workshops.
In October 2019, Metropolitan co-hosted with LADWP the 11th Water System Seismic Conference. The conference is a bi-annual event that brings together utility, consulting, and academic professionals from the United States, Japan, and Taiwan to
share knowledge in research, design
practices, and construction technologies to
prepare for and respond to seismic events.
Conference topics included emerging design
techniques, innovative construction
practices, seismic damage assessments,
seismic mitigation measures, and
emergency response and recovery. In
addition to co-hosting the conference,
Metropolitan staff delivered four
presentations on the organization’s seismic
resilience efforts. The papers and authors
are listed in Appendix B.
In December 2019, Metropolitan co-sponsored the Earthquake Resilience Workshop for Water and Wastewater Utilities in Southern California. The workshop was a partnership with the United States Environmental Protection Agency and local utility and emergency management organizations to provide guidance and information to drinking water and waste water utilities to enhance their ability to enhance their resilience approach.
Staff also presented Metropolitan’s seismic strategy and goals at the Member Agency Managers Meeting in August 2019. Staff described the various activities that Metropolitan conducts to understand the seismic risk and improve the overall resilience of the system. They also used the opportunity to promote the defense-in-depth approach to seismic resilience for the member agencies. This approach is a layered Metropolitan Chief Engineer Providing Opening
Remarks at 11th Water System Seismic Conference
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strategy of system hardening, emergency water supply diversification, and increased system flexibility, including potential interties between member agencies.
Seismic Performance Objectives
Structures
Metropolitan’s facilities are categorized as either an essential facility or regular facility, depending on performance requirements of the structure in accordance with code requirements. The structures are then designed or rehabilitated to meet the design criteria specified in the applicable seismic codes.
Essential facilities are those that are required for Metropolitan's core business-water delivery. All structures that are directly or indirectly related to water conveyance, storage, treatment and distribution are considered essential. Additionally, structures that contribute to Metropolitan’s business continuity are also considered essential. The performance objective for an essential facility is to allow for continuous operation of the structure with limited damage after a maximum considered seismic event. These essential facilities are designed or improved to allow for immediate occupancy or continuous operation after a major seismic event. As an owner/operator of essential lifeline facilities, Metropolitan’s waterrelated facilities will remain functional for disaster relief and fire suppression following a seismic event.
For regular facilities, the objective is to allow safe evacuation of occupants with possible structural and non-structural damage. The performance objective is to ensure life safety and prevent collapse of the structure. A facility designed as a regular facility may require significant repair following a major seismic event.
Pipelines
Metropolitan’s conveyance and distribution pipelines are considered essential pipelines that are required for post-earthquake response and recovery. The pipelines are intended to remain functional and operational during and following a maximum considered earthquake. No uncontrolled release of a substantial amount of water is permitted under this design scenario.
Metropolitan continuously improves its techniques to analyze the response of pipelines to a seismic event to improve its assessment and prediction of earthquake damage to these facilities. Post-earthquake data of ground motion and damage information are used to improve earthquake resilience design methodologies. The data collected is used in advanced seismic pipeline analysis that relies on finite element techniques for soil-structure 3d modeling. Innovation in the development of earthquakeresistant pipeline products contributes to better seismic performance.
For new pipeline seismic design, the performance objective is to ensure the pipeline, pipe joints, and pipeto-structure connections are capable of resisting the seismic shaking resulting from earthquake wave propagation without permanent damage. As the pipeline crosses known earthquake faults, the system will be designed to accommodate the maximum anticipated ground movement from fault displacement using specialized joints or pipe sections. Automatic shutoff valves may be added on either side of the fault to increase system flexibility.
For existing pipeline seismic design, a comprehensive risk assessment of the system using the latest seismicity and pipeline fragility data will be performed. The vulnerabilities of each pipeline segment will be used to determine the priority and schedule of seismic rehabilitation. Seismic resilient design to resist The Metropolitan Water District of Southern California Seismic Resilience Report 2020 Update Report No. 1551-1 14 | P a g e
shaking and accommodate fault displacement will be incorporated as components of the rehabilitation program. Each upgrade will be evaluated individually to balance risk, consequence, performance, and cost to define an economical long-term approach.
Operations Component
Emergency Response Training Exercises
In addition to training emergency response staff on National Incident Management System procedures, Metropolitan regularly conducts emergency response training exercises which have often been based upon a postulated seismic event.
Recent examples include:
“ShakeOut“ Full-Scale Emergency Operations Center (EOC)/Incident Command Post (ICP) Exercise, October 17, 2019
“Joint Infrastructure Security Exercise”- Tabletop Exercise with various Federal, State, and Local emergency management partner agencies- April 10, 2019
“Operation Nomad”- Functional EOC/ICP and member agencies, November 14, 2018 In 2019, Metropolitan started a new five‐year emergency exercise plan that will allow all of its member agencies to participate in at least one of Metropolitan’s annual emergency exercises. The first of these exercises was a tabletop exercise for the Orange County member agencies on August 29, 2019, which focused on a hypothetical incident at the Diemer Water Treatment Plant.
Metropolitan has conducted over 100 exercises since February 2018. This included two large functional emergency exercises for the EOC and multiple tabletop exercises, workshops, and seminars for the 12 Incident Command Posts located at the water treatment plants, conveyance and distribution facilities, and other strategic locations in Metropolitan’s service area.
The Metropolitan EOC also conducts monthly communication tests, which include Metropolitan’s emergency two-way radio system, on-line WebEOC system, Met-Alert mass notification system, and satellite phones. These monthly tests reach out to the member agencies, Treatment Plant Control Centers, ICPs, Metropolitan management, and the Department of Water Resources. These regular exercises help prepare Metropolitan and its member agencies to respond to future emergencies.
Emergency Response Capability
Metropolitan continues to maintain the necessary staffing, materials, and equipment to respond to two simultaneous pipeline breaks. The Machine Shop and Coating Shop at La Verne are available to fabricate pipe sizes up to 12 feet in diameter, and Metropolitan’s construction forces have the necessary equipment and expertise to make the repairs in-house. In addition, Metropolitan has upgraded its satellite phones to ensure communication ability following a seismic event and is in the process of installing high frequency radios at all Incident Command Posts (formerly Incident Command Centers) and the Emergency Operations Center.
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Reporting Component
Formal Report
The interval for development of a formal report will be changed to every five years from the original twoyear interval. Increasing the time interval between report updates will allow for a full Capital Investment Plan cycle to complete and for projects to move through concept, design, and construction.
Seismic Resilience Water Supply Task Force
The Seismic Resilience Water Supply Task Force (Task Force) is a collaborative effort involving Metropolitan, DWR, and LADWP to improve the seismic resilience of the imported water supplies to southern California. Following a major earthquake that disrupts the imported water supplies, the agencies would coordinate resources to repair the imported water supply aqueducts to ensure that deliveries are restored as quickly and to as many people as possible.
In March 2018, Metropolitan, DWR, and LADWP convened an aqueduct workshop to discuss lessons learned from recent large earthquakes in New
Zealand, Japan, and Mexico; share each agency’s
approach to conducting seismic assessments;
and discuss potential interties that may assist
with recovery of water supply to the region. The
group also had initial discussions on
development of an emergency response plan
specific to the Task Force.
The Task Force also conducted two tabletop
emergency exercises in 2018 and 2019. These
exercises were used to give substance to some
of the ideas in the Joint Agency Emergency
Response Plan (ERP).
Metropolitan, DWR, and LADWP are developing a Water Mutual Assistance Agreement (WMUA), which will formalize the Task Force and define the reporting and accounting requirements for mutual assistance following a major seismic event that impacts imported water supplies. A draft of the Joint Agency ERP has also been completed. The Joint Agency ERP will be finalized along with the WMUA. The plan defines the scenarios that would trigger the deployment of the Multi-Agency Coordination Group, which enhances the collaboration in operation, reporting, and plan maintenance.
Seismic Resilience Water Supply Task Force
Aqueduct Workshop – March 2018
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SECTION 4 SEISMIC RESILIENCE NEAR-TERM GOALS
Status of 2018 Listed Goals
The 2018 Seismic Resilience First Biennial Report identified near-term goals to further Metropolitan’s seismic resilience objectives. The near-term goals are listed below along with an update of the work done to date.
System Level Goals
Goal Conduct Rialto Pipeline Alternative Supply Needs Study Status: Metropolitan completed an initial study to identify the near-term and long-term emergency supply needs for member agency demand from the Rialto Pipeline. The Rialto Pipeline is exclusively supplied from the California Aqueduct East Branch and is susceptible to extended disruption from an earthquake on the San Andreas Fault. The study also identified options to meet emergency supply needs. Metropolitan is currently working with member agencies to expand on the emergency supply options.
Goal Complete a Re-evaluation of Metropolitan’s Emergency Storage Needs Status: Metropolitan, in coordination with member agencies, completed a re-evaluation of Metropolitan’s emergency storage needs and presented the recommendations to increase storage from 630,000 acre-feet to 750,000 acre-feet to Metropolitan’s Board in May 2019. A description of the emergency storage re-evaluation is provided in Section 3.
Goal Complete a Comprehensive Evaluation of Metropolitan’s Storage Programs Status: Metropolitan, in coordination with member agencies, will complete the 2020 Integrated Water Resources Plan (IRP). Metropolitan will use newly developed demand and supply forecasts to analyze its entire supply portfolio, including all storage programs, in assessing regional reliability.
Facility Level Goals
Goal Complete Construction of Approved Seismic Upgrade Projects Status: Construction has been completed for the listed projects. Carbon Creek Pressure Control Structure
Ten Control Structures along the Allen-McColloch Pipeline Diemer Administration Building
CRA Pump Plants Switch Houses (Five Buildings)
Weymouth West Wash Water Tank
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Goal Conduct Studies, and Complete Design of Approved Upgrade Projects Status:
Assessment of potential seismic-induced damage to Metropolitan’s water conveyance and distribution pipelines
Studies to estimate damage from shaking and at fault crossings from large earthquakes and liquefaction susceptibility of pipelines are in progress with an estimated completion date of March 2020. See Special Seismic Assessments under Section 3. Seismic upgrade for Diemer West Filter Building
Completed design and construction of seismic upgrades is ongoing with an estimated completion date of December 2020.
Complete evaluation of options, design, and construction contract to strengthen CRA Whitewater Tunnel No. 2
Preliminary design is underway.
Investigate options to improve emergency raw water bypass capabilities at treatment plants Study is ongoing.
Vulnerability Study of CRA electric transmission and distribution systems Completed CRA Electric Transmission System Towers Reliability Study, which considered seismic vulnerability in addition to other hazards.
Seismic Upgrade of Water Quality Lab in La Verne
Project is currently in design.
Seismic Upgrade of Weymouth Administration Building
Project is currently in design.
Seismic Study of Lake Skinner Outlet Tower
Completed voluntary seismic assessment of the tower which considered current dam safety criteria
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Emergency Response Goals
Goal 1: Prepare and Conduct Emergency Exercises
Status:
Conduct a joint agency workshop to prepare a draft Joint Agency Response Plan Conduct high-level training for DWR, LADWP, and Metropolitan staff on the Joint Agency Emergency Response Plan
Run a functional exercise on the Joint Agency Emergency Response Plan Metropolitan conducted joint agency tabletop exercises to develop the Joint Agency Emergency Response Plan in 2018 and 2019. The functional exercise will be conducted following finalization of the Joint Agency Emergency Response Plan.
Goal 2: Execute MOU to Allow for Coordinated Emergency Response Status:
Prepare draft Memorandum of Understanding (MOU) and submit for review Secure LADWP, Metropolitan, and DWR approval for the MOU The Joint Agency Mutual Assistance Agreement is in the final stages of review and is expected to be signed off by all three parties in the near future.