provide additional administrative and maintenance space for future staffing needs. The City also intends to participate in Contra Costa Water District's proposed Los Vaqueros Reservoir Expansion Project and United States Bureau of Reclamation (USBR) B.F. Sisk Dam Raise and Reservoir Expansion Project, both of which would provide the City with reliable options for storage of excess water during wet seasons for use during drought conditions.
Recommended infrastructure improvements for the City’s recycled water system include new pump stations, a new storage tank, and new transmission, and distribution pipelines to serve new
development
areas in the western, southern and eastern portions of the City. Because the conversion of existing
irrigated areas can be costly and disruptive, the Master Plan Update focuses on the
infrastructure needed to deliver recycled water supplies to new development areas
where practical and taking advantage of the recycled water infrastructure that has been constructed to date.
The
Master Plan Update also includes a proposed Recycled Water Exchange Agreement with the USBR, whereby a
portion of the City’s tertiary treated wastewater (recycled water) would be discharged t
o the Delta Mendota Canal (DMC) and a like amount of water (i.e., a one-to-one exchange) could
then be diverted from the DMC by the City for treatment at the City’s JJWTP for potable use. Wit
h the potential reduction in reliability of the City’s surface water supplies from the
CVP and SSJID, this proposed recycled water exchange agreement will be a critical component of the
City’s future water supply portfolio.
Staff anticipates
a decrease to the water development impact fees due to an overall decrease in water usage per
household and drought conservation efforts.
FISCAL IMPACT
This item is
to only to review and receive feedback regarding the Master Plan Update. The cost of completion
of the Master Plan Update was funded from program management fees collected through our development impact fee program. The cost of construction of the physical infrastructure listed in the
Master Plan Update would, if approved, be funded through development impact
fees or other funding mechanisms without any impact to the City’s General Fund.
PUBLIC
OUTREACH / INTEREST
A Public Outreach
Meeting was held for the Master Plan Update on February 14, 2022.
COORDINATION
The City’s
Engineering
Division coordinated with our Operations and Utilities Department and West Y
ost & Associates to complete this update.
CEQA DETERMINATION
The project is an informational item only and exempt from the California Environmental Quality Act as
no discretionary action is being taken by the City Council.
Agenda Item 3.C
August 15, 2023
STRATEGIC PLAN
This agenda item supports the City of Tracy’s Quality of Life Strategic Priority, which is to provide
an outstanding quality of life by enhancing the City’s am enities, business mix and services, and cultivating connections to promote positive change and progress in our community.
ACTION
REQUESTED OF THE CITY COUNCIL
Staff recommends that the City Council review and discuss the Citywide Water System Master
Plan Update.
Prepared by: Veronica Child, Management Analyst II
Reviewed by: Koosun Kim, PE, City Engineer / Assistant Director of Development Services Sara Cowell,
Finance Director
Bijal M. Patel, City Attorney
Karin Schnaider, Assistant City Manager
Approved by:
Midori Lichtwardt, Interim City Manager
ATTACHMENTS
Attachment
A – Citywide Water System Master Plan Update
Attachment B – Presentation – Citywide Water System Master Plan Update
CITY OF TRACY
Citywide Water System
Master Plan Update
FINAL REPORT
MAY 2023
Attachment A
FINAL REPORT | MAY 2023
W E S T Y O S T A S S O C I A T E S
Citywide Water System
Master Plan Update
————
Prepared for
City of Tracy
Project No. 404-12-18-41
May 2023
Project Manager: Amy Kwong, PE Date
May 2023
QA/QC Review: Elizabeth Drayer, PE Date
W E S T Y O S T A S S O C I A T E S
PREFACE
During the time that this Citywide Water System Master Plan was prepared and completed, several development projects have progressed , and some associated water system infrastructure improvements have been completed. As such, tables and figures in this Master Plan showing existing water system facilities may not include all of the current existing water system facilities. Similarly, tables and figures showing future recommended water system facilities may include some water system facilities which have alread y been constructed. This does not change the results or the recommendations of the Citywide Water System Master Plan.
The Tracy Infrastructure Master Plan (TIMP) Impact Fee Nexus Study , being prepared by Harris & Associates based on this Citywide Water Sy stem Master Plan, does consider the recent completion of water system facilities, so that updated water system impact fees reflect only those water system facilities which have not yet been constructed.
The City’s progress in completing water system infrastructure improvements is exciting , and we look forward to the completion of additional recommended infrastructure improvements in the coming years.
Table of Contents
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Executive Summary
Purpose for the Citywide Water System Master Plan Update .......................................................... ES-1 Objectives of the Citywide Water System Master Plan Update ....................................................... ES-1 Key Changes from the 2012 Citywide Water System Master Plan .................................................. ES-2 Existing and Projected Future Water Demands ............................................................................... ES-4 Existing and Projected Future Water Supplies ................................................................................. ES-6 Existing Water Supplies ............................................................................................................. ES-6 Future Water Supplies ............................................................................................................... ES-7 Evaluation of Existing and Future Potable Water System .............................................................. ES-10 Existing Potable Water System ................................................................................................ ES-10 Pipeline Improvements ...................................................................................................... ES-11 2025 Potable Water System .................................................................................................... ES-11 Pipeline Improvements ...................................................................................................... ES-11 New Potable Water Pipelines ............................................................................................ ES-11 Interconnections ................................................................................................................ ES-14 Re-zoning .......................................................................................................................... ES-14 Groundwater Wells ............................................................................................................ ES-14 Buildout Potable Water System ............................................................................................... ES-14 Storage Reservoirs ............................................................................................................ ES-14 Groundwater Wells ............................................................................................................ ES-15 Booster Pump Stations ...................................................................................................... ES-15 New Potable Water Pipelines ............................................................................................ ES-15 Interconnections ................................................................................................................ ES-16 Re-zoning .......................................................................................................................... ES-16 System Control and Data Acquisition (SCADA) System and Backup Power ................... ES-16 JJWTP Expansion ............................................................................................................. ES-16 Participation in Phase 2 Los Vaqueros Reservoir Expansion Project ............................... ES-17 Participation in the B.F. Sisk Dam Raise & Reservoir Expansion Project ........................ ES-17 Water Master Plan Updates .............................................................................................. ES-17 Evaluation of Future Recycled Water System ................................................................................ ES-17 2025 Recycled Water System .................................................................................................. ES-18 Booster Pump Stations ...................................................................................................... ES-18 New Recycled Water Pipelines ......................................................................................... ES-18 Buildout Recycled Water System ............................................................................................. ES-18 Storage Reservoirs ............................................................................................................ ES-18 Booster Pump Stations ...................................................................................................... ES-20 New Recycled Water Pipelines ......................................................................................... ES-20 SCADA System ................................................................................................................. ES-20 Recommended Capital Improvement Program .............................................................................. ES-20 Chapter 1. Introduction
1.1 Citywide Water System Master Plan Update Purpose .................................................................. 1-1
1.2 Water Master Plan Objectives ....................................................................................................... 1-1
1.3 Key Changes from the 2012 Citywide Water System Master Plan ............................................... 1-2
1.4 Report Organization ...................................................................................................................... 1-4
1.5 Acknowledgements ....................................................................................................................... 1-5 Table of Contents
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Chapter 2. Water Supply and Infrastructure System Objectives, Goals, and Recommendations
2.1 Overview ........................................................................................................................................ 2-1
2.2 Overall Water System Objectives and Goals ................................................................................ 2-1
2.3 City of Tracy Water Conservation Programs ................................................................................. 2-2
2.3.1 Existing Water Conservation Programs ............................................................................... 2-2
2.3.2 Water Efficient Landscape Ordinance ................................................................................. 2-3
2.4 Recycled and Non-Potable Water Ordinance ............................................................................... 2-4
2.5 City of Tracy General Plan Water Service Goals, Objectives and Policies ................................... 2-5
2.6 Compliance with California Green Building Standards Code ........................................................ 2-7
2.7 Recommendations for New Development and New Water System Facilities ............................... 2-8
2.8 Principles for Sustainable Infrastructure in the City of Tracy ........................................................ 2-9 Chapter 3. Land Use Assumptions
3.1 Overview ........................................................................................................................................ 3-1
3.2 City of Tracy General Plan and Sphere of Influence ..................................................................... 3-1
3.3 Existing and Planned Development of the City’s Sphere of Influence .......................................... 3-3
3.3.1 Existing Developed Land Uses ............................................................................................ 3-3
3.3.2 Approved Projects ................................................................................................................ 3-3
3.3.3 Additional Planned Development ......................................................................................... 3-6
3.3.4 Miscellaneous Infill Development ......................................................................................... 3-6
3.3.5 Mountain View Annexation .................................................................................................. 3-6
3.4 Development Time Frames Evaluated in this Water System Master Plan Update ....................... 3-8
3.4.1 2025 (Near-Term) Development of the City’s Sphere of Influence ...................................... 3-8
3.4.2 2040 Development of the City’s Sphere of Influence ........................................................... 3-8
3.4.3 Buildout Development of the City’s Sphere of Influence ..................................................... 3-8
3.5 Summary of Land Use Projections ................................................................................................ 3-9 Chapter 4. Existing and Future Water Demands
4.1 Overview ........................................................................................................................................ 4-1
4.2 Existing Service Area .................................................................................................................... 4-1
4.3 Population Served ......................................................................................................................... 4-3
4.4 Historical Potable Water Production and Consumption ................................................................ 4-6
4.4.1 Historical Potable Water Production .................................................................................... 4-6
4.4.2 Historical Potable Water Consumption .............................................................................. 4-10
4.4.3 Potable Unaccounted-for Water/Non-Revenue Water....................................................... 4-12
4.4.4 Per Capita Potable Water Demand.................................................................................... 4-13
4.5 Existing Recycled Water Production and Consumption .............................................................. 4-16
4.6 Water Conservation and Water Use Efficiency ........................................................................... 4-16
4.6.1 Existing Water Conservation .............................................................................................. 4-16
4.6.2 Compliance with the Water Conservation Act of 2009 (SB X7-7) ..................................... 4-16
4.6.3 Making Water Conservation a California Way of Life ........................................................ 4-17
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4.7 Adopted Peaking Factors ............................................................................................................ 4-18
4.7.1 Potable Water System Peaking Factors ............................................................................ 4-18
4.7.2 Recycled Water System Peaking Factors ......................................................................... 4-19
4.8 Future Water Demand Projections .............................................................................................. 4-20
4.8.1 Existing Unit Water Demand Factors and Land Use Assumptions ................................... 4-20
4.8.2 Verification of Unit Water Demand Factors ....................................................................... 4-22
4.8.2.1 General Methodology ............................................................................................... 4-22
4.8.2.2 Residential Unit Water Demand Factors .................................................................. 4-23
4.8.2.3 Non-Residential Unit Water Demand Factors .......................................................... 4-24
4.8.3 Adopted Unit Water Demand Factors ................................................................................ 4-28
4.8.4 Existing (Baseline) Water Demands .................................................................................. 4-29
4.8.5 Recycled Water Use Assumptions ..................................................................................... 4-29
4.8.6 Projected Buildout Water Demands ................................................................................... 4-30
4.9 Future Per Capita Water Use Projections ................................................................................... 4-33 Chapter 5. Existing and Future Water Supplies
5.1 Overview ........................................................................................................................................ 5-1
5.2 Changes to the City’s Water Supplies Since the Completion of the 2012 Citywide Water System Master Plan and the 2015 Urban Water Management Plan ............................................ 5-1
5.3 Existing Potable Water Supplies ................................................................................................... 5-2
5.3.1 Central Valley Project Water via the Delta-Mendota Canal ................................................. 5-4
5.3.1.1 M&I-Reliability Supplies from the CVP ....................................................................... 5-4
5.3.1.2 Ag-Reliability Supplies from the CVP ......................................................................... 5-6
5.3.1.3 Treatment and Use of CVP Surface Water Supplies ................................................. 5-7
5.3.2 Surface Water from BBID Pre-1914 Water Rights ............................................................... 5-8
5.3.3 Stanislaus River Water ........................................................................................................ 5-9
5.3.4 Groundwater ...................................................................................................................... 5-11
5.3.4.1 City Wells .................................................................................................................. 5-11
5.3.4.2 Groundwater Yield .................................................................................................... 5-11
5.3.4.3 Groundwater Quality................................................................................................. 5-12
5.3.4.4 Groundwater Management ....................................................................................... 5-12
5.3.4.4.1 City Groundwater Management Policy and Mitigated Negative Declaration for City Groundwater Production of 9,000 af/yr .......................... 5-12
5.3.4.4.2 Compliance with the 1992 Groundwater Management Act (AB 3030) ........... 5-12
5.3.4.4.3 Tracy Regional Groundwater Management Plan............................................ 5-13
5.3.4.4.4 Compliance with the 2014 Sustainable Groundwater Management Act ........ 5-13
5.3.4.5 Historical Groundwater Use ..................................................................................... 5-15
5.3.4.6 Projected Future Groundwater Use .......................................................................... 5-16
5.3.5 Aquifer Storage and Recovery ........................................................................................... 5-17
5.3.6 Out-of-Basin Water Banking .............................................................................................. 5-18
5.4 Future Potable Water Supplies.................................................................................................... 5-19
5.4.1 Additional ASR Wells ......................................................................................................... 5-19
5.4.2 Additional CVP Water Supplies from USBR Available Through a Recycled Water Exchange Program ............................................................................................................ 5-20
5.4.3 Additional CVP Water Supplies from BBID ........................................................................ 5-21
5.4.4 Additional SCWSP Water Supplies .................................................................................... 5-21
5.5 Existing Non-Potable Water Supplies ......................................................................................... 5-22
5.5.1 Recycled Water .................................................................................................................. 5-22 Table of Contents
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5.5.2 Shallow Non-Potable Groundwater.................................................................................... 5-22
5.6 Reliability of the City’s Water Supplies ........................................................................................ 5-23
5.6.1 Potable Water Supply Reliability ........................................................................................ 5-23
5.6.1.1 Normal Years ............................................................................................................ 5-23
5.6.1.2 Single Dry Years ....................................................................................................... 5-25
5.6.1.3 Multiple Dry Years .................................................................................................... 5-27
5.6.2 Emergency Water Supply Conditions ................................................................................ 5-31
5.6.3 Non-Potable Water Supply Reliability ................................................................................ 5-31
5.7 Sufficiency of the City’s Water Supplies ...................................................................................... 5-31
5.7.1 Potable Water Supply Availability ...................................................................................... 5-31
5.7.2 Recycled Water Supply Availability .................................................................................... 5-33
5.8 Water Management Strategies and Options ............................................................................... 5-34
5.8.1 Recycled Water for Non-Potable Use ................................................................................ 5-34
5.8.2 Future Water Supply Projects ............................................................................................ 5-34
5.8.3 Implementation of Demand Management Measures ......................................................... 5-35
5.8.4 Policy-Based Water Efficiency Tools ................................................................................. 5-35
5.9 Summary of Water Supply Recommendations ........................................................................... 5-36 Chapter 6. System Performance and Operation Criteria
6.1 Overview ........................................................................................................................................ 6-1
6.2 Potable Water System ................................................................................................................... 6-2
6.2.1 General Potable Water System Reliability and Recommendations ..................................... 6-2
6.2.1.1 Water Quality Standards ............................................................................................ 6-2
6.2.1.2 Recommendations for New Developments ................................................................ 6-2
6.2.2 Fire Flow Requirements ....................................................................................................... 6-2
6.2.3 Potable Water System Capacity During High Demand Periods .......................................... 6-5
6.2.3.1 Maximum Day Demand plus Fire Flow ...................................................................... 6-5
6.2.3.2 Peak Hour Demand .................................................................................................... 6-5
6.2.4 Water Treatment Capacity ................................................................................................... 6-5
6.2.5 Potable Water Storage Capacity .......................................................................................... 6-6
6.2.5.1 Operational Storage ................................................................................................... 6-6
6.2.5.2 Fire Storage ................................................................................................................ 6-6
6.2.5.3 Emergency Storage .................................................................................................... 6-7
6.2.5.4 Groundwater Credit .................................................................................................... 6-8
6.2.5.5 Treated Surface Water Supply Credit ........................................................................ 6-8
6.2.5.6 Total Storage Capacity Recommended ..................................................................... 6-9
6.2.6 Potable Water Pumping Facility Capacity ............................................................................ 6-9
6.2.7 Potable Water Critical Supply Facilities ............................................................................. 6-10
6.2.8 Potable Water Transmission and Distribution Pipeline Sizing and Recommended System Pressures ............................................................................................................. 6-10
6.2.8.1 Potable Water Transmission System ....................................................................... 6-11
6.2.8.2 Potable Water Distribution System ........................................................................... 6-11
6.3 Recycled Water System .............................................................................................................. 6-14
6.3.1 Recycled Water Demand Condition Evaluation ................................................................. 6-14
6.3.2 Recycled Water Treatment Capacity ................................................................................. 6-14
6.3.3 Recycled Water Storage Capacity ..................................................................................... 6-14
6.3.3.1 Seasonal Storage ..................................................................................................... 6-14
6.3.3.2 Operational Storage ................................................................................................. 6-14
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6.3.3.3 Total Storage Capacity ............................................................................................. 6-15
6.3.4 Recycled Water Pumping Facility Capacity ....................................................................... 6-15
6.3.5 Recycled Water Transmission Pipeline Sizing and Recommended System Pressures ... 6-15 Chapter 7. Existing Potable Water System Evaluation
7.1 Overview ........................................................................................................................................ 7-1
7.2 Description of Existing Potable Water System Facilities ............................................................... 7-1
7.2.1 John Jones Water Treatment Plant ..................................................................................... 7-1
7.2.2 South County Water Supply Project .................................................................................... 7-3
7.2.3 Groundwater Wells............................................................................................................... 7-4
7.2.4 Water Storage Facilities ....................................................................................................... 7-6
7.2.5 Booster Pump Stations ........................................................................................................ 7-6
7.2.6 Pressure Regulating Stations .............................................................................................. 7-8
7.2.7 Pressure Zone Boundaries .................................................................................................. 7-9
7.2.8 Transmission and Distribution System Pipelines ............................................................... 7-11
7.2.9 SCADA System .................................................................................................................. 7-11
7.3 Hydraulic Model Update .............................................................................................................. 7-11
7.3.1 Existing Hydraulic Model Description................................................................................. 7-11
7.3.2 Review of Existing Water System Facilities ....................................................................... 7-12
7.3.3 Review of Existing Water System Operations ................................................................... 7-14
7.4 Existing Potable Water System Evaluation ................................................................................. 7-14
7.4.1 Existing Potable Water Demands ...................................................................................... 7-15
7.4.2 Existing Water System Facilities Evaluation ...................................................................... 7-17
7.4.2.1 Water Treatment Capacity ....................................................................................... 7-17
7.4.2.2 Storage Capacity ...................................................................................................... 7-17
7.4.2.3 Pumping Capacity .................................................................................................... 7-19
7.4.2.4 Critical Supply Facilities............................................................................................ 7-19
7.4.3 Existing Water System Hydraulic Analysis ........................................................................ 7-22
7.4.3.1 Existing Water System Performance Criteria ........................................................... 7-22
7.4.3.1.1 Peak Hour Demand Scenario ......................................................................... 7-22
7.4.3.1.2 Maximum Day Demand plus Fire Flow Scenario ........................................... 7-23
7.4.3.2 Recommended Improvement Criteria ...................................................................... 7-24
7.4.3.3 Existing Water System Evaluation Results .............................................................. 7-24
7.4.3.3.1 Peak Hour Demand Scenario ......................................................................... 7-24
7.4.3.3.2 Maximum Day Demand plus Fire Flow Scenario ........................................... 7-27
7.5 Summary of Recommended Existing Potable Water System Improvements ............................. 7-31 Pipeline Hydraulic Capacity Improvements ................................................................................ 7-32
7.5.1 Pipeline Renewal and Replacement .................................................................................. 7-32 Chapter 8. Future Potable Water System Evaluation
8.1 Overview ........................................................................................................................................ 8-1
8.2 Pressure Zone Recommendations ................................................................................................ 8-2
8.3 Projected Future Potable Water Demands .................................................................................... 8-5
8.4 Future Potable Water System Facility Evaluation ......................................................................... 8-8
8.4.1 Water Treatment Capacity ................................................................................................... 8-8
8.4.2 Water Storage Capacity ..................................................................................................... 8-10
8.4.3 Pumping Capacity .............................................................................................................. 8-16 Table of Contents
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8.4.4 Critical Supply Facilities ..................................................................................................... 8-20
8.4.5 SCADA System Improvements .......................................................................................... 8-20
8.4.6 Update of Future System Facilities in the Hydraulic Model ............................................... 8-21
8.5 Future Potable Water System Performance Evaluation .............................................................. 8-26
8.5.1 Future Water System Performance Criteria ....................................................................... 8-26
8.5.1.1 Peak Hour Demand Scenario ................................................................................... 8-26
8.5.1.2 Maximum Day Demand plus Fire Flow Scenario ..................................................... 8-27
8.5.2 Recommended Improvements Criteria .............................................................................. 8-28
8.5.3 2025 Water System Evaluation Results ............................................................................ 8-28
8.5.3.1 2025 Peak Hour Demand Scenario .......................................................................... 8-28
8.5.3.2 2025 Maximum Day Demand plus Fire Flow Scenario ............................................ 8-31
8.5.4 Buildout Water System Evaluation Results ....................................................................... 8-35
8.5.4.1 Buildout Peak Hour Demand Scenario ..................................................................... 8-35
8.5.4.2 Buildout Maximum Day Demand plus Fire Flow Scenario ....................................... 8-38
8.6 Summary of Recommended Future Potable Water System Improvements ............................... 8-41
8.6.1 2025 System Improvements .............................................................................................. 8-41
8.6.1.1 Pipelines ................................................................................................................... 8-41
8.6.1.2 Interconnections ....................................................................................................... 8-44
8.6.1.3 Re-Zoning ................................................................................................................. 8-44
8.6.1.4 Groundwater Wells ................................................................................................... 8-44
8.6.2 Buildout System Improvements ......................................................................................... 8-44
8.6.2.1 Storage Facilities ...................................................................................................... 8-44
8.6.2.2 Groundwater Wells ................................................................................................... 8-45
8.6.2.3 Booster Pumping Facilities ....................................................................................... 8-45
8.6.2.4 Pipelines ................................................................................................................... 8-46
8.6.2.5 Interconnections ....................................................................................................... 8-46
8.6.2.6 Re-Zoning ................................................................................................................. 8-46
8.6.2.7 SCADA System/Backup Power ................................................................................ 8-46
8.6.2.8 JJWTP Expansion .................................................................................................... 8-47
8.6.2.9 Participation in Phase 2 Los Vaqueros Reservoir Expansion Project ...................... 8-47
8.6.2.10 Water Master Plan Updates ................................................................................... 8-47 Chapter 9. Recycled Water System Evaluation
9.1 Overview ........................................................................................................................................ 9-1
9.2 Description of Existing Recycled Water System ........................................................................... 9-2
9.2.1 Wastewater Treatment Plant ............................................................................................... 9-2
9.2.2 Booster Pump Stations ........................................................................................................ 9-2
9.2.3 Pressure Zone Boundaries .................................................................................................. 9-2
9.2.4 Transmission and Distribution Pipelines .............................................................................. 9-2
9.2.5 SCADA System .................................................................................................................... 9-4
9.3 Existing Recycled Water Demands ............................................................................................... 9-4
9.4 Recommended Buildout Recycled Water System ......................................................................... 9-4
9.4.1 Future Recycled Water Demand Areas ............................................................................... 9-6
9.4.2 Pressure Zone Recommendations ...................................................................................... 9-7
9.4.3 Allocation of Future Recycled Water Demands ................................................................... 9-8
9.4.4 Recycled Water Exchange Program Seasonality ................................................................ 9-9
9.4.5 Seasonal and Diurnal Storage Facilities ............................................................................ 9-11
9.4.6 Booster Pump Stations ...................................................................................................... 9-12 Table of Contents
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9.4.7 Recycled Water Pipeline Alignments ................................................................................. 9-13
9.4.8 Recycled Water Pipeline Sizes .......................................................................................... 9-14
9.5 Recycled Water System Criteria.................................................................................................. 9-16
9.6 Recycled Water System Evaluation Results ............................................................................... 9-16
9.6.1 Peak Hour Demand Scenario ............................................................................................ 9-16
9.6.2 Fill Period Scenario ............................................................................................................ 9-18
9.7 Summary of Recommended Future Recycled Water System Improvements ............................. 9-20
9.7.1 2025 System Improvements .............................................................................................. 9-22
9.7.1.1 Booster Pumping Facilities ....................................................................................... 9-22
9.7.1.2 Pipelines ................................................................................................................... 9-22
9.7.1.3 Interconnections ....................................................................................................... 9-22
9.7.1.4 SCADA System ........................................................................................................ 9-22
9.7.2 Buildout System Improvements ......................................................................................... 9-23
9.7.2.1 Storage Facilities ...................................................................................................... 9-23
9.7.2.2 Booster Pumping Facilities ....................................................................................... 9-23
9.7.2.3 Pipelines ................................................................................................................... 9-24
9.7.2.4 Interconnections ....................................................................................................... 9-24
9.7.2.5 SCADA System ........................................................................................................ 9-24 Chapter 10. Recommended Capital Improvement Program
10.1 Overview .................................................................................................................................... 10-1
10.2 Recommended Potable Water System Capital Improvement Program .................................... 10-2
10.2.1 Existing Potable Water System Improvements ................................................................ 10-3
10.2.2 2025 Potable Water System Improvements .................................................................... 10-6
10.2.3 Buildout Potable Water System Improvements ............................................................... 10-7
10.2.4 Water Treatment Plant Expansion Costs ....................................................................... 10-12
10.2.5 Summary of Recommended Potable Water System CIP Costs .................................... 10-12
10.3 Recommended Recycled Water System Capital Improvement Program ............................... 10-14
10.3.1 2025 Recycled Water System Improvements ................................................................ 10-14
10.3.2 Buildout Recycled Water System Improvements ........................................................... 10-15
10.3.3 Summary of Recommended Recycled Water System CIP Costs ................................. 10-18
10.4 Capital Improvement Program Timing and Triggers ............................................................... 10-20 List of Tables
Table ES-1. Summary of Future Projected Water Production ......................................................... ES-5 Table ES-2. Historical and Projected Potable Water Consumption by Customer Class .................. ES-5 Table ES-3. Future Water Supply Needs under Single Dry Year Conditions .................................. ES-9 Table ES-4. Summary of Probable Construction Costs for Recommended Potable and Recycled Water System Improvements .................................................................... ES-21 Table 2-1. City of Tracy General Plan Objectives and Policies for Water Service .............................. 2-6 Table 3-1. Summary of Approved Projects ......................................................................................... 3-5 Table 3-2. Projected Development by Time Frame within the City's Sphere of Influence .................. 3-9 Table 4-1. Historical Population Served .............................................................................................. 4-4 Table of Contents
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Table 4-2. Historical Annual City of Tracy Potable Water Production by Source ............................... 4-7 Table 4-3. Historical Annual Potable Water Production including Wheeled Water for Patterson Pass Business Park ................................................................................... 4-10 Table 4-4. Potable Water Consumption ............................................................................................ 4-11 Table 4-5. Summary of Top 15 Potable Water Users in 2017 .......................................................... 4-12 Table 4-6. Potable Unaccounted-for Water ....................................................................................... 4-13 Table 4-7. Historical Per Capita Potable Water Demand .................................................................. 4-14 Table 4-8. Historical Maximum Day Demand Peaking Factors ......................................................... 4-19 Table 4-9. Adopted Peaking Factors ................................................................................................. 4-20 Table 4-10. 2012 WSMP Adopted Unit Water Demand Factors ....................................................... 4-21 Table 4-11. Adopted Dwelling Unit Densities and Floor to Area Ratios (a) ......................................... 4-21 Table 4-12. Refined Single-Family Residential Unit Water Demand Factors ................................... 4-24 Table 4-13. Unit Water Demand Factors for Commercial, Industrial, and Office Land Uses ............ 4-27 Table 4-14. City of Tracy Maximum Allowable Water Use Factors for Irrigation (a) ............................ 4-28 Table 4-15. Adopted Unit Water Demand Factors ............................................................................ 4-28 Table 4-16. Summary of Future Projected Water Production(a,b,c) ..................................................... 4-32 Table 4-17. Historical and Projected Potable Water Consumption by Customer Class ................... 4-33 Table 4-18. Projected Population and Per Capita Potable Water Use.............................................. 4-33 Table 5-1. Existing Water Supplies ..................................................................................................... 5-3 Table 5-2. Historical Annual CVP M&I Allocations (South of Delta) .................................................... 5-5 Table 5-3. Historical Annual CVP Ag Allocations (South of Delta) ...................................................... 5-6 Table 5-4. Historical Annual CVP Surface Water Supplies ................................................................. 5-7 Table 5-5. Historical Annual Deliveries to Patterson Pass Business Park .......................................... 5-8 Table 5-6. Historical Deliveries from the SCWSP to the City of Tracy ................................................ 5-9 Table 5-7. Groundwater Well Characteristics .................................................................................... 5-15 Table 5-8. Historical Groundwater Production by the City of Tracy .................................................. 5-16 Table 5-9. Tracy ASR Well 8 Annual Injection and Extraction .......................................................... 5-18 Table 5-10. Semitropic Water Storage District Banking Partners ..................................................... 5-18 Table 5-11. Projected Existing and Additional Planned Future Water Supplies Available in Normal Years at Buildout ........................................................................................... 5-25 Table 5-12. Projected Existing and Additional Planned Future Water Supplies Available in Single Dry Years at Buildout ...................................................................................... 5-27 Table 5-13. Projected Existing and Additional Planned Future Water Supplies Available Five-Consecutive-Dry Years at Buildout ........................................................................ 5-30 Table 5-14. Summary of Buildout Total Water Supply Versus Demand During Hydrologic Normal, Single Dry, and Multiple Dry Years ................................................ 5-32 Table 6-1. Recommended Fire Flow Requirements............................................................................ 6-4
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Table 6-2. Summary of Recommended Potable Water System Performance and Operational Criteria .................................................................................................. 6-13 Table 6-3. Summary of Recommended Recycled Water System Performance and Operational Criteria .................................................................................................. 6-16 Table 7-1. Existing Surface Water Intake Pumps(a) ............................................................................. 7-3 Table 7-2. Existing Groundwater Wells ............................................................................................... 7-5 Table 7-3. Existing Treated Water Storage Facilities .......................................................................... 7-6 Table 7-4. Existing Booster Pump Stations ......................................................................................... 7-7 Table 7-5. Existing Pressure Regulating Stations and Pressure Reducing Valves ............................ 7-9 Table 7-6. Existing Pressure Zone Boundaries ................................................................................. 7-10 Table 7-7. Existing Potable Water Demands by Pressure Zone ....................................................... 7-15 Table 7-8. Comparison of Available and Required Water Treatment Capacity ................................ 7-17 Table 7-9. Comparison of Available and Required Water Storage Capacity .................................... 7-20 Table 7-10. Comparison of Available and Required Firm Pumping Capacity ................................... 7-21 Table 7-11. Recommended Fire Flow Requirements(a) ..................................................................... 7-23 Table 7-12. Results of Additional Fire Flow Simulations ................................................................... 7-31 able 8-1. Existing and Proposed Pressure Zone Boundaries ............................................................. 8-5 Table 8-2. 2025 Potable Water Demands by Pressure Zone ............................................................. 8-6 Table 8-3. Buildout Potable Water Demands by Pressure Zone ........................................................ 8-6 Table 8-4. Summary of Buildout Average Day Potable Water Demands by Development Project .... 8-7 Table 8-5. Comparison of Available and Required Water Treatment Capacity in 2025 ..................... 8-8 Table 8-6. Comparison of Available and Required Water Treatment Capacity at Buildout ................ 8-9 Table 8-7. Comparison of Available and Required Water Storage Capacity in 2025 ....................... 8-12 Table 8-8. Comparison of Available and Required Water Storage Capacity at Buildout .................. 8-13 Table 8-9. Comparison of Available, Proposed, and Required Water Storage Capacity at Buildout ........................................................................................................................ 8-15 Table 8-10. Comparison of Available and Required Firm Pumping Capacity in 2025 ...................... 8-18 Table 8-11. Comparison of Available, Proposed, and Required Firm Pumping Capacity at Buildout ........................................................................................................................ 8-19 Table 8-12. Recommended Fire Flow Requirements(a) ..................................................................... 8-27 Table 8-13. Results of Additional Fire Flow Simulations for 2025 System........................................ 8-32 Table 8-14. Results of Additional Fire Flow Simulations for Buildout System .................................. 8-38 Table 9-1. Existing Recycled Water Booster Pump Station ................................................................ 9-2 Table 9-2. Recycled Water Distribution Pressure Zones .................................................................... 9-8 Table 9-3. Recycled Water Demand Peaking Factors ........................................................................ 9-8 Table 9-4. Buildout Recycled Water Demands by Pressure Zone ...................................................... 9-9 Table 9-5. Summary of Buildout Average Day Recycled Water Demands by Development Project ....................................................................................................... 9-10 Table of Contents
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Table 9-6. Projected Buildout Recycled Water Supply and Demand ................................................ 9-11 Table 9-7. Diurnal Storage Distribution ............................................................................................. 9-12 Table 9-8. Recycled Water Distribution System Pump Station Design Criteria ................................ 9-13 Table 10-1. Probable Construction Costs for the Recommended Existing Potable Water System CIP .......................................................................................................... 10-4 Table 10-2. Probable Construction Costs for the Recommended 2025 Potable Water System CIP .......................................................................................................... 10-9 Table 10-3. Probable Construction Costs for Recommended Buildout Potable Water System CIP ........................................................................................................ 10-13 Table 10-4. Probable Construction Costs for the Recommended 2025 Recycled Water System CIP ........................................................................................................ 10-16 Table 10-5. Probable Construction Costs for the Recommended Buildout Recycled Water System CIP ........................................................................................................ 10-19 List of Figures
Figure ES-1. Existing and Planned Future Water Supplies vs. Water Demand at Buildout ............ ES-8 Figure ES-2. Recommended Existing Potable Water System Improvements ............................... ES-12 Figure ES-3. Recommended Future Potable Water System Program Improvements ................... ES-13 Figure ES-4. Recommended Future Recycled Water System Program Improvements ................ ES-19 Figure 3-1. General Plan Land Use ..................................................................................................... 3-2 Figure 3-2. Approved Projects ............................................................................................................. 3-4 Figure 3-3. Additional Planned Development ...................................................................................... 3-7 Figure 4-1. Water Service Area ........................................................................................................... 4-2 Figure 4-2. Historical Population Served (1990-2020) ........................................................................ 4-5 Figure 4-3. Historical Annual Water Production (1990-2020) ............................................................. 4-9 Figure 4-4. Comparison of Historical Per Capita Water Demand, Production and Population ......... 4-15 Figure 4-5. Residential Unit Water Demand Factor Methodology ..................................................... 4-23 Figure 4-6. Representative Commercial and Industrial Areas .......................................................... 4-26 Figure 5-1. Historical Water Supplies .................................................................................................. 5-4 Figure 7-1. Existing Potable Water System Facilities .......................................................................... 7-2 Figure 7-2. New and Revised Existing System Facilities .................................................................. 7-13 Figure 7-3. Allocated Water Meters ................................................................................................... 7-16 Figure 7-4. Existing System Pressures Peak Hour Demand ............................................................ 7-25 Figure 7-5. Existing Pipeline Velocities Peak Hour Demand ............................................................ 7-26 Figure 7-6. Existing System Available Fire Flow ............................................................................... 7-29 Figure 7-7. Locations of Additional Simultaneous Fire Flow Simulations ......................................... 7-30 Figure 7-8. Existing System Recommended Improvements ............................................................. 7-33 Table of Contents
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Figure 7-9. Existing System Recommended Improvements from Hydraulic Evaluation ................... 7-34 Figure 8-1. Proposed Development Areas and Pressure Zone Boundaries ....................................... 8-4 Figure 8-2. 2025 Potable Water System Facilities ............................................................................ 8-24 Figure 8-3. Buildout Potable Water System Facilities ....................................................................... 8-25 Figure 8-4. 2025 System Pressures Peak Hour Demand ................................................................. 8-29 Figure 8-5. 2025 Pipeline Velocities Peak Hour Demand ................................................................. 8-30 Figure 8-6. 2025 System Available Fire Flow .................................................................................... 8-33 Figure 8-7. 2025 System Locations of Additional Simultaneous Fire Flow Simulations ................... 8-34 Figure 8-8. Buildout System Pressures Peak Hour Demand ............................................................ 8-36 Figure 8-9. Buildout Pipeline Velocities Peak Hour Demand ............................................................ 8-37 Figure 8-10. Buildout System Available Fire Flow ............................................................................. 8-39 Figure 8-11. Buildout System Locations of Additional Simultaneous Fire Flow Simulations ............ 8-40 Figure 8-12. Proposed Future Water System Recommended Improvements .................................. 8-42 Figure 8-13. 2025 System Recommended Pipeline CIP ................................................................... 8-43 Figure 9-1. Existing Recycled Water System Facilities ....................................................................... 9-3 Figure 9-2. Buildout Recycled Water System Facilities....................................................................... 9-5 Figure 9-3. DMC Exchange Pipeline Alternatives ............................................................................. 9-15 Figure 9-4. Buildout Recycled Water Peak Hour Demand ................................................................ 9-17 Figure 9-5. Buildout Recycled Water Fill Period ................................................................................ 9-19 Figure 9-6. Proposed Future Recycled Water System Improvements .............................................. 9-21 Figure 10-1. Recommended Existing Potable Water System Improvements ................................... 10-5 Figure 10-2. Recommended Future Potable Water System Program Improvements ...................... 10-8 Figure 10-3. Recommended Future Recycled Water System Program Improvements .................. 10-17 Table of Contents
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List of Acronyms and Abbreviations
2018 Bay-Delta Water
Quality Control Plan
2018 Water Quality Control Plan for the San Francisco Bay/Sacramento- San Joaquin Delta Estuary
5-1
AB Assembly Bill 2-1
AC Asbestos Cement 7-12
ADUs Accessory Dwelling Units 3-4
af/ac/yr Acre-Feet Per Acre Per Year 4-25
af/yr Acre Feet Per Year
ASR Aquifer Storage and Recovery 5-2
AWWA American Water Works Association 6-7
BBID Byron Bethany Irrigation District 4-6
BCID Banta-Carbona Irrigation District 5-2
BMOs Basin Management Objectives 5-12
BMP Best Management Practices 4-17
BPS Booster Pump Station 7-7
CARB California Air Resources Board 2-1
CBSC California Building Standards Commission 2-7
CFC California Fire Code 6-3
CI Cast Iron 7-12
CIP Capital Improvement Program 7-1
City City of Tracy 1-1
CUWCC California Urban Water Conservation Council 4-17
CVP Central Valley Project 5-2
DDW Division of Drinking Water 6-2
DI Ductile Iron 7-12
DMC Delta-Mendota Canal 5-2
DWR Department of Water Resources 5-11
EIRs Environmental Impact Reports 3-2
EPA Environmental Protection Agency 6-2
FAR Floor to Area Ratios 4-22
fps Feet Per Second 9-15
ft/kft Feet Per Thousand Feet 6-10
GEI GEI Consultants 5-10
GHG Greenhouse Gas 2-1
GIS Geographic Information System 7-1
GMO Growth Management Ordinance 4-3
GMP Groundwater Management Plan 5-11
gpcd Gallons Per Capita Per Day 2-12
gpm Gallons Per Minute 2-7
GSA Groundwater Sustainability Agency 5-13
GSP Groundwater Sustainability Plan 5-13
IPC International Park of Commerce 3-3
JJWTP John Jones Water Treatment Plant 4-6
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K/J/C Kennedy/Jenks/Chilton 5-10
LEED Leadership in Energy and Environmental Design
Legislature California State Legislature 4-18
lf Linear Feet
M&I Municipal & Industrial 5-4
MG Million Gallons 7-4
mgd Million Gallons per Day 5-6
MOA Memorandum of Agreement 5-13
MSR Municipal Service Review 3-5
MWELO Model Water Efficient Landscape Ordinance 2-3
NEI Northeast Industrial Area 3-4
NFPA National Fire Protection Association 6-7
NRW Non-Revenue Water 4-6
O&M Operations and Maintenance 2-9
PPBP Patterson Pass Business Park 4-8
PRS Pressure Regulating Station 7-9
PRV Pressure Reducing Valve 7-9
psi Pounds Per Square Inch 9-7
PSV Pressure Sustaining Valve 7-9
R&R Renewal and Replacement
RGA Residential Growth Allotment 4-3
RWQCB Regional Water Quality Control Board 5-16
SB Senate Bill 2-1
SB X7-7 Water Conservation Act of 2009 2-1
SCADA Supervisory Control and Data Acquisition 1-
SCS Sustainable Community Strategy 2-1
SCWSP South County Water Supply Project 5-2
SED Substitute Environmental Document 5-9
SGMA Sustainable Groundwater Management Act 2-2
SOI Sphere of Influence 3-1
SSJID South San Joaquin Irrigation District 4-6
SWRCB State Water Resources Control Board 2-3
TDS Total Dissolved Solids 4-6
Tracy Subbasin San Joaquin Valley Groundwater Basin-Tracy Subbasin 5-9 UAFW Unaccounted-for Water 4-6
USBR United States Bureau of Reclamation 4-6
UWMP Urban Water Management Plan 2-2
VFD Variable Frequency Drive 7-3
VVH VVH Consulting Engineers 8-21
WSCP Water Shortage Contingency Plan 2-3
WSID West Side Irrigation District 5-2
WSMP Water System Master Plan 8-1
WWTP Wastewater Treatment Plant 9-1
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ES 1
CITYWIDE WATER SYSTEM MASTER PLAN UPDATE
EXECUTIVE SUMMARY
PURPOSE FOR THE CITYWIDE WATER SYSTEM MASTER PLAN UPDATE The purpose of this Citywide Water System Master Plan Update for the City of Tracy (City) is to provide an evaluation of the required backbone potable water and recycled water system facilities required to serve existing and future needs. The City’s last C itywide Water System Master Plan was completed in 2012 (2012 WSMP) and was based on projected land uses included in the City’s 2011 General Plan. Since that time, significant new residential and commercial development has occurred in the City (including th e International Park of Commerce within the Cordes Ranch Specific Plan area, Tracy Ellis, Tracy Hills and numerous smaller projects) and planning for future developments has been refined. Also, during that same time, the State endured five years of drought starting in 2012, including the driest four consecutive years in California history. These unprecedented conditions led to statewide mandated water conservation, significant surface water supply reductions and curtailments and legislation establishing new water efficiency standards.
All of these factors have led to a need to reevaluate the City’s potable water and recycled water needs, the projected availability and reliability of the City’s water supplies and the required water system infrastructure impr ovements to ensure a safe and reliable water supply for the City’s residents and businesses.
OBJECTIVES OF THE CITYWIDE WATER SYSTEM MASTER PLAN UPDATE This Citywide Water System Master Plan Update has been prepared based on the following overall water system objectives and goals:
• Ensure safe, adequate and reliable water supplies for the City’s existing and future residents and businesses.
• Support the goals, objectives and policies of the City’s General Plan, particularly those contained in the Public Facilities and Services Element. • Comply with existing and future legislation and regulations for both potable and non-potable (recycled) water supplies.
Based on the City’s water system objectives, the objectives of this Citywide Water System Master Plan Update are to:
• Evaluate existing water demands to understand current water use patterns and trends and project future water demands for near-term (2025), future (2040) and General Plan buildout conditions.
• Provide an updated evaluation of the availability and reliability of the City’s existing and future water supplies and their ability to meet existing and future water demands considering recent changes in projected supply reliability.
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• Review and refine performance and operational criteria under which the potable and recycled water systems will be analyzed and recommendations for future facilities will be formulated.
• Evaluate the need for new backbone potable water facilities (including pipelines, storage facilities and pumping facilities) to serve buildout of the City’s General Plan. • Evaluate the need for new backbone recycled water facilities (including pipelines, storage facilities and pumping facilities) to serve buildout of the City’s General Plan. • Develop a capital improvement program for recommended potable and recycled water system facilities.
KEY CHANGES FROM THE 2012 CITYWIDE WATER SYSTEM MASTER PLAN This Cityside Water System Master Plan Update incorporates and considers several changed conditions, new water system facilities, and new water supply opportunities from what was included in the 2012 Citywide Water System Master Plan. A summary of these is provided below:
• Changes in Projected Land Use: Compared to the projected land use in 2012 Citywide Water System Master Plan, there has been a significant shift in the City’s projected land use composition towards residential development and away from commercial and industrial development. However, when compared to the City’s historical and existing land uses, which were primarily residential, the projected land uses for new development are more heavily skewed to non-residential uses (with almost 60 percent of the projected acres of new development being non-residential uses). The future industrial, commercial, and retail growth anticipated in the City’s Sphere of Influence is reflective of the City’s goal to bring jobs and economic growth and improve the City’s jobs-housing balance (see Chapter 3 for additional information).
• Reduction in Unit Water Demands: Due to changes in water use trends and habits resulting from improved water use efficiency, unit water demand factors have been reduced for most land use categories (see Chapter 4 for additional information). • Reduction in Maximum Day and Peak Hour Demand Factors: Due to changes in water use trends and habits from improved water use efficiency, maximum day and peak hour demand factors have been reduced (see Chapter 4 for additional information). • Changes in Recycled Water System Planning: Previously, the City was considering implementing the proposed Gateway Exchange Program, under which recycled water service would be extended to most of the existing parks and large irrigated areas in the City to offset the potable water demands from the Gateway development (now called Westside). The Gateway Exchange Program is no longer being considered, and it is projected that only a few existing parks and irrigated areas will receive recycled water supply. Expansion of the recycled water system will focus on extending service to newly developed areas (see Chapters 4 and 9 for additional information).
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• Reduction in Surface Water Supply Reliability: Due to unprecedented drought conditions from 2011 through 2017 and new flow restrictions resulting from the 2018 Water Quality Control Plan for the San Francisco Bay/Sacramento-San Joaquin Delta Estuary, projected reliabilities of surface water supplies from the Central Valley Project (CVP) and South San Joaquin Irrigation District (SSJID) have been significantly reduced, particularly in dry years. The City has entered into discussions with the Contra Costa Water District and the San Luis & Delta-Mendota Water Authority to explore the City’s potential participation in the Phase 2 Los Vaqueros Reservoir Expansion Project to increase the City’s water supply reliability by providing storage of supplies for use in dry years (see Chapter 5 for additional information).
• Proposed Recycled Water Exchange Agreement: The City is evaluating the potential for indirect reuse of its available recycled water through an exchange agreement with the United States Bureau of Reclamation (USBR) whereby a portion of the City’s tertiary-treated wastewater (recycled water) would be discharged to the Delta Mendota Canal (DMC) and a like amount of water (i.e., a one-to-one exchange) could then be diverted from the DMC by the City for treatment at the City’s John Jones Water Treatment Plant (JJWTP) for potable use. Such supplies would be 100 percent reliable and would not be subject to drought cutbacks. With the potential reduction in reliability of the City’s surface water supplies from the CVP and SSJID, this proposed recycled water exchange agreement will be a critical component of the City’s future water supply portfolio (see Chapter 5 for additional information). • Reduction in Emergency Storage Requirement: The 2012 WSMP used an emergency storage volume requirement of two (2) times the average day demand. After reviewing emergency storage criteria for other similar water systems within the region, and taking into account the City’s redundant sources of supply (CVP, SSJID, and groundwater), it is recommended that the City reduce the minimum quantity of emergency storage volume required to 1.5 times the average day demand for this Citywide Water System Master Plan Update (see Chapter 6 for additional information).
• Addition of New Water System Facilities: Several new water system facilities have been recently completed which provide for added water system capabilities. These include the Cordes water storage tank and pump station, the Tracy Hills water storage tank and pump station (nearing completion as of September 2021), new pump stations at the City’s JJWTP to serve the City’s Pressure Zone 3 and initial phases of the Tracy Hills development, and a recycled water pump station and pipeline on the west side of the City to distribute recycled water supplies from the City’s Wastewater Treatment Plant to recycled water users on the western side of the City (see Chapters 7 and 9 for additional information).
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• Renaming of Potable Water Pressure Zones: To minimize confusion when referring to the City’s primary potable water system pressure zones, the potable water system pressure zones have been renamed as follows:
— Pressure Zone 1 – no change
— Pressure Zone 2 – no change
— City-side Pressure Zone 3 – now referred to as Pressure Zone 3 — Tracy Hills Pressure Zone 3 – now referred to as Pressure Zone 4 — Tracy Hills Pressure Zone 4 – now referred to as Pressure Zone 5 — Tracy Hills Pressure Zone 5 – now referred to as Pressure Zone 6 The remainder of this Citywide Water System Master Plan Update, and all subsequent water system evaluations and studies, will utilize these new pressure zone designations.
EXISTING AND PROJECTED FUTURE WATER DEMANDS
The City of Tracy currently serves a population of about 96,000 people. Total potable water production in 2020 was 18,687 acre-feet per year (af/yr), not including water treated and wheeled to the Patterson Pass Business Park, which equates to a per capita water use of about 174 gallons per capita per day (gpcd). This per capita water use is significantly lower than the City’s historical per capita water use which was as high as 300 gpcd in the early 1980s. Per capita water use was as low as 14 4 gpcd in 201 5 due to extreme drought conditions which resulted in voluntary and mandatory water conservation. The per capita water use has increased somewhat in recent years as water use restrictions have been lifted and customers have resumed more typical water use behavior.
As described in Chapter 4, future water demands for buildout of the City’s General Plan were projected based on revised unit water demand factors reflecting recent water use patterns and trends for the City’s various land uses, consistency with th e Model Water Efficient Landscape Ordinance (MWELO) for landscape irrigation water use and the use of recycled water for landscape irrigation for selected land use designations.
With the planned buildout of the City’s sphere of influence ( SOI), the City’s population is projected to increase to about 186,000 people. At buildout, potable water demands are projected to be about 33,500 af/yr, while recycled water demands (for irrigation of landscaped areas) are projected to be 6,300 af/yr. As noted in the City’s 2012 WSMP, the City’s future use of recycled water for non-potable uses such as landscape irrigation is key to the reduction (offset) of the City’s future potable water demand, and the City’s ability to meet future demands using existing and future available water supplies.
A summary of the projected future water demands and water production at 2025 (near -term), at 2040, and at buildout, is provided in Table ES-1.
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Table ES-1. Summary of Future Projected Water Production (a,b,c) Demand Category
2025 (Near Term) 2040 Buildout
Potable
Water,
af/yr
Recycled
Water,
af/yr
Potable
Water,
af/yr
Recycled
Water,
af/yr
Potable
Water,
af/yr
Recycled
Water,
af/yr
Future 3,000 900 10,900 4,100 15,700 6,200
Existing - City(d) 17,800 100 17,800 100 17,800 100
Total to be Met by City Water
Supply Contracts and Rights 20,800 1,000 28,700 4,200 33,500 6,300 Existing - PPBP Wheeled Water(e) 600 0 600 0 600 0
Total to be Delivered by
City Distribution System 21,400 1,000 29,300 4,200 34,100 6,300 (a) Refer to Appendix A for detailed water demand calculations. (b) Includes unaccounted for water.
(c) Totals rounded to the nearest hundred.
(d) Includes water delivered to existing buildings in the International Park of Commerce (IPC). (e) Does not include water delivered to existing buildings in IPC.
As the City continues to develop, potable water consumption between customer classes is expected to shift due to changes in the City’s projected land use composition. A comparison of the historical average and projected potable water consumption by customer class is shown in Table ES-2. As shown, the residential customer classes are expected to decrease their overall potable water consumption proportion as water use shifts towards non-residential customer classes. This trend is primarily due to large industrial developments such as Cordes Ranch, West Side Industrial, East Side Industrial, UR 3, and Tracy Hills Phase 5, among others.
Table ES-2. Historical and Projected Potable Water Consumption by Customer Class Customer Class
Historical Average
Annual
Consumption(a)
Projected Annual
Consumption in
2025(b)
Projected Annual
Consumption
in 2040(b)
Projected Annual
Consumption at
Buildout(b)
Single Family Residential(c) 60.1% 58.0% 54.0% 53.3%
Multi-Family Residential(d) 6.7% 7.6% 6.9% 8.5%
Residential Subtotal 66.8% 65.6% 60.9% 61.7%
Commercial(e) 15.4% 13.5% 14.2% 14.2%
Industrial 4.9% 9.3% 16.4% 17.6%
Irrigation(f) 12.9% 11.6% 8.4% 6.5%
Total 100% 100% 100% 100%
(a) Refer to Table 4-4.
(b) Includes existing and projected future potable demands. (c) Includes projected future residential demands (excluding irrigation) for Residential - Very Low Density, Residential - Low Density, and Residential - Medium Density land use types. (d) Includes projected future residential demands (excluding irrigation) for Residential - High Density and Residential - Very High Density land use types.
(e) Includes projected future demands (excluding irrigation) for Commercial, Office, and Institutional land use types. (f) Includes projected future irrigation demands to be served by potable water. Accounts for planned conversions of irrigation services to recycled water use.
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Landscape irrigation water use is projected to be a much smaller proportion of the City’s potable water use at buildout because many new development are as will be served by the recycled water system at buildout, and some of the City’s existing irrigated areas will be converted to recycled water use.
EXISTING AND PROJECTED FUTURE WATER SUPPLIES
Chapter 5 of this Citywide Water System Master Plan Update describes updates to the City’s water supply availability and reliability which have occurred since the completion of the 2012 WSMP and the City’s 2015 Urban Water Management Plan (2015 UWMP). The water supply availability and reliability described in Chapter 5 is consistent with the City’s 2020 UWMP, which was adopted in June 2021.
Existing Water Supplies
The City currently receives water supplies from the following sources:
• Untreated surface water from the DMC (CVP) (treated at the City’s John Jones Water Treatment Plant (JJWTP))
• Untreated surface water from Byron Bethany Irrigation District (BBID) pre-1914 rights (treated at the City’s JJWTP)
• Treated surface water from the Stanislaus River via the South County Water Supply Project (SCWSP) (treated and delivered to the City by the SSJID) • Groundwater pumped from eight groundwater wells located within the City Since the completion of the 2012 WSMP and the 2015 UWMP, the availability and reliability of the City’s water supplies have been impacted by drought conditions and associated unprecedented cutbacks in surface water supply deliveries. Also, in recent years new legislation has been passed which will impact future water use and future water supply availability an d reliability, including the Sustainable Groundwater Management Act (SGMA), SB 606 and Assembly Bill 1668 Making Water Conservation a California Way of Life and most recently the 2018 amendments to the Water Quality Control Plan for the San Francisco Bay/Sacramento-San Joaquin Delta Estuary (Bay-Delta Plan Amendment) which was adopted by the State Water Resources Control Board ( SWRCB) in December 2018 and restricts the use of flows from the Lower San Joaquin River and its tributaries (the Stanislaus, Tuolum ne and Merced Rivers) to improve conditions for fish and wildlife.
Specifically, it restricts the use of flows until 40 percent of unimpaired flows are rededicated for water quality and instream fisheries. The Bay-Delta Plan Amendment, depending on its act ual implementation, has potential impacts to the water supplies that the City receives from SSJID.
Also, in 2017, new guidelines and procedures went into effect associated with the updated CVP M&I Water Shortage Policy, which base dry year allocations on a contractor’s historical use of CVP supplies, not its contractual amount of CVP supplies.
These changed conditions significantly impact the availability and reliability of the City’s surface water supplies in dry years (specifically the City’s CVP supplies and SSJID supplies).
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Future Water Supplies
The City has a projected potable water supply production requirement of 33,500 af/yr for buildout of the City’s General Plan. The City will need to develop future water supplies to meet these projected future de mands. This will include expansion of its Aquifer Storage and Recovery Program (up to 1,000 af/yr) and implementation of a proposed Recycled Water Exchange Program (up to 7,500 af/yr) to meet its projected future potable water demands. Furthermore, 6, 300 af/yr recycled water will be needed to meet landscape irrigation demands at buildout.
The City’s Aquifer Storage and Recovery (ASR) Program should be expanded in the future to provide up to 1,000 af/yr of supply . As described in Chapter 5, an evaluation of potential ASR options and operational scenarios should be conducted as additional ASR wells are planned to determine if dedicated SSJID supply pipelines to the ASR wells will be required if the City’s ASR permit cannot be modified to allow for other supplies to be injected.
The proposed Recycled Water Exchange Program would provide for the potential for indirect use of its available recycled water through an exchange agreement with the USBR whereby a portion of the City’s tertiary-treated wastewater (recycled water) would be discharged to the DMC and a like amount of water (i.e., a one -to-one exchange) could then be diverted from the DMC by the City for treatment at the City’s JJWTP for potable use. Such supplies would be 100 percent reliable and would not be subject to drought cutbacks. The project would require development of a project description, NEPA/CEQA review, approval of an exchange agreement, design and construction of a recycled water pipeline that could discharge recycled water to the DMC downstream of the City’s JJWTP intake and expansion of the City’s wastewater treatment plant. Additional discussion of the pipeline required for the Recycled Water Exchange Program is provided in Chapter 9. If such a project is approved and implem ented, the City anticipates that it would initially provide up to 5,900 af/yr of additional potable water supplies to the City, with future expansion as needed to meet future demands.
As shown on Figure ES-1, even with additional supplies, the City may experience water supply shortages in dry years. Table ES-3 provides a summary of the projected water supply needs to meet the single dry year conditions (the most critical hydrologic condition) under the City’s projected near-term (2025), future (2040) and buildout demand conditions. As shown, the projected potable water supplies are less than the projected potable water demands, indicating that the City would need to implement its Water Shortage Contingency Plan to reduce wate r demands and/or develop additional water supplies to meet the projected water demands. Chapter 5 provides a summary of the City’s water management strategies and options, including participation in the Phase 2 Los Vaqueros Reservoir Expansion Project, as described in the City’s 2020 UWMP.
Executive Summary
ES-8 City of Tracy
May 2023 Citywide Water System
n\c\404\12-18-41\wp\R-404-WMPU Master Plan Update
Figure ES-1. Existing and Planned Future Water Supplies vs. Water Demand at Buildout
Executive Summary
ES-9 City of Tracy
May 2023 Citywide Water System
n\c\404\12-18-41\wp\R-404-WMPU Master Plan Update
Table ES-3. Future Water Supply Needs under Single Dry Year Conditions
Near-Term
(2025),
af/yr
Future
(2040),
af/yr
Buildout,
af/yr Comments
Existing Potable Water Supplies
CVP Surface Water Supplies 1,483 1,483 1,483 Based on 25% of historical use SSJID Surface Water Supplies 9,974 6,177 6,177 2025 supply includes temporary contract with City of
Escalon (which ends in 2025)
and a 76% allocation; 2040
and buildout supply assumes a
56% allocation
BBID Pre-1914
(to meet Tracy Hills demand)
800 2,500 3,300 Based on projected potable
water demand at Tracy Hills;
see Appendix A
Groundwater 4,500 4,500 4,500 Increased from normal year supply of 2,500 af/yr
Total Existing
Potable Water Supplies
16,757 14,660 15,460
Existing Dry Year Water Supplies
Semitropic Dry Year Supply 0 0 0 Assumed to not be available in Single Dry Years
ASR Dry Year Supply 700 1,000 1,000 Existing capability is 700 af/yr for Well 8; additional ASR wells
would be needed for expansion
of the ASR program
Total Existing
Dry Year Water Supplies
700 1,000 1,000
Future Potable Water Supplies
Recycled Water Exchange 0 5,000 7,500
Total Future Potable Water
Supplies
0 5,000 7,500
Total Potable Water Supplies 17,457 20,660 23,960
Potable Water Demand 20,800 28,700 33,500 See Table 4-16 in Chapter 4 Recycled Water
Recycled Water Demand for
Landscape Irrigation
1,000 4,200 6,300 See Table 4-16 in Chapter 4
Total Recycled Water Needed,
af/yr
1,000 9,200 13,800 As needed to meet needs for
Recycled Water Exchange and
Landscape Irrigation Total Recycled Water Needed
(average day), mgd
0.9 8.2 12.3
Subsequent revisions to the projected potable water demand and/or the water supply availability and reliability assumptions may change the required quantities and timing of the proposed Recycled Water Exchange Program. However, even if the required quantit ies or timing are modified in the future, the direct use of recycled water for landscape irrigation demands and indirect use of recycled water as part of the proposed Recycled Water Exchange Program will be critical components of the City’s future water supply portfolio.
Executive Summary
ES-10 City of Tracy
May 2023 Citywide Water System
n\c\404\12-18-41\wp\R-404-WMPU Master Plan Update
The planned future direct and indirect use of recycled water will also require an expansion of the City’s Wastewater Treatment Plant (WWTP) to produce adequate quantities of recycled water to meet both the future Recycled Water Exchange Program needs (indirect use), as well as the landscape irrigation demands (direct use), at buildout.
It should also be noted that supply availability and reliability, and actual water demands, may change in the future. As such, the City may need to acquir e additional potable water supplies in the future. The City will need to closely track actual potable water demands and supply availability and reliability as future service areas are approved and developed to determine if existing and future supplies are adequate and/or if and when additional potable or recycled water supplies may be required.
EVALUATION OF EXISTING AND FUTURE POTABLE WATER SYSTEM
Chapters 7 and 8 of this Citywide Water System Master Plan Update identify the improvements necessary to eliminate existing deficiencies and support the City’s projected future potable water demands, respectively. Recommended improvements are based on evaluations of the existing and future (2025 and buildout) potable water system’s treatment, storage, and pumping capacities, as well as its ability to meet recommended performance and operational criteria under maximum day demand plus fire flow and peak hour demand scenarios.
Facility improvements are identified at a Master Plan level and do not necessarily include a ll required on-site infrastructure nor constitute design of improvements. Subsequent detailed design is required to determine the sizes and locations of the proposed improvements. Further, the hydraulic model is not an “all pipes” model (i.e., not all smal ler diameter pipelines are included), so the hydraulic simulations performed may not identify all necessary water system improvements.
West Yost recommends conducting additional hydraulic evaluations as development details become available.
The following r ecommendations exclude non-backbone facilities that only serve a specific development, instead focusing on backbone facility improvements with more widespread system benefit. These shared facilities are designated program facilities.
Existing Potable Water System
The City’s existing potable water system includes the following major facilities: JJWTP, eight groundwater wells, clearwells and storage tanks, booster pump stations, pressure regulating stations, and transmission and distribution system pipelines. The City’s existing distribution system is divided into four pressure zones. Significant new infrastructure has been constructed in recent years to serve new development projects, including new pump stations at the JJWTP to serve Pressure Zones 3 and 4, a new storage tank and pump station in the Cordes Ranch area, and a new storage tank and pump station in Tracy Hills.
Executive Summary
ES-11 City of Tracy
May 2023 Citywide Water System
n\c\404\12-18-41\wp\R-404-WMPU Master Plan Update
Recommendations for the existing potable water distribution system are shown on Figure ES-2 and described below. These existing system improvements are recommended based on existing water demands, and are not triggered by future new development. The existing water system infrastructure in the areas listed below is insufficient to meet the fire flow requirements based on existing land use and water demands. As such, planning and design for these improvements should be prioritized.
Pipeline Improvements
The following pipeline improvements are recommended:
• Improvement #1:
— Replace the existing pipelines in 20th Street between Bessie Avenue and Parker Avenue, Wall Street between Lowell Avenue and 20th Street, Emerson Avenue between Bessie Avenue and Holly Drive, Court Drive between Whittier Avenue and Lowell Avenue, and Lowell Avenue between Parker Avenue and Holly Drive with approximately 6,000 linear feet (lf) of new 8-inch diameter pipelines.
• Improvement #2:
— Install approximately 515 lf of 12-inch diameter pipeline in Ninth Street between School Street and Tenth Street.
• Improvement #3:
— Replace approximately 485 lf of existing 4-inch diameter pipeline in Tracy Boulevard north of Mount Diablo Avenue with new 12-inch diameter pipeline. 2025 Potable Water System
Program facility recommendations for the 2025 potable water system are shown on Figure ES-3 and described below. A complete listing of recommended potable water system improvements (both program and non -program) to serve projected 2025 potable water demands is provided in Chapter 8 along with recommendations for their timing.
Pipeline Improvements
• To serve 2025 potable water demands, replace existing pipelines in Sixth Street, Tracy Boulevard, and Eleventh Street with approximately 1,390 linear feet of new 18-inch and 24-inch diameter pipelines.
New Potable Water Pipelines
• To serve 2025 potable water demands, install approximately 43,010 lf of new pipelines ranging in diameter from 12 to 24 inches.
0 6,0003,000
Scale in Feet
Figure ES-2
Recommended Existing
Potable Water System
Improvements
City of Tracy
Water System Master Plan Update
Last Saved: 10/16/2020 3:39:10 PM N:\Clients\404 Tracy\12-18-41 Water Master Plan Update\GIS\MXD\Report Figures\Fig_ES-2_ECIP_Improvements.mxd : nhoman Notes:
1. The City's existing hydraulic model is not an
all pipes model. Some pipes which are not
hydraulically significant were excluded from
the model.
Symbology
Existing Pipeline
Pipeline Improvement
Pressure Regulating Station
Booster Pump Station
Groundwater Well
Storage Tank
John Jones Water Treatment Plant
Pressure Zone
Zone 1
Zone 2
Zone 3 (IPC/PPBP)
Ellis Reduced Zone
580
205
#1
#2
#3
SCHULTE RD
SCHULTE RD
ELEVENTH ST
LINNE RD
CORRAL HOLLOW RD
TRACY BL
BYRON RD
GRANT LINE RD
HANSEN RD
VALPICO RD
NAGLEE RD
MIDDLE RD
REEVE RD
VON SOSTEN RD
M
AC
ARTHUR
DR
CHRISMAN RD
BANTA RD
LAMMERS RD
C a l i f or ni a
A q u e d u c t
Del ta- M e n d o ta
C
a n a l
Ball Park Well
8"
8"
8"
8"
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8" 8"
8"
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COURT DR
CARLTON WY
LOWELL AV
TRACY BL
TWENTY-THIRD ST
BESSIE AV
PARKER AV
EMERSON AV
WALL ST
PEREIRA AV
TWENTIETH ST
WHITTIER AV
TWENTY-SECOND ST
TWENTY-FIRST ST
HOLLY DR
ELEVENTH ST
GONZALEZST
GILLETT AL
GRUNAUER AL
SPUR LINE RR
NINTH ST
SIXTH ST
M
AC
ARTHUR
DR
EIGHTH ST
JACKSON AL
EAGAN AL
SEVENTH ST
TENTH STCIVIC CENTER PZ
HAMILTON AL
E ST
F ST
EAST ST
SCHOOL ST
CIVIC CENTER DR
12"
12"
10"
12" 10"
6"
8"
6"
8"
12" 10"
12"
8"
8"
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6"
6"
8"
20"
12"
8"
8"8"
6" 12"
12"
8"
6"
12" TENNIS LN
RODEO WY
WEST CT
MT DIABLO AV
FOURTH ST
BURLINGTON DR
TRACY BL
RENOWN DR
12"
8"
12"
8"
8"
8"
12"
10"
12"
8"
8"
12"
36"
12"
12"
6"
0 400200
Scale in Feet
0 400200
Scale in Feet
0 550275
Scale in Feet
INSET #1
CIP ID: ECIP-PI-1
INSET #2
CIP ID: ECIP-PI-2
INSET #3
CIP ID: ECIP-PI-3
3Q
UT
UT
UT
UT
UT
WW WW W
W
7n
!(
!( !(
!(
!(!(!(
!( !(
!(!(
XW
XWXW XWXW XW
XW
XW
XW
XW
¼ÐÚ
¼ÐÚ
¼ÐÚ
¼ÐÚ
¼ÐÚ
¼ÐÚ
¼ÐÚ
¼ÐÚ
¼ÐÚ 7n
7n
7n
7n
7n
7n
7n
7n
7n
7n
§¨¦
580
§¨¦
580
§¨¦
205
§¨¦
205
§¨¦
580
a
BCIP-T-WS
BCIP-PS-WSZ1&2
BCIP-W-WS
BCIP-W-WA
BCIP-W-LP
From Mossdale BPS
←
1234
5 6
BCIP-PRV-AV
BCIP-PRS-WS
BCIP-W-EL
a
NCIP-PRV-2NCIP-PRV-1
BCIP-PRV-C
Equip wells with
ammonia addition
O ld Rive
r
C a l i f o r n i a
A q u ed u c t
D e l t a - M e n d o t a C a n a l
SCHULTE CT
ELEVENTH ST
CORRAL HOLLOW RD
M
AC
ARTHUR
DR
TRACY BL
BYRON RD
GRANT LINE RD
MOUNTAIN HOUSE PK
BANTA RD
HANSEN RD
VALPICO RD
BIRD RD
LOVELY RD
LAMMERS RD
CHRISMAN RD
NAGLEE RD
LINNE RD
HOLLY DR
BETHANY RD
MIDDLE RD
VON SOSTEN RD
AHERN RD
REEVE RD
DURHAM FERRY RD
SCHULTE RD
16"
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0 5,5002,750
Scale in Feet
Figure ES-3
Recommended Future
Potable Water System
Program Improvements
City of Tracy
Water System Master Plan Update
Last Saved: 3/21/2022 11:42:44 AM N:\Clients\404 Tracy\12-18-41 Water Master Plan Update\GIS\MXD\Report Figures\Fig_ES-3_Program Facilities.mxd : cpittner Notes:
1. The City's hydraulic model is not an all
pipes model. Some pipes which are not
hydraulically significant were excluded
from the model.
2. Jack and bore pipeline projects are not
shown, but jack and bore is required for
canal, railroad, or major highway crossings.
3. Install SCADA system monitoring of flows
and pressures at each new facility.
4. Install on-site backup power at each new
pumping facility.
5. Only existing and program facilities are
shown.
Symbology
Proposed Buildout Program Facilities
XW Buildout Pressure Regulating Station
!( Buildout Pressure Reducing Valve
¼ÐÚ Buildout Booster Pump Station
7n Buildout Groundwater Well
UT Buildout Storage Tank
Buildout System Pipeline
W SCADA System Improvement
Proposed 2025 Facilities
!( 2025 Pressure Reducing Valve
2025 System Pipeline
2025 Pipeline CIP
Existing System Facilities
XW Existing Pressure Regulating Station
!( Existing Pressure Reducing Valve
¼ÐÚ Existing Booster Pump Station
7n Existing Groundwater Well
UT Existing Storage Tank
3Q John Jones Water Treatment Plant
Existing System Pipeline
Proposed Existing System Pipeline CIP
Pressure Zone
Zone 1
Zone 2
Zone 3
Ellis Reduced Zone
Zone 4
Zone 5
Zone 6
3Q
¼ÐÚ
¼ÐÚ
¼ÐÚ
¼ÐÚ
¼ÐÚ
7n
7n
BCIP-T-CW3
BCIP-PS-Z3
JJWTP Buildout Program Facilities
20"
7n7n
Well #8
NCIP-PI-1&2
ELEVENTH ST
TRACY BL
18"
24"
BCIP-JJWTP (10 mgd expansion to
40 mgd treatment capacity).
Executive Summary
ES-14 City of Tracy
May 2023 Citywide Water System
n\c\404\12-18-41\wp\R-404-WMPU Master Plan Update
Interconnections
• Install PRVs at Schulte Road and Bud Lyons Way and at Schulte Road and Pavillion Parkway before the transmission main in Schulte Road is re-zoned to Zone 3.
Re-zoning
• Re-zone the existing transmission mains in Lammers Road, Schulte Road, and Hansen Road from Zone 2 to Zone 3 as described in Appendix D.
Groundwater Wells
• Provide ammonia addition for existing City wells (Lincoln Well, Lewis Manor Well, Park & Ride Well and Ball Park Well) (as noted below under Buildout System Improvements, all future wells are also recommended to be equipped with ammonia addition) .
• A feasibility study is recommended to develop an implementation plan for future ASR expansion.
Buildout Potable Water System
Program facility recommendations for the buildout potable water system are shown on Figure ES-3 and described below. A complete listing of recommended potable water system improvements (both program and non -program) to serve projected buildout potable water demands is provided in Chapter 8 along with recommendations for their timing.
Storage Reservoirs
Planning and design of these new storage facilities should be conducted so that the proposed facilities are constructed and operational in time to serve their respective service areas (e.g., Westside, Zone 5 or Zone 6). Because of the additional operational flexibility that Clearwell #3 would provide, it is recommended that Clearwell #3 be constructed as soon as possible. As noted above, no additional storage facilities are required by 2025, but it is recommended that Clearwell #3 be constructed by no later than 2030.
• Westside Tank: Install a new storage tank with a minimum active storage capacity of 1.0 million gallons (MG).
• JJWTP Clearwell #3: Install a new clearwell with a minimum active storage capacity of 1.0 MG to provide storage for Zone 3.
Executive Summary
ES-15 City of Tracy
May 2023 Citywide Water System
n\c\404\12-18-41\wp\R-404-WMPU Master Plan Update
Groundwater Wells
Planning and design of these new groundwater wells should be phased so that the City’s ASR Program can be expanded as needed to meet the City’s water supply needs, particularly in dry years. A feasibility study for the expansion of the City’s ASR Program is included under the 2025 Potable Water System recommendations listed above.
• Westside: Install a new ASR well with a minimum firm pumping capacity of 2,500 gallons per minute (gpm).
• Wainwright: Install a new ASR well with a minimum firm pumping capacity of 2,500 gpm.
• Larsen Park: Install a new ASR well with a minimum firm pumping capacity of 2,500 gpm.
• Ellis: Install a new ASR well with a minimum firm pumping capacity of 1,000 gpm.
Booster Pump Stations
Planning and design of these new booster pumping facilities should be coordinated with the construction of other related facilities (e.g., associated storage tanks) and the timing of new development.
• Zone 3 BPS (JJWTP): Install additional Zone 3 booster pumps at the JJWTP with a minimum firm pumping capacity of 1,500 gpm.
• Westside Zone 1 Tank: Install a new booster pump station with a minimum firm pumping capacity of 4,500 gpm.
• Westside Zone 2 Tank: Install a new booster pump station with a minimum firm pumping capacity of 2,400 gpm.
New Potable Water Pipelines
Planning and design of these new pipelines should be coordinated with the timing of new development.
• To serve buildout potable water demands, install approximately 131,280 lf of new pipelines (in addition to the proposed 2025 pipelines) ranging in diameter from 12 to 20 inches.
Executive Summary
ES-16 City of Tracy
May 2023 Citywide Water System
n\c\404\12-18-41\wp\R-404-WMPU Master Plan Update
Interconnections
Planning and design of these new interconnections should be coordinated with the timing of new development in the respective pressure zones.
• Install the following interconnections between pressure zones to provide supply during peak demands and/or emergency conditions:
— Westside Pressure Regulating Station (PRS) (from Zone 2 into Zone 1) — Avenues Pressure Reducing Valve (PRV) (from Ellis Reduced Zone into Zone 2) • To provide adequate pressure to the Plan C area and prevent the accumulation of stagnant water in dead-end mains, installation of six (6) PRVs is recommended before the Plan C re-zoning occurs (to be funded through Plan C).
Re-zoning
Planning and design of this rezoning should be coordinated with the timing of the new Zone 3 pipeline from the JJWTP.
• Re-zone the Plan C area from Zone 2 to Zone 3 (to be funded through Plan C).
System Control and Data Acquisition (SCADA) System and Backup Power Planning and design of the recommended SCADA system improvements and backup power should be prioritized and completed as soon as possible, as these improvements will improve operational flexibility and reliability.
• Install SCADA system monitoring of flows and pressures at PRS #1-#6 to provide operators with additional understanding and flexibility in system operations. • Add remote operation of Well 8 from the SCADA system to provide additional operational flexibility.
• Install SCADA system monitoring of flows and pressures at each new water supply facility to provide operators with real-time system data and flexibility in system operations.
• Install on-site backup power to any proposed buildout system pumping facility to improve supply reliability.
JJWTP Expansion
• A future additional 10 mgd expansion of the JJWTP (for a total treatment capacity of 40 mgd) is recommended to provide the City with additional water treatment capacity, as well as operational flexibility and reliability. The expansion would also include a new administration/maintenance building to accommodate future staffing needs and maintenance activities.
Executive Summary
ES-17 City of Tracy
May 2023 Citywide Water System
n\c\404\12-18-41\wp\R-404-WMPU Master Plan Update
Participation in Phase 2 Los Vaqueros Reservoir Expansion Project • The City’s participation in the Phase 2 Los Vaqueros Reservoir Expansion Project would increase the City’s water supply reliability by providing storage of supplies for use in dry years.
• The estimated cost for 5,000 acre-feet of storage for the City will be approximately $10 million plus an additional $1.5 million for implementation and will be shared by existing rate payers and new development.
Participation in the B.F. Sisk Dam Raise & Reservoir Expansion Project • The City’s participation in the B.F. Sisk Dam Raise & Reservoir Expansion Project would increase the City’s water supply reliability by providing storage of supplies for use in dry years.
• The estimated cost for 5,000 acre-feet of storage for the City will be approximately $38 million and will be shared by existing rate payers and new development.
Water Master Plan Updates
• Regular updates of this Citywide Water System Master Plan are recommended to evaluate potable water and recycled water infrastructure needs to reflect any changes in future development plans, water use trends and patterns, and water supply availability and reliability, as well as new regulations and operational needs as new potable water and recycled water system infrastructure is constructed. It is recommended that updates be prepared at least once every 10 years, or more often if changing conditions warrant more frequent updates. For purposes of this Citywide Water System Master Plan Update, three future updates are planned.
EVALUATION OF FUTURE RECYCLED WATER SYSTEM
Chapter 9 of this Citywide Water System Master Plan Update identifies the improvements necessary to support the City’s projected future recycled water demands and the recycled water exchange agreement. Recommended improvements are based on evaluations of the future (2025 and buildout) recycled water system’s treat ment, storage, and pumping capacities, as well as its ability to meet recommended performance and operational criteria under maximum day demand plus fill and peak hour demand scenarios.
Recycled water facility improvements are identified at a Master Plan level and do not necessarily include all required on -site infrastructure nor constitute design of improvements. Subsequent detailed design is required to determine the sizes and locations of the proposed improvements.
Further, the recycled water hydraulic m odel is not an “all pipes” model (i.e., not all smaller diameter pipelines are included), so the hydraulic simulations performed may not identify all necessary system improvements. West Yost recommends conducting additional hydraulic evaluations as development details become available.
Executive Summary
ES-18 City of Tracy
May 2023 Citywide Water System
n\c\404\12-18-41\wp\R-404-WMPU Master Plan Update
The following recommendations exclude non-backbone facilities that only serve a specific development, instead focusing on backbone facility improvements with more widespread system benefit. These shared facilities are designated program facilities. 2025 Recycled Water System
Program facility recommendations for the 2025 recycled water system are shown on Figure ES-4 and described below . A complete listing of recommended recycled water system improvements (both program and non-program) to serve projected 2025 recycled water demands is provided in Chapter 9 along with recommendations for their timing.
Booster Pump Stations
• Zone C Booster Pump Station (BPS): Install a new booster pump station with a minimum pumping capacity of 1,700 gpm.
New Recycled Water Pipelines
• To serve 2025 recycled water demands, install approximately 11,370 lf of new pipelines ranging in diameter from 8 to 30 inches.
• To deliver recycled water to the DMC as part of the City’s planned recycled water exchange program, install approximately 23,680 lf of new, 30-inch diameter pipeline (as described above, the exchange program is an essential part of the City’s projected future water supply portfolio and should be implemented as soon as possible).
Buildout Recycled Water System
Program facility recommendations for the buildout recycled water system are shown on Figure ES-4 and described below. A complete listing of recommended recycled water system improvements (both program and non -program) to serve projected buildout recycled water demands is provided in Chapter 9 along with recommendations for their timing.
As described in Chapter 9, planning and design for these improvements should be conducted so that these improvements can be constructed and operational as soon as possible, as funding is available, so that recycled water supplies can be used to meet landscape irrigation and other non-potable water demands to minimize the use of potable water supplies for these uses.
Storage Reservoirs
• Zone A Tank: Install an above ground, welded steel storage tank with a minimum active storage capacity of 5.7 MG.
• WWTP Diurnal Tank: Install a partially buried, prestressed concrete diurnal storage tank at the WWTP with a minimum active storage capacity of 2.3 MG; the need for this storage will depend on WWTP diurnal flow patterns, and it is recommended that the City re-evaluate the required diurnal storage at the WWTP by performing a diurnal flow study in 2040.
205
580
NCIP-PS-C
BCIP-PS-B
BCIP-PS-F
BCIP-T-DS
A F
B
C
D
E
BCIP-T-A
BCIP-PS-A
NCIP-PD-DMC-30
a
BCIP-PS-E BCIP-PS-D
SCHULTE CT
ELEVENTH ST
CORRAL HOLLOW RD
M
AC
ARTHUR
DR
TRACY BL
BYRON RD
GRANT LINE RD
MOUNTAIN HOUSE PK
BANTA RD
HANSEN RD
VALPICO RD
NAGLEE RD
LAMMERS RD
LINNE RD
HOLLY DR
MIDDLE RD
CHRISMAN RD
VON SOSTEN RD
REEVE RD
SCHULTE RD
C a l i f o r n i a A q u e d uc t
D e l t a - M e n d ota
C
anal
12"
30"
8"
30" 30"
30"
24"
24"
24"
30"
12"
12"
16"
18"
18"
24"
0 4,0002,000
Scale in Feet
Figure ES-4
Recommended Future
Recycled Water System
Program Improvements
City of Tracy
Water System Master Plan Update
Last Saved: 4/17/2022 4:53:41 PM N:\Clients\404 Tracy\12-18-41 Water Master Plan Update\GIS\MXD\Report Figures\Fig_ES-4_RW Program Facilities.mxd : rchu Notes:
1. The City's hydraulic model is not an all pipes model.
Some pipes which are not hydraulically significant were excluded from the model.
2. Jack and bore pipeline projects are not shown, but jack and bore is required for canal, railroad, or major
highway crossings.
3. Install SCADA system monitoring of flows and
pressures at each new facility.
4. Only existing and program facilities are shown.
Symbology
Proposed Buildout Program Facilities
Buildout Booster Pump Station
Buidlout Storage Tank
Buildout System Pipeline
Proposed 2025 Program Facilities
2025 Booster Pump Station
2025 System Pipeline
Delta-Mendota Canal Pipeline
Delta-Mendota Canal Discharge Point
Existing System Facilities
Existing Booster Pump Station
Wastewater Treatment Plant
Existing System Pipeline
Legacy Fields
Future Recycled Water Use Area
Recycled Water Pressure Zone
Zone A Transmission
Pipeline
Zone C
Distribution
Pipeline
CORRAL HOLLOW RD
VALPICO RD
Executive Summary
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Booster Pump Stations
• Zone A BPS Expansion: Install additional booster pumps with a minimum pumping capacity of 3,472 gpm.
• Zone B: Install a new booster pump station with a minimum pumping capacity of 5,780 gpm.
• Zone D BPS: Install a new booster pump station with a minimum pumping capacity of 2,700 gpm.
• Zone E BPS: Install a new booster pump station with a minimum pumping capacity of 2,000 gpm.
• Zone F: Install a new booster pump station with a minimum pumping capacity of 4,400 gpm.
New Recycled Water Pipelines
• To serve buildout recycled water demands, install approximately 42,790 lf of new pipelines (in addition to the proposed 2025 pipelines) ranging in diameter from 16 to 30 inches.
SCADA System
• Install SCADA system monitoring of flows and pressures at each new water supply facility to provide operators with real-time system data and flexibility in system operations.
RECOMMENDED CAPITAL IMPROVEMENT PROGRAM
Chapter 10 of this Citywide Water System Master Plan Update presents the recommended Capital Improvement Program (CIP) for the City’s existing and future (2025 and buildout) potable water system and proposed future (2025 and buildout) recycled water system to support the City’s projected buildout potable water and recycled water demands, respectively . These costs are summarized in Table ES-4. A detailed breakdown of the costs is provided in Chapter 10.
Costs exclude non-backbone facilities that only serve a specific development, as costs associated with those facilities will be borne solely by the corresponding developers. Table ES-4 only includes costs for program facilities.
Executive Summary
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Table ES-4. Summary of Probable Construction Costs for Recommended Potable and Recycled Water System Improvements(a)
Recommended Improvements CIP Cost (includes mark-ups)(b,c) Potable Water System
Existing Potable Water System CIP (see Table 10-1) $1,960,000 2025 Potable Water System CIP (see Table 10-2) $21,988,000 Buildout Potable Water System CIP (see Table 10-3)(d) $211,916,000 Previous Water Treatment Plant Expansion Buy-in Cost(e) $27,000,000 Total Potable Water System CIP $262,864,000
Recycled Water System
2025 Recycled Water System CIP (see Table 10-4) $27,924,000 Buildout Recycled Water System CIP (see Table 10-5) $65,528,000 Total Recycled Water System CIP $93,452,000
(a) Includes only costs for program facilities; improvements benefiting only specific developments are excluded. (b) Estimated construction costs do not reflect an adjustment to account for the current economic bidding climate. (c) CIP cost includes mark-ups equal to 40 percent (General Contingency: 15 percent; Design and Planning: 10 percent; Construction Management: 10 percent; and Program Administration: 5 percent) and are based on 2020 dollars. (d) Includes cost for participation in Phase 2 Los Vaqueros Reservoir Expansion Project and the B.F. Sisk Dam Raise & Reservoir Expansion Project which is to be shared between existing rate payers and new development. (e) The JJWTP was last expanded in 2008. The cost presented in this line item represents the buy-in cost for the portion of the expanded capacity to be utilized by new developments (estimated to be 9 mgd). The cost for the recommended additional 10 mgd expansion of the JJWTP is included in the Buildout Potable Water System CIP (see Table 10-3).
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CHAPTER 1
Introduction
1.1 CITYWIDE WATER SYSTEM MASTER PLAN UPDATE PURPOSE
The purpose of this Citywide Water System Master Plan Update for the City of Tracy (City) is to provide an evaluation of the required backbone potable water and recycled water system facilities required to serve existing and future needs. The City’s last C itywide Water System Master Plan was completed in 2012 and was based on projected land uses included in the City’s 2011 General Plan. Since that time, significant new residential and commercial development has occurred in the City (including the International Park of Commerce within the Cordes Ranch Specific Plan area, Tracy Ellis, Tracy Hills and numerous smaller projects) and planning for future developments has been refined. Also, during that same time, the State endured five years of drought starting in 2012, including the driest four consecutive years in California history. These unprecedented conditions led to statewide mandated water conservation, significant surface water supply reductions and curtailments and legislation establishing new water efficiency standards.
All of these factors have led to a need to reevaluate the City’s potable water and recycled water needs, the projected availability and reliability of the City’s water supplies and the required water system infrastructure improvements to ensure a safe and reliable water supply for the City’s residents and businesses.
1.2 WATER MASTER PLAN OBJECTIVES
The objectives of this Citywide Water System Master Plan Update are to:
• Evaluate existing water demands to understand current water use patterns and trends and project future water demands for near-term (2025), future (2040) and General Plan buildout conditions.
• Provide an updated evaluation of the availability and reliability of the City’s existing and future water supplies and their ability to meet existing and future water demands considering recent changes in projected supply reliability. • Review and refine performance and operational criteria under which the potable and recycled water systems will be analyzed and recommendations for future facilities will be formulated.
• Evaluate the need for new backbone potable water facilities (including pipelines, storage facilities and pumping facilities) to serve buildout of the City’s General Plan. • Evaluate the need for new backbone recycled water facilities (including pipelines, storage facilities and pumping facilities) to serve buildout of the City’s General Plan. • Develop a capital improvement program for recommended potable and recycled water system facilities.
Chapter 1
Introduction
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1.3 KEY CHANGES FROM THE 2012 CITYWIDE WATER SYSTEM MASTER PLAN This Cityside Water System Master Plan Update incorporates and considers several changed conditions, new water system facilities, and new water supply opportunities from what was included in the 2012 Citywide Water System Master Plan (WSMP). A summary of these is provided below:
• Changes in Projected Land Use: Compared to the projected land use in 2012 Citywide Water System Master Plan, there has been a significant shift in the City’s projected land use composition towards residential development and away from commercial and industrial development. However, when compared to the City’s historical and existing land uses, which were primarily residential, the projected land uses for new development are more heavily skewed to non-residential uses (with almost 60 percent of the projected acres of new development being non-residential uses). The future industrial, commercial, and retail growth anticipated in the City’s Sphere of Influence is reflective of the City’s goal to bring jobs and economic growth and improve the City’s jobs-housing balance (see Chapter 3 for additional information). • Reduction in Unit Water Demands: Due to changes in water use trends and habits resulting from improved water use efficiency, unit water demand factors have been reduced for most land use categories (see Chapter 4 for additional information). • Reduction in Maximum Day and Peak Hour Demand Factors: Due to changes in water use trends and habits from improved water use efficiency, maximum day and peak hour demand factors have been reduced (see Chapter 4 for additional information).
• Changes in Recycled Water System Planning: Previously, the City was considering implementing the proposed Gateway Exchange Program, under which recycled water service would be extended to most of the existing parks and large irrigated areas in the City to offset the potable water demands from the Gateway development (now called Westside). The Gateway Exchange Program is no longer being considered, and it is projected that only a few existing parks and irrigated areas will receive recycled water supply. Expansion of the recycled water system will focus on extending service to newly developed areas (see Chapters 4 and 9 for additional information). • Reduction in Surface Water Supply Reliability: Due to unprecedented drought conditions from 2011 through 2017 and new flow restrictions resulting from the 2018 Water Quality Control Plan for the San Francisco Bay/Sacramento-San Joaquin Delta Estuary, projected reliabilities of surface water supplies from the Central Valley Project (CVP) and South San Joaquin Irrigation District (SSJID) have been significantly reduced, particularly in dry years. The City has entered into discussions with the Contra Costa Water District and the San Luis & Delta-Mendota Water Authority to explore the City’s potential participation in the Phase 2 Los Vaqueros Reservoir Expansion Project to increase the City’s water supply reliability by providing storage of supplies for use in dry years (see Chapter 5 for additional information).
Chapter 1
Introduction
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• Proposed Recycled Water Exchange Agreement: The City is evaluating the potential for indirect reuse of its available recycled water through an exchange agreement with the United States Bureau of Reclamation (USBR) whereby a portion of the City’s tertiary-treated wastewater (recycled water) would be discharged to the Delta Mendota Canal (DMC) and a like amount of water (i.e., a one-to-one exchange) could then be diverted from the DMC by the City for treatment at the City’s John Jones Water Treatment Plant (JJWTP) for potable use. Such supplies would be 100 percent reliable and would not be subject to drought cutbacks. With the potential reduction in reliability of the City’s surface water supplies from the CVP and SSJID during dry years, this proposed recycled water exchange agreement will be a critical component of the City’s future water supply portfolio (see Chapter 5 for additional information). • Reduction in Emergency Storage Requirement: The 2012 WSMP used an emergency storage volume requirement of two (2) times the average day demand. After reviewing emergency storage criteria for other similar water systems within the region, and taking into account the City’s redundant sources of supply (CVP, SSJID, and groundwater), it is recommended that the City reduce the minimum quantity of emergency storage volume required to 1.5 times the average day demand for this Citywide WSMP Water System Master Plan Update (see Chapter 6 for additional information). • Addition of New Water System Facilities: Several new water system facilities have been recently completed which provide for added water system capabilities. These include the Cordes water storage tank and pump station, the Tracy Hills water storage tank and pump station (nearing completion as of September 2021), new pump stations at the City’s JJWTP to serve the City’s Pressure Zone 3 and initial phases of the Tracy Hills development, and a recycled water pump station and pipeline on the west side of the City to distribute recycled water supplies from the City’s Wastewater Treatment Plant to recycled water users on the western side of the City (see Chapters 7 and 9 for additional information).
• Renaming of Potable Water Pressure Zones: To minimize confusion when referring to the City’s primary potable water system pressure zones, the potable water system pressure zones have been renamed as follows:
— Pressure Zone 1 – no change
— Pressure Zone 2 – no change
— City-side Pressure Zone 3 – now referred to as Pressure Zone 3 — Tracy Hills Pressure Zone 3 – now referred to as Pressure Zone 4 — Tracy Hills Pressure Zone 4 – now referred to as Pressure Zone 5 — Tracy Hills Pressure Zone 5 – now referred to as Pressure Zone 6 The remainder of this Citywide Water System Master Plan Update, and all subsequent water system evaluations and studies, will utilize these new pressure zone designations.
Chapter 1
Introduction
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1.4 REPORT ORGANIZATION
This Citywide Water System Master Plan Update is organized into the following chapters:
Chapter 1: Introduction
Chapter 2: Water Supply and Infrastructure System Objectives, Goals and Recommendations
Chapter 3: Land Use Assumptions
Chapter 4: Existing and Future Water Demands
Chapter 5: Existing and Future Water Supplies
Chapter 6: System Performance and Operational Criteria
Chapter 7: Existing Potable Water System Evaluation
Chapter 8: Future Potable Water System Evaluation
Chapter 9: Recycled Water System Evaluation
Chapter 10: Recommended Capital Improvement Program
The following appendices to this Citywide Water System Master Plan Update contain additional technical information, assumptions and calculations:
Appendix A: Land Use Assumptions and Projected Water Demands for New Developments
Appendix B: JJWTP Expansion Project Site Plan, Process Schematic, and Hydraulic Profile
Appendix C: Existing Potable Water System Hydraulic Grade Schematic Appendix D: Lammers Road and Hood Way Design Recommendation Technical Memoranda
Appendix E: Cost Estimating Assumptions
Appendix F: Proposed Future Potable Water System Facility Improvements Appendix G: Proposed Future Recycled Water System Facility Improvements
Chapter 1
Introduction
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1.5 ACKNOWLEDGEMENTS
The development of this Citywide Water System Master Plan Update would not have been possible without the focused involvement and assistance of City staff. In particular, the following staff provided comprehensive information, significant input and important insights throughout development of this Citywide Water System Master Plan Update:
• Robert Armijo, City Engineer/Assistant Director of Development Services • Steve Bayley, Project Specialist
• Wayne Bogart, Public Works Superintendent
• Aleck Cheney, Engineer
• Veronica Child, Management Analyst II
• Bill Dean, Assistant Director of Development Services • Lea Emmons, Water Treatment Plant Superintendent
• Vicki Lombardo, Senior Planner
• Ilene Macintire, Associate Civil Engineer
• Andrew Malik, Director of Development Services
• Stephanie Reyna-Hiestand, Water Resources Analyst
• Lemar Saffi, Assistant Engineer
• Karin Schnaider, Director of Finance
• Don Scholl, Director of Public Works
• Kul Sharma, Director of Utilities
• Paul Verma, Senior Civil Engineer
(Project Manager for the Citywide Water System Master Plan Update) • Thomas Ward, Construction Inspector
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CHAPTER 2
Water Supply and Infrastructure System
Objectives, Goals, and Recommendations
2.1 OVERVIEW
The recent California drought conditions, environmental restrictions in the San Joaquin Delta, increasing population, and limited water resources are serious problems affecting water agencies statewide. Many water agencies have adopted ordinances and taken other measures to ensure a reliable water supply for their customers. Unfortunately, the challenge of sustaining a water supply for future generations is becoming more and more challenging each year.
This chapter presents an overview of the City’s water supply and infrastructure system objectives and goals, describes existing policies, and provides recommendations for future measures to help the City meet those objectives and goals.
2.2 OVERALL WATER SYSTEM OBJECTIVES AND GOALS
This Citywide Water System Master Plan Update has been prepared based on the following overall water system objectives and goals:
• Ensure safe, adequate and reliable water supplies for the City’s existing and future residents and businesses.
• Support the goals, objectives and policies of the City’s General Plan, particularly those contained in the Public Facilities and Services Element. • Comply with existing and future legislation and regulations for both potable and non-potable (recycled) water supplies including, but not limited to, the following:
— Support the City’s compliance with legislation related to reducing greenhouse gases (Assembly Bill (AB) 321 and Senate Bill (SB) 3752) by improving the efficiency of water system facility operations when feasible. — Comply with the California Green Building Standards Code, and other “green” building guidelines, as they relate to standards for interior and exterior water use, to promote more efficient use of the City’s water supplies.
1 AB 32 California Global Warming Solutions Act of 2006: Signed into law September 27, 2006; requires the California Air Resources Board (CARB) to develop regulations and market mechanisms that will ult imately reduce California’s greenhouse gas (GHG) emissions by 25 percent (to 1990 levels) by 2020. 2 SB 375: Signed into law September 30, 2008; requires each metropolitan region to adopt a “sustainable community strategy” (SCS) in its regional transportation plans to encourage compact development that aligns with regional GHG emissions reduction targets set by the CARB; enhances the CARB’s ability to reach AB 32 goals; intended to promote more environmentally-friendly communities, more sustainable developments, less time people spend in their cars, and more alternative transportation options.
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— Comply with the Water Conservation Act of 2009 (SB X7-7) which was passed in November 2009 to increase water use efficiency by reducing per capita water use statewide with a goal to increase the sustainability and extend the longevity of the City’s existing water supplies. Per SB X7-7, the City’s adopted per capita water use targets are 204 gallons per capita per day (gpcd) (2015 interim target) and 181 gpcd (2020 final target). The City’s per capita water use in 2015 was 142 gpcd, which was well below the City’s 2015 interim target. The City’s per capita water use in 2020 was 181 gpcd, equal to the City’s 2020 final target. Additional discussion on the City’s per capita water use and compliance with SB X7-7 is provided in Chapter 4.
— Comply with the Sustainable Groundwater Management Act (SGMA) which became effective in January 2015 with the passage of comprehensive groundwater legislation contained in SBs 1168 and 1319, and AB 1739. The legislative intent of SGMA is to provide sustainable management of groundwater basins, enhance local management of groundwater, establish minimum standards for sustainable groundwater management, and provide local groundwater agencies with the authority and the technical and financial assistance necessary to sustainably manage groundwater. Discussion on the City’s compliance activities related to SGMA is provided in Chapter 5.
— Comply with SB 606 and AB 1668 which were passed in May 2018 and established new statewide water use efficiency standards for indoor residential water use, outdoor residential water use, commercial, industrial and institutional irrigation of landscaped areas and distribution system water loss. A primer entitled “Making Water Conservation a California Way of Life” was developed to be a reference document for the implementation of the complex 2018 legislation.
Discussion on the City’s compliance with SB 606 and AB 1668 is provided in Chapter 4.
The following sections of this chapter describe the City’s existing policies and recommended measures for water conservation, recycled and non -potable water, and water system facility operations, to help meet these overall water system objectives and goals.
2.3 CITY OF TRACY WATER CONSERVATION PROGRAMS
2.3.1 Existing Water Conservation Programs
The City has an on-going water conservation
program that includes residential surveys,
public and school education programs,
rebates for water -efficient appliances and
other specific programs. These programs have
been successful in reducing water use,
especially during the recent drought. In the late 1980’s and early 1990’s, the City’s overall per capita water use was about 300 gpcd. However, since the late 1990’s, the City’s overall per capita water use has been significantly reduced. Since 2008, the City’s average overall per capita water use has been 170 gpcd.
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Objectives, Goals, and Recommendations
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In 2015 and 2016, which were dry years, and years in which overall water demands were affected by water conservation measures and water use restrictions, the City’s per capita water use dropped to 142 and 146 gpcd, respectively.
The City also has a Water Shortage Contingency Plan (WSCP) which was originally developed in 1992. The City’s WSCP was updated in June 2015 to incorporate mandatory prohibitions on water use required by State Water Resources Control Board (SWRCB), and again updated in early 2021 i n conjunction with the City’s 2020 Urban Water Management Plan (UWMP) based on new requirements for WSCPs. The WSCP includes mandatory water use prohibitions and restrictions which are always in effect, triggers for implementation of various stages of the WSCP based on various water supply shortage scenarios, and specific water use restrictions for each stage of the WSCP, which are intended to reduce the City’s water demand by up to 50 percent and greater than 50 percent in the event of a water supply emergency or a drought condition. Water use restrictions in each stage of the WSCP become increasingly restrictive as needed to reduce the City’s water demand.
The City’s current WSCP is included in Section 8 of the City’s 2020 UWMP. The Tracy Municipal Code (Chapter 11.28 Water Management, Article 5 Drought and Other Water Emergency and Article 6 Water Conservation and Rationing Plan, Water Emergency Plan, Variances and Appeals) will be updated in late 2021 to be consistent with the latest updates to the WSCP.
2.3.2 Water Efficient Landscape Ordinance
About half of the urban water is used for landscape irrigation in California. Large water savings can be gained by efficient landscape design, installation, and maintenance. New development and retrofitted landscape water efficiency standards are governed by the State Model Water Efficient Landscape Ordinance (MWELO) which is codified in the California Code of Regulations Title 23 Waters, Division 2 Department of Water Resources, Chapter 2.7 Model Water Efficient Landscape Ordinance. All agencies must adopt, implement, and enforce the MWELO or a more stringent ordinance. The City has adopted MWELO and it is included in the Tracy Municipal Code Chapter 11.28 Water Management, Article 8 Water Efficient Landscape Ordinance.
Key components of MWELO include requirements for the following:
• Landscape design plans (e.g., plant selection, slopes, guidelines for water features, etc.) • Irrigation design plans (e.g., separate meters for large landscape areas, automatic irrigation controllers utilizing evapotranspiration or soil moisture sensor data, use of rain sensors, etc.)
• Grading design plans (e.g., erosion and runoff protection) • Irrigation scheduling and the development of a maximum applied water allowance (e.g., allowable water days and times, landscape water budgets, etc.) • Landscape and irrigation maintenance scheduling
• Irrigation audits, irrigation surveys and irrigation water use analysis • Use of recycled water (e.g., landscape irrigation, decorative water features) Chapter 2
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Objectives, Goals, and Recommendations
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2.4 RECYCLED AND NON-POTABLE WATER ORDINANCE
In 2002, the City adopted a Recycled and Non -Potable Water Ordinance which established the policy that recycled water may be used for non-potable uses within the City’s designated recycled water use areas (as defined in the Tracy Municipal Code in Chapter 11.30 Recycled and Non-Potable Water). Specific provisions include the following:
11.30.030 (b) Each subdivision for which a tentative map or parcel map is required under Government Code section 66426 and located within designated recycled water use areas is required to install a recycled water distribution system to provide recycled water to the common areas3 of the subdivision and for any industrial cooling or processing uses in the subdivision.
The intent of this existing City policy is to require
new development to use recycled water for
landscape irrigation on professionally managed
and maintained landscapes located within the
City, such as golf courses, parks, greenbelts, and
landscaped streets and medians, and for any
applicable industrial cooling or processing
purposes. This applies to all land use designations
within the City’s General Plan incl uding, but not
limited to, residential, commercial, industrial, and
institutional. The only exception is landscaped
areas within residential land uses which are
maintained by private homeowners (e.g., private
backyards or front yards which are not considered
common areas); recycled water will not be
required for landscape irrigation in these privately
maintained areas.
To further encourage and expand the future use of recycled and/or non-potable water within the City, the following additional measures should be considered:
• Require the use of recycled or non-potable water for all decorative water features and artificial lakes.
• Require that existing large, landscaped areas currently irrigated with potable water supplies, such as City parks and sports fields, be converted to recycled or non-potable water use as opportunities for construction of recycled or non-potable water facilities to serve these existing areas occur .
3 “Common areas” shall include, but not be limited to, golf courses, parks, greenbelts, landscaped streets, and landscaped medians.
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• Require that existing facilities with evaporative cooling systems and other industrial cooling processes currently using potable water supplies be converted to recycled or non-potable water use as opportunities for construction of recycled or non-potable water facilities to serve these existing areas occur.
As described further in Chapters 4, 5, and 9, the City has begun construction of a recycled water distribution system to deliver recycled water supplies to designated use areas.
2.5 CITY OF TRACY GENERAL PLAN WATER SERVICE GOALS, OBJECTIVES AND
POLICIES
The City’s General Plan, last updated in 2011, includes a Public Facilities and Services Element that provides
information and policy guidance to ensure provision of
facilities and services that will support existing and new development in the City. It addresses the changing public services and infrastructure needs of Tracy and provides for their logical and timely extension to keep pace with growth.
Policies supporting well -maintained infrastructure are essential to achieve broader development objectives and support the future envisioned by the r esidents of Tracy.
Specific goals, objectives and policies for water services are included in the Public Facilities and Services Element.
The General Plan goal for the City’s water service is to provide “adequate supplies of water for all types of users” (General Plan Goal PF -6). Specific General Plan
objectives and policies associated with this goal are
summarized in Table 2-1.
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Table 2-1. City of Tracy General Plan Objectives and Policies for Water Service Objectives Policies
Objective PF-6.1
Ensure that reliable
water supply can be
provided within the
City’s service area,
even during drought
conditions, while
protecting the natural
environment.
P1. The City shall promote water conservation by implementing the Best Management Practices contained in the UWMP.
P2. The City shall continue to acquire additional sources of water supplies to meet the City’s future demands.
P3. To the extent feasible, the City shall use surface water supplies to meet daily water needs and reduce reliance on groundwater supplies.
P4. The City shall establish water demand reduction standards for new development and redevelopment to reduce per capita and total demand for water.
Objective PF-6.2
Provide adequate
water infrastructure
facilities to meet
current and future
populations.
P1. The City shall maintain water storage, conveyance and treatment infrastructure in good working condition in order to supply domestic water to all users with adequate quantities, flows and pressures.
P2. Storage reservoirs should be buried or partially buried depending on local groundwater conditions to allow for the joint use of the site with parks or recreational facilities, unless reservoirs are elevated to provide a gravity flow system, in which case the reservoirs shall be screened by landscaping and/or earthen berms.
Objective PF-6.3
Promote coordination
between land use
planning and water
facilities and service.
P1. Structures with plumbing that are located within the City limits shall connect to the City water supply system.
P2. New developments shall dedicate land for utility infrastructure such as treatment facilities, tanks, pump stations and wells as needed to support the development of their project.
P3. The City shall be responsible for constructing new transmission water lines, as needed to meet future needs. Individual development projects shall be responsible for the construction of all water transmission means.
P4. All new water facilities shall be designed to accommodate expected capacity for buildout of areas served by these facilities but may be constructed in phases to reduce initial and overall costs.
P5. The availability of sufficient, reliable water shall be taken into account when considering the approval of new development.
P6. Costs for water service expansion shall be distributed among new water users fairly and equitably.
Objective PF-6.4
Design and manage
water system facilities
for reliability during
catastrophic events
such as fires, power
outages, droughts
and earthquakes.
P1. Groundwater supplies should be reserved for emergency use during water treatment shutdowns, short-term shortages of surface water supplies or during droughts.
P2. Backup emergency power systems shall be provided at all essential water facilities that rely on electric power.
P3. Storage reservoir facilities should be located at naturally high topographic locations to capitalize on gravity flow, whenever possible.
P4. Future water systems and facilities shall be designed to minimize the likelihood of damage from vandalism or terrorist activity.
Objective PF-6.5
Use recycled water to
reduce non-potable
water demands
whenever practicable
and feasible.
P1. The City shall provide recycled water systems, including pipelines, pump stations and storage facilities, to serve primarily City-owned facilities, schools and parks as funding becomes available.
P2. Recycled water piping systems (“purple pipe”) shall be constructed as appropriate in all new development projects to facilitate the distribution and use of recycled water. The specific location and size of the recycled water systems shall be determined during the development review process.
P3. Recycled water shall be used for all public properties and large private open spaces or common areas to the extent feasible.
P4. The City shall plan for recycled water infrastructure in the City’s Infrastructure Master Plans and, to the extent feasible, recycled water should be utilized for non-potable uses, such as landscape irrigation, dust control, industrial uses, cooling water and irrigation of agricultural lands.
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Objectives, Goals, and Recommendations
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2.6 COMPLIANCE WITH CALIFORNIA GREEN BUILDING STANDARDS CODE The California Green Building Standards Code , also known as CALGreen, was the first-in-the-nation mandatory green building standards code. In 2007, the California Building Standards Commission (CBSC) developed green building standards in an effort to meet the goals of California’s landmark initiative AB 32 California Global Warming Solutions Act of 2006 , which established a comprehensive program of cost -effective reductions of GHG to 1990 levels by 2020.
The 2008 CALGreen Code was first published in Part 11 of California’s Title 24 Code and became effective on August 1, 2009. It included primarily voluntary green building standards for non-residential buildings, and mandatory standards for low -rise residential buildings. The 2010 CALGreen Code established mandatory and voluntary provisions for residential and non-residential construction. The 2016 CALGreen Code and later code supplements updated these provisions with an effective date of July 1, 2018. The 2019 CALGreen Code was published July 1, 2019 with an effective date of January 1, 2020.
The City adopted the 2019 CALGreen Code on November 19, 2019.
The key mandatory provisions of CALGreen are as follows:
• Residential Mandatory Measures:
— Reduce indoor potable water use by installing ultra-low-flow fixtures and appliances (e.g., 1.8 gallons per minute (gpm) showerheads, 1.8 gpm kitchen faucets, 1.28 gallons/flush toilets, 0.125 gallons/flush wall-mounted urinals). — Residential developments with a total landscape area equal to or greater than 500 square feet shall establish landscape irrigation water budgets which conform to the local water efficient landscaping ordinance or to the State MWELO where no local ordinance is applicable.
— Newly constructed residential developments may be required to have recycled water supply systems installed where disinfected tertiary recycled water is available from a municipal source.
• Non-Residential Mandatory Measures:
— For buildings in excess of 50,000 square feet, provide separate submeters for each individual leased, rented or other tenant space within the building projected to consume more than 100 gallons per day.
— Reduce indoor potable water use by 20 percent by installing ultra-low-flow fixtures and appliances (e.g., 1.8 gpm showerheads, 1.8 gpm kitchen faucets,
1.28 gallons/flush toilets, and 0.125 gallons/flush wall-mounted urinals). — Establish landscape irrigation water budgets which conform to the local water efficient landscaping ordinance or to the State’s MWELO where no local ordinance is applicable.
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Water Supply and Infrastructure System
Objectives, Goals, and Recommendations
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— Newly constructed non-residential developments are required to have a recycled water supply system installed where a disinfected tertiary recycled water supply pipeline from a municipal source is within 300 feet of the construction site boundary.
Voluntary measures included in the CALGreen Code include further reductions in indoor water use in both residential and non -residential buildings, installation of low -water consumption irrigation systems, installation of rainwater systems, installation of graywater systems, landscaping with noninvasive species, and installation of dual plumbing systems.
2.7 RECOMMENDATIONS FOR NEW DEVELOPMENT AND NEW WATER SYSTEM
FACILITIES
In addition to the various guidelines described above, and t o allow the City to meet its water conservation goals and maintain the long-term sustainability of its water resources, the following recommendations should be considered for new development projects and new water system facilities in the City:
• Require new development projects to offset or mitigate its water demands if demands exceed those accounted for in the Citywide Water System Master Plan Update based on buildout of the City’s adopted General Plan. The offset or mitigation may be achieved by reducing the water demands within the project (through the implementation of water conservation measures and/or incorporation of recycled water use) and/or participating in a project to reduce potable water demands in another portion of the City to offset the potable water demands of the proposed project.
• Establish designated utility corridors within new development areas to be within public rights-of-way to minimize or eliminate the need for utility easements within private property.
• Install solar power systems, or alternative power sources, at existing and new pump stations and other water system facilities, as feasible, to reduce electrical power consumption.
• Increase the frequency of routine operations and maintenance (O&M) activities for existing pump stations and wells to maintain pump efficiencies and reduce power demands.
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Water Supply and Infrastructure System
Objectives, Goals, and Recommendations
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2.8 PRINCIPLES FOR SUSTAINABLE INFRASTRUCTURE IN THE CITY OF TRACY In November 2009, the City developed a list of principles for sustainable infrastructure for use in developing its 2012 Infrastructure Master Plans4. Principles were developed for storm drainage, water, wastewater, recycled water, and roadways and transportation and, for the most part, remain applicable for this Citywide Water System Master Plan Update.
The principles related to water infrastructure are summarized as follows:
• Energy efficient design and control systems should be used in all new facilities to minimize power consumption. Look for opportunities to use solar generation facilities. • Promote and encourage, where feasible, the use of recycled water for non-potable uses in existing and future public landscaped areas.
• Establish and adopt interior and exterior water conservation requirements which are consistent with recommended State guidelines, to the degree possible. • Require existing City customers to participate in water conservation activities that will enable the City to meet or exceed statewide water conservation requirements. • Create a water rate structure that supports and provides incentives for water conservation. • Encourage and create incentives to convert high water use outdoor landscaping to more drought-resistant plantings to facilitate water conservation among existing water users.
As applicable, these sustainability principles are incorporated into this Citywide Water System Master Plan Update as described in the following chapters.
4 See Chapter 2 and Appendix A of the 2012 Citywide Water System Master Plan.
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CHAPTER 3
Land Use Assumptions
3.1 OVERVIEW
The purpose of this Citywide Water System Master Plan Update is to evaluate the required potable water and recycled water infrastructure to serve buildout of the City’s General Plan and Sphere of Influence (SOI). In this Citywide Water System Mast er Plan Update, the term “buildout” is used to refer to full development of approved projects , additional planned developments, and miscellaneous infill, as identified by the City’s Planning Division. However, as it is unclear when buildout will actually occur, no specific year is identified for the buildout condition. Two interim time frames are evaluated in this Citywide Water System Master Plan Update: Year 2025 (near-term) and Year 2040, to help provide prioritization of future system improvements in the period prior to buildout . The following sections present the land use assumptions for the City at 2025, 2040, and buildout time frames.
3.2 CITY OF TRACY GENERAL PLAN AND SPHERE OF INFLUENCE
The City’s General Plan is the principal policy document for guidin g future planning and development of the City of Tracy, including the SOI, which is the area outside of the City limits that the City expects to annex and urbanize in the future. The SOI area in the City’s General Plan is about 16 square miles (existing City limits are approximately 26 square miles, for a total General Plan area of about 42 square miles). The City’s most recent General Plan was adopted by City Council on February 1, 2011 and is used as the basis for the City’s Infrastructure Master Plans, including this Citywide Water System Master Plan Update. Figure 3-1 illustrates the SOI boundary and the land uses included in the General Plan.
As shown on Figure 3-1, some of the areas outside of the City limits, but within the SOI, are designated as Urban Reserve. Proposed future development within these Urban Reserve are as includes a variety of land uses, such as Residential, Commercial, and Industrial.
Due to the nature of the planning and development process, actual development within the SOI may not conform to the planned land uses shown in the General Plan. Where available, more recent land use data from the City’s Planning Division, specific plans, and other available planning documents were used preferentially over the General Plan land uses.
0 5,0002,500
Scale in Feet
Figure 3-1
General Plan Land Use
City of Tracy
Water System Master Plan Update
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1. General Plan land use GIS file recieved from
the City on April 5, 2018.
Symbology
City Limits
Sphere of Influence
General Plan Land Use
Residential Very Low
Residential Low
Residential Medium
Residential High
Traditional Residential - Ellis
Commercial
Office
Industrial
Downtown
Village Center
Public Facilities
Park
Open Space
Agriculture
Aggregate
Urban Reserve
580
580
205
205
SCHULTE RD
SCHULTE RD
ELEVENTH ST
C
O
RRAL
HO
LLO
W
RD
M
AC
ARTHUR
DR
BYRON RD
GRANT LINE RDHANSEN RD
VALPICO RD
BIRD RD
LOVELY RD
LINNE RD
HOLLY DR
BETHANY RD
MIDDLE RD
VON SOSTEN RD
AHERN RD
DURHAM FERRY RD
TRACY BL
MOUNTAIN HOUSE PK
BANTA RD
LAMMERS RD
CHRISMAN RD
NAGLEE RD
REEVE RD
Ol d
Ri v e r
Califor ni a
Aq ued uct
D e l t a - M e n d o t a C a n a l
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3.3 EXISTING AND PLANNED DEVELOPMENT OF THE CITY’S SPHERE OF INFLUENCE Development of the City’s SOI will include the following land use components:
• Existing developed land uses within the City limits
• Approved projects
• Additional planned development
• Miscellaneous infill located in existing developed areas • Annexation of the Mountain View area
Each of these land use components is discussed in more detail below.
3.3.1 Existing Developed Land Uses
Existing developed land use within the City consists primarily of low-density residential land use.
With some exceptions, existing developed land use within the City limits conforms to the General Plan. Water demands from the existing developed land uses will be included in the future water demand projections.
3.3.2 Approved Projects
Approved projects are developments which are far along in the planning process. Future land use can be projected with greater certainty in these areas due to available tentative maps, Environmental Impact Reports (EIRs), hydraulic evaluations, or other planning documents which have been prepared for these developments. Figure 3-2 shows the location of the approved projects in the City.
Table 3-1 summarizes the approved projects in the City. Many of the areas listed in Table 3-1 are partially developed, including the Cordes Ranch, Ellis, and Tracy Hills Specific Plan areas, which have ongoing and rapid development occurring within them.
As discussed in Chapter 4, water demands for the developed portions of these projects are included in the City’s existing water demands1. Land use data regarding the number of residential dwelling units and non-residential acres remaining to be developed within each of these approved projects were obtained from the data sources listed in Table 3-1. This data was then used to estimate the anticipated additional future water demands associated with completion of these specific plans and projects, which are included in the future water demand projections.
1 Water meter billing data from 2017 were used as the basis for the existing water system. Land use for development which occurred after 2017 is presented as future land use in this Water System Master Plan Update. 0 4,5002,250
Scale in Feet
Figure 3-2
Approved Projects
City of Tracy
Water System Master Plan Update
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1. Dobler / Maibes is part of the I-205 Specific Plan
area, but is accounted for separately in this WSMP .
Symbology
City Limits
Sphere of Influence
Specific Plans
I-205 Corridor
Industrial Areas
Northeast Industrial Area
Avenues
Cordes Ranch
Ellis
Tracy Hills
Tracy Village
Westside
Other Approved Projects
Berg Road Subdivision
Dobler / Maibes
Kagehiro
Rocking Horse
Legacy Fields
Small Approved Projects
580
205
205
Northeast Industrial
Area
Industrial
Areas
Industrial
Areas
I-205
I-205
I-205
Legacy Fields
Barcelona
Infill
Home 2
Suites 321 E. Grant Line
Rd. Apartments
SCHULTE RD
SCHULTE RD
ELEVENTH ST
CORRAL HOLLOW RD
M
AC
ARTHUR
DR
TRACY BL
BYRON RD
GRANT LINE RD
NAGLEE RD
HANSEN RD
VALPICO RD
BIRD RD
LOVELY RD
LINNE RD
HOLLY DR
BETHANY RD
MIDDLE RD
VON SOSTEN RD
AHERN RD
DURHAM FERRY RD
MOUNTAIN HOUSE PK
BANTA RD
LAMMERS RD
CHRISMAN RD
REEVE RD
C a l i f o r n i a A q u educt
D
elta-M
endot a
C a nal
Tracy
Hills
Cordes
Ranch
Westside
Tracy
Village
Ellis
Avenues
Berg Road
Subdivision
Dobler
/ Maibes
Rocking
Horse
Kagehiro
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Table 3-1. Summary of Approved Projects
Project Name Primary Planning Document(s) Source(s) of Land Use Data Used I-205 Corridor Specific Plan Specific Plan dated February 1991 Previous hydraulic evaluations(a); Data from Planning Division(b)
Industrial Areas Specific
Plan (North and South)
Specific Plan dated June 1988; major
Specific Plan amendment dated 1999
Data from Planning Division(b)
Northeast Industrial
Specific Plan
(Phases 1, 2, and 3)
Specific Plan dated July 2012 Hydraulic Evaluation of Northeast Industrial Area (NEI) Specific Plan, West Yost
Associates, September 2018
Avenues Specific Plan Specific Plan dated May 2018 Hydraulic Evaluation of Avenues Specific Plan, West Yost Associates, April 2018
Cordes Ranch Specific
Plan
Specific Plan dated September 2013 Previous hydraulic evaluations(c); Data from Planning Division(b)
Ellis Specific Plan Specific Plan dated January 2013 Hydraulic Evaluation of Ellis Specific Plan Phase 2 - The Gardens, West Yost
Associates, December 2016; Hydraulic
Evaluation of Ellis Specific Plan
Phase 3 - Draft TM, West Yost Associates,
July 2019
Tracy Hills Specific Plan Specific Plan dated April 2016 Peer Review and Hydraulic Evaluation for Tracy Hills Phase 1B and 1C, West Yost
Associates, May 2020;
Data from Planning Division(b)
Tracy Village Specific Plan Specific Plan dated May 2018 Hydraulic Evaluation of Tracy Village Specific Plan, West Yost Associates,
February 2018
Westside Specific Plan Specific Plan area was previously included in the Gateway Specific Plan;
Draft EIR is currently being prepared for
the Westside Specific Plan
Preliminary tables from Draft EIR
Berg Road Subdivision
-
Berg Road Properties Development Water
Distribution System Analysis, Black Water,
January 2016
Dobler / Maibes(d) Included in the I-205 Corridor Specific Plan
Data from Planning Division(b)
Kagehiro - Data from Planning Division(e)
Rocking Horse Initial Study and Mitigated Negative
Declaration dated December 2015
Hydraulic Evaluation of South Lammers
Road Development, West Yost Associates,
May 2015
Legacy Fields (Holly Sugar
Sports Park)
Final EIR dated June 2010 2013 City of Tracy Parks Master Plan Small Approved Projects(f) - Previous hydraulic evaluations (a) Land use data from previous hydraulic evaluations was used for the following development projects within the I-205 Corridor Specific Plan area: Sierra Hills, Grant Line Road Apartments, Aspire II, and Harvest. (b) Land Uses with TAZ Estimates_06_25_2021_2025_2040_BU_Independent.xlsx, received from the City on June 25, 2021. (c) Hydraulic Evaluation of International Park of Commerce (IPC) Buildings 3, 4, and 12, West Yost Associates, May 2017; Hydraulic Evaluation of International Park of Commerce (IPC) Building 25, West Yost Associates, July 2017; Hydraulic Evaluation of International Park of Commerce (IPC) Buildings 22, 23, and Thermo Fisher, West Yost Associates, October 2017; Hydraulic Evaluation of International Park of Commerce (IPC) Buildings 9, 10, and 14, West Yost Associates, May 2018; Hydraulic Evaluation of IPC Building 19A Draft TM, West Yost Associates, August 2019. (d) Dobler / Maibes is part of the I-205 Corridor Specific Plan area but is accounted for separately in this WSMP Update. (e) Correspondence from City staff received on August 7, 2019. (f) Includes Home 2 Suites, 321 E. Grant Line Road Apartments, and Barcelona Infill.
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3.3.3 Additional Planned Development
In addition to the approved projects, the City has also identified many additional planned development areas within the City ’s SOI which will be served by the City in the future . As described above, some of these additional planned development areas are designated as Urban Reserve in the City’s General Plan. Projections of future land use in these areas are less certain than those for the approved projects, as there are few, if any, planning documents available. Many of these additional planned development areas are located outside of the existing City limits. As future developments within the City’s SOI, but outside the City limits, are approved, they will be annexed and served by the City. Figure 3-3 shows the locations of these additional planned development areas.
Land use projections for additional planned development areas were provided by the City’s Planning Division 2. This data was then used to estimate the a nticipated additional future water demands associated with development of the additional planned development areas, which are included in the future water demand projections.
3.3.4 Miscellaneous Infill Development
Vacant parcels that are not covered by any of the areas previously discussed may be developed as miscellaneous infill. Land use projections for development of miscellaneous infill parcels were provided by the City’s Planning Division2. This data was used to estimate the anticipated additional future water demands associated with development of the infill parcels, which are included in the future water demand projections.
It should be noted that in more urbanized cities throughout California, there has been a recent increase in applications for Accessory Dwelling Units (ADUs), also known as guest houses or granny suites. An ADU is defined as an attached or detached residential dwelling unit built on the same parcel as an existing primary single -family dwelling, which provides complete independent living facilities for one or more persons, including permanent provisions for living, sleeping, eating, cooking, and sanitation. Discussions with City staff acknowledge the possibility of an increase in development of ADUs in the future. However, due to the uncertainty in the timing and extent of ADU development in the City, they were not included in the future water demand projections.
3.3.5 Mountain View Annexation
As stated in the City’s 2019 Municipal Service Review (MSR), the area of rural residential land use near the intersection of Mountain View Road and Corral Hollow Road may be annexed and served by the City in the future. The location of the Mountain View Annexation is shown on Figure 3-3.
Although the Mountain View area is already developed, extending water service to these homes would increase the City’s water demands. Data from the MSR was used to estimate the anticipated additional future water demands associated with extending service t o the Mountain View area, which are included in the future water demand projections.
2 Land Uses with TAZ Estimates_06_23_2021_2025_2040_BU_Independent.xlsx, received from the City on June 25, 2021.
0 4,0002,000
Scale in Feet
Figure 3-3
Additional Planned
Development
City of Tracy
Water System Master Plan Update
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City Limits
Sphere of Influence
Mountain View
Additional Planned Development
Areas
Berg / Byron Remainder
Chrisman Road
East Side Industrial
Holly Sugar Industrial
I-205 Expansion
Larch-Clover
Rocha
SWC Valpico & Corral Hollow
UR 1
UR 3 (Sandhu)
UR 4 (Bright Triangle)
UR 5 (Bright)
UR 7 (Bright/Castro)
UR 10
West Side Industrial
205
Berg / Byron
Remainder
SWC Valpico
& Corral Hollow
Mountain ViewSCHULTE CT
ELEVENTH ST
CORRAL HOLLOW RD
M
AC
ARTHUR
DR
TRACY BL
BYRON RD
GRANT LINE RD
MOUNTAIN HOUSE PK
BANTA RD
HANSEN RD
VALPICO RD
BIRD RD
LOVELY RD
LAMMERS RD
CHRISMAN RD
NAGLEE RD
LINNE RD
HOLLY DR
BETHANY RD
MIDDLE RD
VON SOSTEN RD
AHERN RD
REEVE RD
SCHULTE RD
Ol d River
C a l i f o r n i a A q u e d u c t
De l t a- Men dot a
Can a l
UR 10
West Side
Industrial
Larch-Clover
I-205
Expansion East Side
Industrial
UR 1
UR 5
(Bright)
Chrisman
Road
UR 7
(Bright/Castro)
Rocha
UR4
(Bright
Triangle)
Holly
Sugar
Industrial
UR 3
(Sandhu)
Notes:
1. Miscellaneous Infill is not shown. It is assumed that small vacant parcels are evenly distributed throughout
the central developed areas of the City.
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Land Use Assumptions
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3.4 DEVELOPMENT TIME FRAMES EVALUATED IN THIS WATER SYSTEM MASTER
PLAN UPDATE
Three development time frames are evaluated in this Water System Master Plan Update:
• 2025 (Near-Term)
• 2040
• Buildout
Assumptions for each development time frame are described below. Projections for timing of development were provided by the City’s Planning Division.
3.4.1 2025 (Near-Term) Development of the City’s Sphere of Influence Most of the near-term development is projected to occur in the areas covered by the approved projects discussed above. Except for the Westside Specific Plan, Avenues Specific Plan , and Dobler/Maibes projects, all of the approved projects listed in Table 3-1 are expected to begin development soon or continue developing through 2025. A small portion of the near -term development is projected to occur within the UR 7 (Bright/Castro), UR 1, Westside Industrial, Larch-Clover, and Berg/Byron Remainder development areas. In addition, approximately 44 acres of miscellaneous vacant parcels are projected to develop by 2025.
3.4.2 2040 Development of the City’s Sphere of Influence Except for the Tracy Hills Specific Plan and Cordes Ranch Specific Plan it was assumed that all of the other approved projects listed in Table 3-1 will be completely developed by 2040. Only a small portion of the Cordes Ranch Specific Plan was assumed to be developed after 2040.
Significant development is projected to occur in many of the additional planned development areas by 2040; only the UR 10, UR 4 (Bright Triangle), UR 3 ( Sandhu), Chrisman Road, Rocha, and SWC Valpico & Corral Hollow future service areas are projected to start development after 2040.
In addition, approximately 215 acres of miscellaneous vacant parcels are projected to develop by 2040 (171 acres in addition to 2025 development).
3.4.3 Buildout Development of the City’s Sphere of Influence The remaining planning areas assumed to be developed after 2040 were assumed to be part of the buildout development of the City’s SOI. In addition, it was assumed that a total of 311 acres of miscellaneous vacant parcels within the City limits will develop by buildout (91 acres in addition to 2040 development). As noted above, actual timing for full buildout of the City’s SOI is uncertain as development plans continually change and the City’s General Plan is periodically updated.
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Land Use Assumptions
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3.5 SUMMARY OF LAND USE PROJECTIONS
Table 3-2 presents the total projected land use to be developed in the City’s SOI by the 2025, 2040, and buildout time frames. Table 3-2 does not include existing developed land within the City, unless it was developed after 2017. Refer to Appendix A for detailed land use assumptions.
Approximately 25,000 new dwelling units and 5, 600 new acres of non -residential land u se are projected to be developed by buildout. A direct comparison with land use projections from the 2012 WSMP is difficult, as some development has occurred between the completion of the 2012 WSMP and the preparation of this Citywide Water System Master Plan Update. In general, the projection for number of dwelling units at buildout has increased significantly since the 2012 WSMP, while the projection for non-residential acreage at buildout has decreased since the 2012 WSMP. However, when compared to the C ity’s historical and existing land uses, which were primarily residential, the projected land uses for new development are more heavily skewed to non-residential uses (with almost 60 percent of the projected acres of new development at buildout being non-residential uses). The future industrial, commercial, and retail growth anticipated in the City’s Sphere of Influence is reflective of the City’s goal to bring jobs and economic growth and improve the City’s jobs-housing balance.
Table 3-2. Projected Development by Time Frame within the City's Sphere of Influence (a) Land Use Type
Total Projected New
Development by 2025
Total Projected New
Development by 2040(b)
Total Projected New
Development at Buildout(c)
Dwelling
Units
Gross
Acres
Dwelling
Units
Gross
Acres
Dwelling
Units
Gross
Acres
Residential – Very
Low Density(d) - - 265 223 1,292(e) 907
Residential – Low
Density(d) 2,880 647 6,490 1,438 8,375 1,871
Residential –
Medium Density(d) 253 49 5,444 608 8,150 902
Residential – High
Density 1,591 81 3,300 181 7,033 380
Residential – Very
High Density 110 3 110 3 110 3
Commercial - 45 - 549 - 818
Office - 1 - 115 - 256
Industrial - 859 - 3,136 - 4,093
Institutional - 3 - 187 - 187
Identified Parks(f) - 139 - 280 - 280
Total 4,834 1,826 15,609 6,720 24,960 9,698
(a) Includes existing development constructed after 2017. (b) Includes new development constructed within 2025 and 2040 time frames. (c) Includes new development constructed within 2025, 2040, and Buildout time frames. (d) For selected projects and development areas, it was assumed that 11.2% of the total gross acres in the very low, low, and medium density residential land use categories will develop as parks. (e) Includes existing units from Mountain View Annexation. (f) Includes park areas identified with the Rocking Horse, Ellis, Avenues, Tracy Hills Phase 1 and Legacy Fields developments.
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CHAPTER 4
Existing and Future Water Demands
4.1 OVERVIEW
The purpose of this chapter is to present the existing potable and recycled water demands currently served by the City, as well as the projected future potable and recycled water demands for the 2025 (near-term), 2040, and buildout time frames. Any additional evaluations regarding the timing and phasing of future water demands outside of the specified time frames will be developed as part of separate evaluations and are not included in this Citywide Water System Master Plan Update.
Accurate and detailed potable and recycled water demand data and projections are required to:
1. Develop and calibrate the potable and recycled water system hydraulic models.
2. Identify deficiencies in the existing potable and recycled water systems and required improvements.
3. Assess the future water system capacity and identify improvements needed to serve proposed development.
Accurate demand projections also play a key role in helping the City identify and secure sufficient water supplies to serve their customer s under various hydrologic conditions. A discussion of the City’s existing and future water supplies is provided in Chapter 5 of this Citywide Water System Master Plan Update.
The following sections of this chapter describe the data and methodology used to determine the City’s potable and recycled water system demands:
• Existing Service Area
• Population Served
• Historical Potable Water Production and Consumption
• Existing Recycled Water Production and Consumption
• Water Conservation and Water Use Efficiency
• Adopted Peaking Factors
• Future Water Demand Projections
• Future Per Capita Water Use Projections
4.2 EXISTING SERVICE AREA
The City is located in San Joaquin County, California, approximately 70 miles south of Sacramento and 60 miles east of San Francisco. The exis ting incorporated area of the City (i.e., City limits) encompasses approximately 26 square miles. As described in Chapter 3, t he City’s SOI is approximately 42 square miles and is 16 square miles larger than the City limits. The SOI encompasses the area outside of and contiguous with the City limits that the City expects to annex and urbanize in the future. Figure 4-1 shows the boundaries of the existing City limits and SOI. 0 7,5003,750
Scale in Feet
205
205
580
580
SCHULTE RDSCHULTE RD
ELEVENTH ST
CO
RR
AL
H
O
LLO
W
RD
GRANT LINE RD
M
AC
ARTHUR
DR
BYRON RD
BANTA RD
HANSEN RD
VALPICO RD
LINNE RD
BETHANY RD
MIDDLE RD
VON SOSTEN RD
DURHAM FERRY RD
TRACY BL
MOUNTAIN HOUSE PK
LAMMERS RD
NAGLEE RD
CHRISMAN RD
REEVE RD
O ld R i ver
Cal i f o r n i a A q u e d u c t
De l t a - M e n d o t a C a nal
Figure 4-1
Water Service Area
City of Tracy
Water System
Master Plan Update
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City Limits / Existing Water Service Area
Sphere of Influence
Chapter 4
Existing and Future Water Demands
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The City’s existing water service area is generally coterminous with the City limits as shown on Figure 4-1. The City currently provides potable water service to all of its residents, as well as approximately 400 residents of the Larch-Clover County Services District and the unincorporated Patterson Pass Business Park. Future growth potential for the City includes completion of ongoing development projects and infill within the City limits, and development of areas outside of the City limits withi n the SOI boundary. Refer to Chapter 3 for details on future land use within the City’s SOI.
4.3 POPULATION SERVED
Approximately 96,000 people live in the City as of January 2020. Population growth was rapid in the City over the 15 -year period 1990 through 2005, with the City growing by 139 percent.
Between 2005 and 2020, however, growth has slowed relative to historical rates; population increased approximately 68 percent over this 15 -year period. The reduction in growth rate has likely been caused by a combination of economic forces, such as the economic downturn of 2008 through 2011, and measures taken by the City to limit growth. In 1987, the City adopted a residential Growth Management Ordinance (GMO), which was amended in 2000 by the voter - initiated Measure A. The objective of the GMO and Measure A was to achieve a steady and orderly growth rate that allows for the adequate provision of services and community facilities and includes a balance of housing opportunities. Under the adopted GMO, build ers must obtain a Residential Growth Allotment (RGA) in order to secure a residential building permit.
Table 4-1 and Figure 4-2 summarize the City’s population between 1990 and 2020.
Year Population(a) Annual Grow
th
Last 5-yr Average
Annual Growth
Last 10-yr Average
Annual Growth
Last 30-yr Average
Annual Growth
1990(b) 32,450
1991(c) 35,871 11%
1992(c) 38,006 6%
1993(c) 40,455 6%
1994(c) 42,111 4%
1995(c) 44,546 6%
1996(c) 45,949 3%
1997(c) 47,428 3%
1998(c) 48,962 3%
1999(c) 51,959 6%
2000(c) 56,070 8%
2001(d) 61,048 9%
2002(d) 65,993 8%
2003(d) 70,060 6%
2004(d) 74,745 7%
2005(d) 78,228 5%
2006(d) 80,152 2%
2007(d) 80,700 1%
2008(d) 81,490 1%
2009(d) 82,040 1%
2010(d) 82,922 1%
2011(e) 83,539 1%
2012(e) 84,357 1%
2013(e) 85,568 1%
2014(e) 86,061 1%
2015(e) 87,194 1%
2016(e) 88,712 2%
2017(e) 90,488 2%
2018(e) 92,395 2%
2019(e) 94,326 2%
2020(e) 95,861 2%
(b) Sourc
e: Department of Finance, E-4 Population Estimates for California Cities and Counties, January 1, 1981 to January 1, 1990. (c) Source: Department of Finance, E-4 Historical Population Estimates for City, County and the State, 1991-2000, with 1990 and 2000 Census Counts, August 2007.
(d) Source: Department of Finance, E-4 Population Estimates for Cities, Counties and the State, 2001–2010, with 2000 and 2010 Census Counts, November 2012.
(e) Sourc
e: Department of Finance, E-5 Population and Housing Estimates for Cities, Counties and the State 2011-2021 with 2010 Census Benchmark, May 2021.
Tab
le 4-1. Historical Population Served
1.9%
1.5%
3.7%
(a) Does
not include Larch Creek Clover CSD service area population which has an estimated total number of accounts (118) and a person per household factor of 3.51 for an estimated population of 414 people. o\c\40
4\12-18-41\eng\ch4\ch4tablesandfigures
Last Revised: 08-20-21
City of Tracy
Cityw
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Master Plan Update
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iguresandtables
Last Revised: 08-20-21
City
of Tracy
Citywide Water System
Master Plan Update
0 10,00
0 20,000
30,000
40,000
50,000
60,000
70,000
80,000
90,000
100,000
1990
19 91
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
Population
Year
Figure 4
-2. Historical Population Served (1990-2020)
Notes
:
- Source: California Department of Finance Reports (see Table 4-1).
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4.4 HISTORICAL POTABLE WATER PRODUCTION AND CONSUMPTION The City’s potable water production is the combined quantity of surface water purchased from the United States Bureau of Reclamation (USBR) and the South San Joaquin Irrigation District (SSJID) plus the groundwater produced by the City’s wells 1, while potable water consumption is the quantity of water actually consumed or used by the City’s customers. As will be discussed later, the difference between production and consumption is unaccounted-for water (UAFW), also referred to as non-revenue water (NRW).
The City currently tracks all of the surface wat er purchased from USBR and SSJID plus the groundwater produced by its wells. The City also meters all of its customers ’ water use and categorizes their water use by customer class. Consequently, the City tracks water use in two ways:
production records and meter (consumption) records. Both are discussed in more detail below, along with a discussion on UAFW and per capita water demands.
4.4.1 Historical Potable Water Production
The City meets its customers’ potable water demands with a combination of surface water purchased from USBR and SSJID plus groundwater pumped from municipal wells. Table 4-2 presents the historical annual potable water production, by source, from 1990 to 2020.
Table 4-2 indicates that since SSJID began surface water deliveries in 2005, the City has significantly increased its surface water use to meet its customers’ water demands, and as a result groundwater production has dramatically decreased. Surface water use in recent years (2010-2020) accounts for over 94 percent of the total annual water production.
The City plans to continue maximizing surface water use because the City’s groundwater is heavily mineralized (e.g., high total dissolved solids (TDS)). Consequently, the reduction in groundwater use will ultimately increase the overall quality of the City’s drinking water. However, the City will continue to rely on groundwater for peaking, drought, and emergency supplies to meet water demands when surface water supplies may be limited. Detailed discussions on water supplies and their historical use and availability are presented in Chapter 5.
1 In 2019, the City also began receiving surface water supplies through an agreement with the Byron Bethany Irrigation District (BBID). The BBID surface water supplies are treated at the City’s John Jones Water Treatment Plant (JJWTP) and are used to meet potable water demands within the City’s Tracy Hills development. Additional discussion on this water supply is provided in Chapter 5.
USBR(a) SSJID(b)
Tot
al
Surface Water
1990(c)
4,96
8 - 4,968 5,838 10,806 3,521 46% 54% 1991(c)
4,99
5 - 4,995 4,815 9,810 3,197 51% 49% 1992(c)
7,14
8 - 7,148 4,002 11,150 3,633 64% 36% 1993(c)
7,80
0 - 7,800 4,127 11,927 3,886 65% 35% 1994(c)
7,78
8 - 7,788 4,901 12,689 4,135 61% 39% 1995(c)
8,38
7 - 8,387 4,310 12,697 4,137 66% 34% 1996(c)
8,81
7 - 8,817 4,562 13,379 4,360 66% 34% 1997(c)
7,53
9 - 7,539 5,789 13,328 4,343 57% 43% 1998(c)
6,28
2 - 6,282 4,797 11,079 3,610 57% 43% 1999(c)
7,55
1 - 7,551 5,559 13,110 4,272 58% 42% 2000(c)
7,78
5 - 7,785 6,548 14,333 4,670 54% 46% 2001(c)
7,30
2 - 7,302 7,321 14,623 4,765 50% 50% 2002(c)
7,87
8 - 7,878 7,802 15,680 5,109 50% 50% 2003(c)
10,1
18 - 10,118 6,847 16,965 5,528 60% 40% 2004(c)
11,1
87 - 11,187 7,176 18,363 5,984 61% 39% 2005(d)
8,92
0 3,146 12,066 5,826 17,892 5,830 67% 33% 2006(d)
6,04
8 8,918 14,966 3,034 18,000 5,865 83% 17% 2007(d)
6,37
4 9,130 15,504 3,672 19,176 6,249 81% 19% 2008(d)
6,50
3 8,017 14,520 2,598 17,118 5,578 85% 15% 2009(d)
4,96
5 10,401 15,366 1,327 16,693 5,439 92% 8% 2010(d)
5,30
3 10,850 16,153 498 16,651 5,426 97% 3% 2011(d)
4,79
0 11,793 16,583 292 16,875 5,499 98% 2% 2012(d)
4,87
8 12,294 17,172 420 17,592 5,732 98% 2% 2013(d)
4,96
0 13,112 18,072 515 18,587 6,057 97% 3% 2014(d)
4,01
8 11,515 15,533 680 16,213 5,283 96% 4% 2015(d)
3,19
3 10,329 13,522 519 14,041 4,575 96% 4% 2016(d)
2,63
4 11,372 14,006 648 14,654 4,775 96% 4% 2017(d)
4,90
6 11,464 16,370 995 17,365 5,658 94% 6% 2018(d)
5,18
4 10,471 15,655 817 16,472 5,367 95% 5% 2019(d)
7,53
7 8,750 16,287 645 16,932 5,517 96% 4% 2020(d)
5,73
3 11,773 17,506 1,181 18,687 6,089 94% 6% (b) SSJ
ID began surface water deliveries to the City in 2005.
(c) Source: Figure 7, WSA for the Holly Sugar Sports Park, June 2009. (d) Source: Annual Production Totals.xls spreadsheets received from the City. (a) Does not include USBR water wheeled to Patterson Pass Business Park and the Safeway Distribution Center.
Tabl
e 4-2. Historical Annual City of Tracy Potable Water Production by Source Year
Surface Water, af/yr
Groundwater,
af/yr
City
Production, af/yr
City
Production, MG
Percent Surface
Water
Percent
Groundwater
o\c\404\1
2-18-41\eng\ch4\ch4tablesandfigures
Last Revised: 08-20-21
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ide Water System
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Figure 4-3 presents the total historical annual potable water production for the City. This historical data indicates that annual water production generally increased at about 3 percent per year from 1990 to 2007. Water production decreased in 2008 and remained relatively constant through 2011, likely in response to poor ec onomic conditions that resulted in vacant properties and unoccupied homes. Water production increased in 2012 and 2013 as economic conditions improved, before decreasing dramatically in 2014 and 2015 due to the voluntary and mandatory water conservation efforts that were implemented by the City’s water customers during the extended drought. Water production has increased in recent years (2016-2020) as water use restrictions were lifted and new development projects are being constructed. While the City’s water production will likely continue to increase as the City expands, the rate at which water production is expected to increase will likely be lower than 3 percent due to the adopted GMO and water conservation and water use efficiency measures implemented in response to the recent drought and recent legislation .
Discussions on the City’s projected future water production are presented below under Section 4.8.6 Projected Buildout Water Demands.
In addition to providing water to its residents, the City also se rves water to the Patterson Pass Business Park (PPBP), which is located outside of the City limits. Water supplied to PPBP is not included in the City’s production totals as presented in Table 4-2 and Figure 4-3 because the water supply for this area is purchased by PPBP from the Byron Bethany Irrigat ion District (formerly the Plain View Water District ). The City is only responsible for providing water treatment and delivery services to PPBP in accordance with a “treat and wheel” agreement. Table 4-3 presents the historical water wheeled to PPBP by the City under this agreement.
The City’s highest monthly water production has historically occurred in either the month of July or August, which corresponds with the high temperatures and minimal rainfall that is experienced in the City during those summer months. The lowest monthly water production has historically occurred in either January or February. These months correspond with the shut -down of the John Jones Water Treatment Plant for maintenance, which typically occurs in the winter months (e.g., December, January, and/or February).
o/c/404/12-18-41/eng/ch4/ch4f
iguresandtables
Last Revised: 08-20-21
City
of Tracy
Citywide Water System
Master Plan Update
10,806
9,810
11,150
11,927
12,689
12,697
13,379
13,328
11,079
13,110
14,333
14,623
15,680
16,965
18,363
17,892
18,000
19,176
17,118
16,693
16,651
16,875
17,592
18,587
16,213
14,041
14,654
17,365
16,472
16,932
18,687
407
354
450
378
363
420
527
538
558
590
585
707
796
948
740
840
0 2,000
4,
000
6,000
8,000
10,000
12,000
14,000
16,000
18,000
20,000
1990
19 91
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
Water Production, af/yr
Year
Figure 4
-3. Historical Annual Water Production (1990-2020)
City P
roduction PPBP an
d Safeway Production
Notes
:
- City Production does not include water wheeled to Patterson Pass Business Park (PPBP) and Safeway Distribution Center.
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Table 4-3. Historical Annual Potable Water Production
including Wheeled Water for Patterson Pass Business Park Year City Production, af/yr(a)
Wheeled USBR Water
for the PPBP, af/yr(b)
Total Production
af/yr MG
2005 17,892 407 18,299 5,963
2006 18,000 354 18,354 5,981
2007 19,176 450 19,626 6,395
2008 17,118 378 17,496 5,701
2009 16,693 363 17,056 5,558
2010 16,651 420 17,071 5,563
2011 16,875 527 17,402 5,670
2012 17,592 538 18,130 5,908
2013 18,587 558 19,145 6,239
2014 16,213 590 16,803 5,475
2015 14,041 585 14,626 4,766
2016 14,654 707 15,361 5,005
2017 17,365 796 18,161 5,918
2018 16,472 948 17,420 5,676
2019 16,932 740 17,672 5,758
2020 18,687 840 19,527 6,363
(a) Source: Annual Production Totals.xls spreadsheets received from the City. (b) The City wheels USBR water for the Patterson Pass Business Park and the Safeway Distribution Center. This water is not part of the City's annual water rights allocations and is therefore tracked separately from the City Production.
4.4.2 Historical Potable Water Consumption
Potable water consumed by customer class between 2015 and 2017 is summarized in Table 4-4.
This data indicates that, on average, residential use (including single family and multi-family land use types) represents approximately 67 percent of the total metered water consumption in the City.
Commercial and Industrial customers represent an average of approximately 15 and 5 percent, respectively, of the total metered water consumption. Irrigation accounts for the remaining 13 percent of the total metered water consumption.
Projected future water consumption by customer class is discussed below under Section 4.8.6 Projected Buildout Water Demands.
Table 4-5 provides a summary of the top 15 potable water users in 2017 by customer classification.
These top users accounted for approximately 11 percent of the total metered water consumption in 2017. The top user is an industrial food processing user, and their overall water use represents more than 4 percent of the City’s 2017 water consumption. The remaining large Commercial, Multi-Family Residential, and Irrigation water users account for about 7 percent of the City’s total water consumption in 2017.
Percent(a) af/y
r Percent(a) af/y
r Percent(a) af/y
r Percent(a) af/y
r Percent(a) af/y
r
2015 61.3% 8,582 7.0% 984 15.2% 2,129 5.2% 725 11.3% 1,579 13,999 2016 60.1% 8,400 7.0% 977 15.0% 2,102 4.9% 685 13.0% 1,811 13,976 2017 58.8% 9,737 6.0% 999 15.8% 2,619 4.7% 784 14.6% 2,413 16,552 Average 60.1% 8,907 6.7% 987 15.4% 2,283 4.9% 731 12.9% 1,935 14,842 Year
Residential
Single-Family
Residential
Multi-Family
Table 4-4. P
otable Water Consumption
(a) Based on meter data recei
ved from the City on October 15, 2019.
(b) Source: City of Tracy AWWA Water Audit Spreadsheets, received from the City on November 1, 2018.
Com
mercial Industrial Irrigation
Total, af/yr(b)
o\c\404\12-18-
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Table 4-5. Summary of Top 15 Potable Water Users in 2017 No. Customer Class
Total Annual
Consumption, ccf
Total Annual
Consumption, MG
Percentage of Total
Annual Consumption, %
1 Industrial 295,480 221 4.10
2 Commercial 123,785 93 1.72
3 Commercial 47,990 36 0.67
4 Irrigation 42,985 32 0.60
5(a) Irrigation 29,466 22 0.41
6 Multi-Family Residential 29,210 22 0.41
7 Irrigation 28,857 22 0.40
8 Commercial 28,070 21 0.39
9 Multi-Family Residential 26,308 20 0.36
10 Commercial 25,167 19 0.35
11 Commercial 23,962 18 0.33
12 Commercial 23,198 17 0.32
13 Commercial 22,344 17 0.31
14 Irrigation 20,720 15 0.29
15 Commercial 20,050 15 0.28
Total 787,592 589 10.9
Source: 2015. May 2018 Reads.csv received from the City on May 30, 2018. (a) Large user appears to be due to a leak and has been resolved.
4.4.3 Potable Unaccounted-for Water/Non-Revenue Water
Unaccounted-for water ( UAFW) within the City is the difference between the recorded water production and metered water consumption. UAFW includes a combination of various water uses that are not metered, such as water used for hydrant testing, firefighting , and system flushing or water that is lost from system leaks and water main breaks. As noted above, unaccounted-for water is also referred to as non-revenue water (NRW).
Potable UAFW between 2015 and 20172 is summarized in Table 4-6. Table 4-6 indicates that the potable UAFW within the City averaged approximately 8.9 percent between 2016 and 2017 (data from 2015 appeared suspect and was not included in the average). This UAFW percentage is lower than the UAFW percentage used in the 201 5 UWMP (9.6 percent), but is above the UAFW percentage (7.5 percent) used in the 2012 WSMP . For planning purposes in this Citywide Water System Master Plan, a UAFW percentage of 9.6 percent (consistent with the 2015 UWMP) was used to project the City’s total future water production requirements.
2 The City’s 2018-2020 consumption data was not available at the time of this evaluation. Based on data provided in the City’s 2020 UWMP, UAFW in 2018 and 2019 dropped to about 6.8 percent and 5.8 percent, respectively, but then increased significantly in 2020 to over 18 percent, although the 2020 data had not yet been validated.
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Table 4-6. Potable Unaccounted-for Water
Year
Total Production,
af/yr(a)
Consumption,
af/yr(b)
Difference,
af/yr
Percentage,
UAFW, %
2015 14,626 13,999 627 4.3
2016 15,361 13,976 1,385 9.0
2017 18,161 16,552 1,609 8.9
Average (2016 and 2017)(c) 8.9
(a) Source: Refer to Table 4-3. Includes water wheeled to Patterson Pass Business Park and Safeway Distribution Center by the City.
(b) Source: City of Tracy AWWA Water Audit Spreadsheets, received from the City on November 1, 2018. (c) Average does not include 2015 because data appears to be suspect.
The City Utilities Department, in conjunction with the Public Works and Construction Management Departments, is implementing several new programs to address water loss. A new process was developed for the coordination of installation of new meters in new development areas with the City’s billing and accounting systems to ensure that new accounts are metered and billed appropriately. The City has also implemented a new construction meter program, whereby the Public Works Department is now installing the meter on the hydrant and providing clamps so that the meter cannot be moved or stolen. These programs were started in Fall 2021 and water loss numbers were reduced immediately. The City will be conducting ongoing investigations to evaluate water loss and make improvements as needed to meet the State’s new water loss standards.
4.4.4 Per Capita Potable Water Demand
Historical per capita potable water demands were calculated by dividing the annual potable water production previously presented in Table 4-2 by the respective annual population previously presented in Table 4-1. Table 4-7 summarizes the per capita potable water demands for the City between 200 9 and 20 20. As shown in Table 4-7, the per capita water demand has averaged approximately 168 gpcd over the past 10 years. The per capita demand decreased significantly in 2015 and 201 6 to 14 4 gpcd and 147 gpcd, respectively . As discussed previously, this sharp decrease in 2015 and 2016 is most likely due to the extreme dry hydrologic (drought) conditions resulting in voluntary and mandatory water conservation. The per capita demand has increased in recent years (2017-2020) as water use restrictions have been lifted and customers have resumed more typical water use behavior.
Figure 4-4 compares the per capita water demand, water production, and population for the period from 2011 to 2020. As shown on Figure 4-4, the population has increased at a relatively constant rate from 2011 to 2020. Therefore, the majority of the variation observed in the per capita water demand is due to variations in the City’s total water production, w hich appears to vary based on economic and hydrologic conditions.
A comparison of per capita water demands with the goals set by SB X7-7 legislation is discussed below in Section 4.6 Water Conservation and Water Use Efficiency and Section 4.9 Future Per Capita Water Use Projections.
Year Population
Served(a)
City Potab
le Water
Production, af/yr(b)
Per Capita
Potable Water
Demand, gpcd
5-yr Average Per Capita Potable
Water Demand, gpcd
10-yr Average Per Capita Potable
Water Demand, gpcd
2009 82,040 16,693 182 2010 82,922 16,651 179 2011 83,539 16,875 180 2012 84,357 17,592 186 2013 85,568 18,587 194 2014 86,061 16,213 168 2015 87,194 14,041 144 2016 88,712 14,654 147 2017 90,488 17,365 171 2018 92,395 16,472 159 2019 94,326 16,932 160 2020 95,861 18,687 174 (b) Source: Refer to T
able 4-2. Includes UAFW. Does not include water wheeled to Patterson Pass Business Park and Safeway Distribution Center, as these are located outside of the City limits.
Tab
le 4-7. Historical Per Capita Potable Water Demand
(a) Source: Refer to T
able 4-1.
162
168
o\
c\404\12-18-41\eng\ch4\ch4tablesandfigures
Last Revised: 08-20-21
City of Tr
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Master Plan Update
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iguresandtables
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Citywide Water System
Master Plan Update
180
18 6
194
168
144
147
171
159
160
174
83,539
84,357
85,568
86,061
87,194
88,712
90,488
92,395
94,326
95,861
16,875
17,592
18,587
16,213
14,041
14,654
17,365
16,472
16,932
18,687
10,000
20,000
30,000
40,000
50,000
60,000
70,000
80,000
90,000
100,000
-
50 100
150
200
250
300
350
400
450
2011 2012 2013 2014 2015 2016 2017 2018 2019 2020
Population
Served
Per Capita Demand, gpcd
Year
Figure 4
-4. Comparison of Historical Per Capita Water Demand, Production and Population Historical P
er Capita Demand Average Per Capita D
emand Popula
tion Served City W
ater Production
Prod
uction, af/yr
Histor
ical Average: 170 gpcd
10,000
Note:
-
Production does not include water wheeled to Patterson
Pass Business Park and Safeway Distribution Center.
20,000
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4.5 EXISTING RECYCLED WATER PRODUCTION AND CONSUMPTION
The City anticipates using recycled water for landscape irrigation to offset potable water demands.
The City ’s Wastewater Treatment Plant can currently produce up to approximately 9 mgd of tertiary-treated wastewater meeting Title 22 requirements, which can be used for landscape irrigation and other non-potable uses. Initially, the City intends to irrigate using recycled water at the Legacy Fields sports complex.
4.6 WATER CONSERVATION AND WATER USE EFFICIENCY
As discussed in Chapter 2, the City has developed a list of principles for sustainable infrastructure to ensure a reliable water supply for future generations. A key principle that relates to the Citywide Water System Master Plan Update is water conservation and water use efficiency . Water conservation and water use efficiency will be necessary to meet requirements set by the State (e.g., the Water Conservation Act of 2009 and Making Water Conservation a California Way of Life legislation) to reduce the City’s per capita water use. Discussions regarding existing and future water conservation and water use efficiency in the City are presented below.
4.6.1 Existing Water Conservation
The City is committed to preserving California’s water resources through water conservation and efficient use of water, and currently has an ongoing Water Conservation Plan that implements the Best Management Practices (BMPs) which were deve loped by the California Urban Water Conservation Council ( CUWCC)3. These BMPs include residential surveys, public and school education programs, rebates for water efficient appliances and other specific programs. These programs have been successful in reducing the City’s water use, especially in the recent dry years.
4.6.2 Compliance with the Water Conservation Act of 2009 (SB X7-7) In February 2008, Governor Arnold Schwarzenegger called for a statewide 20 percent reduction in per capita water use by 2020 and a sked State and local agencies to develop a more aggressive plan of water conservation to achieve the goal. A team of State and federal agencies (the 20x2020 Agency Team) consisting of the DWR, SWRCB, California Energy Commission, Public Utilities Commission, Department of Public Health, California Air Resources Board, CALFED Program, the USBR, and the CUWCC was formed to develop a statewide implementation plan for achieving this goal.
Then, on November 10, 2009, Governor Arnold Schwarzenegger signed Senate Bill X7-7 (SB X7-7), one of several bills passed as part of a comprehensive set of Delta and water policy legislation. SB X7-7, known as the Water Conservation Act of 2009, requires a 20 percent reduction in urban water usage by 2020 and establishes various methodologies for urban water suppliers to establish their interim (2015) and final (2020) per capita water use targets.
3 It should be noted that the CUWCC was replaced by a new organization, the California Water Efficiency Partnership (CalWEP), in March of 2018.
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As documented in the City’s 2015 UWMP, the City’s adopted per capita water use targets were 204 gpcd (2015 interim target) and 181 gpcd (2020 final target). As documented in the City’s 2015 UWMP, the City’s per capita water use in 2015 was 14 6 gpcd, which was well below the 2015 interim target4. In recent years there has been some rebound in per capita water use from the historic low in 2015 (see Table 4-7 and Figure 4-4). As documented in the City’s 2020 UWMP, the City’s per capita water use in 2020 was 181 gpcd, equal to its 2020 final target5.
4.6.3 Making Water Conservation a California Way of Life In May 2016, Governor Jerry Brown signed Executive Order B ‐37‐16, instructing State agencies to help Californians adopt permanent changes to use water more wisely. The Executive Order laid out a framework for moving the State from temporary, emergency water conservation measures to a more lasting approach customized to the unique conditions of each local water agency.
In May 2018, the California State Legislature (Legislature) enacted two policy bills (SB 606 and AB 1668) to establi sh a new foundation for long -term improvements in water conservation and drought planning to adapt to climate change and the resulting longer and more intense droughts in California. These two bills amended existing law to expand authorities and requirements to enable permanent changes and actions for those purposes to improve the State’s water future for generations to come. SB 606 and AB 1668 are direct outcomes of Governor Brown’s Executive Order B-37-16.
The recommendations in the April 2017 report entitled “Making Water Conservation a California Way of Life, Implementing Executive Order B -37-16” and subsequent extensive legislative outreach efforts informed the development of SB 606 and AB 1668. The new laws focus on establishing water use objectives a nd long-term water efficiency standards that apply to urban retail water suppliers, including:
• Indoor Residential Water Use: Although not all standards have been developed, the indoor residential water use efficiency standard has been set by the Legislature. Until January 1, 2025, the standard is set at 55 gpcd, then it drops to the greater of 52.5 gpcd or a standard developed by the DWR between January 2, 2025 and January 1, 2030; and then the greater of 50 gpcd or a standard developed by DWR after January 1, 2030.
4 It should be noted that the 2015 per capita water use calculated in the City’s 2015 UWMP (146 gpcd) is slightly higher than the 2015 per capita water use shown in Table 4-7 and Figure 4-4. The difference is due to a slightly different service area population in the 2015 UWMP per capita water use population. 5 It should be noted that the 2020 per capita water use calculated in the City’s 2020 UWMP (181 gpcd) is slightly higher than the 2020 per capita water use shown in Table 4-7 and Figure 4-4. The difference is due to the inclusion of the Larch Clover CSD in the service area population and the inclusion of the water production wheeled to the PPBP in the 2020 UWMP per capita water use calculation.
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• Outdoor Residential Water Use and Commercial, Industrial and Institutional (CII) Irrigation with Dedicated Meters: Per SB 606 and AB 1668, the SWRCB is required to adopt long-term standards for outdoor irrigation of landscape areas by June 30, 2022. The standards to be set shall incorporate the principles of the State’s MWELO6, which considers evapotranspiration adjustment factors, landscape areas, maximum applied water allowance, reference evapotranspiration, and special landscape area.
• Water Loss (due to leaks in water system pipes): With regard to water loss standards, SB 555, passed in October 2015, requires the SWRCB to develop water loss performance standards for urban retail water suppliers. The SWRCB is required to evaluate the life-cycle cost of achieving these standards. The standards will incorporate local and operational conditions to determine economically achievable water loss reduction for each urban retail water supplier.
The recently passed water efficiency legislation only provides a “provisional standard” for indoor residential water use and does not currently provide specific information on what the water efficiency standards will be for outdoor residential water use and non-residential water uses. These standards will be developed in the coming years and should be further evaluated in subsequent planning studies. Also, there are no guarantees that urban retail water suppliers will meet the water efficiency standards to be set, so West Yost recommends that the City continu e to consider more conservative water demand projections based on recent water use for their future water supply and system planning.
4.7 ADOPTED PEAKING FACTORS
Peaking factors are used to calculate water demands expected under high demand conditions (i.e., maximum day and peak hour). The resulting water demands calculated for maximum day and peak hour conditions are then used to evaluate and size transmission/distribution pipelines and storage facilities, and to define water supply needs and capacity requirem ents. This section describes the methodology used to develop peaking factors for the maximum day and peak hour demand conditions within the City’s potable and recycled water systems.
4.7.1 Potable Water System Peaking Factors
Table 4-8 summarizes the average and maximum day production and the corresponding peaking factors between 2010 and 2018. As shown in Table 4-8, the maximum day peaking factor for the City ranged from a low of 1.5 in 2015 and 2017 to a high of 1.8 in 2018. The average maximum day peaking factor from 2010 to 2018 is equal to 1.6 times the average day demand.
The City currently has an adopted maximum day peaking factor of 2.0 times the average day demand, which is higher than what has been observed in recent years. Based on the data from more recent maximum day tre nds, this higher peaking factor provides a very conservative estimate of the required water supply and distribution facilities to support projected water demands.
6 California Code of Regulations Title 23 Chapter 2.7 Model Water Efficient Landscape Ordinance.
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Consequently, for planning purposes in this Citywide Water System Master Plan Update, a maximum day peaking factor of 1.7 was adopted. This factor provides a slightly more conservative estimate of maximum day demands when compared with the 2010 to 2018 average maximum day peaking factor of 1.6, but will not excessively overestimate maximum day demands as compared with the City’s current adopted maximum day peaking factor of 2.0.
Table 4-8. Historical Maximum Day Demand Peaking Factors Year Date(a)
Maximum Day
Production, mgd(a)
Average Day
Production, mgd(b)
Maximum Day to
Average Day Factor
2010 July 17 25.8 15.2 1.7
2011 July 28 25.5 15.5 1.6
2012 July 13 27.8 16.2 1.7
2013 June 8 27.0 17.1 1.6
2014 June 9 24.9 15.0 1.7
2015 June 20 19.8 13.1 1.5
2016 August 8 22.0 13.7 1.6
2017 August 1 25.0 16.2 1.5
2018(c) August 17 27.2 15.3 1.8
Average 1.6
(a) Source: Max Day Data 201810221430.pdf received from the City on October 22, 2018. (b) Source: Refer to Table 4-3. Includes water wheeled to Patterson Pass Business Park and Safeway Distribution Center. (c) Maximum day production data for 2018 is from compiled SCADA data received from the City on May 3, 2019.
The City currently has an adopted peak hour demand factor of 3.4 times the average day demand, equivalent to a factor of 1.7 times the maximum day demand . SCADA data from 2018 was used to confirm the peak hour factor, which was found to be 1.6 times the maximum day demand. This confirms that the currently adopted peak hour factor of 1.7 times the maximum day demand is still accurate; this factor will continue to be used for planning purposes in this Citywide Water System Master Plan Update. However, because the adopted maximum day demand factor has been decreased from 2.0 times the average day demand to 1.7 times the average day demand, the new adopted peak hour demand factor used for planning purposes in this Citywide Water System Master Plan Update will be 2.9 times the average day demand.
4.7.2 Recycled Water System Peaking Factors
Peaking factors for recycled water systems are somewhat different from potable water systems, in that irrigation periods are generally limited to shorter time periods, typically during the late evenings and very early mornings ( e.g., 10 p.m. to 6 a.m.). For purposes of this Citywide Water System Master Plan Update, an irrigation period of eight (8) hours per day has been assumed. In addition, recycled water demand is anticipated to be at its maximum during the summer and fall months when temperatures and landscape irrigation water demands are at their highest.
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To estimate future monthly recycled water use, the City’s existing monthly potable water use for its dedicated landscape irrigation accounts was evaluated. Based on 2017 data, monthly irrigation water use reaches a maximum in September with irrigation water use equal to 17.6 percent of the total annual irrigation water use. This percentage of irrigation water use during the maximum month can be converted to an average day to maximum day peaking factor equal to 6. 4 times the average day irrigation demand (0.17 6/30 days x 365 days x [24 hours/8 -hour irrigation period]).
This factor is higher than the currently adopted factor of 5.8 times the average day irrigation demand. To be conservative, for planning purposes in this Citywide Water System Master Plan Update, the new (higher) maximum day irrigation peaking factor of 6.4 was adopted.
The peak hour recycled water demand was assumed to be approximately 10 percent above the maximum day irrigation demand, which equates to a peak hour peaking factor of 7.0 (1.1 x 6.4).
Table 4-9 summarizes the maximum day and peak hour peaking factors adopted for this Citywide Water System Master Plan Update.
Table 4-9. Adopted Peaking Factors
Demand Condition Potable Water System Recycled Water System Average Day Annual Use divided by
365 days per year
Annual Use divided by
365 days per year
Maximum Day 1.7 times the Average Day Demand 6.4 times the Average Day Demand (assuming an 8-hour irrigation period)
Peak Hour 2.9 times the Average Day Demand 7.0 times the Average Day Demand (10% above Maximum Day Demand)
4.8 FUTURE WATER DEMAND PROJECTIONS
Future w ater demands projections consist of two components: (1) existing (baseline) water demands, and (2) projected water demands from new developments calculated using unit water demand factors and the land use assumptions discussed previously in Chapter 3 and presented in Appendix A.
Using the land use assumptions presented in Appendix A, future water demands were calculated using a unit water demand methodology based on the proposed land use acreage or residential dwelling units projected for each project or development are a. Subsequent sections describe the current unit water demand factors adopted in the 2012 WSMP and the development of the updated unit water demand factors used to calculate future water demands for this Citywide Water System Master Plan Update, followed by a discussion of total projected water demands for the 2025, 2040, and buildout time frames.
4.8.1 Existing Unit Water Demand Factors and Land Use Assumptions In the 2012 WSMP, unit water deman d factors were generally developed by correlating land use data with existing metered water use . The City’s existing unit water demand factors are summarized in Table 4-10. These factors are typically multiplied by dwelling units or land use area data to calculate a projected water demand estimate.
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Table 4-10. 2012 WSMP Adopted Unit Water Demand Factors Land Use Designation
Unit Water Demand Factor
gpcd gpd/du af/ac/yr
Residential – Very Low Density(a) 130 429 --
Residential – Low Density(a) 130 429 --
Residential – Medium Density(b) 115 310 --
Residential – High Density(b) 100 220 --
Residential – Very High Density 100 150 --
Commercial(c) -- -- 2.0
Office(c) -- -- 1.5
Industrial(c,d) -- -- 1.5
Institutional(c) -- -- 1.5
Parks(e) -- -- 4.0
(a) Assumes exterior water use will be with potable water, except for parks. (b) Assumes exterior water use will be with recycled water (i.e., 15 percent of the total gross acres will be landscaped and irrigated with recycled water).
(c) Unit water demand factor to be applied to 85 percent of the total gross acres only, assuming that 15 percent of the total gross acres will be landscaped and irrigated with recycled water. (d) Assumes that high water use industries will not be developed. (e) Unit water demand factor to be applied to 15 percent of the total gross acres and/or any gross acreage that will require exterior water use.
In addition to these adopted unit water demand factors, the City has also used the following specific assumptions regarding dwelling units per acre for each residential land use type and floor to area ratios (FAR) for Commercial and Industrial land uses . These assumptions help to further refine water demand estimates from various proposed development projects that do not have a specific dwelling unit count or floor area estimate available. Table 4-11 summarizes the adopted dwelling unit and FAR assumptions that the City has recommended for estimating future water demands.
Table 4-11. Adopted Dwelling Unit Densities and Floor to Area Ratios (a) Land Use Designation Range Recommended Density or Ratio Residential – Very Low Density 0.1 to 2.0 du/acre 1.5 du/acre Residential – Low Density 2.1 to 5.8 du/acre 4.35 du/acre Residential – Medium Density 5.9 to 12.0 du/acre 9 du/acre Residential – High Density 12.1 to 25 du/acre 18.75 du/acre Residential – Very High Density Up to 40 du/acre(b) --
Commercial Maximum FAR 1.0 FAR 0.3
Office Maximum FAR 1.0 FAR 0.3
Industrial Maximum FAR 0.5 FAR 0.4
(a) Source: General Plan, DC&E (February 1, 2011).
(b) Source: Water Supply Assessment for the Downtown Specific Plan, West Yost Associates (April 2009).
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4.8.2 Verification of Unit Water Demand Factors
Due to possible changes in water use patterns over time, the existing unit water demand factors presented in Table 4-10 were verified to confirm if they are still representative of the City’s more recent water use patterns. Unit water demand factors that are refined using more recent water use data help to project more accurate water demands. The following sections discuss the methodologies used to “spot check” and verify existing residential and non -residential unit water demand factors.
4.8.2.1 General Methodology
Unit water demand factors were verified using existing land use and parcel information in Geographic Information System (GIS) format, which were correlated to existing (2017) metered water use data. Meter data from 2017 was used to verify the unit water demand factors because it was (1) the most recent data available at the time of the evaluation, and (2) more representative of normal water use than 2015 or 2016 data when there were mandatory water use restrictions in place. To calculate unit water demand factors by land use designation, the City’s existing land use data was first added to the parcel data using GIS analysis tools. Metered water use data was then automatically linked to the land use/parcel data by service addresses first or manually by location if needed. The unit water demand factor for each land use designation was then calculated by dividing the total metered water use by the total parcel area for which it was linked.
The parcel area used in this initial calculation did not include streets and therefore represented net area. Accordingly, the unit water demand factors calculated were “net” factors. Subsequently, the “net” unit water demand factors were adjusted to account for acreage from streets so they could be applied to the gross acreage information provided by City staff for future development7. The following sections describe the updated unit water demand factors first for residential land uses and then for non-residential land uses.
Typically, metered water use data used to determine unit water demand factors would be normalized to represent average water use across multiple years. Although it is expected that some increase or “rebound” in water demand from 2017 could potentially occur in the future , a portion of the observed reduction in water use will likely be permanent. This is supported by the City’s 2018 water production, which was less than 2017 water production. Therefore, due to these permanent changes in water use, the 2017 metered water use data was not normalized based on historical water use.
7 The gross acreage within the existing City limits is 16,616 acres, and the net acreage within the City limits assigned an existing or planned land use is 13,607 acres. Therefore, a fact or of 1.22 was used to convert from net acreage to gross acreage.
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4.8.2.2 Residential Unit Water Demand Factors
Single family residential unit water demand factors (Residential-Very Low Density and Residential-Low Density land uses) were refined by automatically linking metered water use to parcels by service address. Single family residences are typically served by a single meter, and there is typically only one single family residence on a given parcel. Because of this one -to-one relationship between meters and parcels, the unit water demand factors for single family residences could be accurately calculated using this method. In summary, 87 percent of the e xisting single family residential parcels were linked with a water meter by service address. Figure 4-5 illustrates the methodology used to calculate the refined unit w ater demand factors for single family residential land use types.
Figure 4-5. Residential Unit Water Demand Factor Methodology
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Table 4-12 presents the unit water demand factors calculated using the methodology described above. The calculated Residential-Very Low Density factor is 8 percent higher than the factor adopted in the 2012 WSMP. Because this factor is based on a small sample size of 83 parcels, it is recommended that no adjustment be made to the Residential-Very Low Density unit water demand factor. The calculated Residential-Low Density factor is 14 percent lower than the factor adopted in the 2012 WSMP. Although some rebound in water use from 2017 is expected in existing residences, it is also projected that a combination of future State-mandated conservation measures and the installation of water efficient appliances a nd landscaping in new homes will lower residential water use even further in the future. Therefore, it is recommended that the Low Density Residential unit water use factor be adjusted 15 percent lower than the adopted 2012 WSMP factor to reflect more recent water use trends.
Table 4-12. Refined Single-Family Residential Unit Water Demand Factors Land Use
Designation
2017
Metered
Water Use
Linked, af/yr
Number of
Occupied
Parcels/Dwelling
Units Linked(a)
Calculated
Unit Water
Demand
Factor,
gpd/du(b)
2012 WSMP
Unit Water
Demand Factor,
gpd/du
Calculated
Change in
Unit Water
Demand
Factor, %
Recommended
Change in Unit
Water Demand
Factor, %
Residential – Very
Low Density 43 83 464 429 8% 0%
Residential – Low
Density 6,238 15,139 368 429 -14% -15%
(a) Does not include vacant parcels (parcels with no water use in 2017). (b) Assumes one dwelling unit per parcel.
Residential-Medium, Residential -High Density, and Residential -Very High Density land uses generally have multiple meters and multiple addresses associated with a single parcel. Because of this, the methodology described above to calculate unit water demand factors often underestimates the unit water demand factors for these land use categories because not all the meters which supply a given parcel can be automatically linked with a single parcel address. Therefore, the unit water demand factors for Residential -Medium, Residential -High Density, and Residential -Very High Density land uses are recommended to be reduced by 15 percent, consistent with the adjustment for the Residential-Low Density factor.
4.8.2.3 Non-Residential Unit Water Demand Factors
Non-residential land uses generally have multiple water service meters (e.g., domestic and irrigation meters) and multiple addresses associated with a single parcel. Because of this, automatically linking metered water use from multiple meters to a single parcel by address is difficult and would generally underestimate the unit water demand factors for non-residential land use categories because not all the meters which supply a single parcel can be automatically linked with that parcel. Therefore, a different methodology was used to “spot check” and refine the unit water demand factors for non-residential land use categories.
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Representative areas of the City with high concentrations of Commercial and Industrial land uses were first selected as shown on Figure 4-6, and the metered water use from water meters in these areas were manually associated with parcels based on each meter’s spatial location. From the metered water use and parcel acreage that were linked through this process, unit water de mand factors were then calculated for each of these representative areas, which are summarized in Table 4-13.
Unit water demand factors for Commercial land use in the r epresentative areas varied from
1.4 to 2.0 acre-feet per acre per year (af/ac/yr). The much lower factor for the Naglee Mall and West Grant Line Road Shopping Center is likely due to the inclusion of large parking lots which serve the Mall and Shopping Cen ter in the gross acreage linked. The average unit water demand factor for the representative Commercial areas is 1.7 af/ac/yr. To be conservative, it is recommended that a Commercial unit water demand factor of 1.8 af/ac/yr, which is slightly above the ave rage, be adopted. This represents approximately a 10 percent reduction from the 2012 WSMP factor of 2.0 af/ac/yr.
Unit water demand factors for Industrial land use in the representative areas varied from 0.8 to
1.3 af/ac/yr. The Northeast Industrial area l ikely has a higher factor due to the presence of high water use industries such as food processing plants. The IPC and Patterson Pass Business Park areas have a much lower factor because most of the existing buildings are warehouses with low water use. To be conservative, it is recommended that a unit water demand factor of 1.3 af/ac/yr be adopted as the new Industrial unit water demand factor to accommodate the wide range of possible Industrial water uses for planning purposes. This represents approximatel y a 13 percent reduction from the 2012 WSMP factor of 1.5 af/ac/yr.
The unit water demand factor for Office land use was also calculated using this procedure.
However, since there are no highly concentrated areas of Office land use in the City, and the amount of Office land use is relatively small, the metered water use from water meters for all Office parcels was manually linked with each Office parcel to calculate an Office unit water demand factor. The unit water demand factor calculated in this manner was found to have slightly increased from the 2012 WSMP factor of 1.5 af/ac/yr. However, it is recommended that no adjustment be made to the Office unit water demand factor.
0 4,0002,000
Scale in Feet
Figure 4-6
Representative Commercial
and Industrial Areas
City of Tracy
Water System Master Plan Update
Last Saved: 12/23/2019 11:23:35 AM O:\Clients\404 City of Tracy\12-18-41 Water Master Plan Update\GIS\MXD\Report Figures\Fig 4-6_Comm and Ind Areas.mxd : nhoman Symbology
City Limits
Sphere of Influence
Representative Commercial
Areas
Naglee Mall and Grant Line
Road Shopping Center
Tracy Boulevard and East
Grant Line Road
Eleventh Street
Representative Industrial Areas
Northeast Industrial Area
Northern Industrial Area
IPC/Patterson Pass Business
Park
580
205
205
SCHULTE RD
SCHULTERD
SCHULTE RD
ELEVENTH ST
CO
RRAL
HO
LLO
W
RD
M
AC
ARTHUR
DR
BYRON RD
GRANT LINE RDHANSEN RD
VALPICO RD
LOVELY RD
LINNE RD
HOLLY DR
BETHANY RD
MIDDLE RD
VON SOSTEN RD
TRACY BL
MOUNTAIN HOUSE PK
BANTA RD
CHRISMAN RD
LAMMERS RD
NAGLEE RD
REEVE RD
O l
d River
C a l i f o r n i a A q u e d u c t
D elta-M
e nd ota
Can a l
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Table 4-13. Unit Water Demand Factors for Commercial, Industrial, and Office Land Uses Representative Area
2017 Water Use
Linked, af/yr
Gross Acreage
Linked(a)
Unit Water Demand
Factor, af/ac/yr
Commercial Land Use
Naglee Mall and West Grant Line Road
Shopping Center 426 313 1.4
Tracy Boulevard and East Grant
Line Road 253 126 2.0
Eleventh Street 135 81 1.7
Average 1.7
Industrial Land Use
Northeast Industrial Area 1,134 900 1.3
Northern Industrial Area 109 130 0.8
IPC/Patterson Pass Business Park 623 730 0.9
Average 1.0
Office Land Use
All Existing Parcels 87 56 1.6
(a) A factor of 1.22 was used to convert from net acreage to gross acreage.
For Institutional land use, the water meter data which could be linked was insufficient to justify adjusting the Institutional unit water demand factor.
Similarly, the water meter data which could be linked with Parks land use parcels was also insufficient to justify adjusting the Parks unit water demand factor. However, the Parks factor was compared with the maximum allowable water use for parks per MWELO8 to verify that it did not exceed the maximum allowable usage. As shown in Table 4-14, the maximum allowable water use for parks, which qualify as special landscape areas, is 4.3 af/ac/yr based on MWELO guidelines.
Since this is greater than the current Parks unit water demand factor of 4.0 af/ac/yr, it is recommended that no adjustment be made to the Parks unit water demand factor. This factor will also be used for all recycled water irrigation areas within the City.
In the 2012 WSMP, the Parks unit water demand factor was used to calculate water use for irrigated areas for residential and non-residential land uses. However, under current MWELO guidelines, the maximum allowable water use for potable water irrigation in residential and non-residential land use areas is restricted to approximately 2.4 and 1.9 af/ac/yr, respectively, as shown in Table 4-14.
Therefore, these factors will be adopted for planning purposes in this Citywide Water System Master Plan Update to comply with MWELO and the City’s Water Efficient Landscape Ordinance.
8 The State’s MWELO was adopted by the City of Tracy as part of its Water Efficient Landscape Ordinance (City of Tracy Municipal Code, Chapter 11.28 Water Management, Article 8 Water Efficie nt Landscape Ordinance).
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Table 4-14. City of Tracy Maximum Allowable Water Use Factors for Irrigation (a) Land Use Maximum ETAF(b) Water Use Factor, af/ac/yr
Special Landscape Areas(c) 1.00 4.3
Residential 0.55 2.4
Non-Residential 0.45 1.9
(a) Based on the California Code of Regulations, Title 23 Waters, Division 2 DWR, Chapter 2.7 Model Water Efficient Landscape Ordinance (MWELO), updated 2015 and included in the City of Tracy Municipal Code Chapter 11.28 Water Management, Article 8 Water Efficient Landscape Ordinance. (b) ETAF = Evapotranspiration Adjustment Factor = (Plant Factor based on Hydrozone Area)/(Irrigation Efficiency). (c) Special Landscape Areas are areas dedicated solely to edible plants, recreational areas, areas irrigated with recycled water, or water features using recycled water.
4.8.3 Adopted Unit Water Demand Factors
As discussed above, most of the unit water demand factors were verified and refined (if needed) by linking metered water use data to existing land use data either automatically by service address or manually by location. Table 4-15 summarizes the unit water demand factors adopted for this Citywide Water System Master Plan Update. Based on work completed to “spot check” and refine these adopted factors, they are appropriate for use in projecting future water demands as discussed in the following sections.
Table 4-15. Adopted Unit Water Demand Factors
Land Use Designation gpd/du af/ac/yr
Percent Change from
2012 WSMP, %
Residential – Very Low Density(a) 429 -- 0
Residential – Low Density(a) 365 -- -15
Residential – Medium Density(b) 264 -- -15
Residential – High Density(b) 187 -- -15
Residential – Very High Density(b) 128 -- -15
Commercial(c) -- 1.8 -10
Office(c) -- 1.5 0
Industrial(c) -- 1.3 -13
Institutional(c,d) -- 1.5 0
Parks and Areas Irrigated with Recycled Water(d,e) -- 4.0 0 Other Irrigated Area - Residential(f,g) -- 2.4 NA
Other Irrigated Area - Non-Residential(f,h) -- 1.9 NA
(a) Includes exterior water use.
(b) Does not include exterior water use. Assumes that 15 percent of the total gross acres will be landscaped and irrigated. (c) Does not include exterior water use. Water demand factor to be applied to 85 percent of the total gross acres only, assuming that 15 percent of the total gross acres will be landscaped and irrigated. (d) Insufficient data available to adjust factor using water meter data; therefore, no adjustment was made. (e) Factor to be used for turf, recreational areas, edible plants, and areas irrigated with recycled water. (f) Based on the Maximum Allowable Water Use per MWELO and the City's Water Efficient Landscape Ordinance. (g) Unit water demand factor to be applied to gross acreage in residential areas that will require potable water for exterior water use.
(h) Unit water demand factor to be applied to gross acreage in non-residential areas that will require potable water for exterior water use.
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4.8.4 Existing (Baseline) Water Demands
For this Citywide Water System Master Plan Update, the total “existing” water demand component used for future water demand projections was calculated as the sum of the water delivered to the PPBP and IPC in 2017 plus the City’s average water production from 2005 to 2013 for a total of approximately 18,400 af/yr. Because the PPBP and IPC have been gr owing rapidly, recent water production data was considered the most representative of existing water use for th ese areas.
However, due to the recent drought and associated conservation measures, water production data from 2014 through 2016 were considered less representative of future water use in other areas of the City. It should be noted that the estimated existing baseline water demand of 18,400 af/yr is very similar to the average total water production for 2019 and 2020 (18,600 af/yr), thus validating the estimated existing baseline demand.
Because the water delivered to PPBP is wheeled water, only approximately 17,800 af/yr of the existing water demands must be met by the City’s water supply agreements and contracts. The City is responsible for delivering the remaining 600 af/yr to PPBP, and must have adequate water treatment capacity, pumping capacity, and transmission capacity to serve a total of 18,400 af/yr, in addition to projected future water demands.
4.8.5 Recycled Water Use Assumptions
Recycled wate r will be used as a source of water supply for landscape irrigation and other non-potable uses to offset potable water demands on a project-by-project basis where feasible. The City has constructed a recycled water transmission line which extends south along Lammers Road to the intersection with Schulte Road, and further expansions to the recycled water system are planned in the future.
For this Citywide Water System Master Plan Update, the following assumptions were made regarding the recycled water system:
• The transmission main in Lammers Road will be extended south to the Delta Mendota Canal by 2025. Most large development projects located on the west side of the City will be served by the recycled water system by 2025, except for Cordes Ranch, West Side Industrial, and Tracy Hills Specific Plans. • Recycled water service will be extended to Cordes Ranch, West Side Industrial, and Tracy Hills Specific Plans by 2040.
• Future recycled water service areas on the east side of the City (East Side Industrial, Chrisman Road, UR 1, and Rocha), will be served by a separate recycled water transmission main which will not be constructed until after 2040. • Recycled water service will not be extended to developments in the following areas due to the isolated locations and relatively small individual potential recycled water demands within them:
— I-205 Corridor Specific Plan
— Industrial Areas Specific Plan
— Northeast Industrial Specific Plan
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— Berg Road Subdivision
— Berg/Byron Remainder
— Other small approved projects (refer to Table 3-1, footnote (f) for the full list) — Miscellaneous Infill
• Only a small number of existing parks and irrigated areas located close to the recycled water transmission main alignments will be converted to recycled water service. • Within new developments served by recycled water, 15 percent of gross acreage for Residential – Medium Density, Residential – High Density, Residential – Very High Density, Commercial, Office, Industrial, and Institutional land uses will be irrigated with recycled water. This represents irrigation use for common landscaped areas and roadway medians.
• Within new developments served by recycled water, 11.2 percent9 of gross acreage for Residential – Very Low Density, Residential – Low Density, and Residential – Medium Density land uses will develop as neighborhood and community parks which will be irrigated with recycled water.
• Front yards of single-family residences in the Residential – Very Low Density and Residential – Low Density will be irrigated with potable water, even in developments served by recycled water.
• UAFW for the recycled water system will be 5 percent (consistent with the 2015 UWMP).
Potable water demand offsets from recycled water use will be accounted for in the projected water demands. Demands from irrigated acreage in development projects with recycled water supply available will be calculated using the recycled water demand factor of 4.0 af/ac/yr.
4.8.6 Projected Buildout Water Demands
Projected water demands for the 2025, 2040, and buildout time frames were calculated by multiplying the adopted unit water demand factors ( refer to Table 4-15) by the additional future dwelling units or gross acreage projected to occur. As discussed in Chapter 3, data regarding the additional future dwelling units and gross acreage to be developed was provided by the City’s Planning Division or referenced from available planning documents.
The resulting future water demand p rojections from the projected future developments were adjusted to account for UAFW and then added to the existing water demands to provide a projection of the total water production required for each of the evaluated time frames . Refer to Appendix A for detailed land use assumptions and water demand calculations.
9 Consistent with assumption in Appendix D of the 2012 WSMP. A comparison of the future parks area calculated using this assumption and the projection of required park area from the City’s 2013 Parks Master Plan showed them to be within 1 percent of each other.
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Table 4-16 summarizes the projected potable and recycled water production for the City at the 2025, 2040, and buildout time frames. As shown in Table 4-16, even with the use of recycled water, the City’s potable water production is projected to almost double at buildout (from 17,800 af/yr to 33,500 af/yr). Most of the increase in water demand is associated with new development within the City’s specific plans and future service areas. Approximately 70 percent of the increase in potable water demands and 65 percent of the increase in recycled water demands are projected to occur by 2040.
The estimated buildout potable water production is approximately 8 percent lower than the previous estimate of 36,300 af/yr, as presented in the City’s 2012 WSMP. Although many of the unit water demand factors have been decreased by 10 to 15 percent compared to those used in the 2012 WSMP, the projected buildout potable water production did not decrease substantially because:
• The current buildout land use projections include approximately 5,600 more dwelling units than what was assumed in the 2012 WSMP. Although the projected buildout acreage for non-residential land uses (primarily Commercial and Industrial) has decreased since the 2012 WSMP, residential developments typically use more water than non-residential developments; and
• The potable water UAFW factor was increased from the 7.5 percent factor used in the 2012 WSMP to 9.6 percent.
The estimated buildout recycled water production is approximately 16 percent lower than the previous estimate of 7,500 af/yr as presented in the City’s 2012 WSMP. This is because:
• The 2012 WSMP included the Gateway Exchange Program, in which recycled water service would be extended to most of the existing parks and large irrigated areas in the City to offset the potable water demands from the Gateway development (now called Westside). The Gateway Exchange Program is no longer being considered, and it is projected that only a few existing parks and irrigated areas will receive recycled water supply;
• The Tracy Hills Specific Plan previously included a large golf course which was to be irrigated with recycled water. The golf course area is now projected to remain un-irrigated open space instead; and
• The recycled water UAFW factor was decreased from the 7.5 percent factor used in the 2012 WSMP to 5.0 percent.
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Table 4-16. Summary of Future Projected Water Production (a,b,c) Demand Category
2025 (Near Term) 2040 Buildout
Potable
Water,
af/yr
Recycled
Water, af/yr
Potable
Water, af/yr
Recycled
Water, af/yr
Potable
Water, af/yr
Recycled
Water, af/yr
Future 3,000 900 10,900 4,100 15,700 6,200
Existing - City(d) 17,800 100 17,800 100 17,800 100
Total to be Met by City
Water Supply Contracts
and Rights
20,800 1,000 28,700 4,200 33,500 6,300
Existing - PPBP Wheeled
Water(e) 600 0 600 0 600 0
Total to be Delivered by
City Distribution
System
21,400 1,000 29,300 4,200 34,100 6,300
(a) Refer to Appendix A for detailed water demand calculations. (b) Includes UAFW.
(c) Totals rounded to the nearest hundred.
(d) Includes water delivered to existing buildings in the IPC. (e) Does not include water delivered to existing buildings in IPC.
It should be noted that the potable water demand projections presented in the City’s 2020 UWMP are slightly different than those presented in Table 4-16 above. The difference is due to the 2020 UWMP using water demand projections from a previous draft of this Citywide Water System Master Plan Update, which have since been revised due to revisions in the 2040 and Buildout land use assumptions, as well as the 2020 UWMP, which included an estimate of passive conservation due to water savings which resulted primarily from: (1) the natural replacement of existing plumbing fixtures with water -efficient models required under current plumbing code standards, and (2) the installation of water-efficient fixtures and equipment in new buildings and retrofits as required under CALGreen Building Code Standards. Overall, these differences are minor, with the 2020 UWMP projecting a 2025 potable water demand of 20,509 af/yr, a 2040 potable water demand of 28,403 af/yr, and a 2045 (Buildout) potable water demand of 33,079 af/yr.
As the City continues to develop, potable water consumption between customer classes is expected to shift due to changes in the City’s projected land use composition. Table 4-17 compares the historical average and projected potable water consumption by customer class. As shown in Table 4-17, the residential customer classes are expected to decrease their overall potable water consumption proportion as water use shifts towards non-residential customer classes. Although, as discussed above, the ratio of projected non-residential to residential development has decreased since the 2012 WSMP, the planned development within the City’s SOI will still shift towards more non-residential land use. This trend is primarily due to large industrial developments such as Cordes Ranch, West Side Industrial, East Side Industrial, UR 3, and Tracy Hills Phase 5, among others.
Irrigation water use is projected to be a much smaller proportion of the City’s potable water use at buildout because (1) many new development areas will be served by the recycled water system at buildout, and (2) some of the City’s existing irrigated areas will be converted to recycled water use.
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Table 4-17. Historical and Projected Potable Water Consumption by Customer Cl ass Customer Class
Historical Average
Annual
Consumption(a), %
Projected Annual
Consumption in
2025(b), %
Projected Annual
Consumption in
2040(b), %
Projected Annual
Consumption at
Buildout(b), %
Single-Family
Residential(c) 60.1 58.0 54.0 53.3
Multi-Family
Residential(d) 6.7 7.6 6.9 8.5
Residential Subtotal 66.8 65.6 60.9 61.7
Commercial(e) 15.4 13.5 14.2 14.2
Industrial 4.9 9.3 16.4 17.6
Irrigation(f) 12.9 11.6 8.4 6.5
Total 100 100 100 100
(a) Refer to Table 4-4.
(b) Includes existing and projected future potable demands. (c) Includes projected future residential demands (excluding irrigation) for Residential - Very Low Density, Residential - Low Density, and Residential - Medium Density land use types. (d) Includes projected future residential demands (excluding irrigation) for Residential - High Density and Residential - Very High Density land use types.
(e) Includes projected future demands (excluding irrigation) for Commercial, Office, and Institutional land use types. (f) Includes projected future irrigation demands to be served by potable water. Accounts for planned conversions of irrigation services to recycled water use.
4.9 FUTURE PER CAPITA WATER USE PROJECTIONS
The projected potable water demands shown in Table 4-16 were used in combination with population projections to evaluate the City’s projected future per capita water use.
Table 4-18 shows the population projections and projected per capita potable water use for the 2040 and buildout time frames. Population projections for 2040 and buildout were estimated by the City’s Planning Division based on the planned future development and California Department of Finance data for the number of people per household. Based on these assumptions, t he City is projected to have a total future population of approximately 186,000 at buildout, with an overall per capita water use of 161 gpcd.
Table 4-18. Projected Population and Per Capita Potable Water Use Time Frame
Projected Potable Water
Demand, af/yr(a,b) Projected Population(c)
Per Capita Potable
Water Use, gpcd
2040 28,700 170,152 151
Buildout 33,500 185,961 161
(a) Totals rounded to the nearest hundred.
(b) From Table 4-16.
(c) Population projection from the City Planning Division.
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CHAPTER 5
Existing and Future Water Supplies
5.1 OVERVIEW
The purpose of this chapter is to provide an updated evaluation of the availability and reliability of the City’s existing and additional planned future water supply sources to meet the projected buildout water demands for the City as described in Chapter 4. This chapter includes the following sections:
• Changes to the City’s Water Supplies Since the Completion of the 2012 Citywide Water System Master Plan and the 2015 UWMP
• Existing Potable Water Supplies
• Future Potable Water Supplies
• Existing Non-Potable Water Supplies
• Reliability of the City’s Water Supplies
• Sufficiency of the City’s Water Supplies
• Summary of Water Supply Recommendations
5.2 CHANGES TO THE CITY’S WATER SUPPLIES SINCE THE COMPLETION OF THE 2012 CITYWIDE WATER SYSTEM MASTER PLAN AND THE 2015 URBAN WATER
MANAGEMENT PLAN
The 2012 WSMP evaluated the sufficiency of the City’s water supplies to meet the then-projected buildout water demands. The City’s 2015 UWMP, adopted by the City in July 2016, evaluated the City’s existing and future water supplies, together with the City’s water conservation programs, and their ability to meet projected future water demands and comply with SB X7-7. Since those documents were completed, significant new residential and commercial development has occurred in the City and planning for future developments has been refined (as described in Chapter 3).
During this same time, the availability and reliability of the City’s water supplies have been impacted by drought conditions and associated unprecedented cutbacks in surface water supply deliveries. The City’s 2020 UWMP, adopted in June 2021, addresses these changes in water supply availability and reliability. In addition, new legislation has been passed which will further impact future water use and future water supply availability and reliability, including the following:
• Comprehensive groundwater legislation contained in SBs 1168 and 1319, and AB 1739, which are collectively referred to as the Sustainable Groundwater Management Act (SGMA), was approved in September 2014 and became effective on January 1, 2015. The legislative intent of SGMA is to provide sustainable management of groundwater basins, enhance local management of groundwater, establish minimum standards for sustainable groundwater management, and provide local groundwater agencies with the authority and the technical and financial assistance necessary to sustainably manage groundwater.
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• SB 606 and AB 1668 were passed in May 2018 and established new statewide water use efficiency standards for indoor residential water use, outdoor residential water use, commercial, industrial and institutional irrigation of landscaped areas and water loss. A primer entitled “Making Water Conservation a California Way of Life” was developed to be a reference document for the implementation of the complex 2018 legislation.
• In 2018, the SWRCB adopted amendments to the Water Quality Control Plan for the San Francisco Bay/Sacramento-San Joaquin Delta Estuary (Bay-Delta Plan Amendment) which restrict the use of flows from the Lower San Joaquin River and its tributaries (the Stanislaus, Tuolumne and Merced Rivers) to improve conditions for fish and wildlife. Specifically, the Bay-Delta Plan Amendment restricts the use of flows until 40 percent of unimpaired flows are rededicated for water quality and instream fisheries. This restriction could potentially significantly impact the availability of the City’s water supplies from the SSJID. However, due to the uncertainty surrounding the implementation of the Bay-Delta Plan Amendment, SSJID’s 2020 UWMP assumed that the Bay-Delta Plan Amendment would not be implemented. In its 2020 UWMP, the City also presents the SSJID reliability assuming that the Bay-Delta Plan Amendment is not implemented, but the City’s 2020 UWMP also provided a parallel analysis of reliability assuming that the Bay- Delta Plan Amendment is implemented.
5.3 EXISTING POTABLE WATER SUPPLIES
The City currently receives water supplies from the following sources:
• Untreated surface water from the DMC (CVP) (treated at the City’s JJWTP) • Untreated surface water from BBID pre-1914 rights (treated at the City’s JJWTP) • Treated surface water from the Stanislaus River via the South County Water Supply Project (SCWSP) (treated and delivered to the City by the SSJID) • Groundwater pumped from eight groundwater wells located within the City Table 5-1 provides a summary of the City’s existing water supply agreements and contracts . A discussion of each of these water supplies and their anticipated availability and reliability is provided below.
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Table 5-1. Existing Water Supplies
Supply Source
Existing Water Agreements/Contracts
(Supply Quantity, af/yr)
Potable Water Supplies
Surface Water Supplies
USBR CVP Contract with M&I Reliability (treated at City’s JJWTP) 10,000(a) USBR CVP Contract with Ag Reliability (treated at City’s JJWTP) 10,000(b) BBID Pre-1914 rights for use in Tracy Hills (treated at City’s JJWTP) 3,330(c) SSJID South County Water Supply Project 11,120(d)
Groundwater Up to 9,000(e)
Semitropic Water Storage Bank Up to 3,500(f)
ASR Up to 1,000(g)
Non-Potable Water Supplies(h)
Recycled Water Exchange 7,500
Recycled Water (for non-potable uses) 6,300
(a) M&I-reliability CVP water. Assumes the terms of the long-term renewal contract with the USBR are consistent with those of the interim renewal contract entered into between the City and USBR in February 2016. (b) Assignments from Banta-Carbona Irrigation District (BCID) and West Side Irrigation District (WSID). (c) Up to 4,500 af/yr, but no more than the potable water demand for Tracy Hills (3,330 af/yr). This water is only available for use in the portion of Tracy Hills that lies within BBID Raw Water Service Area 2 the CVP Consolidated Place of Use, so the quantity of supply is limited to potable water demand in this area. Therefore, the maximum BBID supply delivered to this area is reduced to 3,330 af/yr.
(d) Includes the 10,000 af/yr allocation and the additional 1,120 af/yr obtained through the 2013 Lathrop-Tracy Purchase, Sale, and Amendment Agreement. Does not include the interim purchase from Escalon. (e) The City is able to withdraw up to 9,000 af/yr of groundwater from the Tracy Subbasin. However, due to the aging infrastructure and water quality issues in the City’s groundwater supplies, the City is projecting to be able to withdraw up to 2,500 af/yr in normal years. During dry years, the City anticipates increasing its groundwater production on a short-term basis from the normal year production of 2,500 af/yr to 4,500 af/yr. (f) The City has purchased 10,500 af of water storage in the Stored Water Recovery Unit, which allows the City to withdraw up to 3,500 af/yr for three consecutive years.
(g) Supplies from ASR are assumed to be dry year supplies. During normal years, the City will not withdraw ASR water. In single dry years and multiple dry years, this water supply is considered to be 100 percent reliable. The City estimates that up to 1,000 af/yr of groundwater can be extracted from buffer storage in the Lower Tulare Formation aquifer associated with the City’s current ASR Program.
(h) While the City’s Wastewater Treatment Plant is currently capable of providing recycled water supply, additional infrastructure will be required to provide for its beneficial use (see additional information in this chapter and in Chapter 9).
Each of these existing supplies is described below. A summary table listing the City’s existing and future water supplies under various hydrologic conditions is provided following the discussion of the City’s future water supplies.
The City’s historical u se of these water supplies is shown on Figure 5-1. As shown, the City’s highest annual water use occurred in 2007 and totaled 19,176 af/yr. Since then, water use has decreased with downturns resulting from the 2008 Great Recession which slowed development growth for several years and the 2011 to 2017 California drought which prompted mandatory statewide water conservation in 2015 and 2016. Since the end of the drought, w ater use has rebounded (increased) somewhat but is still below the highest historical use in 2007. Also shown on Figure 5-1 is the City’s population since 1980. As shown, while the City’s population has more than quadrupled since 1980, water use has only a little more than doubled. Th e relatively low Chapter 5
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increase in water demand as compared to population growth results from the reduction of overall per capita water use from over 300 gpcd in the early 1980s to less than 180 gpcd in recent years as described in Chapter 4.
Figure 5-1. Historical Water Supplies
5.3.1 Central Valley Project Water via the Delta-Mendota Canal
5.3.1.1 M&I-Reliability Supplies from the CVP
In 1974, the City entered into a 40 -year contract with the USBR for an annual entitlement of 10,000 af/yr of surface water from the CVP via the DMC. The original contract expired in 2014; however, since December 2013, the City and USBR have entered into a series of two-year interim renewal contracts to provide water service to the City while the terms of the long -term contract renewal are negotiated and the associated environmental documentation is prepared . The most recent interim renewal contract term begins March 1, 2020 and ends February 28, 2022. The City anticipates on-going contract renewals for this source.
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Allocations for the Municipal and Industrial ( M&I)-reliability CVP water since 2010 are summarized in Table 5-2.
Table 5-2. Historical Annual CVP M&I Allocations
(South of Delta)
Year
Annual CVP M&I Allocation
(percent of contractual amount unless otherwise noted)
2010 75 percent
2011 100 percent
2012 75 percent
2013 70 percent
2014 50 percent
2015 Public health and safety needs or at least 25 percent of historical use, whichever is greater
2016 55 percent of historical use
2017 100 percent of contract amount
2018 Public health and safety needs or at least 75 percent of historical use, whichever is greater
2019 100 percent of historical use
2020 Public health and safety needs or at least 70 percent of historical use, whichever is greater
In February 2017, new guidelines and procedures went into effect associated with the updated CVP M&I Water Shortage Policy. In general, the policy provides for the following:
• When M&I contractor allocations are at 100 percent, the allocation of M&I water will be based on Contract Total.
• When M&I contractor allocations are below 100 percent, the allocation of M&I water will be based on a contractor’s historical use of CVP M&I water. • An M&I contractor’s historical use will be determined by calculating the average quantity of CVP water put to beneficial use within the service area during the last three years of water deliveries that were unconstrained by the availability of CVP water.
It should be noted that before allocation of M&I water to a contractor will be reduced, allocation of irrigation water will be reduced below 75 percent of Contract Total. When allocation of irrigation water has been reduced below 75 percent and still further water supply reductions are necessary, both the M&I and irrigation allocations will be reduced by the same percentage increment. The M&I allocation will be reduced until it reaches 75 percent of historical use, and the irrigation allocation will be reduced until it reaches 50 percent of irrigation Contract Total. The M&I allocation will not be further reduced until the irrigation allocation is reduced to below 25 percent of Contract Total.
When allocation of irrigation water is reduced below 25 percent of Contract Total, USBR will reassess both the availability of CVP water supply and CVP water demand.
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According to the policy, USBR will strive to deliver CVP water to M&I water service contractors at not less than the amount needed to meet public health and safety needs, taking into consideration contractors’ CVP allocations and available non-CVP supplies, provided CVP water is available.
For this Citywide Water System Master Plan Update, consistent with the City’s 2020 UWMP, the following assumptions have been made with regards to delivery of M&I-reliability supplies from the CVP under the various hydrologic conditions:
• Normal Years: 75 percent of historical use
• Single Dry Years: 25 percent of historical use
• Multiple Dry Years: 40 percent of historical use
5.3.1.2 Ag-Reliability Supplies from the CVP
In 2004, the USBR approved the assignment of 5,000 af/yr of Ag -reliability CVP contract entitlement to the City from the BCID. Also in 2004, the USBR approved the assignment of an additional 2,500 af/yr of Ag-reliability CVP contract entitlement water to the City from the WSID with the option to purchase an additional 2,500 af/yr of CVP contract entitlement from the WSID.
The purchase of the additional 2,500 af/yr was approved in December 2013, increasing the City’s assignment of WSID water to 5,000 af/yr.
Deliveries of Ag-reliability water can vary significantly, and during severe water shortages supply may be reduced as much as 100 percent, as they were in 2014 and 2015 . Allocations for the Ag-reliability CVP water since 2010 are summarized in Table 5-3.
Table 5-3. Historical Annual CVP Ag Allocations
(South of Delta)
Year
Annual CVP Ag Allocation, percent of
contractual amount
2010 45
2011 80
2012 40
2013 20
2014 0
2015 0
2016 5
2017 100
2018 50
2019 75
2020 20
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For this Citywide Water System Master Plan Update, consistent with the City’s 2020 UWMP, the following assumptions have been made with regards to delivery of Ag -reliability supplies from the CVP:
• Normal Years: 50 percent of annual entitlement
• Single Dry Years: 0 percent of annual entitlement (based on actual allocation in 2015) • Multiple Dry Years: 0 percent of annual entitlement (based on the average allocations for 2014, 2015 and 2016; 1.67 percent rounded down to 0 percent)
5.3.1.3 Treatment and Use of CVP Surface Water Supplies The City’s CVP surface w ater supplies received via the DMC are treated at the City’s JJWTP, which was originally constructed in 1979, expanded in 1988, and then expanded again in 2008.
The JJWTP is located adjacent to the Delta-Mendota Canal in the southern portion of the City.
The current treatment capacity of the JJWTP is 30 mgd.
The City’s annual combined M&I and Ag CVP surface water supplies used by the City since 2010 are shown in Table 5-4.
Table 5-4. Historical Annual CVP Surface Water Supplies Year Annual CVP Surface Water Supplies, af(a)
2010 5,303
2011 4,790
2012 4,878
2013 4,960
2014 4,018
2015 3,193
2016 2,634
2017 4,906
2018 5,184
2019 7,537
2020 5,733
(a) Does not include CVP supplies which are treated and wheeled for the Patterson Pass Business Park (see Table 5-5 below).
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The City also treats and serves relatively small quantities of CVP/DMC water purchased by others through a “treatment and wheeling agreement” for use at the Patterson Pass Business Park only.
The Patterson Pass Business Park is now built out. The City’s deliveries through the Patterson Pass Business Park Booster Pump Station since 2010 are shown in Table 5-5. A comparable quantity of BBID CVP/DMC water is anticipated to be available for annual delivery to the Patterson Pass Business Park in the future.
Table 5-5. Historical Annual Deliveries to
Patterson Pass Business Park
Year Deliveries to Patterson Pass Business Park, af
2010 420
2011 527
2012 538
2013 558
2014 590
2015 585
2016 707(a)
2017 796(a)
2018 948(a)
2019 740(a)
2020 840(a)
(a) Deliveries shown for 2016 to 2019 may include demands in the International Park of Commerce (Cordes Ranch) due to the metering configuration in place during those years.
5.3.2 Surface Water from BBID Pre-1914 Water Rights
Part of the proposed Tracy Hills Specific Plan area was annexed into the BBID and is entitled to water service from BBID, using BBID’s pre -1914 appropriative water rights. This water is delivered to the City via the DMC and is treated at the City’s JJWTP before delivery to the Tracy Hills Project. The City anticipates that up to 4,500 af/yr of pre-1914 water rights water could be provided by BBID on a year-round basis to serve the Tracy Hills Project in the BBID service area.
However, the volume of water available to the City through this agreement is limited to the demand in the BBID service area portion of the Tracy Hills Project. The projected potable water demand in this area is estimated to be 3,330 af/yr at buildout. Because the water supply is based on pre-1914 appropriative rights, the supply has historically been considered to be firm and well-established.1
1 It should be noted that in August 2021, following the June 2021 adoption of the City’s 2020 UWMP, the SWRCB issued an initial order imposing water right curtailment and reporting requirements in the Sacramento -San Joaquin Delta watershed that included the curtailment of pre-1914 appropriative water right claims in the San Joaquin River watershed. Based on this August 2021 order, the reliability of BBID’s pre-1914 appropriative water rights may be uncertain.
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5.3.3 Stanislaus River Water
The City, in partnership with the cities of Manteca, Lathrop and Escalon, and the SSJID, have constructed a surface water treatment plant near Woodward Reservoir in Stanislaus County and a transmission pipeline to deliver treated surface water to each city. The project is called the S outh County Water Supply Project (SCWSP). This water supply is based on SSJID’s senior pre -1914 appropriative water rights to the Stanislaus River, coupled with an agreement with the USBR to store water in New Melones Reservoir.
As part of the SCWSP, the City was initially allocated up to 10,000 af/yr of water. In 2006, the City entered into a temporary contract with Escalon to purchase Escalon’s allocation of 2,015 af/yr of SCWSP supply until Escalon constructs the necessary infrastructure to convey the SCWSP water; this contract is anticipated to sunset in 2025. In August 2013, the City purcha sed an additional 1,120 af/yr of SCWSP entitlement from the City of Lathrop . Thus, the City’s current contractual amount of SCWSP water is 13,135 af/yr in total. Once the agreement with Escalon sunsets (anticipated to occur in 2025), the City’s contractual allocation will be reduced to 11,120 af/yr.
Treated water deliveries of SCWSP water commenced in July 2005, and deliveries have been essentially uninterrupted since then (see Figure 5-1). In some years, SCWSP deliveries were less than the City’s full project allotment; however, during these years the City did not require its full SCWSP allotment, even though the full contract amount was available from SCWSP. However, since 2010 , the City has actually received more than its allotment in some years . Historical deliveries from the SCWSP to the City since 2010 are shown in Table 5-6.
Table 5-6. Historical Deliveries from the SCWSP
to the City of Tracy
Year SCWSP Deliveries, af
2010 10,850
2011 11,793
2012 12,294
2013 13,112
2014 11,515
2015 10,329
2016 11,372
2017 11,464
2018 10,471
2019 8,750
2020 11,773
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The SCWSP was expected to have high reliability as a result of its senior pre-1914 rights. SSJID’s 2015 UWMP, adopted by SSJID in June 2016, indicate d that it would meet 98.2 to 99.9 percent of urban demands in normal years (the percent of urban demand met increases in the future as agricultural demands decrease), 73.6 to 75.3 percent of urban demands in single dry years, and
85.1 to 87.1 percent of urban demand in multiple dry years. In the City’s 2015 UWMP, supplies from the SCWSP were assumed to have high reliability with normal year allocations at 100 percent of the City’s contractual entitlement, and single dry year and multiple dry year allo cations at 85 percent of the City’s contractual entitlement.
However, in December 2018, the SWRCB released amendments to the Water Quality Control Plan for the San Francisco Bay/Sacramento -San Joaquin Delta Estuary (Bay-Delta Plan Amendment) with significant changes to the previous Bay -Delta Water Quality Control Plan. The Bay-Delta Plan Amendment requires releases of approximately 40 percent of what would naturally flow in watersheds tributary to the San Joaquin River (including the Stanislaus River) during the February to June period. This means that surface water users on those watersheds would be restricted from using and storing water until 40 percent of unimpaired flows are rededicated for water quality and instream fishery purposes. For the Stanislaus River, the resulting surface water cutbacks would be significant. However, there is much uncertainty surrounding the implementation of the Bay-Delta Plan Amendment.
In its 2020 UWMP, SSJID presented a water reliability analysis assuming that the Bay-Delta Plan Amendment will not be implemented given its uncertainties. As an SSJID retail agency customer, the City relies on SSJID for the reliability projections for the Stanislaus River water supply.
Consistent with SSJID’s approach, the City’s 2020 UWMP assu mes that the Bay -Delta Plan Amendment will not be implemented. However, to fully assess the potential impacts of the Bay-Delta Plan Amendment and better plan for the potential shortfalls, the City conducted a parallel set of reliability analyses assuming t hat the Bay -Delta Plan Amendment will be implemented and included it as Appendix G of its 2020 UWMP.
For purposes of this Citywide Water System Master Plan Update, the reliability of the SCWSP supply has been revised to be consistent with the City’s 2020 UWMP. Allocations will be assumed to be as follows:
• Normal Years: Allocations will be assumed to be 100 percent of the City’s contractual entitlement.
• Single Dry Years: Allocations will be assumed to be 56 to 76 percent of the City’s contractual entitlement.
• Multiple Dry Years: Allocations will be assumed to be 56 to 100 percent of the City’s contractual entitlement.
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5.3.4 Groundwater
5.3.4.1 City Wells
The City overlies a portion of the San Joaquin Valley Groundwater Basin -Tracy Subbasin (Tracy Subbasin). The City currently operates eight groundwater production wells and one ASR well. Four wells (Production Wells 1, 2, 3 and 4) are located near the City’s JJWTP and pump directly into the JJWTP clearwells, where the groundwater is blended with tre ated surface water.
Four other wells (Lincoln Well, Lewis Manor Well (Well 5), Park and Ride Well (Well 6), and Ball Park Well (Well 7) are located throughout the City and pump water directly into the distribution system after disinfection. The City’s newe st well, Well 8, located near the intersection of Tracy Boulevard and 6th Street, is an ASR Well, and is capable of injecting treated surface water into the aquifer for storage and extracting it for later use (see additional discussion in Section 5.3.5 below).
5.3.4.2 Groundwater Yield
A 1990 Kennedy/Jenks/Chilton (K/J/C) study estimated a perennial groundwater yield of 6,700 af/yr in the Tracy Subbasin within the Tracy Study Area. However, in 2001, to determine if additional groundwater resources were available i n the Tracy Study Area, the City conducted an updated groundwater analysis. The Estimated Groundwater Yield Study, prepared by Bookman-Edmonston Engineering, provided an evaluation of potential groundwater yield and determined that a 2,300 af/yr increase o f the average annual operational groundwater yield above the groundwater yield recommended in the 1990 K/J/C study could be provided within the estimated sustainable yield of the Tracy Subbasin in the Tracy Study Area, without adverse impact to groundwater resources or quality in the Tracy Study Area over a 50-year timeframe. This expansion of groundwater usage to 9,000 af/yr would be within the City’s estimated share of the aquifer’s sustainable yield of 22,000 af/yr of the 28,000 af/yr total (which includes groundwater usage within West Side Irrigation District, Naglee-Burk Irrigation District, Plain View Water District (now part of the BBID), and BCID). It was also estimated that this expansion of groundwater usage would result in a groundwater level drop of 10 feet but would stabilize at this level.
In 2015, the City hired GEI Consultants (GEI) to perform an assessment on what the effects would be if the City were to pump between 16,000 and 22,000 af/yr for a single year to meet its demands during a drought emergency when no surface water supplies were available. The assessment considered potential impacts on groundwater levels, groundwater quality, and land subsidence.
GEI’s approach to this assessment was to estimate drawdown beneath the City, including drawdown caused by well interference, under scenarios wherein all of the City’s wells were pumped for a single year at rates needed to meet the above stated demands. Drawdown estimates were made using analytical methods and aquifer hydraulic property data from pumping tests performed at two of the City’s wells. Results showed that the City does have capacity to pump its wells to meet these single dry year demands, but that drawdown in the City wells and at locations proximate to the City would exceed that which has been historically observed. GEI (2015) estimated that groundwater levels would recov er from their drawdown within approximately seven years.
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5.3.4.3 Groundwater Quality
Groundwater quality in the Tracy Subbasin varies spatially and with depth. In general, the northern part of the Tracy Subbasin is characterized by a sodium water type, and the southern part of the Tracy Subbasin is characterized by calcium -sodium type water. The northern part of the Tracy Subbasin is also characterized by a wide range of anionic water types, including bicarbonate; chloride; and mixed bicarbonate-chloride. Major anions in the southern part of the Tracy Subbasin include sulfate-chloride and bicarbonate-chloride.
One water quality c oncern that the City actively manages is Total Dissolved Solids (TDS). The City’s groundwater supply typically meets the primary maximum contaminant level (MCL) of 1,000 milligrams per liter (mg/L) but frequently exceeds the secondary MCL of 500 mg/L. In 2019, the City’s groundwater supply ranged from 386 to 876 mg/L of TDS, with an average concentration of 752 mg/L. Because the TDS concentrations are significantly higher in the groundwater supply than in the City’s other water supply sources, in order to m eet the secondary MCL in its overall water supply, the City typically scales back its groundwater production from its estimated sustainable yield of 9,000 af/yr, particularly in normal rainfall years.
5.3.4.4 Groundwater Management
5.3.4.4.1 City Groundwater Management Policy and Mitigated Negative Declaration for City Groundwater Production of 9,000 af/yr
On a local level, in 2001, the City adopted a Groundwater Management Policy , and prepared a Groundwater Management Policy Mitigated Negative Declaration . The Groundwater Management Policy and the Groundwater Management Policy Mitigated Negative Declaration are described below.
Pursuant to the findings of the 2001 Bookman -Edmonston study (discussed above in Section 5.3.4.2), the Tracy City Council adopted a Groundwater Management Policy in 2001 that established the City’s maximum annual groundwater extraction rate of 9,000 af/yr. To comply with CEQA and to evaluate the potential negative effects of increased groundwater extraction on water quality, water levels, and subside nce, the City also prepared a Groundwater Management Policy Mitigated Negative Declaration. The Groundwater Management Policy Mitigated Negative Declaration specifies the frequency and type of monitoring and reporting the City must conduct to evaluate the sustainability of the increased groundwater extraction rate.
Consistent with the Groundwater Management Policy Mitigated Negative Declaration , the City has maintained groundwater production rates well below the estimated sustainable yield of 9,000 af/yr.
5.3.4.4.2 Compliance with the 1992 Groundwater Management Act (AB 3030) The 1992 Groundwater Management Act (AB 3030) established provisions by which local water agencies could develop and implement groundwater management plans (GMPs). GMPs are generally designed to prevent local and regional aquifer overdraft, which reduces available groundwater resources and which, under certain conditions, can lead to degradation of water quality and to land subsidence.
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The City, BBID, BCID, and San Joaquin County formed a Groundwater Advisory Committee to facilitate the development of a regional groundwater management plan (GWMP) for the Tracy Subbasin. The planning area of the Tracy GWMP encompassed the portion of the Tracy Subbasin underlying San Joaquin County. The Tracy GWMP was adopted in 2007.
The key results of the Tracy GWMP included the following:
• Developed a general consensus among stakeholders regarding the characterization of the area’s water problems, current and future demands, and groundwater conditions; • Documented the region’s groundwater management goals and establishing basin management objectives to help measure progress in attaining the goals; • Developed specific solutions and common programs for the basin; and • Provided an implementation plan to direct future groundwater management activities.
The Tracy GWMP concluded that the Tracy Subbasin is full, but experiences groundwater quality issues in portions of the basin associated with nitrate, boron, sulfate, chloride, and total dissolved solids (TDS). As such, many of the groundwater management options that were recommended focused on creating available storage and managing pumping in order to increase water quality within the Tracy Subbasin.
San Joaquin County is the designated Monitoring Entity under the California Statewide Groundwater Elevation Monitoring (CASGEM) program for the portion of the Tracy Subbasin underlying the county. However, upon submission of the G roundwater Sustainability Plan , the CASGEM program will be superseded by the SGMA monitoring efforts.
5.3.4.4.3 Tracy Regional Groundwater Management Plan
In addition to participating in the development of the Tracy Subbasin GMP, in 2005 the City was awarded a DWR g rant for approximately $185,000 to prepare a Tracy Regional Groundwater Management Plan (Tracy Regional GMP) for the portion of the Tracy Subbasin that underlies the City of Tracy. The Tracy Regional GMP was completed in March 2007. A key objective of the Tracy Regional GMP was the development of Basin Management Objectives (BMOs) for groundwater levels, groundwater quality, and land subsidence in the region.
5.3.4.4.4 Compliance with the 2014 Sustainable Groundwater Management Act On August 29, 2014, the California Legislature passed comprehensive groundwater legislation contained in SBs 1168 and 1319, and AB 1739, which are collectively referred to as SGMA. This legislation was signed by Governor Brown on September 16, 2014 and it became effective on January 1, 2015. The legislative intent of SGMA is to provide sustainable management of groundwater basins, enhance local management of groundwater, establish minimum standards for sustainable groundwater management, and provide local groundwater agencies with the authority and the technical and financial assistance necessary to sustainably manage groundwater.
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The Tracy Subbasin is designated by DWR as a medium priority basin. As such, the Tracy Subbasin is subject to the requirements of SGMA, which include the formation of a one or more Groundwater Sustainability Agencies (GSAs) and the development and implementation of one or more Groundwater Sustainability Plans (GSPs) by January 31, 2022. If the statutory deadline is not met for GSP development and/or implementation, the State has the authority to intervene and manage groundwater within non -compliant subbasins. SGMA requires that adopted GSPs result in sustainable groundwater management which avoids undesirable results.
The Tracy S ubbasin contained areas of San Joaquin, Contra Costa and Alameda Counties. The Banta-Carbona Irrigation District, Byron-Bethany Irrigation District, City of Tracy, City of Lathrop, Stewart Tract, West Side Irrigation District, and San Joaquin County are GS As within the Tracy Subbasin. The GSAs recognize that developing and adopting a single GSP for the subbasin would be the most efficient way of achieving sustainability and preventing State intervention into local groundwater management.
Working with San Joaquin County and the Tracy Subbasin GSAs, a Memorandum of Agreement (MOA) has been developed for the development of the San Joaquin County GSP for the Tracy Subbasin. Under the terms of the MOA, San Joaquin County is designated as the lead entity to enter into an agreement with the City of Brentwood to coordinate the allocation of grant funds.
The City, BCID, BBID2, City of Lathrop, San Joaquin County, and Stewart Tract are the six GSAs formed in the Tracy Subbasin and are working cooperatively to develop a single GSP. The Tracy Subbasin GSAs were awarded a DWR grant to develop the GSP. Pursuant to the Grant Agreement, each GSA designated an appointee to form the GSP Coordination Committee, and the San Joaquin County was appointed as the Grant Administrator. The Grant Administrator or any two appointees may call meetings of the GSP Coordination Committee as needed to in the GSP development process.
The GSP for the Tracy Subbasin has been adopted by the GSAs and was submitted to DWR by the statutory deadline of January 31, 2022. The Final GSP is available on the Tracy Subbasin website: https://tracysubbasin.org.
As one of the six GSAs that are managing the Tracy Subbasin., the City has been actively involved in GSP development activities and will continue to be involved throughout SGMA implementation.
The City has one appointee (and an alternate) on the Tracy Subbasin GSP Coordination Committee, which meets quarterly, and the Technical Committee, which meets monthly.
2 The West Side Irrigation District officially merged with Byron-Bethany Irrigation District in September 2020, which occurred later than the release of the draft GSP chapters.
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5.3.4.5 Historical Groundwater Use
As discussed previously, the City currently operates eight groundwater extraction wells and one ASR well. The total production capacity of all of the wells combined is 28.2 mgd, which would equate to a total annual production capability of about 31,600 af/yr if the wells were pumped continuously; however, as described above, the City’s maximum annual groundwater extraction rate has been established to be 9,000 af/yr. Key characteristics of the City’s wells are listed in Table 5-7.
Table 5-7. Groundwater Well Characteristics
City Well
Name/Number
Year
Drilled
Total Well Depth
(Casing Depth),
feet
Casing
Diameter,
inches
Depth of
Perforated
Zone, feet(a)
Design
Capacity,
gpm
Production
Capacity,
mgd
Well 1 1986 1,010 (1,000) 16” 450-550
580-980 1,500 2.2
Well 2 1989 990 (870) 16” 420-850 2,000 2.9
Well 3 1989 1,020 (900) 16” 420-890 2,000 2.9
Well 4 1989 1,020 (950) 16” 380-940 2,000 2.9
Lincoln Well 1990 1,000 (1,000) 16” 490-980 2,500 3.6
Well 5(b)
(Lewis Manor Well) 2000 1,015 (1,000) 18”
410-480
601-630
650-670
805-830
900-930
965-990
2,500 3.6
Well 6
(Park & Ride Well) 2001/02 1,250 (1,216) 18”
550-598
610-636
656-678
738-754
774-796
966-982
1,014-1,122
1,176-1,196
2,000 2.9
Well 7
(Ball Park Well) 2002 1,070 (894) 18”
550-598
570-732
850-874
2,500 3.6
Well 8(c) 2004 850 (850) 18”
370-460
510-640
680-820
2,500 3.6
(a) Source: GEI Consultants, Summary of Groundwater Conditions November 2007 through November 2008, dated January 23, 2009.
(b) Data shown is for the Lewis Manor Replacement Well constructed in 2000. (c) Well 8 went into operation in September 2010, initially as an extraction well and then as a permitted ASR Well.
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It should be noted that only Wells 1, 2, 3, 4 and 8 currently have provisions for ammonia addition.
It is recommended that provisions for ammonia addition be added to the City’s other wells to provide maximum flexibility in the operation of the wells in co njunction with the City’s surface water supplies which are disinfected through chloramination.
The City’s annual groundwater production since 2010 is shown in Table 5-8.
Table 5-8. Historical Groundwater Production
by the City of Tracy
Year Annual Groundwater Production, af
2010 498
2011 292
2012 420
2013 515
2014 680
2015 519
2016 648
2017 995
2018 817
2019 645
2020 1,181
5.3.4.6 Projected Future Groundwater Use
As discussed in Section 5.3.4.2, the City may sustainably pump up to 9,000 af/yr from the local groundwater basin . Since the hard, high TDS groundwater is of lower quality than the City's surface water sources, the City has scaled back its groundwater extraction in most years. However, the City will continue to rely on groundwater for peaking and drought and emergency water supply.
The City anticipates that total extraction during a normal year will be 2,500 af/yr. By reducing groundwater extraction on an average annual basis, the City will: (1) increase the overall quality of its drinking water, thus increasing customer satisfaction and reducing system maintenance and repair caused by the lower -quality groundwater; and (2) recharge the underlying aquifer, effectively increasing the availability of groundwater during a drought or emergency condition (i.e., effectively "banking" groundwater).
The projected use of groundwater during dry years is about 4,500 af/yr and is consistent with the City's Groundwater Management Policy. In the event that the City is unable to secure additional high-quality surface water supplies in the future, the City is able to expand groundwater production up to 9,000 af/yr. In the event of a severe water supply shortage or emergency , the City has the ability to increase production dramatically, up to 22,000 af/yr.
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5.3.5 Aquifer Storage and Recovery
The City’s ASR Program allows the City to optimize conjunctive use of its water supplies through injection of surplus treated (potable) drinking water into selected aquifer zones within the groundwater subbasin for storage when surplus supplies are available, and recovery of that potable water from the aquifer to optimize water quality and meet seasonal peak demands during drought periods, or when emergency or disaster scenarios preclude the use of imported water supplies.
In January 2004 , the City constructed a new well ( Well 8) that was designed to allow for both injection and extraction of water supplies in conjunction with the City’s proposed ASR Program.
In early 2009, the City contracted to construct the above-ground well facilities (including the pump house, pump, motor, S CADA, electrical, telemetry, chemical feed systems, etc.) to have Well 8 operational in September 2010, initially as an extraction well, and in the future as part of the City’s proposed ASR Program. In addition, the City installed two monitoring wells for use in the demonstration project monitoring and testing for the proposed ASR Program.
The City obtained regulatory approval from the Central Valley Regional Water Quality Control Board (R WQCB) to conduct an ASR Demonstration Testing Program. The Phase 1 AS R Demonstration Testing was conducted between January 2011 and September 2011 and involved the injection of 233 acre-feet (76 million gallons) of treated SSJID potable water, storage in the confined aquifer, and subsequent extraction of 340 acre-feet (111 million gallons) of water 3. The Phase 2 ASR Testing was initiated in late December 2011 and was completed in September 2012 with injection of 700 acre-feet. The Tracy City Council approved and adopted a CEQA Negative Declaration (SCH No. 2012102013) for the permanent ASR Program on December 4, 2012.
Injection of treated SSJID water into the ASR well occurs during the winter months (i.e., November through April), when City demands are low and when the City’s JJWTP and groundwater wells can be shut down such that only treated SSJID water is injected per the City’s ASR permit. Extraction occurs primarily in the summer months to meet increased demands associated with irrigation needs, and as needed during droughts and water shortage emergencies. It is estimated that between 685 and 915 af/yr of potable water could be injected into the aquifer, assuming a 5 -month continuous injection rate of 1.5 to 2.0 mgd at Well 8. The City's current strategic plan for ASR operations involves injecting up to 1,000 af/yr over six months during the winter and extracting 75 percent of the injection volume during the following summer. These operations would result in net injection into the Lower Tulare Formation aquifer, which will gradually create a "buffer supply'' that the City can utilize in dry years or during water shortage emergencies.
Net annual ASR injection and extraction amounts from Well 8 since 2013 are shown in Table 5-9.
3 Interim (Final) Status Report for Well 8 ASR Demonstration Program, Memorandum prepared for City of Tracy by Pueblo Water Resources, dated December 7, 2011.
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Table 5-9. Tracy ASR Well 8 Annual Injection and Extraction Year Net Injection or Extraction, af
2013 415 (injection)
2014 221 (extraction)
2015 322 (injection)
2016 165 (injection)
2017 665 (injection)
2018 2 (injection)
2019 0
2020 190 (injection)
5.3.6 Out-of-Basin Water Banking
The Semitropic Groundwater Storage District Groundwater Storage Bank (Semitropic) is a water storage system that began operation in the early 1990s. Located in Kern County betwee n the California Aqueduct and the DMC, Semitropic is one of eight California groundwater banking agencies. Semitropic works by having its banking partners deliver their surplus water to Semitropic for storage. Then, when requested by the banking partner, S emitropic returns the stored water to the California Aqueduct for use by its partners either by exchanging its entitlement or by reversing the intake facility (known as “pumpback”). Through “pumpback ,” Semitropic can deliver a maximum of 90,000 af/yr of water into the California Aqueduct. The State would then deliver the water to the banking partners.
The total storage capacity at Semitropic is 1.65 million acre-feet and, as listed below, there is still a significant amount of storage capacity which is uncommitted and available. The current Semitropic banking partners and their reserved/available storage capacities are listed in Table 5-10.
Table 5-10. Semitropic Water Storage District Banking Partners(a) Partner Agency Storage Allocation, af
Metropolitan Water District of Southern California 350,000 Valley Water (formerly known as Santa Clara Valley Water District) 350,000 Alameda County Water District 150,000
Zone 7 Water Agency 65,000
Newhall Land & Farming Company 55,000
San Diego County Water Authority 45,000
Poso Creek Water Company 60,000
City of Tracy 10,500
Homer, LLC 15,000
Harris Farms, LLC 10,500
Available Capacity 474,750
Unallocated Storage 64,250
Total Storage Capacity 1,650,000
(a) Source: Semitropic Water Storage District website (www.semitropic.com) as of February 12, 2020.
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In June 2006, the City entered into a pilot agreement with Semitropic for 1,000 acre-feet of water storage at Semitropic , which allowed for an annual withdrawa l of up to 333 af/yr (e.g., 1,000 acre-feet divided by 3). The pilot agreement was intended to establish the procedures for water deposits and withdrawals by the City of Tracy and was terminated when the Permanent Agreement with Semitropic was implemented (see below).
On June 5, 2012, the Tracy City Council approved a long -term agreement with Semitropic for 3,500 units of water storage. One unit of water storage allows for a withdrawal of up to 1 af/yr for three years; hence, the agreement would allow for wi thdrawal of 3,500 af/yr for three years (10,500 af total). To store water in Semitropic, the City would not withdraw its share of CVP water from the DMC, but instead allow this water to continue to move through the DMC and California Aqueduct systems for d elivery to and use by Semitropic. This is called “in lieu storage.” Upon request by the City, in accordance with the contract, Semitropic would pump the stored water into the California Aqueduct and a like amount of water would be made available to the Cit y directly from the DMC.
Though the City could utilize this supply in any year, it is most valuable during extended drought years when the City's surface water supplies are reduced. The City anticipates that banking water at Semitropic will increase the reliability of the City's water supply and help close the potential future gap between supply and demand during drought conditions or other water supply shortage emergencies. If the City uses w ater from the Semitropic water bank in any given year, it would manage its supplies during subsequent years such that it could refill the water bank for future use.
The City plans to actively maintain storage in Semitropic as feasible.
As of December 2020, the City currently has 6,887 acre-feet of water in storage at Semitropic.
5.4 FUTURE POTABLE WATER SUPPLIES
The City is currently anticipating the following potential future potable water supplies:
• Additional ASR wells
• Additional CVP water supplies from USBR available through a recycled water exchange agreement
• Additional CVP water supplies from BBID
• Additional SCWSP water supplies
These potential future potable water supplies are described below.
5.4.1 Additional ASR Wells
As described above, the City currently has one ASR well (Well 8) which allows the City to inject excess SCWSP water supplies into the groundwater basin for later extraction when needed. The current injection and extraction capacity is 700 af/yr. The City i s planning to expand the ASR program with the installation of additional ASR wells. The City’s ASR Program will be expanded to provide up to 1,000 af/yr of water supplies from the existing and new ASR wells by 2040. The ASR supply will be used to meet dema nds during dry years, thereby increasing the reliability of Chapter 5
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the City's water supply and helping to close the potential gap between supply and demand during drought conditions or water shortage emergencies.
One constraint with the City’s ASR Program is that the permit only allows for SCWSP water to be injected. This means that the City has to shut down the JJWTP and the groundwater wells during the injection period so that only SCWSP supplies are being utilized. The City is considering requesting an amendment to its ASR permit to allow for the use of treated CVP supplies for ASR injection, in addition to the SCWSP water supplies. This would provide more operational flexibility for ASR injection and allow the City to optimize the storage of surface water supplies in wet years for later extraction in dry years. A potential alternative, if the City’s ASR permit cannot be modified to allow for other water supplies to be injected, would be to construct a dedicated SCWSP water pipeline to the ASR well(s). Future expansion of the ASR program will need to fully evaluate these operational restrictions and potential alternatives.
5.4.2 Additional CVP Water Supplies from USBR Available Through a Recycled Water Exchange Program
The City is evaluating the potential for indirect reuse of its available recycled water through an exchange agreement with the USBR whereby a portion of the City’s tertiary -treated wastewater (recycled water) would be discharged to th e DMC and a like amount of water (i.e., a one -to-one exchange) could then be diverted from the DMC by the City for treatment at the City’s JJWTP for potable use. Such supplies would be 100 percent reliable and would not be subject to drought cutbacks.
The benefits of such an exchange agreement include the following:
• Provides for the beneficial use of recycled water: Recycled water (tertiary treated wastewater) is currently discharged by the City into the Delta with minimal beneficial use.
• Provides an additional potable water supply for the City: Through indirect reuse, it provides an additional potable water supply for City residents and enhances water supply reliability for the community.
• Provides enhanced water supply reliability: Recycled water is a “drought proof” water supply.
• Reduces the City’s dependence on CVP water supply: CVP water has become increasingly unreliable due to drought, climate change and environmental impacts.
Indirect reuse of recycled water would reduce the City’s dependence on CVP water supplies .
• Builds on existing infrastructure: Operations under the exchange agreement would utilize the existing wastewater treatment facilities and recently constructed recycled water pump station and pipelines.
• Reduces salt loading in the Delta: Recycled water has a total dissolved solids content of approximately 660 milligrams per liter. Water of this quality is suitable for reuse but does not meet Delta salinity standards. This results in the USBR having to release additional water from New Melones Reservoir to attain Delta salinity standards.
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The project would require development of a project description, NEPA/CEQA review, approval of an exchange agreement and then design and construction of a recycled water pipeline to discharge recycled water to the DMC downstream of the City’s JJWTP intake. If such a project is approved and implemented, the City anticipates that it would initially provide up to 5,900 af/yr of additional potable water supplies to the City, with future expansion as needed to meet future demands.
5.4.3 Additional CVP Water Supplies from BBID
Additional BBID DMC/CVP water supplies may be available to the City as agricultural land is converted to M&I uses. The land area that could potentially provide this additional water supply includes the portion of BBID's service area that falls wit hin the City's planning areas (excluding the BBID Raw Water Service Area 2). Eligible land area is estimated to be approximately 2,600 acres. While the exact quantity of water that would be available is unknown, a contract ual entitlement equal to 3.4 af/yr/acre may be available, resulting in a total supply of up to 8,800 af/yr (2,600 acres x 3.4 af/yr/acre). However, it should be noted that the additional water supplies would have agricultural reliability similar to the City’s Ag -reliability CVP supplies de scribed in Section 5.3.1.2 above and therefore would be subject to significant cutbacks in dry years.
Agreements between Tracy and BBID, as well as environmental review, would need to occur before such a transaction could take place.
However, because of the uncertainty associated with the availability and reliability of this supply source, especially in dry years, for purposes of this Citywide Water System Master Plan Update, it is assumed that this future water supply will not be available to the City in the future.
5.4.4 Additional SCWSP Water Supplies
The City previously anticipated that an additional 1,880 af/yr of treated water supplies may be available from the SCWSP in the future through a Conserved Water Amendment Agreement. This additional supply would have the same reliability as the supply that the City is currently receiving from the SCWSP, including that recently purchased from the City of Lathrop. Delivery of these additional supplies to the City would be through the same, existing facilities curren tly delivering the City’s existing SCWSP supplies. Delivery of these additional supplies would be subject to approval and environmental review.
However, because of the current uncertainty associated with the availability and reliability of this supply source, especially in dry years as a result of the Bay-Delta Plan Amendment, for purposes of this Citywide Water System Master Plan Update, it is assumed that this future water supply will not be available to the City in the future.
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5.5 EXISTING NON-POTABLE WATER SUPPLIES
5.5.1 Recycled Water
In 2002, the City adopted a Recycled and Non -Potable Water Ordinance requiring all new subdivisions, to the extent practicable, to install the required infrastructure (such as dual-distribution pipelines) to provide rec ycled water to meet non -potable water demands at parks, golf courses, athletic fields, schools, median island landscapes, and industrial sites. The ordinance was codified into the Tracy Municipal Code as Chapter 11.30 “Recycled and Non-Potable Water.” In March 2013, the City adopted Ordinance 1183 amending Chapter 11.30 of the Tracy Municipal Code to update the City’s recycled water requirements to be consistent with State, regional and local standards, including the California SB X7-7, 2010 California Gre en Building Standards Code, California Model Water Efficient Landscape Ordinance, and the City of Tracy Sustainability Action Plan. Approvals and permits for the production, distribution and use of recycled water will be required from the RWQCB and the SWRCB Division of Drinking Water.
Both the 2012 WSMP and Tracy Wastewater Master Plan included recommended capital improvement projects for the development of the City’s recycled water system, including pump station and pipeline facilities to deliver recycled water within the City’s service area for use for landscape irrigation and other non -potable uses. To date, the City has spent approximately $85 million on improvements to the City’s WWTP to allow for the production of tertiary -treated wastewater meeting Title 22 requirements for recycled water use for landscape irrigation and other non-potable uses. In December 2013, the City adopted Development Impact Fees to fund recycled water infrastructure improvements. In 2015, the City received a $18 millio n Proposition 84 grant from DWR to fund construction of pump stations and pipelines to distribute recycled water. In March 2019, the City received an amended order from the SWRCB approving the change in place of use of its treated wastewater. The order allows for the City to change the point of discharge and place of use of treated wastewater by a reduction in discharge to Old River of up to 8.1 mgd, with a maximum annual limit of 5,900 af/yr and use the treated wastewater for industrial and irrigation purposes within the service areas of the City’s Sphere of Influence, BBID within the City’s Sphere of Influence and WSID.
The City recently completed construction of a recycled water pump station at the City’s WWTP and a recycled water pipeline from the WWTP west to Lammers Road and south to Kimball High School. A second phase of construction will include a second pump station and additional recycled water pipeline to further extend the distribution of recycled water supplies within the City.
As described in Chapter 4, at buildout of the City’s General Plan, it is estimated that the recycled water demand for landscape irrigation will be approximately 6,300 af/yr.
5.5.2 Shallow Non-Potable Groundwater
As discussed above, the Tracy Subbasin underlying the City has two aquifers: semi-confined and confined. The uppermost semi-confined aquifer is primarily comprised of alluvial and flood basin formations. The underlying confined aquifer is primarily comprised of the Tulare Formation and it is overlain by the Corcoran Cl ay, which separates the upper semi -confined aquifer from the underlying confined aquifer. The City’s production wells draw from the confined aquifer only and Chapter 5
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the average annual operational groundwater yield of 9,000 af/yr described in previous sections applies only to the confined aquifer. The City does not currently pump any groundwater from the semi-confined aquifer.
The shallow semi-confined groundwater is considered to be suitable for agricultural irrigation purposes. However, due to the poor water quality associated with the shallow groundwater supply, the use of this supply to meet the non-potable demands within the City’s SOI is not recommended and is not discussed further in this Citywide Water System Master Plan Update.
5.6 RELIABILITY OF THE CITY’S WATER SUPPLIES
5.6.1 Potable Water Supply Reliability
The projected reliability for each of the City’s supply sources under normal, single dry and multiple dry year conditions are described below.
5.6.1.1 Normal Years
Normal or wet water years are those that match or exc eed median rainfall and runoff levels. The reliability of each of Tracy’s existing and future water supplies and their projected availability during normal and wet years is described below:
• The City’s contract with the USBR for 10,000 af/yr of DMC/CVP water is subject to M&I reliability. Based on the historical record, the City’s long-term average allocation of DMC/CVP water pursuant to this contract is anticipated to be at least 85 percent of the total entitlement. However, due to recent environmental concerns in the Delta and potential future impacts due to climate change, the normal year supply of DMC/CVP M&I water is assumed to be 75 percent of the City’s historical use.
Based on a historical use of 5,930 af/yr (i.e., the average quantity of CVP water put to beneficial use by the City during the last three years of water deliveries that were unconstrained by the availability of CVP water), the projected normal year supply is 4,448 af/yr.
• The City has received acquired assignments from Banta-Carbona Irrigation District (BCID; 5,000 af/yr) and West Side Irrigation District (WSID; 5,000 af/yr) for a total entitlement of 10,000 af/yr of DMC/CVP water. These supplies are subject to Ag-reliability. The City is conservatively estimating that it will receive 50 percent of its Ag-reliability contractual entitlement, or 5,000 af/yr, in normal years. • The City has acquired up to 4,500 af/yr of pre-1914 appropriative water rights water from BBID. These supplies are restricted in their place of use, and therefore the supply is anticipated to be equal to the projected demand within that place of use (i.e., the Tracy Hills area) ranging from 800 af/yr in 2025 to 3,300 af/yr in 2045. The City anticipates being able to receive 100 percent of this supply in normal years.
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• The City has a total contractual entitlement of 13,135 af/yr of Stanislaus River water provided through the SCWSP, including 10,000 af/yr from its original contract with SSJID, 1,120 af/yr purchased from Lathrop, and 2,015 af/yr purchased on an interim basis from Escalon. The agreement between Tracy and Escalon is assumed to terminate after 2025. Based on information provided by SSJID, the City expects to receive 100 percent of its SCWSP water supply allocation during a normal water year. As such, the City anticipates being able to receive 13,135 af/yr of SCWSP supply in 2025 and 11,120 af/yr afterwards, assuming normal year conditions. • The City is able to withdraw up to 9,000 af/yr of groundwater from the Tracy Subbasin. However, due to the aging infrastructure and water quality issues in the City’s groundwater supplies, the City is projecting to be able to withdraw up to 2,500 af/yr in normal years. This groundwater supply is considered to be 100 percent reliable.
• The City does not anticipate using its Semitropic water or ASR water in normal years. • The City anticipates that a Recycled Water Distribution Network and Exchange agreement will be executed with the USBR by 2030 to provide additional CVP supplies to the City in exchange for the City discharging a like amount of tertiary-treated recycled water to the DMC. The City assumes that the Recycled Water Distribution Network and Exchange will be implemented as needed to meet future demand conditions and is currently projected to supply an amount ranging from 1,925 af/yr in 2030 to 7,500 af/yr in 2045. This water supply is considered to be 100 percent reliable.
• The City’s recycled water supply is expected to be 100 percent reliable. Based on the projected non-potable demands and assuming that the City makes investments in infrastructure and permitting, the City estimates that they will have access to 1,000 af/yr of recycled water supply in 2025, increasing to 6,300 af/yr in 2045.
The reliability of each of the City’s existing and additional planned future water supplies and their projected availability during normal years at buildout is shown in Table 5-11.
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Table 5-11. Projected Existing and Additional Planned Future Water Supplies Available in Normal Years at Buildout
Supply
Percent Allocation/
Entitlement
Projected Available
Supplies, af/yr
Existing Water Supplies
USBR CVP - Tracy Contract(a) 75 4,448
USBR CVP - BCID Contract 50 2,500
USBR CVP - WSID Contract 50 2,500
Total CVP Supplies 9,448
BBID (pre-1914 to meet Tracy Hills demand) 100 3,300
SCWSP (SSJID) (pre-1914) 100 11,120
Groundwater 100 2,500
Semitropic Water Storage Bank(b) 0 0
Total Existing Potable Supplies 26,368
Additional Planned Future Water Supplies(a)
Additional USBR CVP (BBID contract) 0 0
Aquifer Storage and Recovery(b) 0 0
Recycled Water Exchange 100 7,500
Recycled Water (non-potable) 100 6,300
Total Additional Planned Future Potable Supplies 7,500
Total Potable Supplies 33,868
Total Additional Planned Future Non-Potable Supplies 6,300 TOTAL WATER SUPPLY 40,168
Source: City of Tracy 2020 UWMP, Table 7-2, June 2021.
(a) Percent of historical use
(b) Not used in normal years.
5.6.1.2 Single Dry Years
During a single dry year, all of the City’s existing surface water allotments are subject to some level of reduction. Assumed reductions are based on actual reductions in CVP deliveries experienced in the recent drought and the new USBR M&I Reliability Policy adopted in 2017. The actual reductions will vary with the severity of the regional water supply shortage and climatic conditions, and the consideration of contract agreements.
The following describes the availability and reliability of the City’s existing and additional planned future water supplies under single dry year conditions:
• The City’s contract with the USBR for 10,000 af/yr of DMC/CVP water is subject to M&I reliability. During a single dry year, the City estimates to receive 25 percent of the City’s historical use. Based on the historical use of 5,930 af/yr, the projected supply is 1,483 af/yr.
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• The City has a total entitlement of 10,000 af/yr of DMC/CVP Ag-reliability water.
The City anticipates receiving 0 percent of its DMC/CVP Ag-reliability water in a single dry year.
• The City has acquired up to 4,500 af/yr of pre-1914 appropriative water rights water from BBID. This supply is restricted with regard to the place of use (Tracy Hills).
The City anticipates being able to receive 85 percent of its contractual entitlement in a single dry year (3,825 af/yr). As the projected demand is 3,300 af/yr in 2045 and is lower than the 3,825 af/yr of available supply, the reduction in reliability does not result in a reduction to actual amount of water used. Therefore, the supply in a single dry year is anticipated to be equal to the projected demand within the Tracy Hills area, ranging from 800 af/yr in 2025 to 3,300 af/yr in 2045. • The City has a total contractual entitlement of 13,135 af/yr of Stanislaus River water provided through the SCWSP. Based on information provided by SSJID, the City expects to receive 76 percent of its SCWSP water supply allocation during 2025, 2030, and 2035 and 56 percent during 2040 and 2045. In addition, the SCWSP water transferred from Escalon is assumed to be unavailable after 2025. As such, the City estimates 9,974 af/yr of SCWSP supply in 2025, 8,444 af/yr in 2030 and 2035, and 6,177 af/yr afterwards.
• During a single dry year, the City anticipates increasing its groundwater production on a short-term basis from the normal year production of 2,500 af/yr to 4,500 af/yr.
The groundwater supply is considered to be 100 percent reliable. • The City anticipates that 700 af/yr of water will be available for use in a single dry year through operation of its ASR well. An additional 300 af/yr is estimated to be available by 2040 for a total of 1,000 af/yr. This water supply is considered to be 100 percent reliable assuming that the City is consistently able to refill the ASR storage during non-drought years to maintain at least 1,000 af in storage at the beginning of a single dry year.
• The City has acquired 10,500 af/yr of storage in Semitropic, which allows the City to withdraw up to 3,500 af/yr for three consecutive years. Due to the difficulties experienced by the City in accessing stored water via the DMC on a short timeframe, the City has conservatively assumed that the Semitropic water will not be available in a single dry year.
• The City anticipates that a Recycled Water Distribution Network and Exchange agreement will be executed with the USBR by 2030 to provide additional CVP supplies to the City in exchange for the City discharging a like amount of tertiary-treated recycled water to the DMC. The City assumes that the Recycled Water Distribution Network and Exchange will be implemented as needed to meet future demand conditions and is currently projected to supply an amount ranging from 1,925 af/yr in 2030 to 7,500 af/yr in 2045. This water supply is considered to be 100 percent reliable.
• The City’s recycled water supply is expected to be 100 percent reliable. Based on the projected non-potable demands and assuming that the City makes investments in infrastructure and permitting, the City estimates that they will have access to 1,000 af/yr of recycled water supply in 2025, increasing to 6,300 af/yr in 2045.
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The reliability of each of the City’s existing and additional planned future water supplies and their projected availability during a single dry year at buildout is shown in Table 5-12.
Table 5-12. Projected Existing and Additional Planned Future Water Supplies Available in Single Dry Years at Buildout Supply
Percent Allocation/
Entitlement
Projected Available
Supplies, af/yr
Existing Water Supplies
USBR CVP - Tracy Contract(a) 25 1,483
USBR CVP - BCID Contract 0 0
USBR CVP - WSID Contract 0 0
Total CVP Supplies 1,483
BBID (pre-1914 to meet Tracy Hills demand) 100 3,300
SCWSP (SSJID) (pre-1914)(b) 56 6,177
Groundwater(c) 100 4,500
Semitropic Water Storage Bank 0 0
Total Existing Potable Supplies 15,460
Additional Planned Future Water Supplies
Additional USBR CVP (BBID contract) 0 0
Aquifer Storage and Recovery(c) (d) 100 1,000
Recycled Water Exchange(c) 100 7,500
Recycled Water (non-potable)(c) 100 6,300
Total Additional Planned Future Potable Supplies 8,500
Total Potable Supplies 23,960
Total Additional Planned Future Non-Potable Supplies 6,300 TOTAL WATER SUPPLY 30,260
Source: City of Tracy 2020 UWMP, Table 7-3, June 2021.
(a) Percent of historical use.
(b) Percentage of contract entitlement is based on information from SSJID for 2040 and later. (c) Groundwater and recycled water volumes assume the City invests in infrastructure and/or permitting. (d) ASR volumes assume surplus supplies are available in wet years to inject and store, as well as additional investment in ASR construction and operation.
5.6.1.3 Multiple Dry Years
During multiple dry years, the City’s surface water supplies (from both the CVP and SCWSP) may be significantly reduced. Thus, in the event of drought, the City will have to depend more heavily on conservation efforts, groundwater, and the proposed future supply projects.
The following describes the availability and reliability of the City’s existing and additional planned future water supplies under multiple dry year conditions:
• The City’s contract with the USBR for 10,000 af/yr of DMC/CVP water is subject to M&I reliability. During multiple dry years, the City estimates that it will receive 40 percent of the City’s historical use. Based on the historical use of 5,930 af/yr, the projected supply is 2,372 af/yr.
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• The City has a total entitlement of 10,000 af/yr of DMC/CVP Ag-reliability water.
The City anticipates receiving 0 percent of its DMC/CVP Ag-reliability water in multiple dry years.
• The City has acquired up to 4,500 af/yr of pre-1914 appropriative water rights water from BBID. This supply is restricted with regard to the place of use (Tracy Hills).
The City anticipates being able to receive 85 percent of its contractual entitlement in multiple dry years (3,825 af/yr). As the projected demand is 3,300 af/yr in 2045 and is lower than the 3,825 af/yr of available supply, the reduction in reliability does not result in a reduction to actual amount of water used. Therefore, the supply in multiple dry years is anticipated to be equal to the projected demand within the Tracy Hills area, ranging from 800 af/yr in 2025 to 3,300 af/yr in 2045. • The City has a total contractual entitlement of 13,135 af/yr of Stanislaus River water provided through the SCWSP. Based on information provided by SSJID, the City’s SCWSP water supply reliability during multiple dry years range from 56 to 100 percent. In addition, the SCWSP water transferred from Escalon is assumed to be unavailable after 2025.
• During multiple dry years, the City anticipates increasing its groundwater production on a short-term basis from the normal year production of 2,500 af/yr to 4,500 af/yr.
The groundwater supply is considered to be 100 percent reliable. • The City anticipates that 700 af of water will be available for use in multiple dry years through operation of its ASR well. An additional 300 af is estimated to be available by 2040 for a total of 1,000 af. The City is assumed to be unable to refill the ASR storage during multiple dry years. Therefore, the annual ASR supply available is assumed to equal one fifth of the total stored volume (i.e., 140 af/yr between 2025 and 2035 and 200 af/yr between 2040 and 2045). This water supply is considered to be 100 percent reliable assuming that the City is consistently able to refill the ASR storage in non-drought years to maintain at least 1,000 af in storage at the beginning of a multiple dry year sequence.
• The City has acquired 10,500 af/yr of storage in Semitropic, which allows the City to withdraw up to 3,500 af/yr for three consecutive years. Due to the difficulties experienced by the City in accessing stored water via the DMC on a short timeframe, the City has conservatively estimated that the 0 percent of the City’s storage will be available in the first year of a five -consecutive-year drought, and 100 percent will be a vailable over the following four years. Based on the City’s current storage at Semitropic of 6,887 af, the amount available in the second to fifth year of a five-consecutive-year drought is assumed to be 1,722 af/yr (6,887 af divided by four). A similar re liability estimate is provided for all dry -year sequences under the assumption that the City is consistently able to re -fill the water bank in non-drought years to maintain at least 7,000 af/yr in storage at the beginning of a multiple dry year sequence.
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• The City anticipates that a Recycled Water Distribution Network and Exchange agreement will be executed with the USBR by 2030 to provide additional CVP supplies to the City in exchange for the City discharging a like amount of tertiary-treated recycled water to the DMC. The City assumes that the Recycled Water Distribution Network and Exchange will be implemented as needed to meet future demand conditions and is currently projected to supply an amount ranging from 1,925 af/yr in 2030 to 7,500 af/yr in 2045. This water supply is considered to be 100 percent reliable.
• The City’s recycled water supply is expected to be 100 percent reliable. Based on the projected non-potable demands and assuming that the City makes investments in infrastructure and permitting, the City estimates that they will have access to 1,000 af/yr of recycled water supply in 2025, increasing to 6,300 af/yr in 2045.
The reliability of each of the City’s existing and additional planned future water supplies and their projected availability during a five-consecutive-dry year (multiple dry year) period at buildout is shown in Table 5-13.
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Table 5-13. Projected Existing and Additional Planned Future Water Supplies Available Five-Consecutive-Dry Years at Buildout Supply
Percent
Allocation/
Entitlement
Projected Available Supplies, af/yr
Year 1 Year 2 Year 3 Year 4 Year 5
Existing Water Supplies
USBR CVP - Tracy
Contract(a) 40 2,372 2,372 2,372 2,372 2,372
USBR CVP - BCID Contract 0 0 0 0 0 0
USBR CVP - WSID Contract 0 0 0 0 0 0
Total CVP Supplies 2,372 2,372 2,372 2,372 2,372
BBID (pre-1914 to meet
Tracy Hills demand) 100 3,300 3,300 3,300 3,300 3,300
SCWSP (SSJID) (pre-1914) See Note (b) 11,120 11,120 6,177 6,177 11,120 Groundwater(c) 100 4,500 4,500 4,500 4,500 4,500
Semitropic Water Storage
Bank 100 0 1,722 1,722 1,722 1,722
Total Existing Potable Supplies 21,292 23,014 18,071 18,071 23,014 Additional Planned Future Water Supplies
Additional USBR CVP
(BBID contract) 0 0 0 0 0 0
Aquifer Storage and
Recovery(c)(d) 100 200 200 200 200 200
Recycled Water Exchange(c) 100 7,500 7,500 7,500 7,500 7,500 Recycled Water
(non-potable)(c) 100 6,300 6,300 6,300 6,300 6,300
Total Additional Planned Future
Potable Supplies 7,700 7,700 7,700 7,700 7,700
Total Potable Supplies 28,992 30,714 25,771 25,771 30,714 Total Additional Planned Future
Non-Potable Supplies 6,300 6,300 6,300 6,300 6,300
TOTAL WATER SUPPLY 35,292 37,014 32,071 32,071 37,014
Source: City of Tracy 2020 UWMP, Tables 7-4 and 7-5, June 2021. (a) Percent of historical use.
(b) Information provided by SSJID. SSJID’s reliability estimates for a five consecutive year drought were based on the historical supplies available for the SCWSP during the 2012 to 2016 drought period. During 2012, 2013, and 2016 (the first, second, and fifth years), SSJID was able to provide the full allocation to SCWSP participants, whereas during 2014 and 2015 (the third and fourth years), SSJID was only able to provide 75 percent of the full allocation to SCWSP participants. (c) Groundwater and recycled water volumes assume the City invests in infrastructure and/or permitting. (d) ASR volumes assume surplus supplies are available in wet years to inject and store, as well as additional investment in ASR construction and operation.
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5.6.2 Emergency Water Supply Conditions
During the recent drought conditions in California, water supply deliveries from the SWP and CVP (and other surface water supply sources throughout California) were severely reduced and even the availability of pre-1914 water rights was ch allenged. Many water supply agencies, including the City, implemented their Water Shortage Contingency Plans, including mandatory water conservation measures, to reduce water use. Even with 0 percent deliveries from the City’s USBR CVP agricultural supplies in 2014, the diversity of the City’s water supply portfolio together with water conservation efforts by the City’s customers allowed the City to meet all water demands. If the recent drought were to re -occur, and deliveries of surface water supplies are reduced further, the City’s Water Shortage Contingency Plan would be enacted as needed.
The City’s Water Shortage Contingency Plan includes shortage response actions for six water shortage levels up to greater than 50 percent shortage due to foreseeable or unforeseeable events.
The City’s Water Shortage Contingency Plan is included in Appendix H of the 2020 UWMP. The City may implement demand reduction actions, supply augmentation, mandatory restrictions, and other actions as appropriate for the shortage level to reduce the gap between supply and demand.
Further, the City has prepared a Water System Emergency Response Plan which provides a framework for emergency response by the City’s Utilities Department by describing the department's emergency management organization, roles, and responsibilities and emergency policies and procedures. The Water System Emergency Response Plan provides action plans to be implemented to address the emergency.
5.6.3 Non-Potable Water Supply Reliability
Recycled water supplies are generally regarded as being highly reliable water supplies, even during drought conditions. This is because wastewater flows are primarily generated from interior water uses which generally remain about the same throughout the year and during drought conditi ons (reductions in water use during drought conditions are primarily the result of reduced exterior water uses which generally do not become wastewater flows). For this reason, it is assumed that recycled water supplies will be 100 percent reliable under all hydrologic conditions.
5.7 SUFFICIENCY OF THE CITY’S WATER SUPPLIES
5.7.1 Potable Water Supply Availability
Table 5-14 summarizes the projected availability of the City’s existing and planned future potable water supplies compared with projected water demands in normal, single dry and multiple dry years at buildout.
To be conservative, water demands were assumed to be at normal levels. With future planned projects implemented, the results of the assessment show that water supply is sufficient during normal years. However, during a single dry year or a multiple dry year period, the City must depend more heavily on conservation efforts, groundwater, and the proposed future supply projects to overcome the gap between supply and demand. As described in the City’s 2020 UWMP, these findings are primarily due to proje cted reduced reliability of the City’s CVP supplies and SSJID supplies in dry years.
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Table 5-14. Summary of Buildout Total Water Supply Versus Demand During Hydrologic Normal, Single Dry, and Multiple Dry Years(a) Hydrologic Condition Supply and Demand Comparison, af/yr Normal Year(b)
Available Total Water Supply 40,168
Total Water Demand 39,800
Potential Surplus (Deficit) 368
Percent Shortfall of Demand -
Single Dry Year(c)
Available Total Water Supply 30,259
Total Water Demand 39,800
Potential Surplus (Deficit) (9,541)
Percent Shortfall of Demand 24%
Multiple Dry Years(d)
Year 1
Available Total Water Supply(e) 35,292
Total Water Demand 39,800
Potential Surplus (Deficit) (4,508)
Percent Shortfall of Demand 11.3%
Year 2
Available Total Water Supply 37,014
Total Water Demand 39,800
Potential Surplus (Deficit) (2,786)
Percent Shortfall of Demand 7.0%
Year 3
Available Total Water Supply 32,071
Total Water Demand 39,800
Potential Surplus (Deficit) (7,729)
Percent Shortfall of Demand 19.4%
Year 4
Available Total Water Supply 32,071
Total Water Demand 39,800
Potential Surplus (Deficit) (7,729)
Percent Shortfall of Demand 19.4%
Year 5
Available Total Water Supply 37,014
Total Water Demand 39,800
Potential Surplus (Deficit) (2,786)
Percent Shortfall of Demand 7.0%
(a) Water demands are from Table 4-16.
(b) Normal Year supplies are from Table 5-11
(c) Single Dry Year supplies are from Table 5-12.
(d) Multiple Dry Year supplies are from Table 5-13
(e) Assumes 0 percent of the City’s storage in Semitropic is available for the first year.
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To close the gap between supply and demand during dry years, the City will need to implement its Water Shortage Contingency Plan to reduce water demands and implement future water supply projects. This includes full implementation of the proposed Recycled Water Distribution Network and Exchange Program and expansion of the ASR Program. Delays in implementing these projects could result in greater water supply shortages and the need for additional water conservation to meet demands. Investments in wet year w ater supplies will also be needed to refill storage in Semitropic and expand the City’s ASR program.
The dry year shortfalls presented in Table 5-14 include water supply and demand projections with numerous uncertainties and the situation is dynamic and discussed in Section 7 of the 2020 UWMP. The City continues to work on strategies and actions to address the projected water supply shortfall. Uncertainties are itemized below:
• The Bay-Delta Plan Amendment implementation is under negotiation. The SSJID and others are continuing negotiations with the SWRCB on implementation of the Bay-Delta Plan Amendment for water supply cutbacks, particularly during droughts.
This is a dynamic situation and the projected drought cutback allocations may need to be revised before the next (i.e., 2025) UWMP depending on the outcome of ongoing negotiations. The City has considered a conservative estimate of the potential impacts of the Bay-Delta Plan Amendment on the SCWSP (and therefore the City), which is provided in Appendix G of its 2020 UWMP.
• The supply yield of the City’s development of additional ASR and recycled water supplies are accounted for in current supply projections. However, implementation of these projects will require significant investment by the City. Similarly, investments in wet years supplies will be needed to refill storage in Semitropic and expand the City’s ASR program.
• The City continues to work closely with the USBR and SSJID on their rationing policies to ensure that M&I needs can be met. Rationing policies may potentially be revised.
• The City’s projected water demands are subject to change in the future based on water conservation policies and regulations for current and future development, and the pace and extent of development.
• Frequency and duration of cutbacks and, therefore, the shortfalls are also uncertain. In addition to the supply volumes, the above listed uncertainties would also impact the projected frequency and duration of shortfalls.
5.7.2 Recycled Water Supply Availability
Recycled water will be treated to a tertiary level in accordance with Title 22 requirements at the City’s WWTP and will be distributed to recycled water use areas within the City’s SOI for use for landscape irrigation and other non -potable uses and will be used as part of the Recycled Water Distribution Network and Exchange Program. It is anticipated that with expansion of the City’s WWTP adequate recycled water supplies will be available on an annual basis to meet the projected recycled water demands at buildout of the City’s General Plan.
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The projected future use of recycled water supplies to meet non -potable water demands such as landscape irrigation within the City’s service areas is critical to reduce potable water demands and reserve the City’s available potable water supplies for their most important uses and to ensure that the City has adequate water supplies to meet future water demands. Without this future recycled water use within the City’s service areas, and without the Recycled Water Distribution Network and Exchange Program, the City would have inadequate potable water supplies to meet anticipated future water demands.
5.8 WATER MANAGEMENT STRATEGIES AND OPTIONS
The City has developed strategies and actions to address the projected supply shortfalls. These are discussed in the City’s 2020 UWMP and summarized below.
5.8.1 Recycled Water for Non-Potable Use
The City continues to develop recycled water supplies as discussed in Section 5.5.1. Recycled water is planned to augment non-potable demands that would otherwise be supplied with potable water. Buildout potable water demands could be less than the current projections and therefore the resultant supply shortage will likely to be smaller.
5.8.2 Future Water Supply Projects
The City continues to evaluate the expansion of its existing supply and to obtain new supply sources, including the ASR Program and Recycled Water Distribution Network and Exchange Program. Other potential supply options, such as direct potable reuse of recycled water, are also being considered.
The City has also recently entered discussions with the Contra Costa Water District (CCWD) and the San Luis & Delta-Mendota Water Authority to explore the City’s potential participation in the Phase 2 Los Vaqueros Reservoir Expansion Project. Los Vaqueros Reservoir is an offstream storage facility located in the coastal foothills west of the Sacramento-San Joaquin Delta. CCWD completed construction of the Los Vaqueros Projec t in 1997 with an original storage capacity of 100,000 acre-feet. CCWD stores water in Los Vaqueros Reservoir that is diverted from the Delta when water quality is favorable for later release and blending when Delta water quality is degraded.
An initial ex pansion, Phase 1, to 160 ,000 acre-feet was completed in 2012 to address seasonal water quality degradation and drought needs. The reservoir also provides important emergency water supply storage, recreation, and flood management. The proposed Phase 2 expansion project builds upon the successful Phase 1 expansion completed in 2012. The proposed project will include a regional intertie (the Transfer -Bethany Pipeline), improved pump stations and pipelines and could increase the reservoir’s capacity up to 275,000 acre-feet. The Transfer-Bethany Pipeline is currently anticipated to be completed in 2025/2026, with the reservoir expansion to be completed by 2030. The City’s participation in the project would increase the City’s water supply reliability by providing storage of supplies for use in dry years. The estimated cost for 5,000 acre -feet of storage for the City will be approximately $10 million plus an additional $1.5 million for implementation. In October 2021, the Tracy City Council authorized staff to initiate the process to participate in the project and authorized the City Manager to execute the project activity agreement.
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The City is also participating in the proposed B.F. Sisk Dam Raise & Reservoir Expansion Project.
The proposed B.F. Sisk Dam Raise & Reservoir Expansion by the USBR and the San Luis Delta Mendota Water Authority provides a reliable option for storage of excess water during the wet season and use during drought conditions when needed. The B.F. Sisk Dam and Reservoir, located approximately 50 miles south of the City, is a major storage facility of the Central Valley Project from which the City receives surface water. The project’s environmental document has already been prepared for expansion of the reservoir. The proposed project will add 130,000 acre-feet of additional storage capacity in the reservoir. The project’s feasibility study is in its final stages of completion and total cost of the expansion project is estimated at $1 billion. If the City participates in the project, water will be delivered to the City’s JJWTP from the DMC through an exchange agreement with the USBR and other participating agencies. The estimated cost for 5,000 acre-feet of storage for the City will be approximately $38 million . In June 2022, the Tracy City Council authorized staff to initiate the process to participate in the project and authorized the City Manager to execute the project activity agreement.
5.8.3 Implementation of Demand Management Measures
The City has an active water conservation program and continues to implement the demand management measures described in Section 9 of the City’s 2020 UWMP. Further, in response to the anticipated future shortfalls, the City has developed a robust Water Shortage Contingency Plan that systematically identifies ways in which the City can reduce water demands. The Water Shortage Contingency Plan is included in Section 8 of the City’s 2020 UWMP.
5.8.4 Policy-Based Water Efficiency Tools
The City is currently exploring other policy -based water efficiency tools that other supply-constrained agencies across California have implemented. These policy -based tools are often bundled together and referred to as Water Demand Offset (WDO) or Water Neutrality policies. Through these policies, project developers are generally required to offset the new demand anticipated by the development through some combination of demand mitigation options, such as:
• On-site retrofits. Project developer with existing property reduces total projected water demand by retrofitting existing property with efficient water fixtures. If projected water demand is reduced below baseline for existing property, no off-site WDOs are required. If not, offsite WDOs are required.
• Off-site retrofits. Project developer coordinates and pays for installation of water efficient fixtures at other properties or converts existing irrigation systems to recycled water for other off- site properties, typically those owned by other entities. • On-site reuse. Larger scale developments are required to implement on-site reuse of water, including rainwater, greywater, stormwater, and blackwater, as has recently been implemented by the Cities of San Francisco and Menlo Park. • Supply augmentation. Project developer secures its own water supply to serve the development, either through direct provision of water to the development or through an agreement to transfer rights to the water supplier.
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• WDO fees. Project developer pays fees to implementing entity based on the amount of water offset, and the agency uses the fees to fund water conservation programs.
Such conservation programs could include system water loss mitigation projects (e.g., capital improvement, Advanced Metering Infrastructure [AMI] meters, etc.), purchase of water efficient equipment (e.g., NO-DES hydrant flushing machine to recycle water used to flush mains), and recycled water system infrastructure, as well as fixture rebate or retrofit and education-based conservation programs.
Such policies could be designed as a “net neutral” policy wherein the new development is required to offset all new demands associated with the development project and minimize the overall supply reliability impacts for the existing customers.
5.9 SUMMARY OF WATER SUPPLY RECOMMENDATIONS
The following summarizes recommendations related to the City’s water supplies:
• Provisions for ammonia addition should be added to the City’s existing Lincoln Well, Lewis Manor Well, Park & Ride Well and Ball Park Well, and any future wells, to provide maximum flexibility for the City’s use of groundwater in conjunction with the City’s surface water supplies which are disinfected through chloramination. • The City’s ASR Program should be expanded in the future to provide up to 1,000 af/yr of supply. The City is considering requesting an amendment to its ASR permit to allow for the use of treated CVP supplies for ASR injection, in addition to the SCWSP water supplies. This would provide more operational flexibility for ASR injection and allow the City to optimize the storage of surface water supplies in wet years for later extraction in dry years. An evaluation of potential ASR options and operational scenarios should be conducted as additional ASR wells are planned to determine if dedicated SSJID supply pipelines to the ASR wells will be required if the City’s ASR permit cannot be modified to allow for other supplies to be injected. See Chapter 8 for additional discussion about the City’s future ASR wells. • The City should continue discussions with the Contra Costa Water District for the City’s participation in the Phase 2 Los Vaqueros Reservoir Expansion Project. The City’s participation in the project would increase the City’s water supply reliability by providing storage of supplies for use in dry years.
• The proposed Recycled Water Distribution Network and Exchange Program should be developed as soon as possible to provide for the exchange of recycled water supplies for surface water supplies which can be treated and used to meet the City’s potable water demands. The City’s 2020 UWMP assumes an exchange quantity of 7,500 af/yr; however, if this amount could be increased, projected water shortages may be reduced. Subsequent revisions to the projected potable water demand and/or the water supply availability and reliability assumptions may change the required quantities and timing of the proposed Recycled Water Distribution Network and Exchange Program.
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• Development the Recycled Water Distribution Network and Exchange Program will require an expansion of the City’s WWTP to be able to produce the recycled water required for the exchange and the design and construction of a recycled water pipeline to discharge recycled water to the DMC downstream of the City’s JJWTP intake. Additional discussion of the pipeline required for the Recycled Water Distribution Network and Exchange Program is provided in Chapter 9. • The City’s recycled water system should continue to be developed to the maximum extent possible to allow for irrigation demands to be met with recycled water supplies to offset the demand for potable water supplies. The quantity required is estimated to be 6,300 af/yr by buildout based on the recycled water use assumptions described in Chapter 4.
As described in this Citywide Water System Master Plan Update, and in the City’s 2020 UWMP, water supply conditions continue to change in California, and the availability and reliability of the City’s water supplies may continue to change in the coming years. City staff are conti nuously monitoring water supply conditions and making adjustments to water system operations as needed.
Additional ASR wells and/or other infrastructure improvements may be needed to serve developments which rely on water supplies with agricultural rights under various agreements with the City. The water supply recommendations described above, and their associated costs, may need to be refined in the future as water supply conditions change.
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CHAPTER 6
System Performance and Operational Criteria
6.1 OVERVIEW
The purpose of this chapter is to define the recommended performance and operational criteria for the City’s potable and recycled water distribution systems. For the potable water system, these criteria include recommendations for the required fire flow and flow duration, definitions of “emergency events”, and recommendations for surface water treatment capacity, system storage capacity (operational, fire flow, and emergency components), system pumping capacity, minimum and maximum system pressures, and maximum pipeline velocity and head loss. The recycled water system performance and operational criteria includes recommendations for recycled water treatment capacity, system storage capacity (seasonal and operational components), system pumping capacity, minimum and maximum system pressures, and maximum pipeline velocity and head loss.
The City currently uses the City Design Standards (dated February 2020) and City Standard Plans and Specifications (dated February 2020) for the planning and design of its potable and recycled water distribution systems. The City Design Standards and City Standard Plans and Specifications should be referenced for specific design information for water system facilities as applicable.
Key water system design criteria and operational standards from the City Design Standards and City Standard Plans and Specifications documents are incorporated into this chapter; however, additional explanation and discussion have been added to further describe various system recommendations. The following sections of this chapter present the recommended performance and operational criteria for the City’s potable and recycled water systems:
Potable Water System
• General Potable Water System Reliability and Recommendations • Fire Flow Requirements
• Potable Water System Capacity During High Demand Periods • Water Treatment Capacity
• Potable Water Storage Capacity
• Potable Water Pumping Facility Capacity
• Potable Water Critical Supply Facilities
• Potable Water Transmission and Distribution Pipeline Sizing and Recommended System Pressures
Recycled Water System
• Recycled Water Demand Condition Evaluation
• Recycled Water Treatment Capacity
• Recycled Water Storage Capacity
• Recycled Water Pumping Facility Capacity
• Recycled Water Transmission Pipeline Sizing and Recommended System Pressures Chapter 6
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6.2 POTABLE WATER SYSTEM
Components of the recommended performance and operational criteria for the City’s potable water system are discussed below.
6.2.1 General Potable Water System Reliability and Recommendations Attention to enhancing the reliability of the system under all conditions is an important part of maintaining high quality water service. Water system reliability is achieved thr ough a number of system features including : (1) appropriately sized storage facilities, (2) redundant or “firm” pumping, transmission, and treatment facilities where required, and (3) alternate power supplies.
Reliability and water quality are also improve d by designing looped water distribution pipelines and avoiding dead -end distribution mains whenever possible. Looping pipeline configurations reduces the potential for stagnant water and the associated problems of poor taste and low chlorine residuals. In addition, proper valve placement is also necessary to maintain reliable and flexible system operation under normal and abnormal operating conditions.
6.2.1.1 Water Quality Standards
Water quality standards largely pertain to protecting public health and consistently delivering a satisfactory product to the customer. The U.S. Environmental Protection Agency (EPA) and the State Water Resources Control Board Division of Drinking Water (DDW) are the agencies responsible for establishing water quality standards. The EPA and DDW prescribe regulations that limit the amount of certain contaminants in water provided by public water system s. The City, as water purveyor, is responsible for ensuring that the applicable water quality st andards and regulations are met at all times.
6.2.1.2 Recommendations for New Developments
Various policies to reduce water use and comply with water efficiency standards were recommended in Chapter 2 for future service areas and new developments within the City. These policies were recommended to assist the City with achieving its water conservation goals and maintaining the long -term sustainability of its water resources. As new developments are integrated into the City’s existing water system, the recommended policies discussed in Chapter 2 should be reviewed for compliance. In addition, proposed water system facilities located in the future service areas and new developments within the City should also meet the recommended system performance criteria ( e.g., minimum and maximum system pressures) discussed in the following sections and more specifically under Section 6.2.8 Potable Water Transmission and Distribution Pipeline Sizing and Recommended System Pressures.
6.2.2 Fire Flow Requirements
The City’s Public Works Department operates and maintains the water distribution system within the City, but the City’s Fire Department (Fire Department) is concerned with the availability of adequate water supply for firefighting purposes. Consequently, the Fire Department establi shes minimum water flows and residual system pressures during a fire fighting event that the City is responsible for providing from the potable water system.
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The Fire Department uses the California Fire Code (CFC) Table B150.1 Minimum Required Fire Flow and Flow Duration for Buildings , to assist them in establishing minimum fire flows and durations for individual structures. The recommended fire flow requirements for the City based on various land use designations are presented in Table 6-1. These fire flow requirements were developed based on discussions with the Fire Department’s Fire Marshal and will be used for the evaluation of the existing and future water system.
For planning purposes, the minimum fire flows identified in Table 6-1 are to be met concurrently with maximum day demand conditions while maintaining a minimum residual system pressure of 20 pounds per square inch (psi) throughout the water system. This criterion has been decreased from the 2012 WSMP, which used 30 psi as the minimum residual system pressure during a single fire flow event. For this Citywide Water System Master Plan, the criterion has been adjusted for consistency with the Fire Department’s requirements and typical industry standards.
For large pressure zones, the City’s water system should also have the capability to meet a system demand condition equal to the occurrence of a maximum day demand with two simultaneous fire flow events within that pressure zone while maintaining a minimum residual system pressure of 20 psi throughout the water system1. This conservative assumption of two simultaneous fire flow demands will help stress the City’s water system and determine if the water system can provide reliable service during high demand conditions. Additionally, as discussed in subsequent sections of this chapter, fire flows presented in Table 6-1 and their expected duration will also be used to establish the City’s storage capacity requirements.
1 It is assumed that these two fire flow events will consist of one smaller single family residential fire flow combined with another larger industrial fire flow.
Fire
Flow, gpm Duration, hours Recommended
Storage, MG Fire Flow, gpm Duration, hours Recomme
nded
Storag
e, MG(j
)
Sin
gle Family Residential(e) 1,500 2 0
.18 1,500 2 0.18
Mu
lti Family Residential(f) 2,500 2 0
.30 2,500 2 0.30
Commercial/Off
ice(g) 6,000 4 1
.44 3,500 (i) 4 0.72
Ind
ustrial 8,000 4 1.92 4,500 (i) 4 0.96
Ins
titutional(h) 8,000 4 1
.92 4,500 (i) 4 0.96
(i
) Fire flow includes a 500 gpm demand for on-site sprinkler flow. (j) Recommended storage volumes do not include volume associated with 500 gpm sprinkler flow. (b) Unique projects or projects with alternate materials may require higher fire flows and should be reviewed by the Fire Marshal on a case-by-case basis (e.g., proposed commercial/industrial areas and schools).
(c) Specific fire flows were determined from Table B105.1 of the 2016 CFC, and depend on construction type and fire flow calculation area. Refer to Section 903 of the 2016 CFC and Section 9.06.060 of the City of Tracy Municipal Code for automatic sprinkler system requirements. (d) As stated in the City of Tracy Design Standards (February 2020), the Fire Marshal normally allows up to a 50 percent reduction in fire flow if a building is provided with an automatic sprinkler system.
However, the CFC also requires that no fire flow be less than 1,000 gpm for single family residential or 1,500 gpm for all other building types. For a more conservative fire flow estimate, requirements for sprinklered Single Family and Multiple Family Residential buildings were not reduced for this Citywide Water Master Plan. (e) Single Family Residential includes Very Low and Low Density Residential land uses. (f) Multi Family Residential includes Medium, High, and Very High Density Residential land uses. (g) Commercial/Office includes Commercial, Office, Motel/Hotel and Mixed Use land uses.
Ta
ble 6-1. Recommended Fire Flow Requirements(a,b)
Non-Sprinklered(c
) Sp
rinklered(c
,d)
(a) C
onstruction type and fire flow calculation area are not generally known during the development of a master plan; consequently, fire flow requirements set forth in this table are based on previous estimates for these land use types and similar communities. (h) Institutional includes Medical, Public Facilities, School, Airport, Church, and Cemetery land uses.
Land Use
Designation
o\c\40
4\12-18-41\e\Ch6\Ch6 Tables
Last
Revised: 04-05-19
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6.2.3 Potable Water System Capacity During High Demand Periods Maximum day demand plus fire flow and peak hour demand conditions will be used to assess the adequacy of the City’s potable water system during high demand periods. Adopted peaking factors for maximum day and peak hour demands are discussed in Chapter 4. The following sections discuss the assumptions and recommended criteria for each demand condition.
6.2.3.1 Maximum Day Demand plus Fire Flow
In accordance with typical industry standards, the City’s water system should have the capability to meet a system demand condition equal to the occurrence of a maximum day demand concurrent with either one or two simultaneous fire flow event (s) while meeting the recommended system performance criteria ( e.g., minimum and maximum system pressures) discussed under Section 6.2.8 Potable Water Transmission a nd Distribution Pipeline Sizing and Recommended System Pressures.
Maximum day demand plus fire flow should be met from a combination of supply sources (i.e., treated surface water from the JJWTP and SSJID supplies plus groundwater) and treated water storage reservoirs. The analysis of specific fire flow evaluations will be conducted assuming the largest booster pump at each pump station is offline (i.e., firm booster pumping capacity). In addition, the City’s groundwater well system (well pumps) will be ass umed to pump at firm capacity (i.e., firm groundwater pumping capacity) during a specific fire flow evaluation. Firm groundwater pumping capacity assumes that 20 percent of the City’s groundwater wells will be out of service at any given time due to maintenance or operational issues.
These conservative assumptions ensure the reliability and flexibility of the system to provide sufficient flow during emergency fire flow conditions. It is also assumed that the pump stations with only one booster pump or without back -up power capability (either an on -site generator or adaptor for a plug-in generator) will not be available during an emergency fire flow analysis.
6.2.3.2 Peak Hour Demand
Peak hour demand should be met from a combination of supply sources (i.e., treated surface water from the JJWTP and SSJID supplies plus groundwater) and treated water storage reservo irs.
Assumptions regarding firm pumping capacity will also apply during a peak hour demand condition. During a peak hour demand condition, the City’s water system should be able to meet the recommended system performance criteria (e.g., minimum and maximum system pressures) discussed under Section 6.2.8 Potable Water Transmission and Distribution Pipeline Sizing and Recommended System Pressures.
6.2.4 Water Treatment Capacity
Sufficient water treatment capacity from a combination of the existing and/or expanded JJWTP, the City’s treated surface water supplies from SSJID, and groundwater wells should be available to meet the City’s maximum day demand condition. In addition, the City’s goal is to meet maximum day demands without relying on groundwater. S ufficient t reated water pumping capacity should also be available to assist in meeting a maximum day demand condition.
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6.2.5 Potable Water Storage Capacity
The total potable water storage capacity required will be based on the following three components within each pressure zone:
• Operational Storage
• Fire Storage
• Emergency Storage
A discussion of these three storage components, along with a discussion of “credits” for groundwater supply and treated surface water supply, follows.
6.2.5.1 Operational Storage
Over any 24-hour period, w ater demands will vary. Typically, higher water demands will occur during the early morning hours when people are irrigating landscape and getting ready to go to work or school. Water demands will then decline to some nominal baseline level (depending on the proximity to water use patterns of adjacent commercial/industrial areas), and will then begin to increase again depending on outside water needs (and corresponding temperature), until it reaches a higher water demand in the early evening hours as people return home from work or school. Throughout the year, the peaks of this cycle will vary according to customer needs; thereby, creating maximum day and peak hour demands.
Typically, water treatment plants, supply turnouts, and/or wells are operated at a constant rate over a 24-hour period (baseline) and augmented by additional flow from storage tanks, and/or wells during high demand periods, as needed. Storage tanks are normally refilled when demands drop below the baseline water production flow rate. The storage volume used to meet these peak demand periods is called operational storage.
The operational storage requirements should be calculated based on the diurnal demand in a particular pressure zone or service area. If sufficient data is not available to develop a diurnal demand, then the recommended volume of water to be held in reserve for operational storage should be at least equal to 30 percent of the total volume of water used on a maximum day demand condition.
6.2.5.2 Fire Storage
As discussed above, fire flow requirements are identified in the CFC. These requirements are based on flow (in gpm), size of building (in square feet), and type of construc tion (wood frame, metal, masonry, installation of sprinklers, etc.). After a fire flow requirement is established, it is multiplied by the required fire flow duration to produce an estimate of the total volume of fire flow storage required. Table 6-1 presents the recommended fire flow criteria and associated required fire flow storage.
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Sufficient fire flow storage should be available for the following simultaneous fire flow events in larger pressure zones (i.e., Zones 1 and 2):
• A Single Family Residential fire flow of 1,500 gpm for a duration of two hours. The resulting volume required for fire flow storage is 0.18 MG. • An Industrial fire flow of 4,000 gpm for a duration of four hours (if sprinklered). The resulting volume required for fire flow storage is 0.96 MG2.
If unavailable by gravity storage, the fire flow must be supplied with a National Fire Protection Association (NFPA) rated fire pump. If an NFPA rated fire pump is not used, then a pump(s) and motor(s) combination with a backup power source of sufficient capacity to meet the required maximum fire flow and minimum residual pressure requirements, as determined by the Fire Marshal, will be required.
6.2.5.3 Emergency Storage
A reserve of stored water is also required to meet demands during an emergency. An emergency is defined as an unforeseen or unplanned event that may degrade the quality or quantity of potable water supplies available to serve customers. There are three types of emergency events that a water utility typically prepares for:
• Minor emergency. A fairly routine, normal, or localized event that affects a few customers, such as a pipeline break, malfunctioning valve, hydrant break, or a brief power loss. Utilities plan for minor emergencies and typically have staff and materials available to correct them quickly.
• Major emergency. A disaster that affects an entire, and/or large, portion of a water system, lowers the quantity and quality of the water, or places the health and safety of the community at risk. Examples include water treatment plant failures, raw water contamination or major power grid outages. Water utilities infrequently experience major emergencies.
• Natural disaster. A disaster caused by natural forces or events that create water utility emergencies. Examples include earthquakes, forest or brush fires, hurricanes, tornados or high winds, floods, and other severe weather conditions such as freezing or drought that damage or cause water system facilities to not be able to operate.
Determination of the required volume of emergency storage is a policy decision based on the assessment of the risk of failures and the desired degree of system reliability. The amount of required emergency storage is a f unction of several factors including the diversity of the supply sources, redundancy and reliability of the production facilities, and the anticipated length of the emergency outage. In developing an emergency storage requirement for the City, typical industry standards were used.
2 Recommended storage does not include volume associated with 500 gpm sprinkler flow (refer to Table 6-1).
Assumes a 50 percent reduction in the required fire flow due to the installation of fire sprinklers.
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The American Water Works Association (AWWA) states that no formula exists for determining the amount of emergency storage required, and that the decision will be made by the utility based on a judgment about the perceived vulnerab ility of the system. For this Citywide Water System Master Plan, it has been assumed that the emergency storage requirement will be based on minor emergencies and specific major emergency criteria. The 2012 WSMP used an emergency storage volume requirement of two (2) times the average day demand. After reviewing emergency storage criteria for other similar water systems within the region, and taking into account the City’s redundant sources of supply (JJWTP, SSJID, and groundwater), it is recommended that the City reduce the minimum quantity of emergency storage volume required to 1.5 times the average day demand for this Citywide Water System Master Plan Update.
6.2.5.4 Groundwater Credit
Based on the City’s availa ble groundwater wells, groundwater storage can account for a portion of the recommended emergency storage. The following must be true to use the groundwater supply to offset the need to provide surface storage:
• Groundwater supply is of potable water quality and can be reliably accessed (i.e., wells are equipped with on-site emergency generators). • Groundwater supply is not already being relied upon to meet the City’s average day demand requirements.
• Sufficient water distribution facilities are available to distribute this water to demand areas.
It will be assumed that only the firm groundwater supply will be available for a groundwater credit to offset the City’s emergency storage requirement (i.e., 20 percent of wells could be out of service at any given time).
6.2.5.5 Treated Surface Water Supply Credit
Because the City currently has two independent sources of treated surface water supply (JJWTP and SSJID supplies), some quantity of treated surface water supply capacity can account for a portion of the City’s recommend ed emergency storage. For this Citywide Water System Master Plan, it will be assumed that the smaller of the treated surface water supply sources (SSJID) will be available to offset a portion of the emergency storage requirement. However, the following must be true to use treated surface water supply to offset the need to provide surface storage:
• Treated surface water supply can be reliably accessed (i.e., treated surface water supply facility is equipped with on-site emergency generator). • Sufficient treated surface water booster pumping facilities are available to distribute this water to demand areas.
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6.2.5.6 Total Storage Capacity Recommended
The City’s recommended potable water storage capacity should be the sum of the following components:
• Operational: Volume of water necessary to meet diurnal peaks observed throughout the day, assumed to be equivalent to at least 30 percent of the maximum day demand. • Fire Flow: Volume of water necessary to supply two simultaneous fire flow events in larger pressure zones (i.e., Zones 1 and 2).
• Emergency: Volume of water necessary to provide 1.5 times an average day demand. • Groundwater Credit: Equal to the firm groundwater supply that can be reliably accessed (facilities equipped with auxiliary power).
• Treated Surface Water Supply Credit: Equal to the smaller of the available treated surface water supply sources (SSJID).
It should be noted that the sum of groundwater and treated surface water supply credits cannot be greater than the recommended emergency storage volume. The amount of total system storage and system peaking capacity required to meet these criteria will change over time as the City continues to grow and potable water demands increase.
6.2.6 Potable Water Pumping Facility Capacity
Sufficient firm water system pumping capacity should be provided to meet the greater of the following two demand conditions within each pressure zone and any additional pressure zone(s), which are provided service from this particular pressure zone.
1. A maximum day demand with two simultaneous fire flow events in larger pressure zones (i.e., Zones 1 and 2 should assume one smaller single family residential fire flow combined with another larger industrial fire flow) with booster pumps and well pumps assumed to operate at firm pumping capacity.
2. A peak hour demand with booster pumps and well pumps assumed to operate at firm pumping capacity.
The highest demand requirement between these two demand conditions sets the water system pumping capacity requirement. However, sufficient pumping capacity should also be provided so that the maximum day demand within each pressure zone can be supplied using firm pumping capacity with no assistance from storage reservoirs.
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6.2.7 Potable Water Critical Supply Facilities
Critical pumping facilities are defined as those facilities that provide service to pressure zone(s) and/or service area(s) which do not have sufficient emergency storage available (see Section 6.2.5.3 Emergency Storage) and that meet the following criteria:
• The largest pumping facility that provides water to a particular pressure zone and/or service area.
• A facility that provides the sole source of water to single or multiple pressure zones and/or service areas.
• A pumping facility that provides water from a supply turnout. • A pumping facility that provides water from key groundwater supply wells (depends on capacity, quality and location).
All critical pumping facilities should be equipped with an on-site, back-up power generator. At less critical facilities, a plug-in adapter will be u sed to allow interconnection to a portable generator, which will be brought to the site by City staff during a prolonged power outage. In addition, portable generator booster connections will be configured at all tank/booster pump locations.
The City shou ld also consider the following policies to make operations of the City’s pumping facilities more efficient:
• Install solar power systems, or alternative power sources, at existing and new pump stations and other water system facilities, as feasible, to reduce electrical power consumption.
• Increase the frequency of routine O&M activities for existing pump stations and wells to maintain pump efficiencies and reduce power demands.
6.2.8 Potable Water Transmission and Distribution Pipeline Sizing and Recommended System Pressures
The following criteria will be used as guidelines for sizing new transmission and distribution pipelines. However, the City’s existing system will be evaluated on a case –by-case basis. For example, if an existing pipeline experiences head loss in excess of the criteria described below during a maximum day plus fire flow event, this condition, by itself, does not necessarily indicate a deficiency as long as the minimum system pressure criterion is satisfied.
Consequently, the City’s existing system will be evaluated using pressure as the primary criterion; and secondary criteria, such as pipeline velocity, head loss, age, and material type, will be used as indicators to locate where water system improvements may be needed.
New transmission and d istribution pipelines to serve the City’s future service areas should be located within designated utility corridors wherever possible. These designated utility corridors should be within public rights -of-way to minimize or eliminate the need for utility e asements within private property.
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6.2.8.1 Potable Water Transmission System
Transmission pipelines are generally 18-inches in diameter or larger and should be designed based on the criteria described below for average day, maximum day, and peak hour demand conditions.
The criteria reflect industry standards and West Yost’s experience working with the City’s existing water system.
• Average Day Demand
— Pressures should be maintained between a maximum of 100 psi3 and a minimum of 40 psi.
— Maximum velocity within transmission pipelines should be 3 fps. — Head losses within the transmission system pipelines should be limited to 3 feet per thousand feet (ft/kft) of pipeline.
• Maximum Day Demand
— Pressures should be maintained between a maximum of 100 psi4 and a minimum of 40 psi.
— The maximum velocity within the transmission system pipelines should be 6 fps. — Head losses within the transmission system pipelines should be limited to 3 ft/kft of pipeline.
• Peak Hour Demand
— Pressures should be maintained between a maximum of 100 psi4 and a minimum of 40 psi.
— The maximum velocity within the transmission system pipelines should be 6 fps — Head losses within the transmission system pipelines should be limited to 3 ft/kft of pipeline.
6.2.8.2 Potable Water Distribution System
Distribution pipelines are generally less than 18-inches in diameter and should be sized based on the criteria described below for average day, maximum day plus fire flow, and peak hour demand conditions. The criteria reflect industry standards and West Yost’s experience workin g with the City’s existing water system.
• Average Day Demand
— Service pressures should be maintained between a maximum of 80 psi4 and a minimum of 40 psi.
— The maximum velocity within the distribution system pipelines should be 6 fps.
3 A pressure reducing valve will be required on all water services with a static pressure greater than 80 psi. 4 A pressure reducing valve will be required on all water services with a static pressure greater than 80 psi.
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System Performance and Operational Criteria
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— Head losses within the distribution system pipelines should be limited to 7 ft/kft of pipeline
• Maximum Day Demand plus Fire Flow
— The minimum allowable residual pressure should be 20 psi at the flowing fire hydrant during the occurrence of a single fire flow event for smaller pressure zones.
— The minimum allowable residual pressure should be 20 psi at the flowing fire hydrants during the occurrence of two simultaneous fire flow events for larger pressure zones.
— The maximum velocity within the distribution system pipelines should be 12 fps, or the head losses within the distribution system pipelines should be limited to 10 ft/kft of pipeline, whichever criteria is more conservative given the specific hydraulic/system condition.
• Peak Hour Demand
— Service pressures should be maintained between a maximum of 80 psi5 and a minimum of 40 psi.
— The maximum velocity within the distribution system pipelines should be 8 fps, or the head losses within the distribution system pipelines should be limited to 7 ft/kft of pipeline, whichever criteria is more conservative given the specific hydraulic/system condition.
A summary of the recommended potable water system performance and operational criteria is presented in Table 6-2 and reflect typical water system industry standards including the California Safe Drinking Water Act and related laws, and AWWA standards.
5 A pressure reducing valve will be required on all water services with a static pressure greater than 80 psi.
Table
6-2. Summary of Recommended Potable Water System Performance and Operational Criteria Component C
riteria Remarks / Issues
Fire Flow Requirements (flow [gpm] @ duration [hours])
Single Family Residential 1,500 gpm @ 2 hrs
Existing development will be evaluated on case-by-case
basis because of the historical varying standard.
Multi Family Residential 2,500 gpm @ 2 hrs
Comm
ercial/Office 3,500 gpm
@ 4 hrs (with approved automatic sprinkler system)
Industrial 4,500 gpm
@ 4 hrs (with approved automatic sprinkler system)
Instit
utional 4,500 gpm
@ 4 hrs (with approved automatic sprinkler system)
Water
System Capacity
Maximum Day Demand plus Fire Flow Provide firm capacity equal to maximum day demand plus fire flow Assume two simultaneous fire flow events in larger
pressure z
ones (i.e., Zones 1 and 2).
Peak H
our Demand Provide f
irm capacity equal to peak hour demand
Water
Treatment Capacity
Treated
Water Supply Capacity Provide c
apacity equal to maximum day demand --
Treated
Surface Water Supply Capacity Provide c
apacity equal to maximum month demand --
Treated
Water Pumping Capacity Provide c
apacity equal to maximum day demand --
Water
Storage Capacity
Operational 30 percent
of maximum day demand
Fire Ass
ume one Single Family Residential fire flow concurrent with a larger Industrial fire flow in larger pressure zones (i.e., Zones 1 and 2) 1,500 gpm @ 2 hrs = 0.18 MG
2,500 gpm @ 2 hrs = 0.30 MG
3,000 gpm @ 4 hrs = 0.72 MG
4,000 gpm @ 4 hrs = 0.96 MG
Emergency 1.5 x
average day demand --
Groundwater
Credit (GWC) Equal to t
he firm groundwater supply that can be reliably accessed (facilities equipped w
ith auxiliary power) The m
aximum combined emergency storage credit is equal
to the recommended emergency storage capacity.Treated Surface Water Credit (TSWC) Equal to the smaller of the available treated surface water supply sources Total Water Storage Capacity Operational + Fire + Emergency - GWC - TSWC If pos sible, total storage should be evaluated by pressure
zone.
Pumping F
acility Capacity
Pumping Capacity
Provide the greater of maximum day with two concurrent fire flows in larger pressure zones (i.e., Zones 1 and 2) or peak hour demand within each pressure zone
Assume
firm pumping capacity. Sufficient pumping capacity
should also
be provided so that the maximum day demand
can be supplied using firm pumping capacity with no
assistance from storage reservoirs.
Backup Pow
er Equal to the firm capacity of the pumping facility On-site generator for critical stations.(a)
Plug-in portable generator f
or less critical stations.
Water
Transmission Line Sizing
Diameter 18-inches in diameter or larger Locate new
transmission pipelines within designated utility
corridors w
herever possible.
Average Day
Demand Condition --
Criteria
based on requirements for new development,
existing transmission mains will be evaluated on case-by- case basis. Evaluation will include review of age, material type, velocity, head loss, and/or pressure.
Minimum
Pressure [psi] 40 psi
Maximum Pres
sure [psi] 100 psi
Maximum Head los
s [ft/kft] 3 ft/
kft
Maximum Veloc
ity [fps] 3 fps
Maximum Day
Demand Condition --
Minimum
Pressure [psi] 40 psi
Maximum Head los
s [ft/kft] 3 ft/
kft
Maximum Veloc
ity [fps] 6 fps
Peak H
our Demand Condition --
Minimum
Pressure [psi] 40 psi
Maximum Head los
s [ft/kft] 3 ft/
kft
Maximum Veloc
ity [fps] 6 fps
Haz
en Williams "C" Factor 130 For c
onsistency in hydraulic modeling.Pipeline Material Duct ile Iron
Water
Distribution Line Sizing
Diameter Less than 18-inches in diameter
Must
verify pipeline size with maximum day plus fire flow
analysis. Locate new distribution pipelines within
designated ut
ility corridors wherever possible.
Average Day
Demand Condition --
Criteria
based on requirements for new development,
existing distribution mains will be evaluated on case-by- case basis. Evaluation will include review of age, material type, velocity, head loss, and/or pressure.
Minimum
Pressure [psi] 40 psi
Maximum Pres
sure [psi] 80 psi
Maximum Head los
s [ft/kft] 7 ft/
kft
Maximum Veloc
ity [fps] 6 fps
Maximum Day
w/ Fire Flow Demand Condition --
Minimum
Pressure [psi] 20 psi f
or a single fire flow event in smaller pressure zones; 20 psi for two simultaneous
fire flow events in larger pressure zones
Maximum Head los
s [ft/kft] 10 ft/
kft
Maximum Veloc
ity [fps] 12 fps
Peak H
our Demand Condition --
Minimum
Pressure [psi] 40 psi
Maximum Head los
s [ft/kft] 7 ft/
kft
Maximum Veloc
ity [fps] 8 fps
Minimum
Pipeline Diameter -- --
General 8-inches --
Industrial 12-inches --
Dist
ribution to cul-de-sac / dead-end street 6-inches Permanent dead end runs shall be no longer that 250 feet
unless in
a cul-de-sac.
Dist
ribution to fire hydrants 8-inches --
Haz
en Williams "C" Factor 130 For c
onsistency in hydraulic modeling.Pipeline Material Duct ile Iron
Maximum W
ater Service Pressure 80 psi Install
PRV if service pressure is greater than 80 psi.
(a) A
pumping facility is defined as critical if it provides service to pressure zone(s) and/or service area(s) which do not have sufficient emergency storage, and that meet the following criteria:
• The largest facility that provides water to a particular pressure zone and/or service area; • A facility that provides the sole source of water to single or multiple pressure zones and/or service areas; • A facility that provides water from a supply turnout; or • A facility that provides water from key groundwater supply wells (depends on capacity, quality and location). o\c\404\1
2-18-41\e\Ch6\Ch6 Tables
Last Revised: 04-05-19
City o
f Tracy
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System Performance and Operational Criteria
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6.3 RECYCLED WATER SYSTEM
Components of the recommended performance and operational criteria for the City’s backbone recycled water system are discussed below.
6.3.1 Recycled Water Demand Condition Evaluation
A peak hour demand condition during an 8 -hour irrigation period will be used to assess the adequacy of the City’s recycled water system.
6.3.2 Recycled Water Treatment Capacity
Sufficient recycled water treatment capacity should be available to meet the City’s maximum day recycled water demand condition.
6.3.3 Recycled Water Storage Capacity
The total recycled water storage capacity required will be based on the following components:
• Seasonal Storage
• Operational Storage
A discussion of these two storage components follows.
6.3.3.1 Seasonal Storage
As described in Chapter 4, landscape irrigation demands are highest during the summer months (when plant evapotranspiration rates are high) and very low during the winter months. Demand for recycled water supplies to meet these seasonally varying demands w ill also vary month to month, depending on the specific climatic conditions that are occurring. Therefore, some seasonal storage may have to be provided to store recycled wastewater generated during low irrigation demand periods for use during the high sum mer demand periods. The actual quantity of seasonal storage required, if any, will be determined using an annual water balance between total recycled water supply available and the total seasonal recycled water demand.
6.3.3.2 Operational Storage
Sufficient operational storage should be provided to supply the demands of an eight-hour irrigation period during a maximum summer month demand condition, with a 10 percent demand increase occurring for one hour (i.e., peak hour) during the irrigation period. Due to concer ns about water quality, it is recommended that this operational storage be entirely stored within an enclosed reservoir or tank system to limit exposure to potential contaminant sources after treatment, but before distribution and direct use.
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6.3.3.3 Total Storage Capacity
The City’s recommended recycled water storage capacity should be the sum of the following components:
• Seasonal: Volume of recycled water necessary to balance the required annual recycled water demands with the annual recycled water supply available. • Operational: Volume of recycled water necessary to supply the demands of an eight-hour irrigation period during a maximum summer month demand condition, with a 10 percent demand increase occurring for one hour.
The amount of total system storage and system peaking capacity required to meet these criteria will change over time as the City continues to grow and recycled water demands increase.
6.3.4 Recycled Water Pumping Facility Capacity
Sufficient pumping capacity sh ould be provided to meet the City’s peak hour recycled water demand condition within each pressure zone and any additional pressure zone(s), which are provided service from this particular pressure zone.
6.3.5 Recycled Water Transmission Pipeline Sizing and Recommended System Pressures Backbone recycled water system transmission pipelines are generally 16-inches in diameter or larger and should be designed based on the criteria described below for a peak hour demand condition. • Peak Hour Demand
— Service pressures should be maintained between a maximum of 100 psi and a minimum of 60 psi.
— The maximum velocity within the transmission system pipelines should be 10 fps; however, a pipeline velocity of 6 fps is desirable.
A summary of the recommended recycled water system performance and operational criteria is presented in Table 6-3.
Table
6-3. Summary of Recommended Recycled Water System Performance and Operational Criteria Component Criter
ia Remarks / Issues
Demand Condition Evaluation
Peak Hour Demand Provide cap
acity equal to peak hour demand
during an
8-hour irrigation period --
Recycled W
ater Treatment Capacity
Recycled W
ater Treatment Capacity Provide cap
acity equal to a maximum day demand --
Recycled W
ater Storage Capacity
Seasonal Equal to volume
required to balance the annual demands with
the annua
l supply available --
Operationa
l
Equal to volume
required to supply the demands of an eight-
hour irrigation period during a maximum summer month with a 10 perce
nt demand increase occurring for one hour
--
Total W
ater Storage Capacity Seasonal + Oper
ational --
Pumping Facility
Capacity
Pumping Capacity Provide cap
acity equal to peak hour demand within each
pressure
zone Firm p
umping capacity will not be required.
Recycled Water Transmission Line Sizing
Diameter 16-inches in d
iameter or larger --
Peak Hour Deman
d Condition -- --
Minimum
Pressure [psi] 60 psi --
Maximum
Pressure [psi] 100 psi --
Maximum
Velocity [fps] 10 fps Pipeline v
elocity of 6 fps is desirable.
Hazen Williams "C" Factor 130 For co
nsistency in hydraulic modeling.Pipeline M
aterial C-900 PV
C
o\c4
04\12-18-41\e\Ch6\Ch6 Tables
Last Revised: 04-05-19
City of Tracy
Citywide Water Sys
tem
Master Plan Update
7-1 City of Tracy
May 2023 Citywide Water System
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CHAPTER 7
Existing Potable Water System Evaluation
7.1 OVERVIEW
The purpose of this chapter is to first describe the City’s existing potable water distribution system, including the corresponding hydraulic model update. Existing water system information was updated through the review of previous reports, maps, plans, record drawings, operation records, GIS files, and other available data provided to West Yost by City staff. Using this information, the City’s current hydraulic model was then updated to represent the existing potable water system.
The remainder of the chapter presents an evaluation of the City’s existing potable water distribution system and its ability to meet the recommended performance and operational criteria (previously described in Chapter 6) und er existing water demand conditions. The evaluation includes an analysis of water storage capacity, pumping capacity, and the existing water system’s ability to meet recommended water system performance and operational criteria under peak hour demand and maximum day demand plus fire flow scenarios. This evaluation does not include a condition assessment of the City’s existing water system assets and does not cover replacement of existing infrastructure due to age or physical deterioration.
Evaluations, findings, and recommendations for addressing any deficiencies identified within the existing potable water distribution system are included. Recommendations were used to develop a Capital Improvement Program (CIP), which includes an estimate of probable constr uction costs.
The recommended existing potable water system CIP is described further in Chapter 10.
The following sections of this chapter describe the components of the City’s existing potable water distribution system evaluation:
• Description of Existing Potable Water System Facilities • Hydraulic Model Update
• Existing Potable Water System Evaluation
• Summary of Recommended Existing Potable Water System Improvements
7.2 DESCRIPTION OF EXISTING POTABLE WATER SYSTEM FACILITIES This section provides a summary of the City’s existing potable water system facilities. The City’s existing potable water system facilities are located throughout the water service area as shown on Figure 7-1. Additional details regarding each facility are presented below.
7.2.1 John Jones Water Treatment Plant
The City’s JJWTP is located just north of the DMC in the southern portion of the City as shown on Figure 7-1. The JJWTP was originally constructed in 1979, expanded in 1988, and then expanded again in 2008. It currently has a treatment capacity of 30 mgd.
0 5,5002,750
Scale in Feet
Figure 7-1
Existing Potable Water
System Facilities
City of Tracy
Water System Master Plan Update
Last Saved: 3/18/2020 1:23:40 PM N:\Clients\404 Tracy\12-18-41 Water Master Plan Update\GIS\MXD\Report Figures\Fig 7-1_Existing Potable System.mxd : nhoman Notes:
1. All facilities included in the existing system hydraulic model are shown. Not all existing facilities were
included in the model. See Section 7.3.2 for details.
2. Pressure Zones represent the approximate boundaries after the IPC zone split is implemented.
3. The City's hydraulic model is not an all pipes model.
Some pipes which are not hydraulically significant were excluded from the model.
4. Lewis Manor Well is currently inactive.
Symbology
Pressure Regulating Station
Booster Pump Station
Groundwater Well
Storage Tank
John Jones Water Treatment Plant
Pipeline Diameter
Less than 18-inches
Greater than or equal to 18-inches
Pressure Zone
Zone 1
Zone 2
Zone 3 (IPC/PPBP)
Ellis Reduced Zone
City Limits
1234
5 6
Park and Ride
Ball Park
Lincoln
Lewis Manor
Well 8
Wells 1-4
Patterson Pass BPS
Linne Tank and BPS
NEI Tank and BPS
Mossdale BPS (SSJID
Treated Surface Water)
Z1, Z2, and
Z3 BPS
Promontory
PRS
Cordes Tank, BPS,
and PRS
580
205
205
580
5 5
33 SCHULTE RD
SCHULTE RD
ELEVENTH ST
CORRAL HOLLOW RD
M
AC
ARTHUR
DR
BYRON RD
AHERN RD
GRANT LINE RDHANSEN RD
VALPICO RD
BIRD RD
LOVELY RD
KOSTER RD
LINNE RD
HOLLY DR
BETHANY RD
MIDDLE RD
KASSON
RD
VON SOSTEN RD
DURHAM FERRY RD
TRACY BL
MOUNTAIN HOUSE PK
BANTA RD
LAMMERS RD NAGLEE RD
CHRISMAN RD
REEVE RD
O
l d Ri ver
S
a
n
Jo
aq
ui n
Ri
v
e
r
C
al if orni a
Aq ue du c t
Del t a - M e n d o t a C a n a l
Chapter 7
Existing Potable Water System Evaluation
7-3 City of Tracy
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The most recent expansion added treatment through granulated activated carbon and ultraviolet light disinfection. Granulated activated carbon removes dissolved organic compounds contained in the water, and ultraviolet light disinfection provides an additional level of treatment. Several new process upgrades including new flocculation/se dimentation basins, washwater basins, and chemical addition facilities were also added during the expansion. The site plan, process schematic, and hydraulic profile from the JJWTP Expansion Project is provided in Appendix B.
The City operates three surface water intake pumps at the JJWTP with the capacity to pump a total of approximately 27 mgd of raw surface water from the DMC to the JJWTP for treatment. The key characteristics of the existing surface water intake pumps are summarized in Table 7-1.
Table 7-1. Existing Surface Water Intake Pumps(a)
Intake
Pump Name Year Installed
Production
Capacity, mgd Pump Type
Motor
Horsepower Motor Type
Pump No. 1 2008 14(b) Vertical Turbine 150 VFD(c)
Pump No. 2 2008 14(b) Vertical Turbine 150 VFD(c)
Pump No. 3 2008 14(b) Vertical Turbine 150 VFD(c)
(a) Source: JJWTP Expansion Project, Sheet G-8 (Carollo Engineers). (b) Intake pumps were designed for 15 mgd. However, testing of the installed pumps determined that the actual production capacity of each pump is 14 mgd. In addition, due to the hydraulics of the JJWTP intake, the maximum intake pumping capacity with all three pumps running is 27 mgd.
(c) Variable Frequency Drive.
7.2.2 South County Water Supply Project
The City, in partnership with the cities of Manteca, Lathrop and Escalon, and SSJID, constructed a new surface water treatment plant near Woodward Reservoir in Stanislaus County and new transmission pipelines to deliver treated surface water to each city. The City’s treated surface water allocation from the SCWSP is 17 mgd of treatment capacity and 11,120 af/yr of water supply.
Treated surface water from the surface water treatment plant located near Woodward Reservoir is conveyed to the City through a dedicated 36-inch diameter transmission main and pumped to the City by the Mossdale Pump Station located at the intersection of Manthey and Stewart Roads (see Figure 7-1). Water pumped from the Mossdale Pump Station first fills the City’s Linne and NEI storage tanks through 18-inch and 30-inch diameter transmission mains before being pumped into the City’s distribution system to serve system demands. The Mossdale Pump Station is operated by SSJID.
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Existing Potable Water System Evaluation
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7.2.3 Groundwater Wells
The City currently has eight groundwater production wells that provide the City’s potable water system with groundwater supply. Currently, the Lewis Manor Well is inactive due to high levels of manganese. As discussed in Chapter 5, a ninth well, Well 8, was constructed in 2004 to be used for the City’s ASR Program, but can also be used as an extraction well to serve water demands directly under normal and/or emergency conditions.
The groundwater wells located at the JJWTP (Wells 1-4) pump directly into the Chlorine Contact Basin or Clearw ell #2, where the groundwater is blended with the finished surface water and chlorinated prior to distribution. Groundwater from the other remaining wells located in Zone 1 is chlorinated at each well site and pumped directly into the distribution system.
The locations of these existing groundwater wells are shown on Figure 7-1. Table 7-2 presents a summary of these existing groundwater well facilities with key characteristics such as design capacity and age.
Well Name/Number
Well Location/Address Year Drilled
Total Well Depth
(Casing Depth), ft
Casing
Diameter,
inches
Depth
of Perforated
Zone, ft(a)
Design
Capacity,
gpm
Production
Capacity, mgd
450-550
580-980
Well 2 JJWTP 1989 990 (870) 16” 420-850 2,000 2.9
Well 3 JJWTP 1989 1,020 (900) 16” 420-890 2,000 2.9
Well 4 JJWTP 1989 1,020 (950) 16” 380-940 2,000 2.9
Lincoln Well Lincoln Park 1990 1,000 (1,000) 16” 490-980 2,500 3.6 410-480
601-630
650-670
805-830
900-930
965-990
550-598
610-636
656-678
738-754
774-796
966-982
1,014-1,122
1,176-1,196
550-598
570-732
850-874
370-460
510-640
680-820
1,015 (1,000) 18” 2,500 3.6
Well 7
(Ball Park Well)
2001 Bessie Avenue
(east of Tracy Boulevard south of
Grant Line Road)
2002 1,070 (894) 18” 2,500
Well 1
Well 6
(Park& Ride Well)
Well 5
(b)
(Lewis
Manor Well)
(Currently Inactive)
902 Twelfth Street (north of Eleventh
Street between Tracy Boulevard and
Corral Hollow Road)
2000
Table 7‑2. Existi
ng Groundwater Wells
JJWTP 2.21,50016”1,010 (1,000)1986
3.6 2650 North Naglee Road (North of
I-205 adjacent to West Valley Mall) 2001/02 1,250 (1,216) 18” 2,000 2.9 (a)
Source: GEI Consultants, Summary of Groundwater Conditions November 2007 through November 2008, dated January 23, 2009. (b) Well is currently inactive due to high manganese levels. (c) Well 8 can be operated as an injection/extraction well as part of the City’s ASR Program.
3.6Well 8(c) Tracy Boulev
ard and Sixth Street 2004 850 (850) 18” 2,500
o\c\
404\12-18-41\engr\Ch7\Ch 7 Tables\Table 7-2
Last Revised: 01-31-20
City of Tracy
Citywide Water Sy
stem
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Chapter 7
Existing Potable Water System Evaluation
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7.2.4 Water Storage Facilities
The City currently operates five treated water storage reservoirs (two clearwells and three storage tanks). Table 7-3 presents a summary of these existing storage facilities with key characteristics such as storage capacity and age. As shown, the City currently has a total potable water storage capacity of approximately 16.2 MG. However, Clearwell #1 operates as a chlorine contact basin and cannot be counted as system storage capacity. Therefore, the total available potable water storage capacity is reduced to approximately 15.5 MG. The locations of the City’s three storage tanks are shown on Figure 7-1 (the two clearwells are located at the JJWTP).
Table 7-3. Existing Treated Water Storage Facilities
Storage Facility
Name Storage Type Material Year Constructed
Storage Capacity,
MG
Clearwells
#1(a) Partially Buried Tank -- 1978 0.66
#2(b) Partially Buried Tank -- 1987 4.0
Storage Tanks
Linne Fully Buried Tank Concrete 2005 7.1
NEI Partially Buried Tank Concrete 2002 2.4
Cordes Partially Buried Tank Concrete 2015(c) 2.0
Total Storage Capacity, MG 16.2
Total Available Storage Capacity, MG 15.5(d)
(a) Clearwell #1 has a design capacity of 1.0 MG, but it has been reduced to 0.66 MG due to the weir within Clearwell #1.
Also known as the Chlorine Contact Basin.
(b) Clearwell #2 has a design capacity of 5.6 MG, but it has been reduced to 4.0 MG due to the weir within Clearwell #1. (c) Although it was constructed in 2015, the Cordes Tank was not put into service until November 2019. (d) Does not include Clearwell #1 as it is operated as a Chlorine Contact Basin and cannot be counted as system storage capacity.
7.2.5 Booster Pump Stations
The City currently has eight booster pump stations.1 The locations of these existing booster pump stations are shown on Figure 7-1 (Zone 1, Zone 2, and Zone 3 booster pump stations are located at the JJWTP). Table 7-4 presents a summary of the existing booster pump stations with key characteristics such as design capacity and number of booster pumps.
The booster pumps located at the JJWTP pump treated surface water supply (from USBR) stored in Clearwell #2 into the City’s potable water system. The booster pumps located at the Linne and NEI storage tanks pump treated surface wat er supply (from SSJID) stored in their respective storage tanks into the City’s potable water system. The Cordes Booster Pump Station (BPS) pumps treated surface water supply from the Cordes Tank and serves customers located in the PPBP and the IPC development.
1 The Patterson Pass Booster Pump Station is inactive since the Cordes Booster Pump Station is now operating. The Zone 4 Booster Pump Station is operational, but is not included in the existing system evaluation because Zone 4 has just started development.
Boost
er Pump Station
Name Lo
cation Year Installed
Pump 1
,
gpm
Pump 2
,
gpm
Pump 3
,
gpm
Pump 4
,
gpm
Pump 5
,
gpm
Pump 6
,
gpm
Rated Ca
pacity(a),
gpm Fir
m Capacity(b), gpm
Firm Capacity(b), mgd
Zon
e 1(c) JJW
TP 2000 12,000 12,000 24,000 12,000 17.3
Zone 2(c) JJW
TP 1987 3,300 6,700 6,700 3,300 20,000 13,300 19.2
Zone 3 JJWTP 2018 2,600 2,600 370 5,570 2,970 4.3
Zone 4(d) JJW
TP 2018 1,225 1,225 1,225 --(e) 3,675 2,4
50 3.5
Linne(c) Linn
e Tank 2005 4,865 4,865 4,865 4,865 19,460 14,595 21.0
NEI(c) NEI Tan
k 2001 1,400 1,400 1,400 1,400 5,600 4,200 6.0
Patterson Pass(c,f) Schul
te Road, west of Hansen Road 2010 1,000 1,000 1,000 1,000 4,000 3,000 4.3 Cordes(c) Cordes
Tank 2015(g) 675 67
5 1,600 1,600 1,600 1,600 7,750 6,150 8.9
Table 7‑4. Existing Bo
oster Pump Stations
(g)
Although it was installed in 2015, the Cordes BPS was not put into service until November 2019. (a) Maximum pumping capacity of entire pump station.
(b) Assumes that the largest booster pump at the pump station is offline. (c) Pumps are equipped with variable frequency drives. (d) Existing potable water system infrastructure for Zone 4 is not shown on Chapter 7 figures because Zone 4 has just started development and was not included in the existing system evaluation. (e) The City plans to add a fourth 1,225 gpm pump to the Zone 4 BPS in the future. (f) Patterson Pass BPS is currently on standby and will eventually be decommissioned. o\c\404\12-18-
41\engr\Ch7\Ch 7 Tables\Table 7-4
Last Revised: 12-03-19
City o
f Tracy
Citywide Water System
Master Plan Update
Chapter 7
Existing Potable Water System Evaluation
7-8 City of Tracy
May 2023 Citywide Water System
n\c\404\12-18-41\wp\R-404-WMPU Master Plan Update
7.2.6 Pressure Regulating Stations
The City currently has ten pressure regulating stations (PRS) and two pressure reducing valves (PRV) as shown on Figure 7-1 (Zone 4 PRS and Northington Drive PRV are not shown because the areas served by these facilities have just started development). All of the PRS except the Cordes PRS and Promontory Parkway PRS are currently active. Once the IPC zone split occurs (see Section 7.2.7), these two PRS will be placed into service. The IPC zone spl it will permanently convert several of the existing buildings in the IPC development to be served directly from Zone 2 (these buildings are currently served by Zone 3 in the interim).
Each PRS contains a valve which is used to regulate flow into the downst ream pressure zone or sustain pressure within the upstream pressure zone depending on the system pressures within each pressure zone. Each PRS can operate in two different modes:
• Pressure Sustaining Valve (PSV) – The valve will maintain a specified pressure in the upstream pressure zone. If the pressure increases above the valve’s set point, the valve will open and release water into the downstream pressure zone. • Pressure Reducing Valve (PRV) – The valve will allow flow into the downstream pressure zone if the pressure in the downstream pressure zone falls below a specified set point. When the pressure is below the valve’s set point, the valve will remain open until the pressure increases.
Although the stations can operate in two different ways, most stations primarily operate in one of the two modes. The primary function of PRS #1 – #6, the Summit Drive PRS, and the Zone 4 PRS is that of a PSV, while the primary function of the Cordes PRS and the Promontory Parkway PRS will be that of a PRV. The two PRVs (Summit Drive and Northington Drive) can only operate in the pressure reducing mode. Table 7-5 presents a summary of these existing pressure regulating stations and pressure reducing valves with key characteristics such as upstream and downstream pressure zones, valve size, and pressure setting.
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Table 7-5. Existing Pressure Regulating Stations and Pressure Reducing Valves Facility Name
Upstream
Pressure Zone
Downstream
Pressure
Zone
Valve Size,
inches
Elevation,
ft
Pressure Setting
(upstream/
downstream), psi
Pressure Regulating Station
#1 Zone 2 Zone 1 12 63.67 83/56
#2 Zone 2 Zone 1 8 66.57 79/53
#3 Zone 2 Zone 1 6 71.19 78/52
#4 Zone 2 Zone 1 10 64.53 80/54
#5 Zone 2 Zone 1 12 68.29 79/53
#6 Zone 2 Zone 1 12 69.0 78/54
Summit Drive Zone 3 Zone 2 10 160.0 100/60
Cordes(a) Zone 3 Zone 2 16 147.8 76/36
Promontory
Parkway(a) Zone 3 Zone 2 12 149.0 75.5/35.5
Zone 4(b) Zone 4 Zone 3 8 204.5 105/90
Pressure Reducing Valve
Summit Drive Zone 3
Ellis
Reduced
Zone
12 160.0 --/70
Northington Drive(c) Zone 3
Ellis
Reduced
Zone
12 164.0 --/70
(a) Cordes PRS and Promontory Parkway PRS are currently inactive. They will be placed into service when the IPC zone split occurs.
(b) Existing potable water system infrastructure for Zone 4 is not shown on Chapter 7 figures because Zone 4 has just started development and was not included in the existing system evaluation. (c) Northington Drive PRV is not shown on Chapter 7 figures because it was not included in the existing system evaluation.
7.2.7 Pressure Zone Boundaries
The City’s existing potable water system consists of four interconnected pressure zones (Zone 1, Zone 2, Zone 3, and Ellis Reduced Zone) which are isolated from each other by pressure regulating stations, pressure reducing valves, and closed system valves. Zone 3 (previously called City-Side Zone 3) is currently split into two isolated portions: one which serves the Ellis Reduced Zone, and one which serves the International Park of Commerce and the Patterson Pass Business Park (Zone 3 - IPC/PPBP). A fifth pressure zone, Zone 4 (previously called Tracy Hills Zone 3 ), has just started development and is therefore not included in this existing system evaluation. Note that documents produced prior to this WSMP Update refer to these pressure zones using the old nomenclature.
Zone 1 extends from the northern City limits south to Schulte Road and is the most developed of the four pressure zones. Therefore, it has more transmission pipelines to convey water throughout the zone. Zone 1 is primarily served from the 36 -inch diameter transmission main in Tracy Boulevard either by gravity or via the Zone 1 BPS, and from the NEI Tank and BPS located Chapter 7
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at the eastern edge of Zone 1. There are also two major water transmission mains located on the east and west sides of Zone 1 which help distribute water to the lower elevations of the zone: an 18-inch diameter transmission main in Corral Hollow Road and a 20 -inch diameter transmission main in MacArthur Drive. During periods of peak demand or in an emergency, Zone 1 can also be served by the five groundwater wells located within Zone 1 or by Zone 2 facilities via PRS #1-#6.
Zone 2 extends from Schulte Road south to Linne Road and is mostly comprised of residential and light industrial land use. Water demands in Zone 2 are primarily served by the 24 -inch diameter transmission main in Corral Hollow Road, which extends from the Zone 2 BPS at the JJWTP north and west towards Patterson Pass BPS and the IPC, and by the Linne Tank and BPS.
The Ellis Reduced Zone currently consists of the Ellis Specific Plan development located south of Valpico Road and west of Corral Hollow Road. The Ellis Reduced Zone is served by the 20-inch diameter Zone 3 transmission main in Corral Hollow Road which extends from the Zone 3 BPS at the JJWTP to the intersection of Middlefield Drive and Corral Hollow Road.
The Zone 3 - IPC/PPBP pressure zone currently includes the PPBP (i.e., Safeway and Costco) and all of the existing IPC development. This zone is currently served by the Cordes BPS, which supplies water from the Cordes Tank. The Cordes Tank is filled by the Zone 2 transmission mains in Schulte Road and Hansen Road. As discussed above, although all of the IPC devel opment is currently served by Zone 3 – IPC/PPBP, several of the existing buildings are located within the Zone 2 elevation range. The City plans to split the existing IPC water distribution system into two portions: one served by Zone 2 and one served by Zone 3 - IPC/PPBP. To accomplish this, the 16-inch diameter pipeline in Promontory Parkway between Hansen Road and Lammers Road, which is currently constructed but not active, will placed into service as a Zone 2 pipeline. The Cordes PRS and Promontory Parkway PRS (both currently inactive) will be act ivated to provide support to Zone 2 from Zone 3 in the event of an emergency. This IPC zone split is expected to occur in the spring or summer of 2020.
Figure 7-1 shows the approximate boundaries of each pressure zone after the IPC zone split occurs.
A schematic of the City’s potable water system is provided in Appendix C. Table 7-6 provides a summary of the existing pressure zone boundaries with key characteristics such as service elevations and static pressure ranges.
Table 7-6. Existing Pressure Zone Boundaries
Pressure Zone
Nominal
Hydraulic
Grade, ft
Nominal Range
of Service
Elevations, ft
Static
Pressure
Range, psi Supply Sources
Zone 1 195 0 - 75 40 - 75 JJWTP via 36-inch Main, NEI Tank, Wells, and Pressure Regulating Stations
Zone 2 270 75 - 150 40 - 85(a) JJWTP via Zone 2 Pumps and Linne Tank Zone 3 - IPC/PPBP
(formerly City-Side
Zone 3)
368 150 - 245 55 - 95(a) Cordes Tank via Zone 2
Ellis Reduced Zone 323 140 - 185 60 - 80 JJWTP via Zone 3 Pumps (a) Per the California Plumbing Code, services which experience pressures exceeding 80 psi are required to be fitted with a pressure reducing valve.
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7.2.8 Transmission and Distribution System Pipelines
Based on the City’s existing hydraulic model, there are approximately 280 miles of existing pipelines in the City’s water service area. 2 Pipelines in the existing potable water distribution system range from 4 to 42-inches in diameter. Pipeline materials consist mainly of asbestos cement (AC), cast iron (CI), and ductile iron (DI). The City’s existing transmission and distribution system pipeline network is shown on Figure 7-13.
7.2.9 SCADA System
The City has a SCADA (Supervisory Control and Data Acquisition) system installed to pr ovide for remote operation and monitoring of its facilities. Most of the major existing distribution facilities have SCADA installed except for PRS #1 -#6. Well 8 has SCADA installed, but cannot be remotely operated by the SCADA system.
7.3 HYDRAULIC MODEL UPDATE
A computer simulation model (hydraulic model) transforms information about the physical system into a mathematical model that solves for various demand conditions. The hydraulic model then generates information on pressure, flow, velocity and head loss that can be used to analyze system performance and identify system deficiencies. A hydraulic model can also be used to verify the adequacy of recommended or proposed system improvements.
The City currently has a hydraulic model developed to simul ate its potable water system performance. As part of this Citywide Water System Master Plan Update, an update of the current potable water system hydraulic model was performed to ensure that the hydraulic model accurately reflects the City’s existing water system. This section summarizes the tasks completed to update the City’s current hydraulic model of its potable water distribution system.
7.3.1 Existing Hydraulic Model Description
The City’s current hydraulic model of its existing potable water system was last comprehensively updated for the 2012 Citywide Water System Master Plan. Since then, West Yost has been frequently updating the City’s hydraulic model with new and proposed facilities to perform developer studies and other water system analyses requested by the City. The resulting developer hydraulic model contains existing facilities from the 2012 WSMP, existing facilities constructed since the 2012 WSMP was completed, and proposed facilities which have not yet been constructed.
For this Citywide Water S ystem Master Plan Update, West Yost first reviewed the developer hydraulic model and coordinated with the City to determine which system facilities and pipelines
2 The City’s existing hydraulic model is not an all pipes model; therefore, the exact length of existing system pipelines is not known.
3 Pipelines not included in the existing system evaluation are not shown on Figure 7-1. This includes all existing Zone 4 pipelines as well as some existing pipelines in the IPC and the Ellis Specific Plan developments (these pipelines are included in the future system evaluation which is described in Chapter 8).
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have actually been constructed since the 2012 WSMP . Existing facilities which have been constructed since the 2012 WSMP were reviewed to ensure that they accurately represented existing conditions and were incorporated into the existing potable water system model. This task is discussed in more detail below.
7.3.2 Review of Existing Water System Facilities
Based on a review of the available facilities data on the existing potable water system, which was provided to West Yost by City staff, the following facilities have been added or revised in the City’s existing system hydraulic model since the 2012 WSMP:
• PRS #6 and major 20-inch diameter transmission main in Lammers Road • 24-inch diameter transmission main in MacArthur Drive • Cordes Tank, BPS, and PRS
• Major IPC development pipelines
• Promontory Parkway PRS
• Zone 3 BPS
• Zone 3 transmission main in Corral Hollow Road
• Ellis Specific Plan development pipelines
• Summit Drive PRS and PRV
• Other various new pipeline improvements
• Pipelines with incorrect diameters or alignments
As discussed below (see Section 7.4.1), potable water demands for the existing system hydrau lic model were allocated based on 2017 meter data. Therefore, some facilities which serve water to areas without demands in 2017 were not included in the existing system hydraulic model (but are included in the future system hydraulic model described in Chapter 8). These facilities include:
• Zone 4 infrastructure, including the Zone 4 BPS, Zone 4 PRS, and major transmission and distribution pipelines
• Northington Drive PRV
• Some pipelines in the IPC development
• Some pipelines in the Ellis Specific Plan development Figure 7-2 illustrates the locations of the new and revised facilities that were incorporated into the current hydraulic model to accurately represent the City’s existing potable water distribution system.
0 4,0002,000
Scale in Feet
Figure 7-2
New and Revised
Existing System Facilities
City of Tracy
Water System Master Plan Update
Last Saved: 9/25/2020 2:46:17 PM N:\Clients\404 Tracy\12-18-41 Water Master Plan Update\GIS\MXD\Report Figures\Fig 7-2_Updated Facilities.mxd : nhoman Symbology
New Pressure Regulating Station
New Booster Pump Station
New Storage Tank
John Jones Water Treatment Plant
New Pipeline Constructed Since the 2012
WSMP
Added Pipeline (for Model Refinement)
Updated Pipeline (for Model Refinement)
Previously Modeled Pipeline from 2012
WSMP
Pressure Zone
Zone 1
Zone 2
Zone 3 (IPC/PPBP)
Ellis Reduced Zone
City Limits
205
580
Summit Dr
PRS and PRV
PRS #6
Z3 BPS
580
205
Cordes Tank, BPS,
and PRS
Promontory
PRS
SCHULTE RD
SCHULTERD
SCHULTE RD
ELEVENTH ST
CORRAL HOLLOW RD
M
AC
ARTHUR
DR
BYRON RD
GRANT LINE RDHANSEN RD
VALPICO RD
LOVELY RD
LINNE RD
HOLLY DR
MIDDLE RD
VON SOSTEN RD
REEVE RD
TRACY BL
MOUNTAIN HOUSE PK
BANTA RD
LAMMERS RD
NAGLEE RD
CHRISMAN RD
C a l i f o r n i a A q u e d u c t
Del t a-M
en d
o t
a
C a n a l
Notes:
1. The City's hydraulic model is not an all pipes model.
Some pipes which are not hydraulically significant were excluded from the model.
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7.3.3 Review of Existing Water System Operations
The hydraulic model was last calibrated as part of the model update performed for the 2012 WSMP. Recalibration of the model was not considered necessary for this update, since the majority of pipelines added to the hydraulic model since the last update are new pipelines with known roughness factors. However, West Yost coor dinated with City operations staff to confirm that the model accurately reflects existing and planned facility operations. Key changes made to facility operations since the 2012 WSMP include the following:
• In the decade after delivery of SSJID water to the City began, the City preferentially used SSJID water over USBR water to supply its customers. During these years, the JJWTP would shut down for long periods in the winter. However, in recent years the City has begun to use a more balanced mix of USBR and SSJID water. • The Zone 1 BPS at the JJWTP has been seldom used in recent years due to decreased water demands.
• The City’s wells are primarily used as backup sources of supply in the summer. • The Lewis Manor well is inactive due to high manganese levels. • The Cordes Tank and BPS now serve Zone 3 IPC/PPBP, and the Patterson Pass BPS (which previously served the same area) has been placed on standby. • The Zone 3 BPS now serves the Ellis Reduced Zone.
• Booster pump station VFD settings have been adjusted since the 2012 WSMP.
Controls in the existing system hydraulic model have been updated to reflect these operational changes.
In addition, controls in the existing system hydraulic model were updated to reflect system operation changes which will occur in the next year (2020) after the planned IPC zone split is implemented. Key changes made to facility operations to reflect the IPC zone split include:
• Activating the 16-inch diameter pipeline in Promontory Parkway between Hansen Road and Lammers Road
• Activating the Cordes PRS and Promontory Parkway PRS
• Closing and opening valves to isolate Zone 2 and Zone 3 – IPC/PPBP from each other
7.4 EXISTING POTABLE WATER SYSTEM EVALUATION
This section presents the evaluation of the City’s existing potable water distribution system and its ability to meet the City’s recommended performance and operational criteria (previously presented in Chapter 6) under existing demand conditions. This evaluation includes an analysis of existing surface water treatment capacity, storage capacity, pumping capacity, and a hydraulic analysis of the water system’s performance under maximum day demand plus fire flow and peak hour demand scenarios. Recommended improvements for addressing any identified existing potable water Chapter 7
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distribution sy stem deficiencies are summarized in Section 7.5 Summary of Recommended Existing Potable Water System Improvements.
7.4.1 Existing Potable Water Demands
The water demands in the City’s water system model were previously allocated based on spatially-located 2006 meter data and scaled up using the City’s 2007 water production data. For this Citywide Water System Master Plan Update, the previous water demands were updated based on spatially -located 2017 meter data . The location of allocated water meters is shown on Figure 7-3. Allocated demands located in PPBP and IPC were scaled up to the total recorded flow through the Patterson Pass BPS in 2017 to account for water loss and construction meters. Because this area of the City has been growing rapidly, recent water production data was considered the most representative of existing water use in the PPBP and IPC. Allocated demands in all other areas were scaled up to the City’s averag e water production from 2005 through 2013. Due to the recent drought and associated conservation measures, water production data from 2014 through 2017 were considered less representative of existing water use in these areas . Table 7-7 summarizes the City’s existing potable water demands by pressure zone.
Table 7-7. Existing Potable Water Demands by Pressure Zone Pressure Zone
Average Day
Demand(a)
Maximum Day
Demand(b)
Peak Hour
Demand(c)
gpm mgd gpm mgd gpm mgd
Zone 1 7,124 10.3 12,111 17.4 20,660 29.8
Zone 2(d) 3,856 5.6 6,555 9.4 11,182 16.1
Zone 3
PPBP(e) 392 0.6 667 1.0 1,138 1.6
IPC(f) 26 0.04 44 0.1 75 0.1
Ellis Reduced Zone 18 0.03 31 0.0 53 0.1
Total 11,417 16.4 19,408 27.9 33,108 47.7
(a) Based on spatially located 2017 water meter data. Meters located in PPBP and IPC were scaled up to represent recent (2017) data from the Safeway meter (796 af/yr). All other meters were scaled up to represent the City's average water production from 2005 - 2013 (17,620 af/yr).
(b) Maximum day demand is 1.7 times the average day demand. (c) Peak hour demand is 2.9 times the average day demand. (d) Includes water demands from IPC water meters that will be served by Zone 2 after the IPC zone split (FedEx and Medline buildings).
(e) Water demands from PPBP are not included in the City’s water production totals because the water supply for this area is purchased by PPBP from the Byron Bethany Irrigation District. However, the City is responsible for providing water treatment and delivery services to PPBP.
(f) Excludes water demands from IPC water meters that will be served by Zone 2 after the IPC zone split. Includes demands from Amazon, Smucker's, and Buildings 3 and 4.
0 4,0002,000
Scale in Feet
Figure 7-3
Allocated Water Meters
City of Tracy
Water System Master Plan Update
Last Saved: 3/18/2020 1:29:51 PM N:\Clients\404 Tracy\12-18-41 Water Master Plan Update\GIS\MXD\Report Figures\Fig_7-3_Allocated_Meters.mxd : nhoman Notes:
1. Based on water meter shapefile recieved from the City on July 2, 2018.
Symbology
Allocated Water Meter Location
Zone 1
Zone 2
Zone 3 (IPC/PPBP)
Ellis Reduced Zone
Pressure Regulating Station
Booster Pump Station
Groundwater Well
Storage Tank
John Jones Water Treatment Plant
Pipeline
Pressure Zone
Zone 1
Zone 2
Zone 3 (IPC/PPBP)
Ellis Reduced Zone
City Limits
580
205
205
580
SCHULTE RD
SCHULTERD
SCHULTE RD
ELEVENTH ST
CORRAL HOLLOW RD
M
AC
ARTHUR
DR
BYRON RD
GRANT LINE RDHANSEN RD
VALPICO RD
LOVELY RD
LINNE RD
HOLLY DR
MIDDLE RD
VON SOSTEN RD
REEVE RD
TRACY BL
MOUNTAIN HOUSE PK
BANTA RD
LAMMERS RD
NAGLEE RD
CHRISMAN RD
C a l i f o r n i a A q u e d u c t
Del t a-M
en d
o t
a
C a n a l
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7.4.2 Existing Water System Facilities Evaluation
To evaluate the existing potable water system, analyses addressing the following system facilities were conducted:
• Surface Water Treatment Capacity
• Storage Capacity
• Pumping Capacity
• Critical Supply Facilities
The results from the existing potable water system facilities analyses are discussed below.
7.4.2.1 Water Treatment Capacity
Sufficient water treatment capacity from the existing JJWTP , the City’s treated surface water supplies from the South County Water Supply Project, and groundwater wells should be available to meet the City’s existing maximum day demand condition. In addition, the City’s goal is to have sufficient surface water treatment capacity to meet the existing maximum month demand without relying on groundwater . Table 7-8 indicates that the City has sufficient water treatment and capacity to meet existing m aximum day demands and that the City’s current surface water treatment capacity is sufficient to meet existing maximum month potable water demands.
Table 7-8. Comparison of Available and Required Water Treatment Capacity, mgd Demand
Condition JJWTP(a)
South County
Water Supply
Project(b) Groundwater
Total Treated
Water
Capacity
Existing
Maximum Day
Demand
Surface Water
Capacity Surplus
or (Deficit)
Maximum
Day 27 17 21.7(c) 65.7 28 38
Maximum
Month(d) 27 17 0.0(e) 44.0 25 19
(a) Supplied from Zone 1 36-inch diameter transmission main, Zone 2 BPS, and Zone 3 BPS. Although the JJWTP is designed to supply 30 mgd, the actual maximum pumping capacity of the intake pumps is 27 mgd. (b) Supplied from Linne Road and NEI Booster Pump Stations. (c) Equivalent to firm groundwater pumping capacity, assuming that 20 percent of the City's wells would be out of service (i.e., approximately two wells: one in Zone 1, and one at the JJWTP). (d) Estimated to be 90 percent of maximum day demands. (e) The City's goal is to meet maximum month demands without relying on groundwater supply.
7.4.2.2 Storage Capacity
The principal advantages that storage provides for the water system are the ability to equalize demands on supply sources, production facilities, and transmission mains; to provide emergency storage in case of supply failure; and to provide water to fight fires. The City’s water service area has two sources of available storage: above-ground storage (i.e., clearwells and storage tanks) and storage available through the groundwater basin. Together, these two sources of storage must be Chapter 7
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sufficient to meet the City’s operational, emergency, and fire flow storage criteria. The volumes required for each of these three storage components are listed below:
• Operational Storage: 30 percent of a maximum day demand • Emergency Storage: 1.5 times an average day demand
• Fire Flow Storage: The required fire flow rates multiplied by their associated fire flow duration periods, as required by the City’s Fire Department. For larger pressure zones (i.e., Zones 1 and 2), two concurrent fire flow events were assumed for the storage capacity analysis. However, the recommended fire flow storage does not include the volume associated with sprinkler flows.
Because the City’s potable water supply includes supply from groundwater wells, the groundwater basin can account for a portion of the recommended emergency storage, in the form of a groundwater credit. However, the following criteria must be met to use the groundwater supply to offset the need to provide above-ground storage:
• Groundwater supply is of potable water quality and can be reliably accessed (i.e., wells are equipped with on-site emergency generators). • Groundwater supply is not already relied upon to meet the City’s average day demand requirements.
• Groundwater supply is of firm groundwater supply availability (i.e., assumes 20 percent of wells will be out of service at any given time). • Sufficient water distribution facilities are available to distribute this water to demand area.
In addition, the City currently has two independent sources of treated surface water supply, and some quantity of the total treated surface water supply capacity can also account for a portio n of the recommended emergency storage. The treated surface water credit assumes that the smaller of the treated surface water supply sources can be available to offset a portion of the emergency storage requirement. However, the following criteria must be met to use treated surface water supply to offset the need to provide above-ground storage:
• Treated surface water supply can be reliably accessed (i.e., treated surface water supply facility is equipped with on-site emergency generator). • Sufficient treated surface water booster pumping facilities are available to distribute water to demand areas.
In summary, the Emergency Storage Credit is equal to the sum of the groundwater and treated surface water supply credits. However, the Emergency Storage Credit can only provide a maximum storage credit equal to the City’s required emergency storage volume.
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The existing potable water storage facilities, in conjunction with the available Emergency Storage Credit, were evaluated to determine whether the City’s existing potable water system has sufficient storage capacity to provide the required operational, emergency, and fire flow storage. Table 7-9 provides a detailed summary of t he City’s existing available potable water storage capacity, Emergency Storage Credit, and required storage capacity . Table 7-9 indicates that the City currently has a potable water storage capacity surplus of approximately 4.2 MG in Zone 1, Zone 2, and Ellis Reduced Zone, and a 0.7 MG surplus in Zone 3 - IPC/PPBP.
7.4.2.3 Pumping Capacity
The pumping capacity in the City’s existing potable water system was evaluated to assess its ability to deliver a reliable firm capacity to the existing water service area. Firm capacity assumes a reduction in total pumping capacity to account for pumps that are out of service at any given time due to mechanical breakdowns, maintenance, water quality, or other operational issues. At each booster pump station, firm booster pumping capacity was defined as the total booster pump station capacity with the largest pump out of service. For groundwater well pumps, the firm groundwater pumping capacity assumed that 20 percent of the wells would be out of service at any given time.
The pumping capacity criterion for the City, described previously in Chapter 6, requires the City’s potable water system to have sufficient firm pumping capacity to mee t the greater of either a maximum day demand with two simultaneous fire flow events (one fire flow event in smaller pressure zones) or a peak hour demand. In addition, sufficient firm treated water pumping capacity should be available to meet a maximum day demand condition.
Table 7-10 provides a detailed summary of the City’s existing available firm pumping capacity at each pump station and provides a comparison between the City’s available firm pumping capacity and the requirements stated above. This pumping capacity analysis indicates that the City’s existing booster and groundwater pumping capacity can sufficiently meet the pumping capacity criterion for the existing water service area during the governing flow scenario in each pressure zone.
7.4.2.4 Critical Supply Facilities
All critical pumping facilities should be equipped with an on -site, emergency backup power generator to provide pumping capacity during a power outage. Critical pumping facilities are defined as those facilities that provide service to pressure zone(s) and/or service area(s) which do not have sufficient emergency storage, and that meet at least one of the following criteria:
• The largest pumping facility that provides water to a particular pressure zone and/or service area.
• A facility that provides the sole source of water to single or multiple pressure zones and/or service areas.
• A pumping facility that provides water from a supply turnout. • A pumping facility that provides water from key groundwater supply wells (depends on capacity, quality, and location).
Ground
water
Credit(a)
Treated Surface
W
ater Supply
Credit(b)
Total Emergency
Storage Credit(c)
NEI Active 2.4 --
Li
ncoln Well Active -- 5.40
Lewis Manor Well Inactive -- --
Park and Ride Well Active -- 4.32
Ball Park Well Active -- 5.40
Well 8(g) Active -- --
Linne Active 7.1 --
W
ell 1(h) Active -- --
Wel
l 2(g,h) Active -- --
Wel
l 3(g,h) Active -- --
Wel
l 4(g,h) Active -- --
Clearwel
l #2 Active 4.0 --
Cordes Active 2.0 -- 0.00 0.90(j) 2.90 0.31 0.90 0.96(k) 2.17 0.7 Zone 1,
Zone 2, and Ellis Reduced Zone(f)
Zone 3
IPC/PPBP
25.50 23.76 37.26 8.08 23.76 1.14(i) 32.97 4.2
(g) Wel
l does not contribute to Groundwater Credit because it does not have on-site backup power.
Table 7-9. Com
parison of Available and Required Water Storage Capacity Station Status
Availa
ble Storage Capacity, MG Required Storage Capacity, MG
Storage Surplus
(Deficit), MGReservoir Capacity
Emergency Storage Credit
Total Available Storage Operational (d) Emergency(e) Fire Flow Total Required Storage
(a) Credit base
d on 1.5 days of pumping capacity from active groundwater wells with on-site backup power because the required emergency storage capacity is equal to 1.5 times the average day demand.
See Table 7-2 for individual well capacity.
(d) Based on 30 percent of a maximum day demand (see Table 7-7). (c) Equal to the sum of the groundwater and treated surface water supply credits; however, the maximum credit is equal to the required emergency storage capacity. (b) Credit based on 1.5 days of available treatment capacity (17 mgd) from the SCWSP because the required emergency storage capacity is equal to 1.5 times the average day demand. (i) Based on storage required for two concurrent fire flow events; a Single Family Residential fire flow and an Industrial fire flow (see Table 6-1). (j) Surplus Treated Surface Water Supply Credit from other pressure zones can be used to provide emergency storage for Zone 3. (e) Based on 1.5 times the average day demand (see Table 7-7). (f) The Ellis Reduced Zone is currently isolated from the Cordes Tank and BPS. (k) Based on storage required for an Industrial fire flow (see Table 6-1). (h) Well does not contribute to Groundwater Credit because water produced by the well must be blended with chlorinated water from the JJWTP prior to distribution. The JJWTP is assumed to be offline in an emergency. o\c\404\12-18-41\en
gr\Ch7\Ch 7 Tables\Table 7-9
Last Revised: 01-31-20
City of Tra
cy
Citywide Water System
Master Plan Update
Pump
Station Backup Power Status Firm Capacity(a), gpm
T
otal Firm Pumping Capacity
from Supply Sources, gpm(b)
Existi
ng Maximum Day
Demand, gpm
Pumpi
ng Capacity from Supply
Source
s Surplus (Deficit),
gpm(b)
Total
Firm Pumping
Capacity, gpm
Existing Maximum Day Demand
with Fire Flow Event(s), gpm
Existing Peak Hour
Demand, gpm
Pumping Capacity Surplus
(Deficit), gpm(b)
NEI Acti
ve 4,200
Zone 1 Active 12,000
Lincoln Well Active 2,500
Lewis Manor Well Inactive --
Park and Ride Well Active 2,000
Ball Park Well Active 2,500
Well 8 Active --
Linne Active 14,595
Zone 2 Active 13,300
Well 1(c) Acti
ve --
Well 2(c) Acti
ve --
Well 3(c) Acti
ve --
Well 4(c) Acti
ve --
Cordes Active 6,150
Patterson Pass(f) Inac
tive --
Zone 3 Active 2,970 2,970 31 2,939 2,970 1,531(i) 53 1,439 Tab
le 7-10. Comparison of Available and Required Firm Pumping Capacity Zones 1 a
nd 2
Zone 3 IPC/PPBP
6,150 939
51,095 24,666(e) 31,842 19,2
53 44,106 19,377(d) 24,728
NA(g)NA(g)NA(g)
(i) Max
imum day demand plus a 1,500 gpm Single Family Residential fire flow. (b) Pumping capacity surplus (deficit) is the total available firm pumping capacity minus the greater of the maximum day demand with required fire flow event(s) or peak hour demand. (e) Maximum day demand plus a 1,500 gpm Single Family Residential fire flow and a simultaneous 4,500 gpm Industrial fire flow. (h) Maximum day demand plus a 4,500 gpm Industrial fire flow.
Elli
s Reduced Zone
(a) Firm booste
r pumping capacity was defined as the total booster pump station capacity with the largest pump out of service and firm groundwater pumping capacity assumed that 20 percent of the City's wells would be out of service (i.e., approximately two wells: one in Zone 1, and one at the JJWTP). (f) Patterson Pass BPS is inactive since the Cordes BPS is now operating; therefore, it does not provide additional pumping capacity to the system. (c) Wells 1-4 located at JJWTP pump directly into the Chlorine Contact Basin or Clearwell #2; therefore, these wells do not provide additional pumping capacity to the system. 5,211(h) 1,213
(d) Incl
udes maximum day demand for Zone 3 IPC/PPBP.
(g) Zone 3 IPC/PPBP is supplied treated water via Zone 2 facilities. o\
c\404\12-18-41\engr\Ch7\Ch 7 Tables\Table 7-10
Last Revised: 12-03-19
City o
f Tracy
Citywide Water System
Master Plan Update
Chapter 7
Existing Potable Water System Evaluation
7-22 City of Tracy
May 2023 Citywide Water System
n\c\404\12-18-41\wp\R-404-WMPU Master Plan Update
As shown previously in Table 7-10, most of the City’s existing pumping facilities have on -site emergency backup power installed, except for Wells 2 through 4 and Well 84. However, these wells do not meet the criteria listed above and are not considered critical supply facilities.
Therefore, the City is currently equipped with sufficient backup power generators to provide pumping capacity during a power outage at its most critical pumping facilities.
7.4.3 Existing Water System Hydraulic Analysis
The system performance criteria recommended for and results of the existing potable water distribution system hydraulic analysis are discussed below.
7.4.3.1 Existing Water System Performance Criteria
Steady state hydraulic analyses using the updated hydraulic model were conducted to help identify areas of the existing potable water system that do not meet the recommended system performance criteria as presented previously in Chapter 6. The results of the existin g potable water system evaluation are presented below for the following scenarios:
• Peak Hour Demand—A peak hour flow condition was simulated for the existing water distribution facilities to evaluate their capability to meet a peak hour demand scenario. Peak hour demands are met by the combined supply from treated surface water, storage tanks, and groundwater.
• Maximum Day Demand plus Fire Flow—To evaluate the existing potable water system under the maximum day demand plus fire flow scenario, individual fire flow demands were first assigned and simulated at various locations within the City’s water service area. InfoWater’s “Available Fire Flow Analysis” tool was used to determine the available fire flow while meeting the maximum day demand plus fire flow performance criteria. Additional fire flow simulations were also performed to simulate a condition equal to a maximum day demand with two concurrent fire flow events. Maximum day plus fire flow demands are met by the combined supply from treated surface water and storage tanks.
The recommended system performance criteria for each scenario are discussed in more detail below.
7.4.3.1.1 Peak Hour Demand Scenario
As shown in Table 7-7, the peak hour demand for the existing water service area was calculated to be 33,108 gpm (47.7 mgd). This peak hour demand represents a peaking factor of 2.9 times the average day demand. During a peak hour demand scenario, a minimum pressure of 40 psi must be maintained throughout the water system. In addition, maximum head losses for distribution mains should not exceed 7 ft/kft and maximum velocities should not exceed 8 fps. For transmission mains, maximum head losses should not exceed 3 ft/kft and maximum velocities should not exceed 6 fps.
4 Well 8 currently has a plug-in adapter installed to allow interconnection to a portable generator.
Chapter 7
Existing Potable Water System Evaluation
7-23 City of Tracy
May 2023 Citywide Water System
n\c\404\12-18-41\wp\R-404-WMPU Master Plan Update
7.4.3.1.2 Maximum Day Demand plus Fire Flow Scenario
As shown in Table 7-7, the maximum day demand for the existing water service area was calculated to be 19,408 gpm (32.9 mgd). This maximum day demand represents a peaking factor of 1.7 times the average day demand. Fire flow demands were assigned and simulated at various locations within the City’s water service area to determine if the min imum residual pressure criterion of 20 psi could be met during a maximum day demand plus fire flow scenario5. Fire flow demands were assigned based on General Plan land use designations and are summarized below in Table 7-11.
Table 7-11. Recommended Fire Flow Requirements(a)
Land Use Category Fire Flow, gpm Duration, hours
Single Family Residential(b) 1,500 2
Multi-Family Residential(c) 2,500 2
Commercial/Office(d) 3,500(f) 4
Industrial 4,500(f) 4
Institutional(e) 4,500(f) 4
(a) Specific fire flow requirements were determined from Table B105.1 of the 2016 CFC and depend on construction type and fire flow calculation area. Non-residential fire flow requirements are based on the assumption that an automatic sprinkler system has been installed. See Table 6-1 for further explanation of how the fire flow requirements were developed. (b) Includes Very Low and Low Density Residential land uses. (c) Includes Medium and High Density Residential land uses. (d) Includes Commercial, Office, Downtown, and Village Center land uses. (e) Includes Medical, Public Facilities, School, Airport, Church, and Cemetery land uses. (f) Fire flow includes a 500 gpm demand for on-site sprinkler flow, which is not included in the recommended fire flow storage volume.
The City’s water system should also have the capability to meet a system demand condition equal to the occurrence of a maximum day demand with two concurrent fire flow events in the larger pressure zones (i.e., Zones 1 and 2). It is assumed that the two fire flow events will consist of one smaller single family residential fire flow combined with another la rger industrial fire flow. This conservative assumption of two simultaneous fire flow demands will help stress the City’s water system and determine if the existing water system can provide reliable service during high demand conditions. Consequently, two concurrent fire flow demands were simulated at various locations within Zones 1 and 2 during a maximum day demand condition to determine if the minimum residual pressure criterion of 20 psi could be met during simultaneous fire flow events.
5 The maximum pipeline head loss and maximum pipeline velocity criteria for a maximum day demand plus fire flow scenario were not applied to the City’s existing water system. Because fire flow conditions occur infrequently, no improvements for the existing water system would be recommended if a location failed to meet these secondary criteria if the primary pressure criterion was met.
Chapter 7
Existing Potable Water System Evaluation
7-24 City of Tracy
May 2023 Citywide Water System
n\c\404\12-18-41\wp\R-404-WMPU Master Plan Update
7.4.3.2 Recommended Improvement Criteria
The system performance criteria described above were used to evaluate the existing potable water system during peak hour demand and maximum day demand plus fire flow scenarios. The existing potable water system is expected to deliver peak hour flow and maximum day demand plus fire flow within the acceptable pressure, velocity and head loss ranges as identified in the system performance criteria presented in Chapter 6. However, the system was evaluated using pressure as the primary criterion. If necessary, recommended improvements needed to comply with the system performance criteria were added to the existing potable water system model to fix any deficiencies found and are discussed below.
7.4.3.3 Existing Water System Evaluation Results
The results from the hydraulic model for the peak hour demand and maximum day demand plus fire flow analyses are presented below.
7.4.3.3.1 Peak Hour Demand Scenario
During a peak hour demand scenario, results indicate that the existing potable water system is capable of maintaining the City’s minimum pressure criterion of 40 psi at all existing service locations, as shown on Figure 7-4. Under this scenario, system pressures at existing ser vice locations ranged from 4 0 to 85 psi. It should be noted that, per the California Plumbing Code, services which experience pressures exceeding 80 psi are required to be fitted with a pressure reducing valve.
As shown on Figure 7-5, there are two locations within the existing system where the distribution system pipelines did not meet the maximum velocity criterion of 8 fps during a peak hour demand scenario. The follo wing list details pipelines in the existing potable water system that exceeded the maximum velocity criterion and summarizes any recommended improvements. • Location #1: The 12-inch diameter discharge pipeline from the Ball Park Well off of Tracy Boulevard had a velocity of 8.3 fps.
Recommendation:
No mitigation is recommended for the 12-inch diameter discharge pipeline from the Ball Park Well, because pipeline velocity is a secondary criterion and no improvements for pipelines exceeding the velocity criterion in the existing potable water system are recommended unless the primary criterion (pressure) is not met. • Location #2: The 12-inch diameter distribution pipeline located in Sixth Street immediately east of the 36-inch diameter transmission main tie-in had a velocity of 8.3 fps.
Recommendation:
No mitigation is recommended for the 12-inch diameter discharge pipeline in Sixth Street immediately east of the 36-inch diameter transmission main tie-in, because pipeline velocity is a secondary criterion and no improvements for pipelines exceeding the velocity criterion in the existing potable water system are recommended unless the primary criterion (pressure) is not met. 0 4,0002,000
Scale in Feet
Figure 7-4
Existing System Pressures
Peak Hour Demand
City of Tracy
Water System Master Plan Update
Last Saved: 3/18/2020 1:31:51 PM N:\Clients\404 Tracy\12-18-41 Water Master Plan Update\GIS\MXD\Report Figures\Fig_7-4_Ex_Sys_Peak_Hour_Press.mxd : nhoman Notes:
1. The City's existing hydraulic model is not an all pipes model. Therefore, not all existing pipes are shown
or evaluated.
2. Per the California Plumbing Code, services which
experience pressures exceeding 80 psi are required
to be fitted with a pressure reducing valve.
Symbology
Peak Hour Pressure
Less than 40 psi
40 psi to 50 psi
50 psi to 60 psi
60 psi to 70 psi
70 psi to 80 psi
Greater than 80 psi
Pressure Regulating Station
Booster Pump Station
Groundwater Well
Storage Tank
John Jones Water Treatment Plant
Pipeline
Pressure Zone
Zone 1
Zone 2
Zone 3 (IPC/PPBP)
Ellis Reduced Zone
580
205
205
580
SCHULTE RD
SCHULTERD
SCHULTE RD
ELEVENTH ST
CORRAL HOLLOW RD
M
AC
ARTHUR
DR
BYRON RD
GRANT LINE RDHANSEN RD
VALPICO RD
LOVELY RD
LINNE RD
HOLLY DR
MIDDLE RD
VON SOSTEN RD
REEVE RD
TRACY BL
MOUNTAIN HOUSE PK
BANTA RD
LAMMERS RD
NAGLEE RD
CHRISMAN RD
C a l i f o r n i a A q u e d u c t
D e l t a - M e ndota
C
anal
0 4,0002,000
Scale in Feet
Figure 7-5
Existing Pipeline Velocities
Peak Hour Demand
City of Tracy
Water System Master Plan Update
Last Saved: 3/18/2020 1:33:42 PM N:\Clients\404 Tracy\12-18-41 Water Master Plan Update\GIS\MXD\Report Figures\Fig_7-5_Ex_Sys_Velocity.mxd : nhoman Symbology
Pipeline Diameter ≥ 18-inches
Velocity ≤ 6 fps
Velocity > 6 fps
Pipeline Diameter < 18-inches
Velocity ≤ 8 fps
Velocity > 8 fps
Pressure Regulating Station
Booster Pump Station
Groundwater Well
Storage Tank
John Jones Water Treatment Plant
Pressure Zone
Zone 1
Zone 2
Zone 3 (IPC/PPBP)
Ellis Reduced Zone
580
205
205
580
#1
#2
SCHULTE RD
SCHULTERD
SCHULTE RD
ELEVENTH ST
CORRAL HOLLOW RD
M
AC
ARTHUR
DR
BYRON RD
GRANT LINE RDHANSEN RD
VALPICO RD
LINNE RD
HOLLY DR
MIDDLE RD
VON SOSTEN RD
REEVE RD
TRACY BL
MOUNTAIN HOUSE PK
BANTA RD
LAMMERS RD
NAGLEE RD
CHRISMAN RD
C a l i f o r n i a A q u e d u c t
D e l t a - M e ndota
C
anal
Well 8 NINTH ST
SIXTH ST
BEECHNUT AV
TRACY
BL
12"
12"
12"
12"
12"
8"
36"
36"
Ball Park Well
TRACY BL
GRANT LINE RD
TWENTY-THIRD ST
12" 4"
12"
12"
12" 12"
#1
#2
Notes:
1. The City's existing hydraulic model is not an all pipes model. Therefore, not all existing pipes are shown
or evaluated.
Chapter 7
Existing Potable Water System Evaluation
7-27 City of Tracy
May 2023 Citywide Water System
n\c\404\12-18-41\wp\R-404-WMPU Master Plan Update
7.4.3.3.2 Maximum Day Demand plus Fire Flow Scenario
Fire flow demands were assigned based on Table 7-11 and simulated at various locations within the City’s water service area. InfoWater’s “ Available Fire Flow Analysis ” tool was used to determine the available fire flow while meeting a minimum residual pressure of 20 psi within the existing water system during a maximum day demand scenario.
As shown on Figure 7-6, the results from the hydraulic model indicate that there are seven fire flow junctions, grouped into four areas, where the available fire flow is less than the minimum required fire flow. The following list details the areas in the existing potable water system that failed to meet the fire flow requirements and summarizes any recommended improvements. • Location #1: The hydrant at the southern end of Rhonda Way is surrounded by industrial land use, which has a fire flow requirement of 4,500 gpm. This hydrant is served by an 8-inch diameter distribution pipeline in Rhonda Way which terminates at the hydrant. The available fire flow simulated at this hydrant while maintaining a 20 psi minimum residual pressure was approximately 3,640 gpm.
Recommendation:
No mitigation is recommended for the hydrant at the southern end of Rhonda Way because the deficient hydrant is located on a short dead-end line. The deficient hydrant is less than 300 ft away from a hydrant at the intersection of Rhonda Way and Larch Road which is capable of providing 4,500 gpm at 20 psi residual pressure. • Location #2: Four hydrants within the neighborhood located east of Tracy Boulevard, south of Juanita Market, west of Holly Drive, and north of Carlton Way are not capable of meeting minimum fire flow requirements. This neighborhood is located in an older part of the City, and many of the distribution pipelines in the neighborhood are 4-inches or 6-inches in diameter with low C-factors. The northern-most deficient hydrant, at the intersection of Wall Street and 20th Street, was assigned a fire flow requirement of 1,500 gpm, but could only provide approximately 1,230 gpm. The other three deficient hydrants, located at the intersections of Wall Street and Emerson Avenue, Emerson Avenue and Court Drive, and Court Drive and Lowell Avenue, were assigned a fire flow requirement of 2,500 gpm, but could only provide approximately 820 gpm, 1,590 gpm, and 2,350 gpm, respectively.
Recommendation:
It is recommended that the existing pipelines in 20th Street between Bessie Avenue and Parker Avenue, Wall Street between Lowell Avenue and 20th Street, Emerson Avenue between Bessie Avenue and Holly Drive, Court Drive between Whittier Avenue and Lowell Avenue, and Lowell Avenue between Parker Avenue and Holly Drive be replaced with new 8-inch diameter pipelines to improve fire flow to this area.
Chapter 7
Existing Potable Water System Evaluation
7-28 City of Tracy
May 2023 Citywide Water System
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• Location #3: The hydrant at the intersection of School Street and Ninth Street was assigned a fire flow requirement of 2,500 gpm due to the high density residential units located along School Street. This hydrant is currently served by an 8-inch diameter distribution pipeline in School Street which terminates east of the hydrant.
The available fire flow simulated at this hydrant while maintaining a 20 psi minimum residual pressure was approximately 2,330 gpm.
Recommendation:
It is recommended that a new 12-inch diameter pipeline be installed in Ninth Street between School Street and Tenth Street.
• Location #4: The hydrant at the intersection of Tracy Boulevard and Fourth Street was assigned a fire flow requirement of 2,500 gpm due to the medium density residential units located in the vicinity. This hydrant is served by an existing 4-inch diameter pipeline in Tracy Boulevard and an existing 6-inch diameter pipeline in Fourth Street. The available fire flow simulated at this hydrant while maintaining a 20 psi minimum residual pressure was approximately 1,350 gpm.
Recommendation:
It is recommended that the existing 4-inch diameter pipeline in Tracy Boulevard north of Mount Diablo Avenue be replaced with a new 12-inch diameter pipeline to improve the fire flow to this area. This improvement was previously recommended in the 2012 WSMP.
Four additional fire flow simulations were performed within the hydraulic model to simulate a condition equal to a maximum day demand with two concurrent fire flow events. Two concurrent fire flow events were simulated during a maximum day demand condition to determine if the minimum residual pressure criterion of 20 psi could be met. Figure 7-7 shows the locations of the additional fire flow simulations. Locations were selected within each pressure zone based on the existing land use designations and spatial distance from supply sources to stress the City’s water system. As summarized in Table 7-12, results from the hydraulic model indicate that all four of the concurrent fire flow simulations met the minimum residual pressure criterion of 20 psi.
0 4,0002,000
Scale in Feet
Figure 7-6
Existing System
Available Fire Flow
City of Tracy
Water System Master Plan Update
Last Saved: 3/23/2020 9:47:43 AM N:\Clients\404 Tracy\12-18-41 Water Master Plan Update\GIS\MXD\Report Figures\Fig_7-6_Fireflow_Results.mxd : nhoman Notes:
1. The available fire flow shown is the maximum flow
available while maintaining 20 psi residual system
pressure.
2. The City's existing hydraulic model is not an all
pipes model. Therefore, not all existing pipes
are shown or evaluated.
Symbology
Available Fire Flow
Does Not Meet Requirement
Meets Requirement
Pressure Regulating Station
Booster Pump Station
Groundwater Well
Storage Tank
John Jones Water Treatment Plant
Pipeline
Fire Flow Requirement
1,500 gpm
2,500 gpm
3,500 gpm
4,500 gpm
205
580
#1
#2
#3
#4
SCHULTE CT
ELEVENTH ST
CORRAL HOLLOW RD
M
AC
ARTHUR
DRTRACY BL
BYRON RD
GRANT LINE RD
MOUNTAIN HOUSE PK
BANTA RD
HANSEN RD
VALPICO RD
LAMMERS RD
NAGLEE RD
LOVELY RD
LINNE RD
HOLLY DR
MIDDLE RD
CHRISMAN RD
VON SOSTEN RD
REEVE RD
SCHULTE RD
C a l i f o r n i a A q u e d u c t
D e l t a - M e ndota
C
anal
0 4,0002,000
Scale in Feet
Figure 7-7
Locations of Additional
Simultaneous Fire Flow
Simulations
City of Tracy
Water System Master Plan Update
Last Saved: 12/3/2019 9:35:05 AM O:\Clients\404 City of Tracy\12-18-41 Water Master Plan Update\GIS\MXD\Report Figures\Fig_7-7_Multi-Fireflow_Results.mxd : nhoman Symbology
Simultaneous Fire Flows
Location #1
Location #2
Location #3
Location #4
Pressure Regulating Station
Booster Pump Station
Groundwater Well
Storage Tank
John Jones Water Treatment Plant
Existing Pipeline
Pressure Zone
Zone 1
Zone 2
Ellis Reduced Zone
#1: 1,500 gpm
#1: 4,500 gpm
#2: 4,500 gpm
#2: 1,500 gpm
#4: 4,500 gpm
#4: 1,500 gpm
#3: 4,500 gpm
#3: 1,500 gpm
SCHULTERD
SCHULTE RD
SCHULTE RD
ELEVENTH ST
CO
RRAL
HO
LLO
W
RD
LOVELY RD
M
AC
ARTHUR
DR
TRACY
BL
BYRON RD
GRANT LINE RD
VALPICO RD
LINNE RD
MIDDLE RD
VON SOSTEN RD
BANTA RD
LAMMERS RD
HOLLY DR
NAGLEE RD
CHRISMAN RD
REEVE RD
C a l i f o r n i a A q u educt
D e l t a - M e n d o t a C a n a l
Notes:
1. The City's existing hydraulic model is not an all pipes model. Therefore, not all existing pipes are shown
or evaluated.
Chapter 7
Existing Potable Water System Evaluation
7-31 City of Tracy
May 2023 Citywide Water System
n\c\404\12-18-41\wp\R-404-WMPU Master Plan Update
Table 7-12. Results of Additional Fire Flow Simulations Pressure Zone Location # Fire Flow Demand, gpm(a) Residual Pressure, psi Zone 1
1 1,500 51
4,500 32
2 1,500 52
4,500 45
Zone 2
3 1,500 67
4,500 52
4 1,500 67
4,500 32
(a) It is assumed that the two concurrent fire flow events will consist of one smaller Single Family Residential fire flow combined with another larger Industrial fire flow.
7.5 SUMMARY OF RECOMMENDED EXISTING POTABLE WATER SYSTEM
IMPROVEMENTS
The recommended hydraulic improvements for the existing potable water distribution system are summarized below. These existing system improvements are recommended based on existing water demands, and are not triggered by f uture new development. It should be noted that these recommendations only identify facility improvements at a master plan level and do not necessarily include all required on -site infrastructure nor constitute design of improvements. Subsequent detailed de sign is required to determine the exact sizes and final locations of these proposed improvements. Recommended improvements are based on available information on the City’s existing water system and existing water demands as presented in Table 7-7.
It should also be noted that the existing hydraulic model is not an “all pipes” model ( i.e., not all smaller diameter pipelines are included); therefore, the hydraulic simulations performed as discussed above may not identify all necessary water system hydraulic improvements. While some small diameter pipelines which were not previously included in the hydraulic model were added in this Citywide Water System Master Plan as part of the model refinement process, there may still be other small diameter pipelines not represented in the hydraulic model. Consequently, it is recommended that City staff review older parts of the water system where smaller diameter pipelines are typically found and consider possible upsizing of these lines as the City plans for future pipeline renewal and replacement projects. Ongoing replacement of older and/or smaller diameter pipelines will improve the available fire flow capacity of the existing potable water system.
Chapter 7
Existing Potable Water System Evaluation
7-32 City of Tracy
May 2023 Citywide Water System
n\c\404\12-18-41\wp\R-404-WMPU Master Plan Update
Pipeline Hydraulic Capacity Improvements
The locations of all recommended pipeline improvements are shown on Figure 7-8.
Several pipeline improvements are recommended to mitigate existing fire flow deficiencies. These fire flow deficiencies are not triggered by projected future water demands from new development.
The existing water system infrastructure in the areas listed below is insufficien t to meet the fire flow requirements based on existing land use and water demands. As such, planning and design for these improvements should be prioritized. Detailed locations of these improvements are shown on Figure 7-9.
• Improvement #1: Replace the existing pipelines in 20th Street between Bessie Avenue and Parker Avenue, Wall Street between Lowell Avenue and 20th Street, Emerson Avenue between Bessie Avenue and Holly Drive, Court Drive between Whittier Avenue and Lowell Avenue, and Lowell Avenue between Parker Avenue and Holly Drive with approximately 6,000 linear feet (lf) of new 8-inch diameter pipelines. • Improvement #2: Install approximately 515 lf of 12-inch diameter pipeline in Ninth Street between School Street and Tenth Street.
• Improvement #3: Replace approximately 485 lf of existing 4-inch diameter pipeline in Tracy Boulevard north of Mount Diablo Avenue with new 12-inch diameter pipeline; this improvement was previously recommended in the 2012 WSMP.
7.5.1 Pipeline Renewal and Replacement
As the City’s water system ages, older water pipelines will deteriorate and have decreased hydraulic capacity and greater chance of leaking or breaking. To address this, the City should implement a renewal and replacement (R&R) program to proactively replace at-risk water pipelines before they fail. This Citywide Water System Master Plan Update does not include a condition assessment of existing facilities or development of a renew al and replacement (R&R) program. Therefore, it is recommended that the City perform a separate study which evaluates the condition of existing water system assets and develops a prioritized list for asset replacement based on age, material, failure history, and other parameters.
0 3,0001,500
Scale in Feet
Figure 7-8
Existing System
Recommended Improvements
City of Tracy
Water System Master Plan Update
Last Saved: 9/25/2020 3:06:42 PM N:\Clients\404 Tracy\12-18-41 Water Master Plan Update\GIS\MXD\Report Figures\Fig_7-8_Ex_Sys_Improvements.mxd : nhoman Notes:
1. See Figure 7-9 for detailed views of
recommended improvements from hydraulic
evaluation (areas #1 - #3).
Symbology
Recommended Improvement from
Hydraulic Evaluation
Existing Pipeline
Pressure Regulating Station
Booster Pump Station
Groundwater Well
Storage Tank
John Jones Water Treatment Plant
Pressure Zone
Zone 1
Zone 2
205
#1
#2
#3
SCHULTERD
SCHULTE RD
SCHULTE RD
ELEVENTH ST
CORRAL HOLLOW RD
TRACY BL
BYRON RD
GRANT LINE RD
BANTA RD
LOVELY RD
VALPICO RD
BETHANY RD
MIDDLE RD
VON SOSTEN RD
M
AC
ARTHUR
DR
LAMMERS RD NAGLEE RD
HOLLY DR
CHRISMAN RD
REEVE RD
O
ld
R i v e r
D e l t a- Mendot a
Canal
Figure 7-9
Existing System
Recommended Improvements
from Hydraulic Evaluation
City of Tracy
Water System Master Plan Update
Last Saved: 12/5/2019 8:07:48 AM O:\Clients\404 City of Tracy\12-18-41 Water Master Plan Update\GIS\MXD\Report Figures\Fig_7-9_Ex_Sys_Improvements_Hyd.mxd : nhoman Notes:
1. See Figure 7-8 for the locations of the recommended improvements.
SIXTH ST
F ST
GILLETT AL
NINTH ST
SEVENTH ST
EAGAN AL
JACKSON AL
TENTH ST
CIVIC CENTER PZ
SPUR LINE RR
EAST ST
SCHOOL ST
12"
12"
10"
6"
12"
8"
6"
8"
12"
8"
6"
8"
10"
8"
12"
8" 8"
Ball Park Well
8"
8"
8"
8"
8"
8"
8"
8"
8" 8"
8"
12"
12"
8"
6"
10"
10"
6"
12"
8"
12"
12"
12"
12"
12" 12"
8"
8"6"
12"
12"
12"
16"
8"
4"
6"
4"
6"
12"
6"
12"
6"
6"
8"
8"
6"
8"
8"
4"
6"
6"
8"
6"
6"
6"
12"
4"
16"
4"4"
6"
12"
8"
12"
6"
12"
12"
8"
4"8"
6"
6"
6"
10"
8"
12"
10"
8"
8"
10"
8"
8"4"12"
10"
6"6"
10"
8"
4"
8" 8"
12"
12"
8"
6"
12" 8"
6"
4"
4"
6"
4"
6"
12"
8"
12"
16"
4"
4"
6"
16"
8"
CARLTON WY
LOWELL AV
GRANT LINE RD
COURT DR
ALCOTT PL
BEVERLY PL
TWENTY-THIRD ST
TRACY BL BESSIE AV PARKER AV
ALTOGA AV
EMERSON AV
PEREIRA AV
TWENTIETH ST
WALL ST
WHITTIER AV
TWENTY-SECOND ST
TWENTY-FIRST ST
HOLLY DR
#1 #2
TENNIS LN
WEST CT
RODEO WY
MT OSO AV
MT DIABLO AV
FOURTH ST
TRACY BL
BURLINGTON DR
RENOWN DR
12"
8"
8"
8"
8"
8"12"
8"
8"
12"
10"
12"
8"
8"
12"
12"
8"
12"
36"
12"
6"
#3
Symbology
Groundwater Well
Recommended Improvement from
Hydraulic Evaluation
Existing Pipeline
0 400200
Scale in Feet
0 250125
Scale in Feet
0 400200
Scale in Feet
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CHAPTER 8
Future Potable Water System Evaluation
8.1 OVERVIEW
The purpose of this chapter is to present the development and evaluation of the City’s proposed potable water backbone transmission and distribution system for the 2025 and buildout timeframes.
This chapter identifies the additional improvements that will be required in addition to the existing potable water system infrastructure improvements (described in Chapter 7) to support the City’s projected potable water demands in the future. Development of the future potable water system includes an evaluation of the following: (1) the required future water treatment, storage and pumping capacity; and (2) the future water system’s ability to meet recommended water system performance and operational criteria under maximum day demand plus fire flow and peak hour demand scenarios.
The future water system was evaluated at both the 2025 and buildout timeframes. The future water system was not evaluated at the 2040 timeframe discussed in Chapters 4 and 5 because new water system facilities should be sized to accommodate buildout demands. Future updates to the WSMP may evaluate the 2040 timeframe as a near-term condition.
Using the City’s recommended performance and operational criteria d escribed in Chapter 6, preliminary sizing of major transmission pipelines and facilities required to serve future development projects was developed based on the projected potable water demands presented in Chapter 4. To evaluate the suitability of these preliminary sized facilities to meet the recommended performance and operational criteria, they were subsequently incorporated into the hydraulic model of the existing potable water system (evaluated in Chapter 7). This updated hydraulic model of the future potable water system was then used to evaluate maximum day demand plus fire flow and peak hour demand conditions for the 2025 and buildout timeframes to identify any deficiencies and to refine the preliminary sizing of major transmission pipelines and facilities.
Evaluations, findings, and recommendations for supporting projected future potable water demands and addressing any deficiencies identified within the future potable water backbone transmission and distribution system are included in this chapter. Recommendations were used to develop a CIP, which includes an estimate of probable construction costs for Master Plan Program facilities. The recommended potable water system CIP is described further in Chapter 10.
The following sections of this chapter describe the components of the City’s future potable water backbone transmission and distribution system evaluation:
• Pressure Zone Recommendations
• Projected Future Potable Water Demands
• Future Potable Water System Facility Evaluation
• Future Potable Water System Performance Evaluation
• Summary of Recommended Future Potable Water System Improvements
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Future Potable Water System Evaluation
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To assist in the evaluation of the City’s overall future potable water system, the future infrastructure recommended in this chapter includes the infrastructure required to serve the Tracy Hills development and, for consistency, is based on the adopted water use, peaking factors, and system performance criteria described in previous chapters of this WSMP Update. Although the Tracy Hills development is located within separate and distinct pressures zones from the rest of the City, West Yost has included the Tracy Hills development in the future potable water system evaluation because it will be a part of the City’s overall futu re potable water system operations since it will be served directly from the City’s JJWTP. The Tracy Hills Phase 1 water system infrastructure included in this WSMP Update is based on prepared plans and drawings, and the infrastructure for Tracy Hills Phases 2 through 5 is based on the Tracy Hills Water Study prepared by RJA in December 2014. However, projected land use for Tracy Hills used in this WSMP Update is not from the Tracy Hills Water Study, but is instead based on development data provided by the City’s Planning Department, as discussed in Chapter 3 and presented in Appendix A . Including the Tracy Hills development in the 2025 and buildout hydraulic model evaluations ensures that the future potable water system will be adequate to serve potable wat er demands to the entire City (including Tracy Hills) and can provide water service at acceptable system pressures and pipeline velocities. Because planning for future phases of Tracy Hills is subject to change, the sizing of any future water system improvements to serve Tracy Hills should be confirmed based on the latest development plans and associated water demand projections.
8.2 PRESSURE ZONE RECOMMENDATIONS
The City’s existing potable water system currently consists of several interconnected pressure zones (Zone 1, Zone 2, Zone 3, and Ellis Reduced Zone) . With the exception of the Tracy Hills development, all of the City’s future development projects will be located in one of these existing pressure zones. In addition to the pl anned IPC re -zoning discussed in Chapter 7, there are two planned re-zoning projects which will alter the existing pressure zone boundaries in the 2025 and buildout time frames.
Zone 3 (formerly called City-Side Zone 3) is currently split into two isolated portions: one which serves the Ellis Reduced Zone, and one which serves the International Park of Commerce and the Patterson Pass Business Park. The City plans to connect these two isolated portions by constructing new transmission pipelines and by re -zoning some existing transmission pipeline from Zone 2 to Zone 3. A detailed description of the planned modifications to the City’s water system required to fully integrate Zone 3 are provided in Appendix D. The City plans to install new PRVs at the intersection of Schulte Road and Bud Lyons Way and the intersection of Schulte Road and Pavillion Parkway to avoid stagnant water in the dead -end Zone 2 pipelines created by the re - zoning. Once Zone 3 is fully integrated, the Zone 3 BPS will primarily be used to fi ll the Cordes Tank. The Cordes BPS will serve the integrated Zone 3 and the Ellis Reduced Zone (via several PRVs) when the Cordes Tank is not being filled. For this WSMP Update, it was assumed that this re-zoning project will be complete by 2025.
Another re-zoning project, referred to as “Plan C”, will re-zone a small area bounded by Middlefield Drive to the north, Whirlaway Lane to the east, Linne Road to the south, and Corral Hollow Road to the west from Zone 2 to Zone 3. As currently zoned, the Plan C area experiences low pressures because it is located at the top of Zone 2. To improve pressure in the Plan C area, a new Zone 3 transmission pipeline will be constructed. This transmission pipeline will exit the JJWTP from the Chapter 8
Future Potable Water System Evaluation
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east and tie into the existing pipeline in Linne Road, which will also be re-zoned to Zone 3. This new Zone 3 pipeline will support the Plan C area and provide redundant transmission capacity for Zone 3.
To prevent service pressures from exceeding 80 psi in the Plan C area after re-zoning, the City plans to install PRVs at the intersection of Middlefield Drive and Corral Hollow Road and at the Whirlaway pipeline connection to Linne Road. The City also plans to install four new PRVs to separate the Plan C area from the Zone 2 service areas to the north and east. These PRVs will prevent stagnant water from forming in the dead-end pipelines created by the re-zoning. It should be noted that alternative approaches to resolving the stagnant water issue may be possible and should be further evaluated before proceeding with this improvement. It was assumed that the Plan C re-zoning will not occur by 2025 and is therefore only included in the buildout evaluation. Funding for this improvement will be provided through Plan C funds.
In order to serve water demands in the Tracy Hills development, which is located at higher elevations than the City’s existing customers, the City plans to add three additional pressure zones onto the existing service area , called Zones 4, 5, and 6. These pressure zones were previously referred to as Tracy Hills Zone 3, Tracy Hills Zone 4, and Tracy Hills Zone 5, respectively. Note that documents produced prior to this Water System Master Plan Update use the old nomenclature.
As currently planned , these pressure zones will be exclusive to the proposed Tracy Hills development. Although the service elevations of Zone 3 and Zone 4 partially overlap, the two pressure zones will operate at different hydraulic grades and will be hydraulically separate.
The approximate boundaries of the existing and proposed pressure zones and the locations of future development projects are shown on Figure 8-1. Table 8-1 provides a summary of the existing and proposed pressure zone boundaries with key characteristics such as service elevations and static pressure ranges.
System pressures at some service elevations in the Tracy Hills development are expected to be high (up to 1 18 psi or more) due to the service elevation ranges proposed for Zones 5 and 6 as developed in the Tracy Hills Water Study (RJA, 2014) . To be consistent with the study, the proposed service elevation ranges for Zones 5 and 6 were not adjusted for this Citywide WSMP Update. However, it is recommended that these proposed pressure zones for the Tracy Hills development be reviewed and redefined, if possible, to reduce the occurrence of such high system pressures.
As discussed in Chapter 6, the highest recommended system pressure for the Citywide WSMP Update is 100 psi and any water service connection s located in areas with service connection pressures exceeding 80 psi will require the installation of individual PRVs to reduce the pressure below 80 psi.
0 4,5002,250
Scale in Feet
Figure 8-1
Proposed Development Areas
and Pressure Zone Boundaries
City of Tracy
Water System Master Plan Update
Last Saved: 7/2/2021 7:13:46 AM N:\Clients\404 Tracy\12-18-41 Water Master Plan Update\GIS\MXD\Report Figures\Fig_8-1_Proposed Development Projects.mxd : rchu Notes:
1. Dobler / Maibes is part of the I-205 Specific Plan
area, but is accounted for separately in this WSMP .
2. Pressure zone boundaries shown reflect planned
re-zoning of areas to take place by buildout.
3. Small Approved Projects include Home 2 Suites,
321 E. Grant Line Road Apartments, and Barcelona
Infill.
Symbology
Pressure Zone
Specific Plans
I-205 Corridor
Industrial Areas
Northeast
Industrial Area
Avenues
Cordes Ranch
Ellis
Tracy Hills
Tracy Village
Westside
Other Approved
Projects
Berg Road
Subdivision
Dobler / Maibes
Kagehiro
Rocking Horse
Legacy Fields
Small Approved
Projects
Annexations
Mountain View
Annexation
Additional Planned
Development Areas
Berg / Byron
Remainder
Chrisman Road
East Side
Industrial
Holly Sugar
Industrial
I-205 Expansion
Larch-Clover
Rocha
SWC Valpico &
Corral Hollow
UR 1
UR 3 (Sandhu)
UR 4 (Bright
Triangle)
UR 5 (Bright)
UR 7
(Bright/Castro)
UR 10
West Side
Industrial
580
205
205
Northeast Industrial
Area
Industrial
Areas
Industrial
Areas
I-205
I-205
I-205
Legacy Fields
Mountain View
SWC Valpico
& Corral Hollow
Berg / Byron
Remainder
Zone 1
Zone 2
Zone 2
Zone 3
Zone 3Zone 4
Zone 5Zone 6
Ellis Reduced
Zone
Barcelona
Infill
Home 2
Suites
321 E. Grant Line
Rd. Apartments
SCHULTE CT
ELEVENTH ST
CORRAL HOLLOW RD
M
AC
ARTHUR
DRTRACY BL
BYRON RD
GRANT LINE RD
MOUNTAIN HOUSE PK
BANTA RD
NAGLEE RD
LAMMERS RD
HANSEN RD
VALPICO RD
BIRD RD
LOVELY RD
LINNE RD
HOLLY DR
BETHANY RD
MIDDLE RD
CHRISMAN RD
VON SOSTEN RD
AHERN
RD
REEVE RD
DURHAM FERRY RD
SCHULTE RD
C a l i f o r n i a
A qu e d uc t
D e l t a - M e n d o ta
C
anal
Tracy
Hills
Cordes
Ranch
Westside
Tracy
Village
Ellis
Avenues
Berg Road
Subdivision
Dobler /
Maibes
Rocking
Horse
Kagehiro
UR 10
West Side
Industrial
Larch-Clover
I-205
Expansion East Side
Industrial
UR 1
UR 5
(Bright)
Chrisman
Road
UR 7
(Bright/Castro)
Rocha
UR4
(Bright
Triangle)
Holly
Sugar
Industrial
UR 3
(Sandhu)
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Table 8-1. Existing and Proposed Pressure Zone Boundaries Pressure Zone
Nominal
Hydraulic Grade, ft
Nominal Range of
Service Elevations, ft
Static Pressure
Range, psi
Zone 1 195 0 - 75 40 - 75
Zone 2 270 75 - 150 40 - 85(a)
Zone 3 (formerly
City-Side Zone 3) 368 150 - 245 55 - 95(a)
Ellis Reduced Zone 323 140 - 185 60 - 80
Zone 4 (formerly
Tracy Hills Zone 3) 425 209 - 325 43 - 93(a)
Zone 5 (formerly
Tracy Hills Zone 4)(b) 580 305 - 470 47 - 118(a)
Zone 6 (formerly
Tracy Hills Zone 5)(b) 735 460 - 630 45 - 118(a)
(a) Per the California Plumbing Code, services which experience pressures exceeding 80 psi are required to be fitted with a pressure reducing valve.
(b) Based on Tracy Hills Water Study prepared by RJA, December 2014.
8.3 PROJECTED FUTURE POTABLE WATER DEMANDS
Future potable water demands were developed based on the additional projected future land use information provided by the City, and the adopted unit water demand factors as described in Chapter 4. Based on the existing and proposed pressure zone boundaries, the projected potable water demands were calculated and categorized by pressure zone. Table 8-2 summarizes the City’s 2025 potable water demands (including existing demands) by pressure zone. Table 8-3 summarizes the City’s buildout potable water demands (including existing and 2025 demands) by pressure zone. Table 8-4 provides additional detail of the projected average day water demands at buildout for each future development project by pressure zone (not including existing demands).
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Table 8-2. 2025 Potable Water Demands by Pressure Zone
Pressure Zone
Average Day
Demand(a)
Maximum Day
Demand(b)
Peak Hour
Demand(c)
gpm mgd gpm mgd gpm mgd
Zone 1 7,590 10.9 12,903 18.6 22,011 31.7
Zone 2 4,251 6.1 7,227 10.4 12,329 17.8
Zone 3
PPBP(d) 392 0.6 667 1.0 1,138 1.6
Ellis Reduced Zone 186 0.3 316 0.5 540 0.8
Other 474 0.7 806 1.2 1,375 2.0
Zone 4 370 0.5 629 0.9 1,074 1.5
Total 13,264 19.1 22,550 32.5 38,467 55.4
(a) Equal to existing water demands plus projected 2025 water demands presented in Table 4-16. (b) Maximum day demand is 1.7 times the average day demand. (c) Peak hour demand is 2.9 times the average day demand. (d) Water demands from PPBP are not included in the City’s water production totals because the water supply for this area is purchased by PPBP from the Byron Bethany Irrigation District. However, the City is responsible for providing water treatment and delivery services to PPBP.
Table 8-3. Buildout Potable Water Demands by Pressure Zone Pressure Zone
Average Day
Demand(a)
Maximum Day
Demand(b)
Peak Hour
Demand(c)
gpm mgd gpm mgd gpm mgd
Zone 1 11,249 16.2 19,123 27.5 32,622 47.0
Zone 2 5,816 8.4 9,887 14.2 16,866 24.3
Zone 3
PPBP(d) 392 0.6 667 1.0 1,138 1.6
Ellis Reduced Zone 342 0.5 582 0.8 993 1.4
Other 1,286 1.9 2,185 3.1 3,728 5.4
Zone 4 1,187 1.7 2,018 2.9 3,443 5.0
Zone 5 568 0.8 965 1.4 1,646 2.4
Zone 6(e) 309 0.4 526 0.8 897 1.3
Total 21,149 30.5 35,954 51.8 61,333 88.3
(a) Equal to existing water demands plus projected buildout water demands presented in Table 4-16. (b) Maximum day demand is 1.7 times the average day demand. (c) Peak hour demand is 2.9 times the average day demand. (d) Water demands from PPBP are not included in the City’s water production totals because the water supply for this area is purchased by PPBP from the Byron Bethany Irrigation District. However, the City is responsible for providing water treatment and delivery services to PPBP.
(e) Tracy Hills demands were allocated by pressure zone based on recent land use data provided by the City's planning division. The proportion of Tracy Hills demands allocated to Zone 6 in this WSMP is significantly greater than allocated to Zone 6 (formerly Tracy Hills Zone 5) in the Tracy Hills Water Study prepared by RJA (December 2014). Demands should be confirmed using the most recent land use data before development of Zones 5 and 6 begins.
Table
8-4. Summary of Buildout Average Day Potable Water Demands by Development Project(a,b )
gpm pe
rcent of total gpm percent of total gpm percent of total gpm percent of total gpm percent of total gpm percent of total gpm percent of total UR 5 (Bright) 181.79 4.14% 0.00% 0.00% 0.00% 0.00% 0.00% 181.79 1.81% UR 7 (Bright/Castro) 136.40 3.10% 0.00% 0.00% 0.00% 0.00% 0.00% 136.40 1.36% Rocking Horse 0.00% 63.37 3.08% 0.00% 0.00% 0.00% 0.00% 63.37 0.63% Tracy Village 0.00% 183.40 8.91% 0.00% 0.00% 0.00% 0.00% 183.40 1.82% UR 1 535.24 12.18% 219.02 10.64% 0.00% 0.00% 0.00% 0.00% 754.26 7.50% Ellis 0.00% 0.00% 324.35 21.10% 0.00% 0.00% 0.00% 324.35 3.23% Avenues 0.00% 134.59 6.54% 0.00% 0.00% 0.00% 0.00% 134.59 1.34% UR 10 0.00% 0.00% 87.91 5.72% 0.00% 0.00% 0.00% 87.91 0.87% Tracy Hills 0.00% 0.00% 0.00% 1,187.29 100.00% 567.61 100.00% 309.45 100.00% 2064.35 20.53% Westside 389.47 8.87% 389.47 18.92% 0.00% 0.00% 0.00% 0.00% 778.94 7.75% Cordes Ranch 0.00% 464.82 22.58% 627.36 40.82% 0.00% 0.00% 0.00% 1092.17 10.86% UR 4 (Bright Triangle) 239.63 5.45% 0.00% 0.00% 0.00% 0.00% 0.00% 239.63 2.38% UR 3 (Sandhu) 437.60 9.96% 69.79 3.39% 0.00% 0.00% 0.00% 0.00% 507.39 5.05% I-205 Expansion 325.93 7.42% 0.00% 0.00% 0.00% 0.00% 0.00% 325.93 3.24% West Side Industrial 0.00% 0.00% 492.57 32.05% 0.00% 0.00% 0.00% 492.57 4.90% East Side Industrial 280.33 6.38% 0.00% 0.00% 0.00% 0.00% 0.00% 280.33 2.79% Larch-Clover 402.17 9.15% 0.00% 0.00% 0.00% 0.00% 0.00% 402.17 4.00% Chrisman Road 89.42 2.04% 0.00% 0.00% 0.00% 0.00% 0.00% 89.42 0.89% Rocha 0.00% 144.91 7.04% 0.00% 0.00% 0.00% 0.00% 144.91 1.44% Berg/Byron Remainder 116.54 2.65% 0.00% 0.00% 0.00% 0.00% 0.00% 116.54 1.16% Berg Road Subdivision 16.84 0.38% 0.00% 0.00% 0.00% 0.00% 0.00% 16.84 0.17% SWC Valpico & Corral Hollow 0.00% 79.07 3.84% 0.00% 0.00% 0.00% 0.00% 79.07 0.79% Kagehiro 0.00% 55.70 2.71% 0.00% 0.00% 0.00% 0.00% 55.70 0.55% Dobler/Maibes 24.13 0.55% 0.00% 0.00% 0.00% 0.00% 0.00% 24.13 0.24% Holly Sugar Industrial 113.61 2.59% 0.00% 0.00% 0.00% 0.00% 0.00% 113.61 1.13% Northeast Industrial Area 446.12 10.15% 0.00% 0.00% 0.00% 0.00% 0.00% 446.12 4.44% Industrial Areas Specific Plan 0.00% 146.92 7.14% 0.00% 0.00% 0.00% 0.00% 146.92 1.46% I-205 Corridor Specific Plan 46.93 1.07% 0.00% 0.00% 0.00% 0.00% 0.00% 46.93 0.47% Mountain View 0.00% 54.38 2.64% 0.00% 0.00% 0.00% 0.00% 54.38 0.54% Legacy Fields 32.44 0.74% 0.00% 0.00% 0.00% 0.00% 0.00% 32.44 0.32% Small
Approved Projects(c) 202.6
9 4.61% 0.00 0.00% 0.00% 0.00% 0.00% 0.00% 202.69 2.02% Infill (misc.) 375.96 8.56% 53.02 2.58% 4.87 0.32% 0.00% 0.00% 0.00% 433.85 4.32% Total 4,393.25 100% 2,058.45 100% 1,537.05 100% 1,187.29 100% 567.61 100% 309.45 100% 10,053.10 100% (a) W
ater demands shown are for new development only and do not include existing potable water demands. See Appendix A for detailed demand calculations by project or development area. (b) Water demands shown include UAFW.
(c) Includes Home 2 Suites, 321 E. Grant Line Road Apartments, and Barcelona Infill.
Also includes the following identified projects within the I-205 Corridor Specific Plan area: Sierra Hills, Grant Line Road Apartments, Aspire II, Harvest.
Zone 6 T
otalZone 1 Zone 2 Zone 3 and Ellis Reduced Zone Zone 4 Zone 5 Project or Development Area
n\c\404\12-1
8-41\e\ch8\ch8tables
Last Revised: 07-01-21
City o
f Tracy
Citywide Water System
Master Plan Update
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8.4 FUTURE POTABLE WATER SYSTEM FACILITY EVALUATION
To develop the future potable water system, analyses addressing the following system facilities were conducted:
• Water Treatment Capacity
• Water Storage Capacity
• Pumping Capacity
• Critical Supply Facilities
The results from the future potable water system facilities analyses are discussed below.
Recommendations for supporting projected future potable water demands and addressing any deficiencies identified within the future potable water backbone transmission and distribution system are summarized in Section 8.6 Summary of Recommended Future Potable Water System Improvements.
8.4.1 Water Treatment Capacity
Sufficient water treatment capacity from the JJWTP, the South County Water Supply Project, and groundwater wells will be required to meet the City’s 2025 and buildout maximum day demand conditions. In addition, the City’s goal is to have sufficient surface water treatment capacity to meet the 2025 and buildout maximum month demands without relying on groundwater.
Table 8-5 shows that the City’s current water treatment capacity is sufficient to meet 2025 maximum day potable water demands and that the City’s current surface water treatment capacity is sufficient to meet 2025 maximum month potable water demands.
Table 8-5. Comparison of Available and Required Water Treatment Capacity in 2025, mgd Demand Condition JJWTP(a)
South County
Water Supply
Project(b) Groundwater
Total Treated
Water
Capacity
2025
Demand
Treated Water
Capacity Surplus
or (Deficit)
Maximum Day 27 15.5 21.7(c) 64.2 32 32
Maximum Month(d) 27 15.5 0.0(e) 42.5 29 13
(a) Supplied from Zone 1 36-inch diameter transmission main, Zone 2 BPS, Zone 3 BPS, and Zone 4 BPS. Although the JJWTP is designed to supply 30 mgd, the actual maximum pumping capacity of the intake pumps is 27 mgd. (b) Supplied from Linne Road and NEI Booster Pump Stations. It is anticipated that as Manteca and Lathrop develop, Tracy's share of the deliverable capacity from this source will be reduced to 15.5 mgd. (c) Equivalent to firm groundwater pumping capacity, assuming that 20 percent of the City's wells would be out of service (i.e., approximately two wells: one in Zone 1, and one at the JJWTP). (d) Estimated to be 90 percent of maximum day demands.
(e) The City's goal is to meet maximum month demands without relying on groundwater supply.
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Table 8-6 shows that the City’s current water treatment capacity is sufficient to meet buildout maximum day potable water demands . Although the City’s current surface water treatment capacity is not sufficient to meet buildout maximum month potable water demands, the deficit could be made up using 4 mgd of groundwater.
Table 8-6. Comparison of Available and Required Water Treatment Capacity at Buildout, mgd Demand Condition JJWTP(a)
South County
Water Supply
Project(b) Groundwater
Total Treated
Water
Capacity
Buildout
Demand
Treated Water
Capacity Surplus
or (Deficit)
Maximum Day 27 15.5 32.5(c) 75.0 52 23
Maximum Month(d) 27 15.5 0.0(e) 42.5 47 (4)
(a) Supplied from Zone 1 36-inch diameter transmission main, Zone 2 BPS, Zone 3 BPS, and Zone 4 BPS. Although the JJWTP is designed to supply 30 mgd, the actual maximum pumping capacity of the intake pumps is 27 mgd. (b) Supplied from Linne Road and NEI Booster Pump Stations. It is anticipated that as Manteca and Lathrop develop, Tracy's share of the deliverable capacity from this source will be reduced to 15.5 mgd. (c) Equivalent to firm groundwater pumping capacity, assuming that 20 percent of the City's wells would be out of service (i.e., approximately three wells: two in Zone 1, and one at the JJWTP). Includes the capacity of recommended wells to be constructed by buildout.
(d) Estimated to be 90 percent of maximum day demands.
(e) The City's goal is to meet maximum month demands without relying on groundwater supply.
Based on discussion with City staff, plans for a future 15 mgd expansion at the JJWTP were already envisioned and integrated into the planning and associated environmental review process during the most recent 15 mgd expansion (from 15 to 30 mgd) completed in 2008. Based on the updated future demand projections, an expansion of the JJWTP would not be required if the City is able to pump groundwater at a sustainable rate to supplement surface water treatment capacity.
However, as a part of the City’s wastewater permit, the City needs to reduce the use of the groundwater as part of its Salinity Reduction Plan, as well as to comply with the Groundwater Sustainability Plan prepared for compliance with the Sustainable Groundwater Management Act .
As such, a future additional 10 mgd expansion of the JJWTP is recommended to provide the City with additional water treatment capacity, as well as operational flexibility and reliability, if the use of groundwater supplies needs to be limited or if there is a supply outage from South County Water Supply Project. The expansion would also include a new administration/maintenance building to accommodate future staffing needs and maintenance activities.
Additional JJWTP treated water storage and pumping facilities are also recommended at buildout.
Based on the additional demands in Zone 3 at buildout, it is recommended that a new clearwell be constructed at the JJWTP to provide operational flexibility for the water treatment plant and to provide additional operational and emergency storage capacity to serve future developments. For this Citywide WSMP Update, it was assumed that the new clearwell will have a minimum active (useable) storage capacity of 1.0 MG. Buildout demands will also require new booster pumps to be installed at the JJWTP. Section 8.4.3 Pumping Capacity provides additional discussion regarding the additional treated surface water booster pumping capacity required at the JJWTP to serve buildout maximum day demands.
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8.4.2 Water Storage Capacity
The principal advantages that storage provides for the water system are the ability to e qualize demands on supply sources, production facilities, and transmission mains; to provide emergency storage in case of supply failure; and to provide water to fight fires. The City’s water service area has two sources of available storage: above ground storage (i.e., clearwells and storage tanks) and storage available through the groundwater basin. Together, these two sources of storage must be sufficient to meet the City’s operational, emergency, and fire flow storage criteria. The volumes required for each of these three storage components are listed below:
• Operational Storage: 30 percent of a maximum day demand. • Emergency Storage: 1.5 times an average day demand.
• Fire Flow Storage: The required fire flow rates multiplied by their associated fire flow duration periods, as required by the City’s Fire Department. For larger pressure zones, two concurrent fire flow events were assumed for the storage capacity analysis.1 However, the recommended fire flow storage does not include the volume associated with sprinkler flows.
Because the City’s potable water supply includes supply from groundwater wells, the groundwater basin can account for a portion of the recommended em ergency storage, in the form of a groundwater credit. However, the following must be true to use the groundwater supply to offset the need to provide surface storage reservoirs:
• Groundwater supply is of potable water quality and can be reliably accessed (i.e., wells are equipped with on-site emergency generators). • Groundwater supply is not already relied upon to meet the City’s average day demand requirements.
• Groundwater supply is of firm groundwater supply availability (i.e., assumes 20 percent of wells will be out of service at any given time). • Sufficient water distribution facilities are available to distribute this water to demand areas.
1 Two concurrent fire flow events were not simulated in Zones 4, 5 and 6 for the Tracy Hills development because these smaller pressure zones do not justify the use of two simultaneous fire flow events.
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n\c\404\12-18-41\wp\R-404-WMPU Master Plan Update
In addition, the City currently has two independent sources of treated surface water supply, and some quantity of the total treated surface water supply capacity can also account for a portion of the recommended emergency storage. The treated surface water credit assumes that the smaller of the treated surface water supply sources can be available to offset a portion of the emergency storage requirement. However, the following must be true to use treated surface water supply to offset the need to provide above-ground storage:
• Treated surface water supply can be reliably accessed (i.e., treated surface water supply facility is equipped with on-site emergency generator). • Sufficient treated surface water booster pumping facilities are available to distribute this water to demand areas.
In summary, the Emergency Storage Credit is equal to the sum of the groundwater and treated surface water supply credits. However, the Emergency Storage Credit can only provide a maximum storage credit equal to the City’s required emergency storage volume.
The existing potable water storage facilities (including the Tracy Hills At -Grade Tank, which is currently under construction), in conjunction with the available Emergency Storage Credit, were evaluated to determine whether the Ci ty’s current potable water system has sufficient storage capacity within each pressure zone to provide the required operational, emergency, and fire flow storage for the 2025 and buildout timeframes.
Table 8-7 provides a comparison of the City’s available potable water storage capacity and emergency storage credit with the required 2025 storage capacity . The comparison indicates that the City’s existing facilities will b e sufficient and that no additional storage facilities need to be constructed by 2025.
Table 8-8 provides a comparison of the City’s available potable water storage capa city and emergency storage credit with the required buildout storage capacity. The comparison between the City’s available and required storage capacities indicates that the City will have the following potable water storage capacity deficits within each pressure zone at buildout:
• Zones 1 and 22: 0.2 MG
• Zone 3: 1.2 MG
• Zone 4: 0.6 MG
• Zone 5: 2.6 MG
• Zone 6: 1.1 MG
2 Under existing conditions, Zones 1 and 2 are interconnected through six existing pressure regulating stations (PRS). Therefore, Zones 1 and 2 were evaluated together for the future potable water system facility evaluation. [A] [B] [C] [D] [E] [F] [G] = [C]
+ [F] [H] [I] [J] [K] = [H] + [I] + [J] [L] = [G] - [K] Groundwater
Credit(a)
Treated
Surface
Wate
r Supply
Credit(b)
Total Em
ergency
Storage Credit(c)
NEI Ac
tive 2.4 --
Lincoln Well Active -- 5.40
Lewis Manor Well Inactive -- --
Park and Ride Well Active -- 4.32
Ball Park Well Active -- 5.40
Well 8(f)
Acti
ve -- --
Linne Active 7.1 --
Well 1(g)
Acti
ve -- --
Well 2(f,g)
Acti
ve -- --
Well 3(f,g)
Acti
ve -- --
Well 4(f,g)
Acti
ve -- --
Clearwell #2 Active 4.0 --
Cordes Active 2.0 -- 0.00 2.27(i) 4.27 0.7
7 2.27 1.14(h) 4.19 0.1
Tracy Hills At-Grade Under Construction 3.8 -- 0.00 0.00 3.75 0.27 0.80 0.18(j) 1.25 2.5
(h) B
ased on storage required for two concurrent fire flow events; a Single Family Residential fire flow and an Industrial fire flow (see Table 6-1). (i) Surplus Treated Surface Water Supply Credit from other pressure zones can be used to provide emergency storage for Zone 3. (j) Based on storage required for a Single Family Residential fire flow (see Table 6-1).
Zone
3 and Ellis Reduced Zone
(g) W
ell does not contribute to Groundwater Credit because water produced by the well must be blended with chlorinated water from the JJWTP prior to distribution. The JJWTP is assumed to be offline in an emergency.
Zone
4 (a) Credit
based on 1.5 days of pumping capacity from active groundwater wells with on-site backup power because the required emergency storage capacity is equal to 1.5 times the average day demand.
See Table 7-2 for individual well capacity.
(b) Credit based on 1.5 days of available treatment capacity (17 mgd) from the SCWSP because the required emergency storage capacity is equal to 1.5 times the average day demand. (c) Equal to the sum of the groundwater and treated surface water supply credits; however, the maximum credit is equal to the required emergency storage capacity. (d) Based on 30 percent of a maximum day demand (see Table 8-2). (e) Based on 1.5 times the average day demand (see Table 8-2). (f) Well does not contribute to Groundwater Credit because it does not have on-site backup power.
Zone
1 and Zone 2
25.50 25.58 39.08 8.70 25.58 1.14(h) 35.41
3.6 Tab
le 8-7. Comparison of Available and Required Water Storage Capacity in 2025 Station Status
Av
ailable Storage Capacity, MG Required Storage Capacity, MG Storage Surplus
(Deficit), MGReservoir Capacity
Emergency Storage Credit
Total Available Storage Operational (d) Emerge
ncy(e) Fire Flow
Total Required Storage
n\c\
404\12-18-41\engr\Ch8\Ch 8 Tables\Table 8-8
Last Revised: 03-03-20
City of Tra
cy
Citywide Water System
Master Plan Update
[A] [B] [C] [D] [E] [F] [G] = [C]
+ [F] [H] [I] [J] [K] = [H] + [I] + [J] [L] = [G] - [K] Groundwater
Credit(a)
Treated
Surface
Wate
r Supply
Credit(b)
Total Em
ergency
Storage Credit(c)
NEI Ac
tive 2.4 --
Lincoln Well Active -- 5.40
Lewis Manor Well Inactive -- --
Park and Ride Well Active -- 4.32
Ball Park Well Active -- 5.40
Well 8(f)
Acti
ve -- --
Linne Active 7.1 --
Well 1(g)
Acti
ve -- --
Well 2(f,g)
Acti
ve -- --
Well 3(f,g)
Acti
ve -- --
Well 4(f,g)
Acti
ve -- --
Clearwell #2 Active 4.0 --
Cordes Active 2.0 -- 0.00 3.27(i) 5.76 1.4
8 4.36 1.14(h) 6.99 (1.2)
Trac
y Hills At-Grade Under Construction 3.8 -- 0.00 0.00 3.75 0.87 2.56 0.96(j) 4.40 (0.6) -- -- -- -- 0.0
0 0.00 0.00 0.42 1.23 0.96(j) 2.60 (2.6)
-- -- -- -- 0.0
0 0.00 0.00 0.23 0.67 0.18(k) 1.08 (1.1)
Zo
ne 1 and Zone 2
Zone 3 and Ellis Reduced Zone
25.50 36.86 50.36 12.53 36.86 1.14(h) 50.53
(0.2)
Tab
le 8-8. Comparison of Available and Required Water Storage Capacity at Buildout Station Status
Av
ailable Storage Capacity, MG Required Storage Capacity, MG Storage Surplus
(Deficit), MGReservoir Capacity
Emergency Storage Credit
Total Available Storage Operational (d) Emerge
ncy(e) Fire Flow
Total Required Storage
(d) B
ased on 30 percent of a maximum day demand (see Table 8-3). (c) Equal to the sum of the groundwater and treated surface water supply credits; however, the maximum credit is equal to the required emergency storage capacity. (b) Credit based on 1.5 days of available treatment capacity (17 mgd) from the SCWSP because the required emergency storage capacity is equal to 1.5 times the average day demand.
Zone
4 Zone 5
Zone 6
(a) Credit
based on 1.5 days of pumping capacity from active groundwater wells with on-site backup power because the required emergency storage capacity is equal to 1.5 times the average day demand.
See Table 7-2 for individual well capacity.
(k) Based on storage required for a Single Family Residential fire flow (see Table 6-1). (i) Surplus Treated Surface Water Supply Credit from other pressure zones can be used to provide emergency storage for Zone 3. (e) Based on 1.5 times the average day demand (see Table 8-3). (j) Based on storage required for an Industrial or Institutional fire flow (see Table 6-1). (g) Well does not contribute to Groundwater Credit because water produced by the well must be blended with chlorinated water from the JJWTP prior to distribution. The JJWTP is assumed to be offline in an emergency. (f) Well does not contribute to Groundwater Credit because it does not have on-site backup power. (h) Based on storage required for two concurrent fire flow events; a Single Family Residential fire flow and an Industrial fire flow (see Table 6-1). n\c\
404\12-18-41\engr\Ch8\Ch 8 Tables\Table 8-8
Last Revised: 07-01-21
City of Tra
cy
Citywide Water System
Master Plan Update
Chapter 8
Future Potable Water System Evaluation
8-14 City of Tracy
May 2023 Citywide Water System
n\c\404\12-18-41\wp\R-404-WMPU Master Plan Update
It should be noted that in the period be fore the future Clearwell #3 is completed, the full storage capacity in Clearwell #2 is not available. During normal operations, the water level in Clearwell #2 is maintained near the maximum water level, at water surface elevation (WSEL) 197.5 feet, approximately 11.5 feet above the floor. This maximum WSEL provides approximately 4 MG of storage in Clearwell #2. Under emergency conditions, the City is able to significantly draw down the WSEL in Clearwell #2 with the Zone 2 pumps. However, because the Zone 4 and Zone 5 pump station suction pipe cannot draw water from Clearwell #2 at a WSEL less than approximately five feet above the floor, the available storage in Clearwell #2 is currently limited to 2.25 MG. Until the Tracy Hills tanks are in service, sufficient operational, emergency, and fire flow storage must be maintained in Clearwell #2 to serve Tracy Hills and prevent dewatering of the Zone 4 and Zone 5 pumps.
Once in service, the Tracy Hills Zone 4 tank will provide sufficient operational, emergency, and fire storage for Zone 4. Similarly, the planned Zone 5 tank will provide sufficient operational, emergency, and fire storage for Zones 5 and 6 once constructed. With these tanks in service, the full volume of Clearwell #2 may be used in an emergency. Although this will dewater the Zone 4 and Zone 5 pumps, the Tracy Hills tanks will provide emergency supply to Zones 4 and 5 until service from the JJWTP can be restored. The water level in Clearwell #2 should still be maintained at greater than five feet above the floor for normal operations.
An additional clearwell (Clearwell #3) is proposed at the JJWTP and will be hydraulically connected to Clearwell #2 and the Zone 4 and Zone 5 pump stations. Once Clearwell #3 is constructed, the suction piping for the Tracy Hills pump stations will be connected to the pump wet well in Clearwell #3 at a low enough elevation to allow the Tracy Hills pump stations to continue in operation as long as volume remains in Clearwell #3, allowing the City to use the full volume of operational, emergency, and fire flow storage in both Clearwell #2 and Clearwell #3 without dewatering the Zone 4 and Zone 5 pumps.
Based on the storage capacity deficits identified in Table 8-8, Table 8-9 summarizes the recommended facility improvements to provide additional buildout storage capacity. The proposed specific facility improvements are based on those presented in the 2012 WSMP and in the Tracy Hills Water Study (RJA, December 2014) , but were modified to reflect the reduced buildout storage capacity requirements.
[A] [B] [C] [D] [E] [F] [G] = [C] + [F] [H] [I] [J
] [K] = [H] + [I] + [J] [L] = [G] - [K]
Groundwater
Credit(a)
Trea
ted Surface
Wa
ter Supply
Credit(b)
Total Eme
rgency
Storage Credit(c)
NEI Acti
ve 2.4 --
Lincoln Well Active -- 5.40
Lewis Manor Well Inactive -- --
Park and Ride Well Active -- 4.32
Ball Park Well Active -- 5.40
Well 8(f)
Activ
e -- --
Linne Active 7.1 --
Well 1(g)
Activ
e -- --
Well 2(f,g)
Activ
e -- --
Well 3(f,g)
Activ
e -- --
Well 4(f,g)
Activ
e -- --
Clearwell #2 Active 4.0 --
Westside Tank Proposed(h) 1.0 --
W
estside ASR Well Proposed -- 5.40
Wainwright ASR Well Proposed -- 5.40
Larsen Park ASR Well Proposed -- 5.40
Cordes Active 2.0 --
JJWTP Clearwell #3 Proposed(h)
1.0 --
Ellis
ASR Well Proposed -- 2.16
Tracy Hills At-Grade Under Construction 3.8 -- 0.00 0.00 3.75 0.87 2.56 0.96(k) 4.40 (0.6)
Gravity Tank(l) Prop
osed(h)
3.2 -- 0
.00 0.00 3.2 0.42 1.23 0.96(k) 2.60
0.6 Gravity Tank(m) Prop
osed(h)
1.1 -- 0
.00 0.00 1.10 0.23 0.67 0.18(n) 1.08
0.0 Table 8-9. Co
mparison of Available, Proposed, and Required Water Storage Capacity at Buildout Station Sta
tus
Available Storage Capacity, MG Required Storage Capacity, MG Storage Surplus
(Deficit), MGReservoir Capacity
Emergency Storage Credit
Total Available Storage Operational (d) Eme
rgency(e) Fire Flow
Total Required Storage
Zone 1 and Zone 2
25.50 36.86 36.8651.36 12.53 1.14(i) 50
.53 0.8
0.4 Zone 3 and Ellis Reduced Zone
7.36 1.14(i) 6.99
1.48 4.360.00
Zone 4
Zone 5
Zone 6
(a) Credit
based on 1.5 days of pumping capacity from active groundwater wells with on-site backup power because the required emergency storage capacity is equal to 1.5 times the average day demand.
See Table 7-2 for the individual capacity of existing wells. Proposed ASR wells in Zone 1 and Zone 2 were assumed to have a capacity of 2,500 gpm. The proposed Ellis ASR Well was assumed to have a capacity of 1,000 gpm.
4.86(j)
(n)
Based on storage required for a Single Family fire flow (see Table 6-1). (m) Based on previous recommendations from the Tracy Hills Water Study prepared by RJA (December 2014). Sizing of the proposed tank should be confirmed before development of Zone 6 begins. (g) Well does not contribute to Groundwater Credit because water produced by the well must be blended with chlorinated water from the JJWTP prior to distribution. The JJWTP is assumed to be offline in an emergency. (b) Credit based on 1.5 days of available treatment capacity (17 mgd) from the SCWSP because the required emergency storage capacity is equal to 1.5 times the average day demand. (c) Equal to the sum of the groundwater and treated surface water supply credits; however, the maximum credit is equal to the required emergency storage capacity. (d) Based on 30 percent of a maximum day demand (see Table 8-3). (e) Based on 1.5 times the average day demand (see Table 8-3). (f) Well does not contribute to Groundwater Credit because it does not have on-site backup power. (h) Proposed reservoir capacity is the recommended active and useable reservoir storage capacity and does not include dead and freeboard storage, which will be determined during design. (l) The Tracy Hills Water Study prepared by RJA (December 2014) recommended two Zone 5 (formerly Tracy Hills Zone 4) tanks with a combined capacity of 8.8 MG. Recommended Zone 5 capacity is significantly smaller than previously evaluated due to decrease in demand factors and emergency storage requirement. Sizing of the proposed tanks should be confirmed before development of Zone 5 begins. (i) Based on storage required for two concurrent fire flow events; a Single Family Residential fire flow and an Industrial fire flow (see Table 6-1). (j) Surplus Treated Surface Water Supply Credit from other pressure zones can be used to provide emergency storage for Zone 3. (k) Based on storage required for an Industrial or Institutional fire flow (see Table 6-1). n\c\40
4\12-18-41\engr\Ch8\Ch 8 Tables\Table 8-8
Last Revised: 07-01-21
City
of Tracy
Citywide Water System
Master Plan Update
Chapter 8
Future Potable Water System Evaluation
8-16 City of Tracy
May 2023 Citywide Water System
n\c\404\12-18-41\wp\R-404-WMPU Master Plan Update
A portion of the buildout storage capacity requirement is met by additional Emergency Storage Credit provided by the new ASR wells recommended in Chapter 5. It was assumed that three of the ASR wells will be located in Zones 1 and 2, while the fourth ASR well will be locat ed in Zone 3.
The ASR well in Zone 3 was assumed to have a lower production capacity due to the less ideal aquifer conditions underlying Zone 3. All new wells should be equipped with ammonia addition.
It is recommended that the City construct a 1.0 MG pumped storage tank near the Westside Specific Plan development in Zone 1. In addition to providing additional storage capacity needed to meet the operational storage requirement for Zones 1 and 2, the Westside Tank would provide localized storage for the nort hwest sector of the City. Localized storage provides supply reliability in the chance that storage from the JJWTP or any other storage facility is unavailable for any reason.
It is recommended that the City construct a Clearwell (Clearwell #3) with a mini mum volume of
1.0 MG at the JJWTP to provide additional storage capacity for Zone 3. In addition to providing storage, Clearwell #3 would provide operational flexibility for the JJWTP. Because of the additional operational flexibility that Clearwell #3 wou ld provide, it is recommended that Clearwell #3 be constructed as soon as possible. As noted above, no additional storage facilities are required by 2025, but it is recommended that Clearwell #3 be constructed by no later than 2030.
It is also recommended that the City construct a 3.2 MG gravity storage tank in Zone 5 and a
1.1 MG gravity storage tank in Zone 6. The remaining 0.6 MG storage capacity deficit in Zone 4 is to be provided by Zone 5 via a PRV. It should be noted that the 3.2 MG capacity of the Z one 5 Tank recommended in this WSMP Update is significantly smaller than the 8.8 MG recommended in the Tracy Hills Water Study (RJA, December 2014) for several reasons: (1) s ince the Tracy Hills Water Study was conducted, the proposed land use plan for Tracy Hills has changed; (2) the water demand factors used to project demands for Tracy Hills in this WSMP Update are lower than those used in the Tracy Hills Water Study; and (3) the emergency storage capacity requirement used in this WSMP Update is lower than that used in the Tracy Hills Water Study. As proposed land use plans may continue to be refined, the size of the Zone 5 and Zone 6 tanks should be confirmed before development of Zones 5 and 6 begins.
8.4.3 Pumping Capacity
The existing and proposed pumping capacity in the City’s potable water system was evaluated to assess its ability to deliver a reliable firm capacity to serve the water service area for the 2025 and buildout timeframes. Firm capacity assumes a reduction in total pumping capacity to account for pumps that are out of service at any given time due to mechanical breakdowns, maintenance, water quality, or other operational issues. At each booster pump station, firm boo ster pumping capacity was defined as the total booster pump station capacity with the largest pump out of service. For groundwater well pumps, the firm groundwater pumping capacity assumed that 20 percent of the wells could be out of service at any given time.
Chapter 8
Future Potable Water System Evaluation
8-17 City of Tracy
May 2023 Citywide Water System
n\c\404\12-18-41\wp\R-404-WMPU Master Plan Update
The pumping capacity criterion for the City, described previously in Chapter 6, requires the City’s potable water system to have sufficient firm pumping capacity to meet the greater of either a maximum day demand with two simultaneous fire flow events3 or a peak hour demand. In addition, sufficient firm treated water pumping capacity should be available to meet a maximum day demand condition.
Table 8-10 provides a comparison between the City’s available firm pumping capacity and the required 2025 pumping capacity under different water demand conditions. The City’s existing pumping facilities are sufficient to meet the 2025 pumping capacity requirements.
Table 8-11 provides a comparison between the City’s available and proposed buildout firm pumping capacity for the different water demand scenarios. The proposed pumping facility improvements are based on:
• The necessity to deliver water from proposed storage facilities to the system. • The necessity to provide treated water pumping capacity to meet buildout maximum day demands (e.g., JJWTP Clearwell #3 pumps).
• The necessity for localized pumping capacity to support system pressure during periods of high demand (fire flow and peak hour).
The pumping capacity analysis indicate s that the City’s existing and proposed firm booster and groundwater pumping capacity will be sufficient to meet the pumping capacity criterion for the buildout water service area during the governing demand scenario within each pressure zone . It should be noted that Zones 5 and 6 will provide water supply by gravity, rather than by pumping, to meet potable water demands during maximum day plus fire flow and peak hour demand conditions.
It is recommended that the City construct Zone 1 and Zone 2 booster pumps at the proposed Westside Tank. Although the proposed capacity of these booster pumps is more than required to meet the Zone 1 and 2 pumping capacity requirements, the capacity of these pumps is needed to maintain sufficient system pressure during periods of high demand (fire flow and peak hour) in the northwest quadrant of the City.
It is also recommended that the City install additional Zone 3 booster pumps on the proposed Clearwell #3. It is recommended that these pumps have a capacity of at least 1,500 gpm to provide operational flexibility for the Zone 3 BPS.
A new Zone 5 BPS (located at the JJWTP) and a Zone 6 BPS must also be constructed to supply water to Zones 5 and 6, respectively. The Zone 5 BPS was sized based on the Tracy Hills Water Study (RJA, December 2014). The Zone 6 BPS recommended in this WSMP Update is larger than previously recommended in the Tracy Hills Water Study because the proposed land use plan for Tracy Hills has changed since the study was conducted. Sizing of the Zone 6 BPS should be confirmed before development of Zone 6 begins.
3 Two concurrent fire flow events were not simulated in Zones 4, 5 and 6 for the Tracy Hills development because these smaller pressure zones do not justify the use of two simultaneous fire flow events.
Pump Station Backup Pow
er Status Firm Capacity(a), gpm
T
otal Firm Pumping
Capacity from Supply
Sources, gpm(b)
2025 M
aximum Day
Demand, gpm
Pumping Capacity from
Supply Sources Surplus
(Deficit), gpm(b)
Total F
irm Pumping
Capacity, gpm
2025 Maximum Day
Demand with Fire Flow
Event(s), gpm
2025 Peak Hour
Demand, gpm
Pumping Capa
city Surplus
(Deficit), g
pm(c)
NEI Active 4,20
0 Zone 1 Active 12,000
Lincoln Well Active 2,500
Lewis Manor Well Inactive --
Park and Ride Well Active 2,000
Ball Park Well Active 2,500
Well 8 Active --
Linne Active 14,595
Zone 2 Active 13,300
Well 1(d)
Active --
W
ell 2(d)
Active --
W
ell 3(d)
Active --
W
ell 4(d)
Active --
Cord
es Active 6,150
Patterson Pass(f)
Inactiv
e --
Zone 3 Active 2,970
Zone 4 Active 2,450
Tracy Hills At-Grade Under Construction 5,900
(d) Wel
ls 1-4 located at JJWTP pump directly into the Chlorine Contact Basin or Clearwell #2; therefore, these wells do not provide additional pumping capacity to the system. (e) Equal to maximum day demand plus a 1,500 gpm Single Family Residential fire flow and a simultaneous 4,500 gpm Industrial fire flow. (f) Patterson Pass BPS is inactive since the Cordes BPS is now operating; therefore, it does not provide additional pumping capacity to the system. (g) Equal to maximum day demand plus a 1,500 gpm Single Family Residential fire flow. (a) Firm booster pumping capacity was defined as the total booster pump station capacity with the largest pump out of service and firm groundwater pumping capacity assumed that 20 percent of the City's wells would be out of service (i.e., approximately two wells: one in Zone 1, and one at the JJWTP). (b) Maximum day water demands should be met through firm treated water pumping capacity. The firm pumping capacity available from NEI and Linne is limited to 17 mgd based on the available water supply from the SCWSP. (c) Pumping capacity surplus (deficit) is the total firm pumping capacity minus the greater of the maximum day demand with required fire flow event(s) or peak hour demand.
Zone 4
2,45
0 629 1,821 8,350 2,095(g) 1,074 6,22
1 Zone 3 and Ellis Reduced Zone
2,970 1,790 1,180 9,120 7,676(e) 3,053 1,33
0 Table
8-10. Comparison of Available and Required Firm Pumping Capacity in 2025 Zones 1
and 2
44,106 20,131 23,975 51,095 26,839(e) 34,340 16,7
55 n\c\404\12-18-41\e
ngr\Ch8\Ch 8 Tables\Table 8-8
Last Revised: 03-03-20
City of Tra
cy
Citywide Water System
Master Plan Update
Backup Power Status Firm Cap
acity(a), gp
m
Total Firm Pumping
Capacity from Supply
Sources, gpm(b)
Build
out Maximum Day
Demand, gpm
Pumping Capacity from
Supply Sources Surplus
(Deficit), gpm(b)
Total Firm Pumping
Capacity, gpm
Buildout Maximum Day
Demand with Fire Flow
Event(s), gpm
Buildout Peak Hour
Demand, gpm
Pumpin
g Capacity Surplus
(Def
icit), gpm(c)
Active 4,200
Active 12
,000
Active 2,500
Inactive --
Active 2,000
Active 2,500
Active --
Active 14,595
Active 13,300
Active --
Active --
Active --
Active --
Proposed 4,500
Proposed 2,400
Proposed --
Proposed --
Proposed --
Active 6,150
Inactive --
Clearwell #2 Pumps Active 2,970
Clearwell #3 Pumps Proposed 1,500
Proposed --
Active 3,675
Under Construction 8,200
Proposed 2,410 2,410 1,491(k)
919
Prop
osed 550 550 526 24
(c) P
umping capacity surplus (deficit) is the total firm pumping capacity minus the greater of the maximum day demand with required fire flow event(s) or peak hour demand. (e) Equal to maximum day demand plus a 1,500 gpm Single Family Residential fire flow and a simultaneous 4,500 gpm Industrial fire flow. (i) Equal to maximum day demand plus a 4,500 gpm Industrial fire flow. (a) Firm booster pumping capacity was defined as the total booster pump station capacity with the largest pump out of service and firm groundwater pumping capacity assumed that 20 percent of the City's wells would be out of service (i.e., approximately two wells: one in Zone 1, and one at the JJWTP). It was assumed that the proposed ASR wells do not contribute to pumping capacity in a normal hydrologic year. (f) Patterson Pass BPS is inactive since the Cordes BPS is now operating; therefore, it does not provide additional pumping capacity to the system. (d) Wells 1-4 located at JJWTP pump directly into the Chlorine Contact Basin or Clearwell #2; therefore, these wells do not provide additional pumping capacity to the system.
Zone 4
Zone
5 Zone 6
3,675 2,018
4,470 3,435
NA
Tab
le 8-11. Comparison of Available, Proposed, and Required Firm Pumping Capacity at Buildout Zones 1 and
2 Zone 3 and Ellis Reduced Zone
44,106 29,010 15,096 57,995 35,754(e) 49,487 8,50
8 Pump Station
NEI
Zone 1
Lincoln Well
Lewis Manor Well
Park and Ride Well
1,035 10,620 9,590
(e) 5,859 1,18
5 Ball Park Well
Well 8
Linne
Zone 2
Well 1
(d)
Wel
l 2(d)
Wel
l 3(d)
Wel
l 4(d)
Westsid
e Ranch Tank Zone 1
Westside Ranch Tank Zone 2
Westside Ranch ASR Well
Wainwright ASR Well
Larsen Park ASR Well
Cordes
Patterson Pass
(f)
(b) M
aximum day water demands should be met through firm treated water pumping capacity. The firm pumping capacity available from NEI and Linne is limited to 17 mgd based on the available water supply from the SCWSP. 11,875 6,43
2(i) 3,443 5,35
71,657
NA
Zone 6(l)
Zone 3(g)
Ellis ASR W
ell
Zone 4(h)
Tracy Hil
ls At-Grade(h)
Zone 5(j)
(h) B
uildout firm capacity includes the capacity of an additional pump to be installed after 2025. (g) Zone 3 pumps on Clearwell #2 and Clearwell #3 are considered a single booster pump station for purposes of determining firm capacity. (j) Based on previous recommendations from the Tracy Hills Water Study prepared by RJA (December 2014). Water demands from Zone 5 (formerly Tracy Hills Zone 4) and Zone 6 (formerly Tracy Hills Zone 5) will be served from a single Zone 5 BPS located at the JJWTP. Water supplied by the Zone 5 BPS will be subsequently boosted by the Zone 6 BPS to serve Zone 6 water demands. (k) Equal to maximum day demands for Zone 5 and Zone 6. (l) Recommended firm pump station capacity is larger than previously recommended in Tracy Hills Water Study prepared by RJA (December 2014). Required firm capacity should be confirmed before Zone 6 begins development. n\c\
404\12-18-41\engr\Ch8\Ch 8 Tables\Table 8-8
Last Revised: 07-01-21
City of Trac
y
Citywide Water System
Master Plan Update
Chapter 8
Future Potable Water System Evaluation
8-20 City of Tracy
May 2023 Citywide Water System
n\c\404\12-18-41\wp\R-404-WMPU Master Plan Update
8.4.4 Critical Supply Facilities
All critical pumping facilities should be equipped with an on -site, emergency backup power generator to provide pumping capacity during a power outage. Critical pumping facilities are defined as those facilities that provide service to pressure zone(s) and/or service area(s) which do not have sufficient emergency storage, and that meet the following criteria:
• The largest pumping facility that provides water to a particular pressure zone and/or service area,
• A facility that provides the sole source of water to single or multiple pressure zones and/or service areas,
• A pumping facility that provides water from a supply turnout, or • A pumping facility that provides water from key groundwater supply wells (depends on capacity, quality, and location).
As shown previousl y in Table 8-11, most of the City’s existing pumping facilities have on -site emergency backup power installed, except for Wells 2 through 4 and Well 84. As shown in Table 8-11, proposed future pumping facilities for the buildout potable water system are assumed to have an on-site backup power generator installed to improve supply reliability.
8.4.5 SCADA System Improvements
As stated in Chapter 7, the City does not have SCADA installed on PRS #1-#6. As the City’s water system continues to grow and serve larger water demands, the ability to operate the system efficiently and properly regulate flow between zones will be essential. PRS #1-#6 can provide a significant amount of water supply from Zone 2 to Zone 1 and should be monitored to provide operators with complete real -time system operations data. The addition of SCADA syst em monitoring at PRS #1-#6 w ould provide operators with the ability to operate the City’s water system more efficiently between the use of the Zone 1 BPS and the pressure regulating stations to maintain pressures in Zone 1. The addition of SCADA system mon itoring to PRS #1-#6 would also provide the ability to create diurnal curves that are specific to each zone, which will help provide a better understanding of water demand patterns within each zone. Therefore, it is recommended that SCADA system monitoring of flow and pressure be installed at PRS #1-#6 to provide operators with additional understanding and flexibility in system operations.
Similarly, SCADA improvements at Well 8 to allow remote operation is also a recommended improvement to provide additional operational flexibility as the system continues to grow.
All new booster pump stations, storage tanks, groundwater wells, and PRVs should be equipped with SCADA for remote monitoring and operation.
4 Well 8 currently has a plug-in adapter installed to allow interconnection to a portable generator. On -site backup power is not recommended due to site constraints.
Chapter 8
Future Potable Water System Evaluation
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May 2023 Citywide Water System
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8.4.6 Update of Future System Facilities in the Hydraulic Model Facilities recommended based on the future potable water system facility evaluation were incorporated into the existing hydraulic model (including existing system improvements described in Chapter 7 ) to evaluate th e performance of the proposed future potable water system. Major transmission pipelines were also added to distribute water to new demand areas. In addition, some smaller distribution pipelines were added to provide additional detail and system looping. Th e preliminary locations and sizes of some of the future facilities and pipelines were based on the following previously prepared reports/technical memoranda and/or data provided by the developers:
• Draft Peer Review and Hydraulic Evaluation for Tracy Hills Phase 1B and 1C (May 22, 2019), prepared by West Yost Associates.
• Tracy Hills Water Study Technical Memorandum (December 5, 2014), prepared by Ruggeri-Jensen-Azar.
• Water System Evaluation for the City of Tracy’s Initial Pressure Zone 3 Area (June 3, 2013), prepared by West Yost Associates.
• Ellis Specific Plan Water System Analysis - Phase 1 (August 13, 2015), prepared by West Yost Associates.
• Hydraulic Evaluation of Ellis Specific Plan Phase 2 – The Gardens (December 9, 2016), prepared by West Yost Associates.
• Draft Hydraulic Evaluation of Ellis Specific Plan Phase 3 – Town and Country (July 11, 2019), prepared by West Yost Associates.
• Design Recommendations for Lammers Road Pipeline (September 25, 2019), prepared by West Yost Associates.
• Hydraulic Evaluation of International Park of Commerce (IPC) Building 25 (July 28, 2017), prepared by West Yost Associates.
• Hydraulic Evaluation of International Park of Commerce (IPC) Buildings 9, 10, and 14 (May 3, 2018), prepared by West Yost Associates.
• Hydraulic Evaluation of Valpico and MacDonald Apartments (July 16, 2012), prepared by West Yost Associates.
• Hydraulic Evaluation of Tracy Village Specific Plan (February 16, 2018), prepared by West Yost Associates.
• Hydraulic Evaluation of Avenues Specific Plan (April 30, 2018), prepared by West Yost Associates.
• Hydraulic Evaluation of South Lammers Road Development (May 20, 2015), prepared by West Yost Associates.
• Berg Road Properties Development Water Distribution System Analysis (January 14, 2016), prepared by BlackWater Consulting Engineers, Inc.
Chapter 8
Future Potable Water System Evaluation
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• Improvement Plans for Kagehiro Phase 1 and Kagehiro Phase 2 (received on September 3, 2019) prepared by VVH Consulting Engineers. • Water Exhibit of International Park of Commerce for Prologis (received June 2018) provided by Kier and Wright.
The proposed locations and sizing of facilities and pipelin es described in the documents listed above were incorporated into the future potable water system hydraulic model. Locations of other future facilities and pipelines were based on the 2012 WSMP and recommendations from City staff. The 2012 WSMP facilities were modified as needed to account for existing potable water system facilities constructed since the 2012 WSMP, updated planning data , and the updated projected future water demands.
It should be noted that the elevations of new junctions that have been added into the hydraulic model were assigned based on their spatial location and the closest corresponding elevation contour.5 These elevations may not accurately represent the actual elevation of water services since grading will typically occur during the construction of a new development project.
However, these preliminary junction elevations are the best estimates of the prop osed service elevations at this time. As future development projects are constructed, service elevations for each future development should be confirmed to correspond to the service elevation ranges developed for each pressure zone, as identified in Table 8-1, to meet the minimum and maximum system pressure criteria.
In addition to proposed future facilities, some existing facilities which were not inclu ded in the existing system hydraulic model (refer to Section 7.3.2 for more information) were added to the future water system model. These facilities include:
• Zone 4 infrastructure, including the Zone 4 BPS, Zone 4 PRS, and major transmission and distribution pipelines
• Northington Drive PRV
• Some pipelines in the IPC development
• Some pipelines in the Ellis Specific Plan development The Tracy Hills At -Grade Tank and BPS, which has been designed and is currently under construction, was also included in the future water system hydraulic model.
5 Digital topology information was extracted as a GIS shapefile using the software program TopoDepot®. TopoDepot® provides elevation contours generated from the USGS National Elevation Database Digital Elevation Model.
Chapter 8
Future Potable Water System Evaluation
8-23 City of Tracy
May 2023 Citywide Water System
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To provide emergency and/or peaking water supply between pressure zones, the following future interconnections are recommended and were incorporated into the hydraulic model to allow for the flow of water between pressure zones6:
• Westside PRS – Supplies water from Zone 2 to Zone 1
• Avenues PRV – Supplies water from the Ellis Reduced Zone to Zone 2 • One (1) additional Ellis PRV – Supplies water from Zone 3 to the Ellis Reduced Zone • Zone 4 PRV – Supplies water from Zone 5 to Zone 4
• Two (2) Zone 5 PRVs – Supply water from Zone 6 to Zone 5 All of the facilities discussed above were included in the buildout water system hydraulic model, however, not all future facilities were needed to serve 2025 demands. The 2025 water system model only includes future pipelines in areas expected to develop by 2025 (refer to Chapter 3 and Appendix A for details). None of the recommended futur e tanks, pump stations, or interconnections between pressure zones were included in the 2025 water system model.
Figure 8-2 illustrates the locations of the proposed 2025 facilities and pipeline alignments.
Figure 8-3 illustrates the locations of the proposed buildout facilities and pipeline alignments.
Preliminary pipeline sizes are not shown on Figure 8-2, as they will be refined based on hydraulic evaluations discussed below in Section 8.5 Future Potable Water System Performance Evaluation.
Recommended pipeline sizes are presented in Section 8.6 Summary of Recommended Future Potable Water System Improvements.
6 Pressure Regulating Stations (PRS) contain a combination of one pressure sustaining valve (PSV) and one pressure reducing valve (PRV) to control the flow of water between pressure zones. 580
580
205
205
580
Tracy Hills At-Grade Tank and BPS
From Mossdale BPS
←
Summit Dr
PRS and PRV
Existing Zone 2 pipelines in Lammers Rd,
Schulte Rd, and Hansen Rd will be
re-zoned to Zone 3.
Install new Zone 2 pipeline in Lammers Rd
between Valpico Rd and Schulte Rd.
Patterson Pass BPS
Lincoln
Ball Park
Park and Ride
Lewis Manor
Well 8
NEI Tank and BPS
Linne Tank and BPS
Cordes Tank, BPS,
and PRS
Promontory PRS
Wells 1-4
1234
5 6
Z1, Z2, and
Z3 BPS
ELEVENTH ST
CORRAL HOLLOW RD
M
AC
ARTHUR
DRTRACY BL
BYRON RD
GRANT LINE RD
MOUNTAIN HOUSE PK
BANTA RD
HANSEN RD
VALPICO RD
BIRD RD
LOVELY RD
LAMMERS RD
CHRISMAN RD
NAGLEE RD
LINNE RD
HOLLY DR
BETHANY RD
MIDDLE RD
VON SOSTEN RD
AHERN RD
REEVE RD
DURHAM FERRY RD
SCHULTE RD
O ld Rive
r
C
al if orni a
A qu ed uc t
D e l t a - M e n d o t a C a n a l
0 5,0002,500
Scale in Feet
Figure 8-2
2025 Potable Water
System Facilities
City of Tracy
Water System Master Plan Update
Last Saved: 8/24/2021 11:53:00 AM N:\Clients\404 Tracy\12-18-41 Water Master Plan Update\GIS\MXD\Report Figures\Fig_8-2_2025 Potable Water System Facilities.mxd : rchu Notes:
1. Pressure Zones represent the approximate boundaries after the IPC zone split and other planned 2025 re-zoning projects are implemented.
2. The City's hydraulic model is not an all pipes model.
Some pipes which are not hydraulically significant were excluded from the model.
3. Lewis Manor Well is currently inactive.
4. Patterson Pass BPS will be inactive after the planned 2025 re-zoning projects are implemented.
5. Existing facilities which were excluded in the existing system hydraulic model to represent 2017 water demand conditions are now shown as existing. See Section 7.3.2 for details.
6. The Tracy Hills At-Grade Tank and BPS will provide storage and pumping capacity for Zone 4. It is currently
under construction.
Symbology
Proposed 2025 Facilities
Proposed 2025 Pressure Reducing Valve
Proposed 2025 System Pipeline
Existing Facilities
Existing Pressure Regulating Station
Existing Pressure Reducing Valve
Existing Booster Pump Station
Existing Groundwater Well
Existing Storage Tank
John Jones Water Treatment Plant
Existing System Pipeline
Proposed Existing System Pipeline CIP
Pressure Zone
Zone 1
Zone 2
Zone 3
Ellis Reduced Zone
Zone 4
Sphere of Influence
580
580
205
205
580
Z6 Tank
Z5 Tank
Tracy Hills At-Grade Tank and BPS
Westside PRS
Z6 BPS
See Inset Map for JJWTP
Buildout Facilities
Westside
Tank and BPS
Westside Well
Wainwright Well
Larsen Park Well
Ellis Well
From Mossdale BPS
(Additional pump at buildout)
←
Summit Dr
PRS and PRV
Lincoln
Ball Park
Park and Ride
Lewis Manor
Well 8
NEI Tank and BPS
Linne Tank and BPS
Patterson Pass BPS
Cordes Tank, BPS,
and PRS
Promontory PRS
Wells 1-4
"Plan C" Re-zoning
1234
5 6
O ld Rive
r
C
al if orni a
A qu ed uc t
D e l t a - M e n d o t a C a n a l
ELEVENTH ST
CORRAL HOLLOW RD
M
AC
ARTHUR
DR
TRACY BL
BYRON RD
GRANT LINE RD
MOUNTAIN HOUSE PK
BANTA RD
HANSEN RD
VALPICO RD
BIRD RD
LOVELY RD
LAMMERS RD
CHRISMAN RD
NAGLEE RD
LINNE RD
HOLLY DR
BETHANY RD
MIDDLE RD
VON SOSTEN RD
AHERN RD
REEVE RD
DURHAM FERRY RD
SCHULTE RD
0 5,0002,500
Scale in Feet
Figure 8-3
Buildout Potable Water
System Facilities
City of Tracy
Water System Master Plan Update
Last Saved: 10/9/2020 3:00:01 PM N:\Clients\404 Tracy\12-18-41 Water Master Plan Update\GIS\MXD\Report Figures\Fig_8-3_Buildout Potable System.mxd : rchu Notes:
1. Pressure Zones represent the approximate boundaries after the IPC zone split and other planned buildout re-zoning projects are implemented.
2. The City's hydraulic model is not an all pipes model.
Some pipes which are not hydraulically significant were excluded from the model.
3. Lewis Manor Well is currently inactive.
4. Patterson Pass BPS will be inactive at buildout.
5. Existing facilities which were excluded in the existing system hydraulic model to represent 2017 water demand conditions are now shown as existing. See Section 7.3.2 for details.
6. The Tracy Hills At-Grade Tank and BPS will provide storage and pumping capacity for Zone 4. It is currently
under construction.
Symbology
Proposed Buildout Facilities
Buildout Pressure Regulating Station
Buildout Pressure Reducing Valve
Buildout Booster Pump Station
Buildout Groundwater Well
Buildout Storage Tank
Buildout System Pipeline
Existing and 2025 Facilities
Existing Pressure Regulating Station
Existing Pressure Reducing Valve
Proposed 2025 Pressure Reducing Valve
Existing Booster Pump Station
Existing Groundwater Well
Existing Storage Tank
John Jones Water Treatment Plant
Existing System Pipeline
Proposed 2025 System Pipeline
Proposed Existing System Pipeline CIP
Pressure Zone
Zone 1
Zone 2
Zone 3
Ellis Reduced Zone
Zone 4
Zone 5
Zone 6
Sphere of Influence
Existing
Clearwell #2 Future
Clearwell #3
Z2 and Z3 BPS
Z4 BPS
Z5 BPS
Additional
Z3 pumps
(Additional pump
at buildout)
Well #4
Z1 BPS
JJWTP Buildout Facilities
Chapter 8
Future Potable Water System Evaluation
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May 2023 Citywide Water System
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8.5 FUTURE POTABLE WATER SYSTEM PERFORMANCE EVALUATION
To evaluate the performance of the City’s proposed future potable water system, additional projected potable water demands were first allocated into the updated future system hydraulic model (see Tables 8-2 through 8-4). This updated hydraulic model was then used to evaluate the City’s 2025 and buildout potable water backbone transmission and distribution systems and their ability to meet the City’s recommended performance and operational criteria under future maximum day demand plus fire flow and peak hour demand scenarios.
The performance criteria recommended for and results of the future potable water backbone transmission and distribution system evaluation are discussed below. Recommendations for supporting projected future potable water demands and addressing any deficiencies identified within the future potable water backbone transmission and distribution system are summarized in Section 8.6 Summary of Recommended Future Potable Water System Improvements.
8.5.1 Future Water System Performance Criteria
Steady state hydraulic analyses using the updated future potable water system hydraulic model were conducted to help identify areas of the future potable water system that do not meet the recommended system performance criteria as presented previously in Chapter 6. The results of the future potable water system evaluation are presented below for the following potable water demand scenarios:
• Peak Hour Demand—A peak hour flow condition was simulated for the future water distribution facilities to evaluate their capability to meet a peak hour demand scenario. Peak hour demands are met by the combined supply from treated surface water, storage tanks, and groundwater.
• Maximum Day Demand plus Fire Flow—To evaluate the future potable water system under the maximum day demand plus fire flow scenario, individual fire flow demands were first assigned and simulated at various locations within the City’s water service area. InfoWater’s “Available Fire Flow Analysis” tool was used to determine the available fire flow while meeting the maximum day demand plus fire flow performance criteria. Additional fire flow simulations were also performed to simulate a condition equal to a maximum day demand with two concurrent fire flow events in the larger pressure zones. Maximum day plus fire flow demands are met by the combined supply from treated surface water, storage tanks, and groundwater.
The performance criteria and results for each scenario are discussed in more detail below.
8.5.1.1 Peak Hour Demand Scenario
As shown in Tables 8-2 and 8-3, the peak hour demands for the 2025 and buildout water service areas were calculated to be 38,467 gpm (55.4 mgd) and 61,333 gpm (88.3 mgd), respectively. Peak hour demand represents a peaking factor of 2.9 times the average day demand. During a peak hour demand scenario, a minimum pressure of 40 psi must be maintained throughout the water system.
In addition, maximum head loss per thousand feet of distribution main should not exceed 7 ft/kft and maximum velocities should not exceed 8 fps. For transmission mains, maximum head loss per Chapter 8
Future Potable Water System Evaluation
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May 2023 Citywide Water System
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thousand feet of transmission main should not exceed 3 ft/kft and maximum velocities should not exceed 6 fps. Details of the system pressures and pipeline characteristics as simulat ed in the hydraulic model under the peak hour demand scenario are discussed below.
8.5.1.2 Maximum Day Demand plus Fire Flow Scenario
As shown in Tables 8-2 and 8-3, the maximum day demand s for the 2025 and buildout water service area s were calculated to be 22,550 gpm ( 32.5 mgd) and 35,954 gpm ( 51.8 mgd), respectively. Maximum day demand represents a peaking factor of 1.7 times the average day demand. Fire flow demands were assigned and simulated at various locations within the City’s water service area to determine if the minimum residual pressure criterion of 20 psi could be met during a maximum day demand plus fire flow scenario. Fire flow demands in future development areas were assigned based on proposed land use, and are summarized below in Table 8-12.
Table 8-12. Recommended Fire Flow Requirements(a)
Land Use Category Fire Flow, gpm Duration, hours
Single Family Residential(b) 1,500 2
Multi-Family Residential(c) 2,500 2
Commercial/Office(d) 3,500(e) 4
Industrial 4,500(e) 4
Institutional(f) 4,500(e) 4
(a) Specific fire flow requirements were determined from Table B105.1 of the 2016 CFC, and depend on construction type and fire flow calculation area. Non-residential fire flow requirements are based on the assumption that an automatic sprinkler system has been installed. See Table 6-1 for further explanation of how the fire flow requirements were developed. (b) Includes Very Low and Low Density Residential land uses. (c) Includes Medium and High Density Residential land uses. (d) Includes Commercial, Office, Downtown, and Village Center land uses. (e) Fire flow includes a 500 gpm demand for on-site sprinkler flow, which is not included in the recommended fire flow storage volume.
(f) Includes Medical, Public Facilities, School, Airport, Church, and Cemetery land uses.
The City’s water system should also have the capability to meet a system demand condition equal to the occurrence of a maximum day demand with two concurrent fire flow events in the larger pressure zones (Zone 1, Zone 2, and Zone 3). It is assumed that the two fire flow events will consist of one smaller single family residential fire flow combined with another larger industrial fire flow.
This conservative assumption of two simultaneous fire flow demands will help stress the City’s water system, and determine if the future water system can provide reliable service during high demand conditions. Consequently, two concurrent fire flow demands were simulated at various locations within the City’s water service area during a maximum day demand condition to determine if the minimum residual pressure criterion of 20 psi could be met during simultaneous fire flow events.
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8.5.2 Recommended Improvements Criteria
The performance criteria described above was used to evaluate the future potable water system during peak hour demand and maximum day demand plus fire flow scenarios. The future potable water system is expected to deliver peak hour flow and maximum day demand plus fire flow within the acceptable pressure, velocity and head los s ranges as identified in the performance criteria presented in Chapter 6. However, the system was evaluated using pressure as the primary criterion.
If necessary, recommended improvements needed to comply with the performance criteria were added to the future potable water system to fix any deficiencies found and are discussed below.
8.5.3 2025 Water System Evaluation Results
The results from the 2025 hydraulic model for the peak hour demand and maximum day demand plus fire flow analyses are presented below.
8.5.3.1 2025 Peak Hour Demand Scenario
During a peak hour demand scenario, results indicate that the 2025 potable water system could adequately deliver peak hour demands to meet the City’s minimum pressure criterion of 40 psi at all existing and future service locat ions as illustrated on Figure 8-4. Under this scenario, system pressures at service locations ranged from 40 to 113 psi. It should be noted that, per the California Plumbing Code, any individual service connection pressure exceeding 80 psi will require the installation of an individual PRV. As discussed previously, new junction elevations in the hydraulic model may not accurately represent the actual elevation of water services since grading will typically occur during the construction of a new development. Therefore, the system pressures simulated by the hydraulic model are best estimates of the proposed service pressures at this time.
It is recommended that as the water system infrastructure for future development projects are designed, the proposed service elevations for each future development project should correspond to the service elevation ranges developed for each pressure zone (see Table 8-1) and that additional hydraulic analyses should be performed to confirm that the recommended minimum and maximum system pressure criteria can be met.
As illustrated on Figure 8-5, there is one location within the 2025 system where the distribution system pipelines did not meet the maximum velocity criterion of 8 fps during a peak hour demand scenario. The following list details pipelines in the 2025 potable water system that exceeded the maximum velocity criterion and summarizes any recommended improvements. • The existing 12-inch diameter distribution pipelines which cross the railroad tracks between Sixth Street and Tracy Boulevard east of the 36-inch diameter transmission main tie-in had a velocity of 11.4 fps.
Recommendation:
It is recommended that the existing 12-inch diameter pipelines located between Sixth Street and Tracy Boulevard east of the 36-inch diameter transmission tie-in be replaced with a new 18-inch diameter pipeline. The recommended diameter of the new pipeline is sized to accommodate buildout demands.
580
580
205
205
580
From Mossdale BPS
←
SCHULTE CT
ELEVENTH ST
CORRAL HOLLOW RD
M
AC
ARTHUR
DR
TRACY BL
BYRON RD
GRANT LINE RD
MOUNTAIN HOUSE PK
BANTA RD
HANSEN RD
VALPICO RD
BIRD RD
LOVELY RD
LAMMERS RD
CHRISMAN RD
NAGLEE RD
LINNE RD
HOLLY DR
BETHANY RD
MIDDLE RD
VON SOSTEN RD
AHERN RD
REEVE RD
DURHAM FERRY RD
SCHULTE RD
O ld Rive
r
C
alifornia
A
queduc t
D e l t a - M e n d o t a C a n a l
0 5,0002,500
Scale in Feet
Figure 8-4
2025 System Pressures
Peak Hour Demand
City of Tracy
Water System Master Plan Update
Last Saved: 10/9/2020 1:06:56 PM N:\Clients\404 Tracy\12-18-41 Water Master Plan Update\GIS\MXD\Report Figures\Fig_8-4_2025 System Pressures Peak Hour Demand.mxd : rchu Notes:
1. The City's hydraulic model is not an all pipes model.
Some pipes which are not hydraulically significant were excluded from the model.
2. Per the California Plumbing Code, services which
experience pressures exceeding 80 psi are required
to be fitted with a pressure reducing valve.
Symbology
Peak Hour Pressure
Less than 40 psi
40 psi to 50 psi
50 psi to 60 psi
60 psi to 70 psi
70 psi to 80 psi
Greater than 80 psi
Pressure Regulating Station
Pressure Reducing Valve
Booster Pump Station
Groundwater Well
Storage Tank
John Jones Water Treatment Plant
Pipeline
Pressure Zone
Zone 1
Zone 2
Zone 3
Ellis Reduced Zone
Zone 4
Sphere of Influence
580
580
205
205
580
From Mossdale BPS
←
a
SCHULTE CT
ELEVENTH ST
CORRAL HOLLOW RD
M
AC
ARTHUR
DR
TRACY BL
BYRON RD
GRANT LINE RD
MOUNTAIN HOUSE PK
BANTA RD
HANSEN RD
VALPICO RD
BIRD RD
LOVELY RD
LAMMERS RD
CHRISMAN RD
NAGLEE RD
LINNE RD
HOLLY DR
BETHANY RD
MIDDLE RD
VON SOSTEN RD
AHERN RD
REEVE RD
DURHAM FERRY RD
SCHULTE RD
O ld Rive
r
C
alifornia
A
queduc t
D e l t a - M e n d o t a C a n a l
0 5,0002,500
Scale in Feet
Figure 8-5
2025 Pipeline Velocities
Peak Hour Demand
City of Tracy
Water System Master Plan Update
Last Saved: 10/9/2020 1:13:32 PM N:\Clients\404 Tracy\12-18-41 Water Master Plan Update\GIS\MXD\Report Figures\Fig_8-5_2025 Pipeline Velocities Peak Hour Demand.mxd : rchu Notes:
1. The City's hydraulic model is not an all pipes model.
Some pipes which are not hydraulically significant were excluded from the model.
Symbology
Pipeline Diameter ≥ 18-inches
Velocity > 6 fps
Velocity ≤ 6 fps
Pipeline Diameter < 18-inches
Velocity > 8 fps
Velocity ≤ 8 fps
Pressure Regulating Station
Pressure Reducing Valve
Booster Pump Station
Groundwater Well
Storage Tank
John Jones Water Treatment Plant
Pressure Zone
Zone 1
Zone 2
Zone 3
Ellis Reduced Zone
Zone 4
Sphere of Influence
Well 8TRACY BL
TENTH ST
SIXTH ST
ROOSEVELT AV
NINTH ST
BEECHNUT AV
12"
12"
12"
8"
10"
8"
6" 6"12"
10"
10"
36"
Inset Map Extent
Chapter 8
Future Potable Water System Evaluation
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• The existing 12-inch diameter distribution pipelines located in Sixth Street west of the 36-inch diameter transmission main tie-in and in Tracy Boulevard between Sixth Street and Tenth Street, had a velocity of 9.4 fps.
Recommendation:
It is recommended that the existing 12-inch diameter pipeline in Sixth Street west of the 36-inch diameter transmission main tie-in, the 12-inch diameter pipeline in Tracy Boulevard between Sixth Street and Eleventh Street, and a 40 ft section of existing 12-inch diameter pipeline in Eleventh Street, be replaced with new 24-inch diameter pipeline. The recommended diameter of the new pipeline is sized to accommodate buildout demands.
8.5.3.2 2025 Maximum Day Demand plus Fire Flow Scenario Fire flow demands were assigned based on the fire flow requirements summarized in Table 8-12 and simulated at various locations within the City’s 2025 water service area. InfoWater’s “Available Fire Flow Analysis” tool was used to determine the available fire flow (while meeting the maximum day demand plus fire flow minimum residual pressure of 20 psi and the maximum velocity performance criteria in proposed pipelines of 12 fps) at each fire flow junction within the 2025 water system during a maximum day demand scenario. Figure 8-6 illustrates the results of the 2025 maximum day plus fire flow evaluation. With the exception of the hydrant located at the southern end of Rhonda Way (discussed in Chapter 7), results indicate that all evaluated locations within the model were able to meet the minimum fire flow requirements.
Six additional fire flow simulations were performed within the 2025 system hydraulic model to simulate a condition equal to a maximum day demand with two concurrent fire flow events.
Figure 8-7 illustrates the locations of the additional fire flow simulations. Locations were selected within each pressure zone based on the existing and proposed land use designations and spatial distance from supply sources to stress the City’s water system. As summarized in Table 8-13, results from the hydraulic model indicate that all s ix of the concurrent fire flow simulations met the minimum residual pressure criterion of 20 psi.
Chapter 8
Future Potable Water System Evaluation
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Table 8-13. Results of Additional Fire Flow Simulations for 2025 System Pressure Zone Location # Fire Flow Demand, gpm(a) Residual Pressure, psi Zone 1
1 1,500 48
4,500 30
2 1,500 50
4,500 44
Zone 2
3 1,500 67
4,500 52
4 1,500 66
4,500 33
5 1,500 60
4,500 26
Zone 3 6
1,500 48
4,500 31
(a) It is assumed that the two concurrent fire flow events will consist of one smaller Single Family Residential fire flow combined with another larger Industrial fire flow.
580
580
205
205
580
From Mossdale BPS
←
SCHULTE CT
ELEVENTH ST
CORRAL HOLLOW RD
M
AC
ARTHUR
DR
TRACY BL
BYRON RD
GRANT LINE RD
MOUNTAIN HOUSE PK
BANTA RD
HANSEN RD
VALPICO RD
BIRD RD
LOVELY RD
LAMMERS RD
CHRISMAN RD
NAGLEE RD
LINNE RD
HOLLY DR
BETHANY RD
MIDDLE RD
VON SOSTEN RD
AHERN RD
REEVE RD
DURHAM FERRY RD
SCHULTE RD
O ld Rive
r
C a l i f o r n i a
A q u e d u c t
D e l t a - M e n d o t a C a n a l
0 5,0002,500
Scale in Feet
Figure 8-6
2025 System
Available Fire Flow
City of Tracy
Water System Master Plan Update
Last Saved: 7/2/2021 7:32:18 AM N:\Clients\404 Tracy\12-18-41 Water Master Plan Update\GIS\MXD\Report Figures\Fig_8-6_2025 System Available Fire Flow.mxd : rchu Notes:
1. The available fire flow shown is the maximum flow
available while maintaining 20 psi residual system
pressure and velocities of less than 12 fps in
proposed pipelines.
2. The City's hydraulic model is not an all pipes model.
Some pipes which are not hydraulically significant were excluded from the model.
Symbology
Available Fire Flow
Does Not Meet Requirement
Meets Requirement
Pressure Regulating Station
Pressure Reducing Valve
Booster Pump Station
Groundwater Well
Storage Tank
John Jones Water Treatment Plant
Pipeline
Fire Flow Requirement
1,500 gpm
2,500 gpm
3,500 gpm
4,500 gpm
580
580
205
205
580
From Mossdale BPS
←
#1: 1,500 gpm
#1: 4,500 gpm
#2: 4,500 gpm
#2: 1,500 gpm
#4: 4,500 gpm
#4: 1,500 gpm
#3: 4,500 gpm
#3: 1,500 gpm
#5: 1,500 gpm
#5: 4,500 gpm
#6: 1,500 gpm
#6: 4,500 gpm
SCHULTE CT
ELEVENTH ST
CORRAL HOLLOW RD
M
AC
ARTHUR
DR
TRACY BL
BYRON RD
GRANT LINE RD
MOUNTAIN HOUSE PK
BANTA RD
HANSEN RD
VALPICO RD
BIRD RD
LOVELY RD
LAMMERS RD HOLLY DR
CHRISMAN RD
NAGLEE RD
LINNE RD
BETHANY RD
MIDDLE RD
VON SOSTEN RD
AHERN RD
REEVE RD
DURHAM FERRY RD
SCHULTE RD
O ld Rive
r
C a l i f o r n i a
A q u e d u c t
D e l t a - M e n d o t a C a n a l
0 5,0002,500
Scale in Feet
Figure 8-7
2025 System Locations of
Additional Simultaneous
Fire Flow Simulations
City of Tracy
Water System Master Plan Update
Last Saved: 10/9/2020 1:15:39 PM N:\Clients\404 Tracy\12-18-41 Water Master Plan Update\GIS\MXD\Report Figures\Fig_8-7_2025 Multi_Fireflow.mxd : rchu Notes:
1. The City's hydraulic model is not an all pipes model.
Some pipes which are not hydraulically significant were excluded from the model.
Symbology
Simultaneous Fire Flows
Location #1
Location #2
Location #3
Location #4
Location #5
Location #6
Pressure Regulating Station
Pressure Reducing Valve
Booster Pump Station
Groundwater Well
Storage Tank
John Jones Water Treatment Plant
Pipeline
Pressure Zone
Zone 1
Zone 2
Zone 3
Ellis Reduced Zone
Zone 4
Chapter 8
Future Potable Water System Evaluation
8-35 City of Tracy
May 2023 Citywide Water System
n\c\404\12-18-41\wp\R-404-WMPU Master Plan Update
8.5.4 Buildout Water System Evaluation Results
The results from the buildout hydraulic model for the peak hour demand and maximum day demand plus fire flow analyses are presented below. The results assume that the recommended 2025 pipeline replacements discussed in Section 8.5.3.1 2025 Peak Hour Demand Scenario are constructed before buildout.
8.5.4.1 Buildout Peak Hour Demand Scenario
During a peak hour demand scenario, results indicate that the buildout potable water system could adequately deliver peak hour demands to meet the City’s minimum pressure criterion of 40 psi at all existing and future service locations as illustrated on Figure 8-8. Under this scenario, system pressures at service locations ranged from 40 to 118 psi. It should be noted that, per the California Plumbing Code, any individual service connection pressure exceeding 80 psi will require the installation of an individual PRV. As discussed previously, new junction elevations in the hydraulic model may not accurately represent the actual elevation of water services since grading will typically occur during the construction of a new development. Therefore, the system pressures simulated by the hydraulic model are best estimates of the proposed service pressures at this time.
It is recommended that as the water system infrastructure for future development projects are designed, the proposed service elevations for each future development project should correspond to the service elevation ranges developed for each pressure zone (see Table 8-1) and that additional hydraulic analyses should be performed to confirm that the recommended minimum and maximum system pressure criteria can be met.
As illustrated on Figure 8-9, there is one location within the buildout system where the transmission system pipelines did not meet the maximum velocity criterion of 6 fps during a peak hour demand scenario. The following list details pipelines in the buildout potable water system that exceeded the maximum velocity criterion and summarizes any recommended improvements. • The existing 18-inch diameter transmission pipeline in Tracy Boulevard between Linne Road and Windsong Drive had velocities ranging from 6.0 fps to 6.5 fps.
Recommendation:
No mitigation is recommended for the 18-inch diameter pipeline in Tracy Boulevard because the simulated velocities are only slightly higher than the maximum criterion of 6 fps. In addition, upsizing this pipeline does not provide a significant improvement in system pressures.
580
580
205
205
580
From Mossdale BPS
←
SCHULTE CT
ELEVENTH ST
CORRAL HOLLOW RD
M
AC
ARTHUR
DR
TRACY BL
BYRON RD
GRANT LINE RD
MOUNTAIN HOUSE PK
BANTA RD
HANSEN RD
VALPICO RD
BIRD RD
LOVELY RD
LAMMERS RD
CHRISMAN RD
NAGLEE RD
LINNE RD
HOLLY DR
BETHANY RD
MIDDLE RD
VON SOSTEN RD
AHERN RD
REEVE RD
DURHAM FERRY RD
SCHULTE RD
O ld Rive
r
C a l i f o r n i a
A q u e d u c t
D e l t a - M e n d o t a C a n a l
0 5,0002,500
Scale in Feet
Figure 8-8
Buildout System Pressures
Peak Hour Demand
City of Tracy
Water System Master Plan Update
Last Saved: 10/9/2020 1:45:06 PM N:\Clients\404 Tracy\12-18-41 Water Master Plan Update\GIS\MXD\Report Figures\Fig_8-8_Buildout System Pressures Peak Hour Demand.mxd : rchu Notes:
1. The City's hydraulic model is not an all pipes model.
Some pipes which are not hydraulically significant were excluded from the model.
2. Per the California Plumbing Code, services which
experience pressures exceeding 80 psi are required
to be fitted with a pressure reducing valve.
Symbology
Peak Hour Pressure
Less than 40 psi
40 psi to 50 psi
50 psi to 60 psi
60 psi to 70 psi
70 psi to 80 psi
Greater than 80 psi
Pressure Regulating Station
Pressure Reducing Valve
Booster Pump Station
Groundwater Well
Storage Tank
John Jones Water Treatment Plant
Pipeline
Pressure Zone
Zone 1
Zone 2
Zone 3
Ellis Reduced Zone
Zone 4
Zone 5
Zone 6
580
580
205
205
580
From Mossdale BPS
←
a
SCHULTE CT
ELEVENTH ST
CORRAL HOLLOW RD
M
AC
ARTHUR
DR
TRACY BL
BYRON RD
GRANT LINE RD
MOUNTAIN HOUSE PK
BANTA RD
HANSEN RD
VALPICO RD
BIRD RD
LOVELY RD
LAMMERS RD
CHRISMAN RD
NAGLEE RD
LINNE RD
HOLLY DR
BETHANY RD
MIDDLE RD
VON SOSTEN RD
AHERN RD
REEVE RD
DURHAM FERRY RD
SCHULTE RD
O ld Rive
r
C a l i f o r n i a
A q u e d u c t
D e l t a - M e n d o t a C a n a l
0 5,0002,500
Scale in Feet
Figure 8-9
Buildout Pipeline Velocities
Peak Hour Demand
City of Tracy
Water System Master Plan Update
Last Saved: 10/9/2020 2:58:28 PM N:\Clients\404 Tracy\12-18-41 Water Master Plan Update\GIS\MXD\Report Figures\Fig_8-9_Buildout Pipeline Velocities Peak Hour Demand.mxd : rchu Notes:
1. The City's hydraulic model is not an all pipes model.
Some pipes which are not hydraulically significant were excluded from the model.
Symbology
Pipe Diameter ≥ 18-inches
Velocity > 6 fps
Velocity ≤ 6 fps
Pipe Diameter < 18-inches
Velocity > 8 fps
Velocity ≤ 8 fps
Pressure Regulating Station
Pressure Reducing Valve
Booster Pump Station
Groundwater Well
Storage Tank
John Jones Water Treatment Plant
Pressure Zone
Zone 1
Zone 2
Zone 3
Ellis Reduced Zone
Zone 4
Zone 5
Zone 6
LINNE RD
W INDSONG DR
TRACY
BL
DIETRICK AV
REGIS
DR
VIOLET PL
SAGEWOOD CT
TWIN OAKS DR
TWIN OAKS CT
SUNNYSIDE LN
TREANA
CT
SPUR LINE RR
8"
8"
8"
10"
8"
8"
8"
8"
8"
8"
8"
6"
8"
6"
8"
16" 8" 8"
8"
8"
8"
16"
8"
8"
6"
16"
8"
8"
8"
8"
8"
8"
8"
16"
10"
18" 24"
18"
36"
18"
24"
18"
18"
Inset Map Extent
Chapter 8
Future Potable Water System Evaluation
8-38 City of Tracy
May 2023 Citywide Water System
n\c\404\12-18-41\wp\R-404-WMPU Master Plan Update
8.5.4.2 Buildout Maximum Day Demand plus Fire Flow Scenario Fire flow demands were assigned based the fire flow requirements summarized in Table 8-12 and simulated at various locations within the City’s buildout water service area. InfoWater’s “Available Fire Flow Analysis” tool was used to determine the available fire flow (while meeting the maximum day demand plus fire flow minimum residual pressure of 20 psi and the maximum velocity performance criteria in proposed pipelines of 12 fps) at each fire flow junction within the buildout water system during a maximum day demand scenario. Figure 8-10 illustrates the results of the buildout maximum day plus fire flow evaluation. With the exception of the hydrant located at the southern end of Rhonda Way (discussed in Chapter 7), results indicate that all evaluated locations within the model were able to meet the minimum fire flow requirements.
Seven additional fire flow simulations were performed within the buildout system hydraulic model to simulate a condition equal to a maximum day demand with two concurrent fire flow ev ents.
Figure 8-11 illustrates the locations of the additional fire flow simulations. Locations were selected within each pressure zone based on the existing and propose d land use designations and spatial distance from supply sources to stress the City’s water system. As summarized in Table 8-14, results from the hydraulic model indicate that all seven of the concurrent fire flow simulations met the minimum residual pressure criterion of 20 psi.
Table 8-14. Results of Additional Fire Flow Simulations for Buildout System Pressure Zone Location # Fire Flow Demand, gpm(a) Residual Pressure, psi Zone 1
1 1,500 54
4,500 40
2 1,500 56
4,500 50
7 1,500 43
4,500 39
Zone 2
3 1,500 68
4,500 55
4 1,500 68
4,500 34
5 1,500 61
4,500 31
Zone 3 6
1,500 70
4,500 60
(a) It is assumed that the two concurrent fire flow events will consist of one smaller Single Family Residential fire flow combined with another larger Industrial fire flow.
580
580
205
205
580
From Mossdale BPS
←
SCHULTE CT
ELEVENTH ST
CORRAL HOLLOW RD
M
AC
ARTHUR
DR
TRACY BL
BYRON RD
GRANT LINE RD
MOUNTAIN HOUSE PK
BANTA RD
HANSEN RD
VALPICO RD
BIRD RD
LOVELY RD
LAMMERS RD
CHRISMAN RD
NAGLEE RD
LINNE RD
HOLLY DR
BETHANY RD
MIDDLE RD
VON SOSTEN RD
AHERN RD
REEVE RD
DURHAM FERRY RD
SCHULTE RD
O ld Rive
r
C a l i f o r n i a
A q u e d u c t
D e l t a - M e n d o t a C a n a l
0 5,0002,500
Scale in Feet
Figure 8-10
Buildout System
Available Fire Flow
City of Tracy
Water System Master Plan Update
Last Saved: 7/2/2021 7:57:51 AM N:\Clients\404 Tracy\12-18-41 Water Master Plan Update\GIS\MXD\Report Figures\Fig_8-10_Buildout System Available Fire Flow.mxd : rchu Notes:
1. The available fire flow shown is the maximum flow
available while maintaining 20 psi residual system
pressure and velocities of less than 12 fps in
proposed pipelines.
2. The City's hydraulic model is not an all pipes model.
Some pipes which are not hydraulically significant were excluded from the model.
3. The buildout storage and pumping capacity analysis
include a maximum fire flow requirement of 4,500 gpm
in Zone 5 to account for the potential construction of
a school in Zone 5. However, because the location
of this potential school is unknown, fireflow
requirements were limited to 2,500 gpm in Zone 5 in
the hydraulic analysis. Once the location of
the school is known, additional analysis should be
performed to determine which pipelines must be upsized
to accomodate the higher fire flow requirement.
Symbology
Available Fire Flow
Does Not Meet Requirement
Meets Requirement
Pressure Regulating Station
Pressure Reducing Valve
Booster Pump Station
Groundwater Well
Storage Tank
John Jones Water Treatment Plant
Pipeline
Fire Flow Requirement
1,500 gpm
2,500 gpm
3,500 gpm
4,500 gpm
580
580
205
205
580
From Mossdale BPS
←
#1: 1,500 gpm
#1: 4,500 gpm
#2: 4,500 gpm
#2: 1,500 gpm
#4: 4,500 gpm
#4: 1,500 gpm
#3: 4,500 gpm
#3: 1,500 gpm
#5: 1,500 gpm
#5: 4,500 gpm
#6: 1,500 gpm
#6: 4,500 gpm
#7: 4,500 gpm
#7: 1,500 gpm
SCHULTE CT
ELEVENTH ST
CORRAL HOLLOW RD
M
AC
ARTHUR
DR
TRACY BL
BYRON RD
GRANT LINE RD
MOUNTAIN HOUSE PK
BANTA RD
HANSEN RD
VALPICO RD
BIRD RD
LOVELY RD
LAMMERS RD HOLLY DR
CHRISMAN RD
NAGLEE RD
LINNE RD
BETHANY RD
MIDDLE RD
VON SOSTEN RD
AHERN RD
REEVE RD
DURHAM FERRY RD
SCHULTE RD
O ld Rive
r
C a l i f o r n i a
A q u e d u c t
D e l t a - M e n d o t a C a n a l
0 5,0002,500
Scale in Feet
Figure 8-11
Buildout System Locations of
Additional Simultaneous
Fire Flow Simulations
City of Tracy
Water System Master Plan Update
Last Saved: 10/9/2020 2:12:28 PM N:\Clients\404 Tracy\12-18-41 Water Master Plan Update\GIS\MXD\Report Figures\Fig_8-11_Buildout Multi_Fireflow.mxd : rchu Notes:
1. The City's hydraulic model is not an all pipes model.
Some pipes which are not hydraulically significant were excluded from the model.
Symbology
Simultaneous Fire Flows
Location #1
Location #2
Location #3
Location #4
Location #5
Location #6
Location #7
Pressure Regulating Station
Pressure Reducing Valve
Booster Pump Station
Groundwater Well
Storage Tank
John Jones Water Treatment Plant
Pipeline
Pressure Zone
Zone 1
Zone 2
Zone 3
Ellis Reduced Zone
Zone 4
Zone 5
Zone 6
Chapter 8
Future Potable Water System Evaluation
8-41 City of Tracy
May 2023 Citywide Water System
n\c\404\12-18-41\wp\R-404-WMPU Master Plan Update
8.6 SUMMARY OF RECOMMENDED FUTURE POTABLE WATER SYSTEM
IMPROVEMENTS
The recommended backbone potable water system improvements required to serve future potable water demands are summarized below and shown on Figure 8-12 and Figure 8-13. These future system improvements are triggered by additional demands from new development, unlike the improvements discussed in Chapter 7. It should be noted that these recommendations only identify facility improvements at a master plan level and do not necessarily include all required on -site infrastructure nor constitute design of improvements. Subsequent detailed design is required to determine the exact sizes and final locations of these proposed facility improvements.
The evaluation of the City’s future water system is dependent on:
• Projected future development projects and land use data (refer to Chapter 3) • Adopted water use factors (refer to Chapter 4)
• Adopted peaking factors (refer to Chapter 4)
• Characteristics and capabilities of existing water supply facilities (refer to Chapter 5) • City water system performance criteria (refer to Chapter 6) If any of these are significantly altered, the recommendations listed below may need to be reevaluated and revised.
It should also be noted that the future hydraulic model is not an “all pipes” model ( i.e., not all smaller diameter pipelines are included); therefore, the hydraulic simulations performed as discussed above may not identify all necessa ry water system improvements. Consequently, it is recommended that further hydraulic evaluations be performed as additional details are provided for each future development project.
8.6.1 2025 System Improvements
The recommended backbone potable water system imp rovements required to serve 2025 potable water demands are summarized below. Planning and design for these improvements should be conducted so that these improvements are constructed and operational by 2025.
8.6.1.1 Pipelines
• To serve 2025 water demands, install approximately 73,020 linear feet of new pipelines ranging in diameter from 12 to 24 inches as shown on Figure 8-12. • To serve 2025 water demands, install additional new pipelines of 10 inches in diameter or less within individual development projects; the length of small diameter pipelines needed to serve 2025 water demands is unknown, as not all 2025 development areas have detailed water system infrastructure plans prepared. • To serve 2025 water demands, upsize approximately 1,390 linear feet of existing pipelines as shown on Figure 8-13.
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580
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580
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205
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205
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580
Z6 Tank
Z5 Tank
Install one additional pump at
Tracy Hills At-Grade Tank BPS
Westside PRS
Z6 BPS
a
Westside
Tank and BPS
Westside
Well
Wainwright Well
Larsen Park Well
Ellis Well
From Mossdale BPS
←
"Plan C" Re-zoning
1234
5 6 Figure 8-13 Extent
Existing Zone 2 pipelines in Lammers Rd,
Schulte Rd, and Hansen Rd will be
re-zoned to Zone 3.