CleanPowerSF Sfpuc Commission
March 12, 2024

APPENDIX B. WATER AVAILABILITY MODELING
Purpose of this Appendix
This appendix presents supporting information and relevant details for modeling associated with Water Availability described in Chapters 2 and 3 of the AWS Plan.

Water System Modeling
The SFPUC uses a water supply planning methodology that was developed during and after the six-year drought that occurred in California from 1987 – 1992. This methodology includes using a water system simulation model (Hetch Hetchy/Local Simulation Model) and also includes the use of a planning drought simulation referred to as the “design drought”. Excerpts from Hetch Hetchy/Local Simulation Model) documentation are presented below to describe the model and the design drought simulation procedure.

Model Overview (Excerpted from Hetch Hetchy/Local Simulation Model) The SFPUC has developed a computerized mathematical model to simulate system operations. The model, known as the Hetch Hetchy/Local Simulation Model, simulates the operation of San Francisco's Hetch Hetchy facilities, the Don Pedro Project, and the Bay Area reservoir, conveyance, and treatment systems.

The model simulates system operations over the course of an 82-year sequential hydrologic period from July 1920 through September 2002 [now extended to 2017]. The model incorporates actual historical information about the hydrology (the amount of runoff as snowmelt and rainfall) that occurred in each year over the [97]-year record for each of the three watershed areas under consideration: the Tuolumne River system, the Alameda Creek system, and the Peninsula watershed system. This [97]-year period includes many different types and sequences of actual hydrological events that have occurred ranging from flood events to droughts of different magnitude and duration. The long-term [97]-year historical record is used in the model to represent the range of hydrologic conditions that could occur in the future. The model is used to assess how the system would perform as the result of an assumed system configuration and assumed operational objectives.

The model uses actual historical hydrology for the depiction of runoff within the watersheds. However, the model is not expected to explicitly replicate observed historical operations in all cases. The past operation of the system in an actual year will differ to some degree from the operations simulated by the model for that year as a result of many factors. These factors include the anomalies in past operation that required system operators to adjust operations throughout the year to respond to prevailing, changing conditions of weather, demand, and facility conditions (maintenance or unplanned facility outages). Also, the model does not incorporate the dynamic physical and institutional changes that have occurred to the system throughout history. Rather, the model is intended to depict operations with an assumed consistent set of systematic operational

rules and objectives with a defined system configuration. This steady state of system configuration and operation is then evaluated over a broad range of hydrologic conditions. The utility of the model is the comparison of system performance that changes due to altering the assumptions for the operational rules and objectives, and system configuration.

Planning Methodology and Design Drought (Excerpted from Hetch Hetchy/Local Simulation Model)
Under normal conditions there are sufficient water supplies from rainfall, snowmelt, and storage such that water deliveries fulfill customer purchase requests and no systemwide water delivery reduction (rationing) is required.

System operations during drought periods require more complex planning and system management than during non-drought years. SFPUC drought planning uses as a backdrop the concepts of a “design drought” and “system firm yield.” System firm yield is a measure of the amount of water that can be delivered to customers without shortages during all anticipated hydrologic sequences, including drought periods when rainfall, snowmelt, and/or streamflow conditions are substantially below normal for consecutive years. For planning purposes, the SFPUC uses a design drought that contemplates a more severe drought than historical events and evaluates the system firm yield assuming the system is experiencing the design drought. This premise is founded on experience that illustrates that drought sequences can get more extreme as our hydrologic record lengthens. The design drought is a planning tool developed by the SFPUC used to anticipate and plan for drought; the SFPUC uses a design drought based on the hydrology of the six years of the worst sequential historical drought (1987-1992) plus the 2½ years of the 1976-1977 drought for a combined total of an 8½ year design drought sequence.

The Regional Water System has experienced drought periods in the last 30 years: most notable are the droughts that occurred from 1976 through 1977, and from 1987 through 1992. [More recently, droughts have occurred in 2012-2016 and 2020 – 2022.] During the 1987–1992 drought, even with the implementation of customer rationing, the amount of carryover storage in the regional system was more severely depleted than during any previous period of time, and the SFPUC had to adjust its normal operating procedures to avoid ‘running out of water’.

The 1987–1992 drought began at the end of the 1986 rainy season. Subsequent annual flows in the Tuolumne River were about 50 percent of average. The SFPUC’s entitlement to Tuolumne River flow was reduced to about 16 percent of the total river flow, and less than 50 percent of the normal amount of water delivered to customers was available from the river. As the drought progressed, the SFPUC developed and implemented short-term procedures to impose rationing on customers that resulted in a near 25 percent annual systemwide reduction in water deliveries. The extended drought resulted in the SFPUC adopting a mandatory rationing program from 1988 to 1989 and again

from 1990 to 1993. Based on the experience of the 1987–1992 drought, the SFPUC modified its operational procedures with regard to drought planning.

The SFPUC system operations currently include a process for declaring a water shortage and a method for allocating reductions. The general protocol links total reservoir storage conditions to suggested delivery reductions. Each year, during the spring snowmelt period, the SFPUC evaluates the amount of total water storage throughout the system and determines if there is enough water available to serve full deliveries to customers within the context of the current year’s supply and the design drought. At a certain reservoir storage, the SFPUC may impose delivery reductions. If reservoir storage becomes further depleted in a following year, the SFPUC may need to impose further delivery reductions. Currently with existing purchase requests there are three stages of delivery reduction: the first stage involves a 5 to 10 percent systemwide delivery reduction and is achieved by voluntary rationing; the second stage imposes an 11 to 20 percent systemwide delivery reduction and requires mandatory rationing; and, at the third stage of response, a 20 percent or greater systemwide delivery reduction would result in mandatory rationing with further reduced allocations. Prior to the initiation of any water delivery reductions, the SFPUC would hold a public meeting, open for public comment, to outline the water supply situation, the proposed water use reduction objectives, alternatives to water use reduction, and compliance monitoring methods.

The SFPUC quantifies water availability through the performance of two types of analyses. Each of these analyses provides a statement of the ability of the SFPUC Regional Water System to deliver water. The first type of analysis defines the system firm yield of the SFPUC system. As stated above, system firm yield is a measure of the amount of water that can be delivered to customers without shortages during all anticipated hydrologic sequences. System firm yield is the average annual water delivery that can be sustained without shortage throughout the 8½ year design drought. The second type of analysis identifies the reliability of the SFPUC Regional Water System during a recurrence of a long record of hydrologic conditions. The hydrologic record used for these analyses is the [97]-year sequence of hydrology previously described. A system firm yield study will identify the rules of operation and delivery rationing that maximizes water deliveries during the design drought. Those rules are then applied within a system performance study to identify the reliability of water deliveries and system operation over a long sequence of hydrology.

The system firm yield study is focused on operations and water deliveries during drought sequences. As described previously, the SFPUC uses a design drought that contemplates a more severe drought than historical events and defines the system firm yield assuming the system is experiencing the design drought. To quantify the system firm yield, operation of the SFPUC system is tested during the design drought with increasing levels of delivery and varying protocols for rationing until useable reservoir storage is depleted at the end of the design drought. These deliveries are the metric of the amount of water available after satisfying all of the other commitments of the system such as required stream releases and flow obligations to the Districts. Since the level of delivery

(percentage of full purchase request) can vary year to year within the design drought, the system firm yield is expressed as the average annual water delivery that can be sustained throughout the entire 8½ year design drought. The analysis that defines system firm yield simulates system reservoir storage being fully depleted at the end of the design drought sequence.

In 2020, SFPUC developed the Water Supply and Demand Worksheet, which provides a simplified presentation of some important elements of the water supply planning methodology; it was developed to make the water supply planning methodology more accessible to decision- makers and interested members of the public. The Alternative Water Supply Program has used some of the presentation metrics from the worksheet for the evaluation of water availability.

The worksheet allows users to view and modify assumptions about RWS system demand, water supply projects and obligations, and RWS operation during the design drought, to see the effect on available RWS water supply and rationing. Links to the Water Supply and Demand Worksheet and companion Worksheet User Guide can be found on the SFPUC website (https://www.sfpuc.org/programs/future-water-supply-planning/planning-tools-and- documents).

A-35
Appendix C:

AWS Program Cost
Development Approach

APPENDIX C

APPENDIX C. AWS PROGRAM COST DEVELOPMENT APPROACH
Purpose of this Appendix
This appendix presents supporting information and relevant details for the AWS Program costs shown in the AWS Plan.

AWS Proforma Modeling
To begin to understand the level of investment needed for the AWS Program, the SFPUC has undertaken financial analysis to evaluate the costs for implementing the AWS Program. In conjunction with preliminary feasibility analyses and cost estimates that are being prepared for individual projects within the AWS Program, a Proforma Model is being developed to assess the costs for the AWS Program (AWS Proforma Model) over the 2045 planning horizon. The intent of the model is to use a uniform set of planning assumptions to provide a framework that would allow staff to incorporate updates on a continuing basis including adding new projects in the AWS Program portfolio.

While development of the AWS Proforma Model is not complete at the time of publication of this AWS Plan, initial estimates derived from the model have been used to reflect potential capital costs and unit costs for each AWS project, where the costs represent a snapshot as of May 2023.

Cost Estimating Considerations for the AWS Plan
The AWS Program portfolio includes a diverse set of projects. The projects vary widely in terms of their location, water production, operation, and capital infrastructure needs. The range of complexity also varies among projects, with one (Calaveras Reservoir Expansion) undertaken entirely by the SFPUC to those such as the Los Vaqueros Expansion (LVE) Project that include multiparty arrangements between various agencies with different interests. Further, the projects are in different stages of planning and vary in their individual schedules to deliver water. The projects thus present a unique set of challenges for cost estimating.

Project-level planning, including feasibility studies and alternatives’ analyses, are ongoing and continue to proceed in parallel with the development of the AWS Proforma Model. As costs are updated in project planning, those changes are reflected in the AWS Proforma Model, but there may be a lag. Additionally, the cost estimate for a project in its feasibility study may be based on different or incomplete assumptions compared to the AWS Proforma Model, which uses some uniform assumptions, which were standardized to the extent possible, based on past SFPUC infrastructure projects.

As noted previously, five of six AWS Projects involve multiparty partnerships. For most, cost- sharing among partners and other offsets such as state and federal grants have not been determined at this time and will only be available as project-level planning proceeds. The intent of the financial analysis at the present time is generally to develop the total capital costs or

100% of the costs for capital investment toward the projects, notwithstanding the potential cost-sharing and cost offsets or cost of integrating or operating projects in the future.

Cost Estimate Classifications
The cost estimates developed at the project-level are generally based on Association for the Advancement of Cost Engineering (AACE, Inc., 2005)1 standards of project cost estimating used to classify the degree of project definition and maturity (see Table C-1). As each AWS Project is further defined and cost components are refined, the expected range of cost accuracy will also continue to improve, moving the project into a different cost classification. The cost estimates for the AWS Projects are currently predominantly Class 5 estimates except for the LVE Project and Daly City Recycled Water Expansion Projects, which are further along in planning and therefore have a higher degree of specificity. The cost estimate for the LVE Project is a Class 2 cost estimate and that for the Daly City Recycled Water Expansion Project is a Class 3 cost estimate. The table below describes the standard classifications for infrastructure cost estimating.

Table C-1: COST ESTIMATE CLASSES
Cost Estimate
Class
Description Expected Range of
Accuracy*
Class 5 Class 5 estimates are prepared for any number of strategic business planning purposes, such as but not
limited to market studies, assessment of initial
viability, evaluation of alternate schemes, project
screening, project location studies, and long‐range
capital planning. They are generally prepared based
on very limited information and subsequently have
wide accuracy ranges.
‐ 20% to ‐50% on
the low side, and
+30% to +100% on
the high side

Class 4 Class 4 estimates are typically used for project screening, determination of feasibility, concept
evaluation, and preliminary budget approval. They are
generally prepared based on limited information and
subsequently have fairly wide accuracy ranges.
-15% to -30% on
the low side, and
+20% to +50% on
the high side
Class 3 Class 3 estimates are generally prepared to form the basis for budget authorization, appropriation, and/or
-10% to -20% on
the low side, and

1 AACE, Inc. AACE International Recommended Practice No. 18R-97, Cost Estimate Classification System – As Applied in Engineering, Procurement, and Construction for the Process Industries, 2005.

funding. As such, they typically form the initial control estimate against which all actual costs and resources
will be monitored. Class 3 estimates are typically
prepared to support full project funding requests and
become the first of the project phase “control
estimates” against which all actual costs and resources will be monitored for variations to the budget. They
are used as the project budget until replaced by more
detailed estimates.
+10% to +30% on
the high side
Class 2 Class 2 estimates are generally prepared to form a detailed control baseline against which all project
work is monitored in terms of cost and progress
control. For contractors, this class of estimate is often used as the “bid” estimate to establish contract value. -5% to -15% on the
low side, and +5%
to +20% on the
high side
Class 1 Class 1 estimates are generally prepared for discrete parts or sections of the total project rather than
generating this level of detail for the entire project.

Class 1 estimates are typically prepared to form a
current control estimate to be used as the final
control baseline against which all actual costs and
resources will now be monitored for variations to the
budget and form a part of the change/variation
control program.
-3% to -10% on the
low side, and +3%
to +15% on the
high side
* Expected range of accuracy provided depends on the technological complexity of the project, appropriate reference information, and other risks (after inclusion of an appropriate contingency determination). Ranges could exceed these shown in unusual circumstances.

Source: AACE, Inc, 2005
AWS Project Cost Calculations
The bolded terms described in this section are the terms used in Table 5-1 of the AWS Plan.

Each AWS Project has its own schedule with anticipated phases including planning, engineering design, environmental review and permitting, construction, and construction management The AWS Plan provides a Status for each project by stating the phase the project is in as of May 2023 (at the time the AWS Plan was prepared) with the Cost Estimate Classification as described in Table C-1. The table then identifies the SFPUC Supply Assumed, which estimates the volume of water that may be available to address dry year needs for the SFPUC toward the identified gap. For most projects, this supply assumed demonstrates a current assumption of potential benefit and is not used in the calculation of costs. The Estimated Online Date

identifies a projected date when the project could begin deliveries. This date and the corresponding schedule for construction help determine the level of escalation costs assumed for a project, which is typically to the mid-point of construction. If the project construction schedule is delayed, additional escalation costs may be incurred.

The Total Capital Costs are presented in two ways in Table 5-1 of the AWS Plan. First, the Escalated costs reflect the real costs anticipated over multiple years of planning and construction. As broken down in Table C-2 below, the capital costs include Construction Costs, Owner’s Administrative Costs, and Development Costs. These categories of costs include contingencies and escalation factors, as shown. For the Daly City Recycled Water Project, which has a Class 3 cost estimate a 30% contingency is assumed. For other projects that have Class 5 cost estimates, a 35% contingency is assumed. The Los Vaqueros Expansion Storage project utilizes a different contingency calculation based on its project proforma model.

Total capital cost is the sum of Construction, Owner’s Administrative Costs, and Development Costs. It includes contingency and escalation factors as part of construction cost estimating and other costs (Owner’s Administrative and Development) are based on percentages of those total construction costs.

Table C-2: CALCULATION OF ESCALATED CAPITAL COSTS
Cost Component Definition Cost Basis and
Calculation
Construction Cost Cost associated with building a project.

Components:

Based largely on project-
level feasibility studies
and may include
additional assumptions
for land, etc. if not
included in study
Direct costs associated with construction of
proposed project facilities and connections
and updates to existing structures or
facilities, as applicable and
Indirect costs associated with construction
such as contractor general conditions,
overhead and profit, and insurance
Contingency A contingency is intended to account for
changes in costs over a project timeline
A contingency of 30%
applied to construction
cost for Class 3 estimate
A contingency of 35%
applied for Class 5
estimates

Additional contingency
of 10% on the escalated
construction cost
described below
Escalation Escalation accounts for planning and
construction anticipated to occur in the
future and varies with the project schedule.

Escalation factor is
applied to construction
cost after a contingency
of 30% or 35%
Escalation factor is based
on project schedule and
SFPUC’s standard rates
(i.e., yearly escalation rate
of 6% for 2023 and 2024
and 4% for 2025 and
thereafter)
Owner’s
Administrative
Cost
Costs associated with administration during
construction.

Components:

Calculated as 22.1% of
escalated construction
cost with contingencies
Environmental avoidance & mitigation
(0.1%)
Security upgrades (0.5%)
Project management (3%)
Environmental construction compliance
(0.5%)
Cost components based
on past SFPUC
infrastructure projects Construction management - engineering support (4%)
Construction management - contract
management and administration (12%)
Legal project support (0.5%)
Operations and water quality support (1.5%)

Development
Cost
Costs associated with developing and
planning a project anticipated to be incurred
prior to construction.

Calculated as 15% of the
construction cost
Cost components based
on past SFPUC
infrastructure projects
and standard industry
practice
Components:

Land and right-of-way (ROW) acquisition
(0.5%)
Project management (1%)
Pre-design planning (2%)
Environmental review and permitting (1%)
Engineering design (10%)
Legal ROW support (0.5%)

The calculation of Estimated Capital Cost per Acre-Foot is the unit cost based on the total capital cost in current terms or the 2023 $ Capital Costs divided by the Project Capacity in acre-feet over a period of 30 years. While the project life of many of these projects may be greater than 30 years, convention on SFPUC-financed projects has been to consider costs over the standard 30-year financing period.

Capital Cost Per Acre-Foot = Total Capital Cost in 2023 $ X 1,000,000 Project Capacity in Acre-Feet per Year X 30 (financing period)

For most projects, the Project Capacity represents the maximum yield of the project, regardless of whom may receive deliveries as that may not be confirmed. In some instances, assumptions have been made for the purpose of this Plan. For the ACWD-USD Purified Water Project, only the first phase evaluated in the Feasibility Study is assumed in the AWS Plan although a subsequent phase could be implemented. However, due to the complexity of the project and the distinct nature of the second phase relative to the first phase, it is not assumed. The LVE Project, as an exception, only reflects costs and capacity related to the presumed SFPUC share of the regional storage project. This is because the project is further along in identifying cost allocations and potential benefits. While these costs and volumes may still change as the project progresses, key cost components are known and the project has its own detailed proforma model that has been reviewed and vetted among project partners. Because the SFPUC will

definitively not lead project construction or operation on its own, applying SFPUC standard cost metrics was not appropriate for this project.

For storage projects, the project capacity is the annual average water supply available over 7½ years of the SFPUC’s 8½ year design drought accounting for evaporative (8%) and conveyance (10%) losses. As has been assumed for the Regional Groundwater Storage and Recovery Project, dry year storage is not typically drawn down in the first years of a drought when a drought is not yet declared, so available supply is assumed over 7½ years. As an example, the 3.9 mgd capacity for the LVE Project represents average annual deliveries of a full reservoir over 7½ years of the design drought.

Future AWS Project Cost Factors
The AWS Proforma Model remains under development. Meanwhile, project planning will continue to progress in parallel and costs will continue to be updated and detailed. This could include information that is not available as of May 2023 such as, but not limited to, the following cost categories:
• Grants and Loans: The estimated costs for the AWS Program do not account for or include any reductions from grants or other funding sources.
• Operations & Maintenance (O&M) costs: The costs shown in the AWS Plan do not include (O&M costs, which will be estimated for AWS Projects as part of the continuing financial analysis for the AWS Program. Table C-3 shows potential O&M costs anticipated for an AWS Project.
• Ownership and Financing: The estimated costs do not account for or include plan of financing. Actual financing strategies, financing instruments, and cost of funds are yet to be determined and may be dependent on the ownership structure for a project. The costs will be updated to incorporate the ownership structure and financing mechanisms for the project as they are known. AWS staff will continue to work with the Finance team to identify capital planning and budgeting options.
• Cost share: Except for the Calaveras Reservoir Expansion Project, all AWS Projects involve multiparty partnerships. The costs estimated at this time represent total capital costs and do not represent the share of individual partners. The cost share is not known at this time and will be determined in collaboration with project partners. As the financial analysis continues, additional costs will also be included such as those associated with the connection of the AWS Projects with the local systems, project operations and benefits from the projects and as they are apportioned among partners.
• Project operations and benefits: Details on project operations and benefits are not available for most projects. Delivery schedules of water would vary significantly with time, precipitation (dry or wet years), type of project (e.g., water supply, storage, conveyance), and other factors which will need to be coordinated with project partners and assessed for benefits and operations. As planning progresses, cost-shares for projects will also reflect the benefits for the SFPUC associated with project implementation.

• Alternatives’ Analyses: For most projects, several scenarios are being assessed. As alternatives are selected, the infrastructure and operational requirements will likely shift affecting the costs and schedule for projects.

Table C-3: POTENTIAL O&M COSTS
Total O&M Cost
O&M Costs: Costs to operate the project to produce and deliver water, here assumed over 30 years and the maintenance of facilities and equipment.

Calculated as total of components listed
above over the 30-year project operation
(components based mostly on industry
practices and SFPUC’s past project data)
Chemicals usage
Staffing
Insurance costs
Electricity
O&M contingencies
Renewal and Replacement
Contingencies and Escalation

A-45
Appendix D:

Response to Comments

APPENDIX D

APPENDIX D. RESPONSE TO COMMENTS
This Appendix D was prepared between September 2023 and January 2024 and represents a new component of the Final AWS Plan. It includes a copy of each of the 14 written comment letters received during the public review period for the Draft AWS Plan (June 28 to August 31, 2023), with over 160 specific comments marked and coded for ease of reference (e.g., A-1, A-2, A-3 through N-1, N-2, N-3). All formal comment letters received and included in this appendix are shown in Table 1 below. Each comment letter is followed immediately by responses to the corresponding comments prepared by SFPUC staff. The responses are largely contained within this appendix; any edits or other modifications to the AWS Plan are referenced in the specific response. Acronyms that are used in other parts of the document are not defined again in this section but can be found in the main body and/or Glossary of the AWS Plan.

Table 1: Comments Received on the Draft AWS Plan
Commenter Date Received Comment Letter
Designation
Alameda County Water District (ACWD) August 31, 2023 I Bay Area Water Supply & Conservation Agency
(BAWSCA) August 31, 2023 F
California Water Service (Cal Water) August 31, 2023 J City of Santa Clara August 31, 2023 K
Coastside County Water District August 15, 2023 C
Dave Warner, Member of the Public August 30, 2023 E
David Happs, Member of the Public August 31, 2023 H
Restore Hetch Hetchy August 31, 2023 N
San José Municipal Water System (SJMWS) August 31, 2023 L SFPUC Citizens’ Advisory Committee (CAC) Water
Subcommittee August 29, 2023 M
Sierra Club, California; Tuolumne River Trust; San
Francisco League of Conservation Voters; Golden
State Salmon Association; California Sportfishing
Protection Alliance; Sierra Club, San Francisco Bay
August 31, 2023 G
Steve Lawrence, Member of the Public July 11, 2023 B
Tuolumne River Trust
August 31, 2023 (includes
some comments sent via
email on July 10, 2023)
A
William L. Martin, Member of the Public August 30, 2023 D

Preceding release of the draft document for public comment, the AWS Plan was presented to the SFPUC Commission at a public meeting on June 27, 2023. The AWS Plan was also presented at the following that were open to the public:
• BAWSCA Board Policy Committee, June 14, 2023
• Bay Area Water Stewards (BAWS), June 15, 2023
• SFPUC Citizens’ Advisory Committee (CAC) Water Subcommittee, June 27, 2023 • BAWSCA Board of Directors, July 20, 2023
On August 22, 2023, the CAC Water Subcommittee discussed comments and questions on the AWS Plan in a public meeting where AWS staff was present and available to provide clarifications or respond to comments in person. A transcript of that meeting was submitted as a formal comment letter and is included in this appendix (Comment Letter M).

Some topics received numerous comments across individual letters. For such common topics, staff have prepared Global Responses that are provided ahead of all individual comment letters and responses. These Global Responses are referenced in individual responses, as appropriate. The topics with Global Responses include:

1. Demands

2. Design Drought

3. Rationing

4. Projects with Irrigation Districts

Global Response 1: Demands
The SFPUC has received numerous comments requesting changes to how regional water demands are estimated and projected. Like other planning tools, demand projections are developed outside of the AWS planning process and are used for estimating needs broader than those represented in the AWS program. Furthermore, the SFPUC is responsible for forecasting only retail demands, while Wholesale Customer demands are projected by individual customers and analyzed and reported by BAWSCA.

Nevertheless, ensuring that d emand projections reflect the best available data and assumptions is critical for a program that identifies a water supply gap and potential solutions largely based on demands of retail and wholesale customers 20 years in the future.

The SFPUC’s demand forecasting methodology has evolved over time to reflect its planning needs. For over a decade, the SFPUC used an end -use model, which more accurately reflected the impact of changing plumbing codes and conservation measures than a land use demand model would be able to do, for example. More recently, the SFPUC has been using an econometric model to forecast water demands. An econometric model focuses on the relationship between economic variables - such as employment growth, economic tre nds, and policy changes - and water demand. Moving to an econometric model has helped improve the quality of demand projections. BAWSCA has similarly moved from an end -use model to an econometric model to reflect Wholesale Customer demand projections.

As the SFPUC faces significant future decisions to invest in alternative water supplies, staff recognize the need to continue improving the quality and accuracy of its demand forecasting. To this end, the AWS Plan includes a new Recommendation 5 in Chapter 6 to revisit the SFPUC retail demand modeling.

Staff would also work closely with BAWSCA as it updates Wholesale Customers’ demand projections.

Implementation of changes to the demand modeling will be a significant undertaking but would be completed before the AWS Plan is updated in 2026.

As part of this effort, the following improvements to the water demand forecasting will be evaluated:
• Compare prior estimates to delivery and sales data to identify key factors that may need to be recalibrated, changed, or added;
• Review model assumptions and the sensitivity of select factors such as estimated housing units and residents per unit; and
• Consider presenting demands as a range or reflecting more than a single potential outcome;

The resulting demand scenario(s) would be incorporated into future AWS gap estimates to support future investment recommendations.

Global Response 2: Design Drought
The SFPUC has received comments calling for a risk analysis on the use of an 8.5-year design drought or for a reduction in the design drought duration from 8.5 to 7.5 years. The design drought is an important planning tool used by the SFPUC for various water supply planning, including but not limited to, the AWS Plan.

By putting two historically significant droughts together, the design drought creates a planning scenario that helps the SFPUC maintain reliable water supply infrastructure and delivery that can withstand extreme and prolonged periods of reduced snowmelt a nd precipitation. While the SFPUC acknowledges the low probability of an 8.5-year drought occurring, according to what we know about the historic hydrology of the region, we also recognize that the global climate is changing, and that California weather may become more variable as a result. Preparing for this type of scenario helps the SFPUC safeguard the water supply needs of our customers.

The SFPUC remains committed to adaptive management practices that enable responsiveness to changing conditions and will continue to revisit its planning tools periodically. At this time, the SFPUC will not modify its design drought as part of the AWS planning process.

Global Response 3: Rationing
The SFPUC received multiple comments expressing either confusion or disagreement with how rationing is quantified and how it relates to the volume of water available (i.e., total system yield as described in Section 2.3.1).

Rationing is expected to be necessary on the RWS during droughts, and it is included in water supply planning as part of the SFPUC’s approach to drought management. Section 2.3.1 describes the baseline water availability from the RWS during dry years and includes rationing that would be needed with the WSIP program completed. The level of rationing that is identified in this section is approximately 12% of the total system yield, which is consistent with what was developed for and adopted under the WSIP PEIR. While it is not a standalone policy, it was developed for the WSIP program using the standard water supply planning methodology employed by the SFPUC and described in Appendix K of the 2020 UWMP.

In Section 3.2.1, the AWS Plan describes how both water supply ( i.e. firm yield) and the volume associated with rationing would change with the implementation of the Bay -Delta Plan Amendment by keeping the level of rationing constant at 12% of the total system yield. Maintaining the same level of rationing isolates the Bay-Delta Plan Amendment as the only variable, demonstrating the impact of its implementation as compared to the baseline scenario described in Chapter 2. This comparison is shown in Table 3 -1. As described in the 2020 UWMP, another way to look at the effect of the Bay - Delta Plan Amendment scenario in the absence of new supplies could be to increase rationing to 40%- 50%. However, the AWS planning effort focuses on exploring options to reduce t he need for such rationing measures back down to the 12% level that is expected to be achievable, even as conservation continues to drive down per capita consumption. While each drought is unique and future rationing decisions may be affected by State mandates or the need to fill a near-term supply shortfall, for AWS planning, 12% continues to be a reasonable long -term planning assumption. During the most recent drought that ended in 2023, the SFPUC called for 10% -11% system -wide water use reductions compared to Fiscal Year 2019-2020 levels.

While rationing can be thought of as a function of demand, it can also be represented as a volume of unrationed deliveries, or avoided deliveries. Analogous to thinking of conservation as a supply, by thinking of it this way, rationing can be counted on as part of water availability in dry years. In other words, customer demands aren't altered across wet and dry years, only water available (the combination of delivered water and avoided deliveries [rationing]) changes in dry years. For AWS planning, keeping water demands constant avoids potential confusion associated with having different numbers for both demand and water availability in calculating the water supply gap.

Global Response 4: Projects with Irrigation Districts
The SFPUC has committed to working with irrigation districts in the Central Valley to explore opportunities to increase supply reliability and fishery protection in the Tuolumne River. Conjunctive use opportunities and other improvements to storing wet year water for dry year use in the basin are expected to be evaluated in addition to opportunities of inter-basin San Joaquin tributary exchanges.

The SFPUC will continue to work with its partners in the San Joaquin basin to reach the shared goals of supply reliability and fishery protection through the creation of additional water resources. The SFPUC is prepared to contribute financially to the development of these resources. Community support in the San Joaquin basin for these types of projects will be cr itical to their successful implementation and the SFPUC recognizes the necessity of this support and stands ready to play its appropriate role.

Recommendation 4 in Chapter 6 include s providing periodic updates to align with AWS Project milestones.

OFFICES
San Francisco

Modesto

Sonora

Mailing Address
P.O. Box 3727
Sonora, CA 95370

Phone
(415) 882-7252

Website
www.tuolumne.org

BOARD MEMBERS
John Kreiter, Chair
Harrison “Hap” Dunning,
Vice Chair
Cindy Charles, Treasurer
Marek Robinson, Secretary
Jose Borroel
Eddie Corwin
Eric Gonzalez
Camille King
Marty McDonnell
Homero Mejia
John Nimmons
Eric Riemer
Iris Stewart-Frey
Bart Westcott
Brad Wurtz

August 31, 2023

AWS Planning Team
SFPUC
[email protected]

Re: Draft Alternative Water Supply Plan

Dear Manisha, Steve and Others:

Please accept the following comments on the SFPUC’s draft Alternative Water Supply Plan. I would appreciate responses to the questions I raise.

1) Problems with Figure 2-6.

The historic purchases graph appears to have several problems. a) It is missing FY 14-15.
b) The bars for FY 09/10, 12/13 and 13/14 appear to be about the same, but the purchases are different (significantly for FY 13/14).
c) Purchases for FY 20/21 are higher than reported in the Water Resources Annual Report (195 mgd).

Please correct Figure 2-6.

2) Rationing should be based on demand, not supply.

The following statement from Table 3-1 is confusing, and potentially incorrect. Rationing is based on a percentage of demand, not supply.

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2 Look at it this way. Imagine your salary is $100,000/year, and you spend $90,000/year on living expenses, banking $10,000/year for your retirement. $100,000 is your annual “supply,” and $90,000 is your annual “demand.”

The economy experiences a recession, and your boss is forced to cut your salary by 20%, bringing your annual income (supply) down to $80,000/year. You now need to cut costs and reduce your spending (demand) by $10,000/year in order to preserve your retirement fund. This is the equivalent of rationing.

Reduced spending (rationing) is based on your spending (demand), not your salary (supply).

The statement in the Plan that “The volume of delivery reduction is proportional to the available water supply” appears incorrect, or at least misleading.

Please explain.

3) Water supply loss figures related to the Bay Delta Plan don’t match.

The AWS Plan states:

The Bay-Delta Plan Amendment, if implemented as adopted in 2018, would result in new instream flow requirements that would reduce the SFPUC’s available water supply by an estimated 93 mgd per year. (p. 36)

And:

The Bay-Delta Plan Amendment, if implemented as adopted in 2018, would result in new instream flow requirements that would reduce projected water availability from the RWS in dry years from 257 mgd to 152 mgd. (p. XII)

The second statement suggests the Bay Delta Plan would reduce supply by 105 mgd (257 mgd minus 152 mgd). One would think the two figures should match up, but there’s a difference of 12 mgd. Why is this?

Could it be that the 105 mgd figure was calculated using the SFPUC’s “rationing policy” rather than its rationing methodology?

Please explain.

4) How was the SFPUC’s “rationing policy” adopted?

The AWS Plan states:

The SFPUC estimates that the water demand addressed through rationing is 30 mgd, based on the adopted rationing policy that was adopted under the WSIP Programmatic Environmental Impact Report (PEIR) in 2008. This policy assumes that rationing is approximately 12% as an A-5
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3 annual average over the 8.5-year design drought sequence. Over the 8.5 years of simulated drought, rationing is initially 0% and increases up to a maximum of 20%, with the annual average over the sequence being about 12%. (p. 23)

Resolution 08-0200, which codified the WSIP, does not mention the SFPUC’s “rationing policy.” Please explain how it was adopted.

5) Several BAWSCA agencies are requesting more water than their ISGs allow.

I looked at the BAWSCA agencies’ purchase request projections for 2045 (provided in 2021), and discovered that four agencies requested more water than they are entitled to under their Individual Supply Guarantees (ISG). Following are those agencies.

The total difference between ISGs and requests is 3.61 mgd. If this is correct, shouldn’t 3.61 mgd be subtracted from the 244 mgd cited as “Demands” in the AWS Plan?

6) The South Bay Purified Water Project would widen the water supply gap.

The first goal listed in Chapter 6 of the AWS Plan is to “Avoid widening the water supply gap.” (p. 111)

Most people who follow SFPUC issues have been under the impression the South Bay Purified Water Project was conceived to meet the current demand of 9 mgd from San Jose and Santa Clara. We assumed this was aimed at making the decision on whether to make the cities permanent customers without increasing BAWSCA’s Water Supply Assurance a little easier. It turns out this is not the case. The Plan states:

The cities of San Jose and Santa Clara are currently interruptible customers of the SFPUC and have requested permanent status, as discussed in Chapter 2 (Background). The two cities’ combined projected demand is 15.5 mgd for the planning horizon. They have requested a guaranteed supply from the SFPUC of 9 mgd (total). In order for the SFPUC to consider granting San Jose and Santa Clara permanent status and to minimize impacts to the existing permanent Wholesale Customers, the two cities must secure a reliable supply to meet their additional demands beyond the 9 mgd that they have requested as a guarantee. This project would produce 6.5 mgd of purified water to serve the needs of San Jose and Santa Clara beyond the cities’ purchases from the SFPUC, while augmenting RWS supplies by 3.5 mgd in dry years.

Implementation of this project would support the SFPUC’s decision to make San Jose and Santa Clara permanent customers. (Appendix A)

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4 The project would produce 6.5 mgd to meet the additional requests from San Jose and San Jose in all years. In dry years, the project would produce an additional 3.5 mgd for use by the SFPUC. Assuming the SFPUC would use its 3.5 mgd to help meet the cities’ existing demands (9 mgd) from the RWS, the water supply gap would still be 5.5 mgd (9 mgd minus 3.5 mgd).

Making San Jose and Santa Clara permanent customers would widen the SFPUC’s water supply gap.

7) Which AWS projects are covered by the $4 billion to $10 billion cost estimate?

Does the $4 billion to $10 billion cost estimate cited on page 124 apply only to the AWS projects listed in Table 1? How many mgd would the $4 to $10 billion produce?

8) Will more than half of the initial AWS Plan funding be used for the Daly City Recycled Water Project?

I find it hard to believe that $116 million of the recommended $209 million for the AWS Project and Programmatic Recommendations would be used to develop only 0.7 mgd of recycled water in Daly City.

Am I reading the Plan correctly?

9) Why isn’t a partnership with the Irrigation Districts a top priority?

The AWS Plan makes it appear that the SFPUC and Irrigation Districts are holding collaboration on water supply projects in Stanislaus County hostage to the Tuolumne River Voluntary Agreement. Collaboration has tremendous potential, and failing to at least analyze opportunities in the AWS Plan is a lost opportunity. The Plan states:

These projects [joint projects with Irrigation Districts] are part of the Proposed Voluntary Agreement and are not the focus of the AWS Program. These projects may be included as part of future updates to the AWS Program. However, the results of Proposed Voluntary Agreement negotiations will determine how these actions may progress and potentially reduce the impact of the Bay-Delta Plan Amendment on SFPUC’s future water supply gap and are therefore an essential component of the SFPUC’s long-term water supply planning efforts. (p. 52)

In 2012, while attempting to gain public support for the proposed water transfer between the Modesto Irrigation District and the SFPUC, MID staff gave a presentation to their board titled “Comprehensive Water Resources Management Plan.” Staff identified 25,000 to 40,000 acre feet of water that could be saved if they had the funding for infrastructure improvements. It was proposed that the funding would come through the sale of water to the SFPUC. The total estimated cost of all the proposed improvements was $115 million.

The AWS Plan should at least analyze the potential for water conservation and groundwater recharge in the Irrigation Districts’ service areas.

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5 Thank you for the opportunity to provide comments and raise questions.

Sincerely,

Peter Drekmeier
Policy Director

Response to Comment Letter A
Tuolumne River Trust
Peter Drekmeier, Policy Director
August 31, 2023
A-1 Figure 2-6 has been updated in Final AWS Plan to reflect this comment, adding data for FY14-

15. A-2 Figure 2-6 has been updated in Final AWS Plan to reflect this comment, correcting the size of the bars to more accurately reflect the data.

A-3 Purchase n umbers shown in the FY 2020 -21 Annual Report do not include losses. A new footnote to Figure 2-6 has been added to clarify that retail numbers include losses.

A-4 See Global Response 3.

A-5 The difference calculated in the comment (105 mgd) represents the impact of not only the Bay-Delta Plan (93 mgd) but the impact of implementing rationing. See Global Response 3.

The 12-mgd difference between 93 mgd and 105 mgd is the difference between the water demand addressed through rationing in the with and without Bay -Delta Plan scenarios (30 mgd versus 18 mgd) with the level of rationing (12% of total system yield) being held constant across the two scenarios.

The second statement referenced in the comment will be updated to clarify that this reduction in projected water availability is expressed as total system yield. The statement will be updated to read: "The Bay-Delta Plan Amendment, if implemented as adopted in 2018, would result in new instream flow requirements that would reduce projected water availability from the RWS in dry years, expressed as total system yield, from 257 mgd to 152 mgd." A-6 See Global Response 3.

A-7 While individual Wholesale Customers have ISGs, the SFPUC has a perpetual obligation to provide up to the Supply Assurance of 184 mgd to Wholesale Customers. The WSA allows for the transfer of ISGs between customers. Therefore, as long as the collective de mand of the Wholesale Customers is below the Supply Assurance, the SFPUC plans to be able to meet aggregate demands.

A-8 The South Bay Purified Water does not widen the water supply gap of 92 mgd in 2045, it would reduce that gap by 3.5 mgd. The Cities of San Jose and Santa Clara have been purchasing water from San Francisco since 1975. Their historical purchases from San Francisco have been approximately 4.5 mgd each, or 9 mgd cumulative demand for the two cities. These historic deliveries are consistent with the projected demands through 2045, which are included in the calculation of the projected water supply gap. The cities of San Jose and Santa Clara are classified as Interruptible Customers of San Francisco. This means that their supply can be suspended by the SFPUC with 10 years of notice.

The policy decision of whether to make San Jose and Santa Clara permanent will not reduce or eliminate their demands on the RWS, it will only address the question of new obligations.

The South Bay Purified Water Project is a partnership among Santa Clara, San Jose, and the SFPUC. Based on current project planning, this project would be owned and operated by San Jose and Santa Clara and would provide a dry-year supply to the SFPUC of at least 3.5 mgd to help address the dry year shortfall on the RWS for all customers. If San Jose and Santa Clara are made permanent customers of the SFPUC, the South Bay Purified Water project may partially offset the dry year delivery needs from the RWS by 3.5 mgd. San Jose and Santa Clara are motivated to partner with the SFPUC in this pro ject due to their desire to become permanent customers. In the absence of a decision to make these cities permanent customers, San Jose and Santa Clara will not be inclined to support the implementation of this project and make 3.5 mgd available to supplement RWS deliveries in dry years.

A-9 The $4 billion to $10 billion cost estimate in the AWS Plan reflects the current estimated total capital costs for the projects listed in Table 5 -1. The estimates are based on current capital planning estimates used for the AWS projects, including the expansion of Calaveras Reservoir, which includes two scenarios ranging from 2.7 mgd to 28.6 mgd. The $4 billion estimate reflects projects totaling 22.2 mgd and the $10 billion estimate reflects projects totaling 48.1 mgd. Note that these capital cost esti mates are based on early planning studies and do not account for any potential cost-share or potential future federal or state funding.

A-10 The single largest funding request is for the Daly City Recycled Water Expansion Project because the full cost of this project would be incurred within the next 10 years. Unit costs for this project, as shown in Figure 5 -1, are in line with other AWS Projects. Much of the cost associated with t he other project recommended for potential implementation , the Los Vaqueros Expansion Project, will be incurred outside of the 10-year CIP window.

A-11 As referenced in the comment, Section 4.3 discusses joint projects with Irrigation Districts. To clarify that outcomes of the Voluntary Agreement will be included in future AWS Plan updates, the last three sentences in that section have been edited to state: “These projects are part of a broader cooperative effort with the Irrigation Districts in parallel with the Voluntary Agreement process. Developments and any resultant effects on the supply gap will be included in future AWS Plan updates .” See Global Response 4 and updated Recommendation 3 in Chapter 5 for additional information.

From: Steve Lawrence <[email protected]>
Sent: Sunday, July 9, 2023 4:52 PM
To: Alternative Water Supply <[email protected]>
Subject: Draft Alternative Water Supply Plan
CAUTION: This email originated from outside of the organization. Do not click links or open attachments unless you recognize the sender and know the content is safe.

It seems firm yield is 227 mgd, +30 rationing, = 257 "firm yield." But that doesn't consider the elephant in the room: Bay Delta Plan and state's curtailment of SFPUC's right to divert as it has been doing for many years (until curtailment). Why not? Is there a settlement yet? If so, what is it? If not, well, it's important that there be one for AWS to be meaningful, no?

I read that the expected/forecast demand in 2045 is 244, and also read that the gap (shortfall) is 92, suggesting/implying that 152 is expected from...I can only guess from upcountry sources. Is that right? And that's before considering actions that might reduce the shortfall, such as enlarging Calaveras, expanding Los Vaqueros, and developing pure/purified water? (Any others now known?)

In sum, I'm confused about the numbers, and assumptions that apply to them, which seem inconsistent (not the same throughout)--is that right? I wish there were more clarity and simplicity so that a reader could follow, as: we expect this supply from upcountry and storage we now have in place, we plan and here assume we'll develop this set of projects reducing shortfall by x, which leaves y to be made up; here are some possibles we might develop, together with estimates of how much we think they'll yield if we do.

Steve Lawrence
(per offer to ask in email of July 6)
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Response to Comment Letter B
Steve Lawrence, Member of the Public
July 11, 2023
B-1 Table 2-2 describes dry year availability in the RWS with completion of WSIP projects as part of the background for the AWS Plan. Chapter 3 introduces the Bay-Delta Plan Amendment as a driver for the future water supply gap that is the focus of the AWS Plan. Table 3 -1 provides a side-by-side comparison of the two scenarios. Negotiations on the Voluntary Agreement continue to be in progress. As more information becomes available, it will be reflected in future updates to the AWS Plan.

B-2 The 152 mgd is the total system water yield in dry years with the implementation of the Bay - Delta Plan, as shown in Table 3-1. The projected gap of 92 mgd does not account for candidate AWS Projects that are described in Chapter 5 including storage expansi on and water supply projects that could help fill that gap.

B-3 The AWS Plan describes dry year water supply availability under different conditions and over time. Chapter 2 is intended to provide baseline information on water supply availability. With WSIP implemented, the RWS can deliver 227 mgd in dry years and up to an additional 30 mgd can be achieved through rationing; this would be sufficient to meet 2045 demands of 244 mgd.

Chapter 3 builds on the baseline and describes how dry year water supply availability could change with the implementation of the Bay-Delta Plan Amendment, creating a gap of 92 mgd based on 2045 demands under drought conditions. Table 3-3 shows that of this gap, 11 mgd could be met with additional rationing, leaving 81 mgd to be met with new supplies or other actions that can reduce the gap. Chapter 5 then describes the potential projects that could fill 22-48 mgd of the gap. The AWS Plan acknowledges that the identified AWS Projects alone do not fully close the gap. It also recommends actions in Chapter 6 to continue to address the gap through project development and programmatic actions.

For greater clarity on the distinction between the information presented in Chapter 2 and 3, the following statements have been added in the opening paragraph of each chapter, respectively:
“Chapter 2 is intended to provide baseline information on water supply availability. Chapter 3 builds on this baseline and describes how dry -year water supply availability could change with the implementation of the Bay-Delta Plan Amendment.”
“This chapter builds on the information presented in Chapter 2 and layers on an analysis of how dry-year water supply availability could change with the implementation of the Bay -Delta Plan Amendment.”

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Response to Comment Letter C
Coastside County Water District
Mary Rogan, General Manager
August 15, 2023
C-1 This comment expresses support for the SFPUC's efforts to evaluate projects that augment regional water supplies and improve the reliability of the RWS through the AWS Program. The SFPUC recognizes this comment.

C-2 This comment expresses support for the SFPUC's efforts to locate projects through the RWS and to consider the benefits and impacts throughout the RWS through the AWS Program. The SFPUC recognizes this comment.

C-3 This comment expresses support for the SFPUC's efforts toward adoption of the Proposed Voluntary Agreement by the State. The SFPUC recognizes this comment.

C-4 This comment expresses support for the SFPUC to provide regular updates to the AWS Plan, as identified as a recommendation in Chapter 6 of the AWS Plan. The SFPUC recognizes this comment.

C-5 This comment expresses support for the SFPUC to hire additional staff for the AWS Program, as identified as a recommendation in Chapter 6 of the AWS Plan. The SFPUC recognizes this comment.

C-6 This comment expresses support for the SFPUC in exploring the feasibility of grant programs or low interest loans to support wholesale customer local water supply projects to reduce reliance on the RWS, as identified as a recommendation in Chapter 6 of the AWS Plan. The SFPUC recognizes this comment.

C-7 Stakeholders, community members, and other local leaders are welcome to submit letters of support to [email protected].

C-8 The SF -Peninsula Regional PureWater Project description in Chapter 5 lists out the current project partners, but not all interested parties are listed. The SFPUC will work closely with CCWD as an interested party as project planning progresses. The SFPUC r emains open to working with CCWD as a project partner on this project in the future.

C-9 This comment expresses support for the comments submitted by BAWSCA on the Draft AWS Plan. The SFPUC recognizes this comment . SFPUC's responses to BAWSCA’s comment letter are included in this Appendix.

August 29, 2023

William L. MarƟn
San Francisco, CA 94112
WlmarƟ[email protected]

San Francisco Public UƟliƟes Commission

SubmiƩed via email to [email protected]

Public Comment submiƩed regarding the proposed AlternaƟve Water Supply Plan

1. PopulaƟon Growth and Total Water Demand

On August 9, 2023, the San Francisco Chronicle published an arƟcle enƟtled “San Francisco Exodus: City may never recover populaƟon as other parts of Bay Area grow.” The arƟcle cites the California Department of Finance (CDOF) projecƟons, showing both San Francisco and San Mateo counƟes losing populaƟon between now and 2060. The CDOF projects a populaƟon gain of about 636,000 for the enƟre Bay Area.

In contrast, the AssociaƟon of Bay Area Governments (ABAG) projects a Bay Area populaƟon gain of 2 million. A major reason for the discrepancy between the Department of Finance and ABAG concerns Plan Bay Area 2050’s projecƟon of increased housing development, leading to a stronger economy and thus greater populaƟon.

The draŌ AlternaƟve Water Supply Plan (“the AWS Plan”) fails to consider populaƟon growth properly.

That failure leads the Plan to specify levels of water demand which are highly uncertain to occur. The Plan should be amended to reflect a range of possible outcomes. For example, the range of populaƟon growth cited in the Chronicle arƟcle for the enƟre Bay Are is 636,000 to 2,000,000. However, both San Francisco and San Mateo counƟes are projected to grow more slowly if at all than the rest of the Bay Area. This is the SFPUC’s service area, and it’s projected to be the slowest growing part of the Bay Area.

The Plan needs to be amended to consider a range of possible outcomes for populaƟon growth in the service area.

Once amended in this way, the AWS Plan needs to be further adjusted to consider a range of total water demand. Generally, fewer people means less water consumed. However, more people does not mean more water consumed. A review of the populaƟon growth experienced by San Francisco and San Mateo counƟes from 1980 (just aŌer one of the most severe droughts on record) to 2020 (right before the pandemic) shows significant growth. But total water demand in the service area did not increase accordingly. In fact, it went down – significantly - and remains down today, at about 190 million gallons per day (mgd). Please also note that past SFPUC projecƟons for total water demand have overesƟmated demand; it is highly likely that the Plan does so once again.

Thus the AWS Plan fails to fully account for two of its most important variables, populaƟon growth and total water demand. A much larger range of outcomes for both independent variables need to be included in the Plan, meaning that they need to be fully modeled across all possible combinaƟons to ensure that the best possible combinaƟon of alternaƟve water supply projects are undertaken.

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2. Effluent Treatment and Water Recycling and Reuse

On August 21, 2023, the San Jose Mercury News published an arƟcle enƟtled “FighƟng Future ‘Red Tides’ in San Francisco Bay.” San Francisco Bay suffered a significant harmful algal bloom (HAB) on August 31, 2022, killing thousands of fish and endangering people and their pets. A second less severe bloom occurred in July 2023.

In response, Eileen White, ExecuƟve Director of the San Francisco Bay Water Quality Control Board (SF Bay Water Board), said, as quoted in the Mercury News arƟcle, “The science is telling us that we need to reduce nutrient loads as quickly as possible. What has happened is a game changer.”

According to various reports, San Francisco’s discharges into San Francisco Bay are responsible for about 20% of the nutrient loading. The Mercury News arƟcle states that San Francisco and the East Bay Municipal UƟliƟes District (EBMUD) are running behind other municipaliƟes in dealing with this problem. The arƟcle also states that some of the South Bay agencies have reduced nitrogen releases by about 85% from previous levels.

This is an opportunity for the SFPUC, but the AWS Plan fails to address it. The SFPUC can accomplish two of its goals at the same Ɵme: reducing nutrient loading and creaƟng a new alternaƟve water supply. As noted in the Mercury News arƟcle, some of the newer technologies for reducing nutrients do not always result in excess water. The SFPUC should avoid using these technologies unless they are proven to be very cost-effecƟve on a short-term basis. The long-term plan should be a combinaƟon of reduced nutrient loading and water recycling and reuse.

Given the criƟcal nature of HABs, and the fact that the SF Bay Water Board is now looking at this issue, the AWS Plan should be amended to prioriƟze the combinaƟon of reduced nutrient loading and water recycling and reuse as its primary alternaƟve water supply. This “double-barreled” acƟon will have two long-term posiƟve results:
 A new, permanent source of water for use in San Francisco  Greatly reduced nutrient loading, which has the added benefits of helping the SF Bay Water Board meet its obligaƟons of protecƟng San Francisco Bay and improving the SFPUC’s environmental credibility.

The Mercury News arƟcle also addresses the high costs associated with reduced nutrient flows. The SFPUC should be partnering with the SF Bay Water Board and the other agencies surrounding the San Francisco Bay to pool their resources. It is highly likely that a concerted, organized effort could generate some of the funds required for upgrading all of the systems together. As a major contributor of nutrient flows, the SFPUC should take the lead posiƟon in solving this problem. The AWS Plan should be amended to specifically make this a goal of the plan.

Thank you for including these issues in the revised AWS Plan.

Best regards,

William L. MarƟn
WlmarƟ[email protected]

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Response to Comment Letter D
William L. Martin, Member of the Public
August 30, 2023
D-1 No demand projections were developed specifically for the AWS Plan. The SFPUC demand forecasting model is an econometric model that incorporates inputs from San Francisco’s Planning department – including population projections – and applies economic factors to estimate water demands. The SFPUC recognizes the importance of continuing to improve demand forecasts. See Global Response 1. A new Recommendation 5 is being added to the AWS Plan to evaluate potential modifications to its retail demand forecasting model, including the consideration of a range of possible future demand scenarios to s upport future AWS planning and recommendations.

D-2 Historically, population has increased while water demand has decreased, indicating that each person is becoming more efficient with their water use and using less gallons per day than in the past. However, this historical trend cannot be expected to continue due to a concept known as demand hardening: at some point, individual water use will become so efficient that no additional reduction can be achieved. At this point, as population increases, demand will also increase. Recommendation 5 in the AWS Plan will consider a range of possible future demand scenarios that may account for this phenomenon. See Global Response 1 for more information on the SFPUC’s demand forecasting model.

D-3 See Global Response 1. The new Recommendation 5 in Chapter 6 includes review of past projections compared to deliveries in order to better calibrate the demand forecasting model for the future.

D-4 Any updates to the retail demand forecasting model and coordination with BAWSCA will be reflected in future AWS Plan updates, beginning in FY 2026-2027 with the intent of supporting future AWS investment recommendations. The new Recommendation 5 includes development of a range of potential demand scenarios and evaluation of potential modifications to the retail demand forecasting model.

D-5 The SFPUC’s Wastewater Enterprise, as well as wastewater agencies around the Bay Area, are working with State regulators to address water quality issues including nutrient loading.

Purified and recycled water projects described in the AWS Plan would reduce total wastewater discharges. Such projects would be required to meet water quality regulations at the time of implementation, including nutrient standards to meet objectives in the Basin Plan.

D-6 The selection of technologies for purified water treatment will be based on a number of factors including effectiveness, regulatory and permitting requirements, cost, and other factors.

Performance criteria for purified water projects will be developed prior to completing alternatives’ analyses.

D-7 While the primary goal of AWS projects described in the AWS Plan is to improve dry year supply availability, additional benefits such as impact to nutrient loading in receiving waters

can be identified during the project planning process for each AWS project and reflected in future AWS Plan updates.

D-8 The stated goal of the AWS Plan (pg. 7) is to "identify water supply projects that increase the dry-year reliability of RWS supplies and address the long-term water supply gap in alignment with the LOS Goals and Objectives." Of the six AWS Projects highlighted in the AWS Plan, three purified water projects and one recycled water project include partnerships with wastewater agencies around the San Francisco Bay. While not an explicit goal of the Plan, project -specific impacts to nutrient flows can be in cluded in the considerations for each project as they are evaluated in the future.

August 30, 2023
AWS Plan – Progress but missing valuable context for understanding Dear SFPUC AWS Team,
The Draft June 2023 Alternative Water Supply Plan is a significant advance from the quarterly reports, but it is missing key data which leads to a flawed executive summary and conclusion. As potentially billions of dollars of investment are at stake in the context of already high water rates, providing missing data and improving the executive summary is well worthwhile. 1) Need to add a more conservative demand scenario: Few people believe that we will have anywhere close to a 92 mgd water supply gap in 2045 should the Bay Delta Plan be implemented as is. This is in part because SFPUC Urban Water Management Plans and BAWSCA’s demand projections 20 years out have consistently over projected demand by a wide margin. Two potential scenarios to consider using are i) the SFPUC Finance Department demand projections along with a variant of BAWSCA’s Scenario E from its demand sensitivity analysis, and ii) demand projections based on current per capita demand projections and the latest population projections from California’s Department of Finance. See Exhibit A for calculation and presentation of such a scenario.

Adding a more realistic demand scenario in the executive summary better supports the more realistic AWS strategy mentioned in the body of the report, a better supports modular implementation of additional supply if and when long term demand increases appear more probable.

2) Need to consider risk and consumer resilience: Understanding how responsive customers are to a reduced water supply helps inform both the need for and urgency of alternative water supplies. At one time there was a claim that a 20% reduction in water supply would result in $2 billion in lost sales to the Bay Area economy.1 However during the 2012-2016 drought, rationing reached ~23% and the economy thrived both in terms of economic activity and job growth. The Bay Area economy has demonstrated that it is remarkably resilient to rationing in the 20% range and possibly higher.

3) Need to better understand rate impact of AWS alternatives: For each alternative the impact to water rates, both wholesale and retail should be identified for two scenarios, 3a) where demand causes the AWS alternative to be fully utilized and 3b) where the AWS alternative ends up to be excess supply. If fixed costs go up while demand stays flat, rates have to unnecessarily increase which in turn drives demand down further. Knowing such information helps decision makers and the public better understand AWS investment risks and trade-offs.

The AWS plan provides a good start at such information when discussing financing and affordability on pages 124-125 of the document. Here it states that for a proposed incremental

1 David Sunding, “Draft Report: Socioeconomic Impacts of Water Shortages within the Hetch Hetchy Regional Water System Service Area prepared for San Francisco Public Utilities Commission” (March 13, 2014), page 62, table 5-3
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$209 million investment, retail rates would increase 0.9% above current 10 year rate projections and wholesale rates would go up 7.6%. While some of the funds are used for planning for other projects, the majority of the funds are used for the Los Vaqueros expansion (LVE 5a, b & c) and Daly City projects (1), which combined would have a 4.6 mgd increase in dry year supply. It would be valuable to put this data in the context of scenarios 3a & 3b described above.

4) Need to remove alarmist climate change statements. The statement in section 3.2.3 regarding climate change exacerbating impacts from other drivers of change is alarmist, hard to understand and leaves out an important part of the sentence it is taken from. The rest of the sentence states, “and is not the single most important driver of vulnerability for the San Francisco Public Utilities Commission’s (SFPUC’s) Regional Water System (RWS).” In the executive summary of the 2021 Long Term Vulnerability Assessment (LTVA), the first result listed in the executive summary (ES.4) is, “According to climate projections and expert elicitations, there is a central tendency of warming of +2°C and +4°C by 2040 and 2070 (Representative Concentration Pathway [RCP] 8.5 respectively, with no clear direction of change in mean annual precipitation over the planning horizon.” There is a wealth of data in the LTVA that supports this statement, including tables that show drought recurrence intervals getting longer.

A better sentence to finish that paragraph would be something like, “The 2021 LTVA found no significant climate change exposure to the RWS, but the SFPUC remains vigilant as climate science continues to advance.”

5) Need to mention other means of reducing the water supply gap: i) Reducing the design drought’s recurrence interval from once in 70,000 years to once in 10,000 years would reduce the need for AWS by at least 20 mgd. In other words there should be a formal risk analysis on the design drought. Note that the recurrence interval goal for San Francisco’s sewer system overflowing is once in 100 years. The intent of the comparison is to show that constituents would likely prefer an investment in the sewer system rather than investing in AWS to keep a 70,000 year design drought recurrence interval ii) The current rationing policy should be reviewed in the context of the strong positive consumer and economic responses to recent droughts and could result in several additional mgd of supply.

6) Need to show AWS needs in the executive summary: A 92 mgd water supply gap translates to 81 mgd of AWS as shown in figure 3-3. This information should be included in the executive summary so that AWS needs are better understood. See section 4 of Exhibit A for how the executive summary table could be improved to show this.

7) When mentioning environmental stewardship, the Tuolumne ecological situation needs to be included. Section 1.2 of the report has this sentence: “Sustained stewardship of the environment from which RWS supplies are drawn is vital to the work of the SFPUC and a part of its mission.” If such a sentence is included, there should be an acknowledgement of the environmental damage in the lower Tuolumne and some discussion about how the SFPUC is addressing it. Doing so would provide useful context, particularly if the discussion tied to the Bay Delta Plan
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Sincerely,

Dave Warner

Exhibit A: Two other Demand Scenarios; A look at Demand Forecasting Accuracy; Improving Executive Summary Table

1) 2045 Demand based upon SFPUC finance department sales projections As part of its budget presentation at the February 14, 2023commission meeting the SFPUC’s finance department presented these water sales projections:

Extrapolating these projections to 2045:

Wholesale sales: 142 mgd
Retail sales 48 mgd
Water loss2 6 mgd
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Total 2045 demand 196 mgd
This is 20% lower than the 244.1 mgd of demand used in the Draft AWS plan. Using a demand figure of 196 mgd leads to a water supply gap of 44 mgd. After deducting the rationing benefit of 12% or 5 mgd, this comes to 39 mgd of AWS needed.3

2 Retail sales projections exclude water losses, hence estimated retail water losses are included here. 3 See section 3.1.1 and figure 3.3 (pages 35-36) of the draft AWS plan for rationing’s contribution to reducing the water supply gap.

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2) 2045 Demand based on July 2023 California Dept of Finance population projections The July 2023 California Department of Finance population projections are significantly lower than those used in the UWMP/AWS plan demand projections. In BAWSCA’s recent innovative demand sensitivity analysis, the study found that population was the most significant factor affecting demand. Adjusting the AWS demand projections for the lower population projections reduces 2045 RWS demand from 244.1 mgd to 187.2 mgd which leads to a water supply gap of 35 mgd. After deducting the rationing benefit of 12%, this comes to 31 mgd of AWS needed.

The table below shows the differences in population projections and the proportional impact on demand.

2045 water demand of 187.2 mgd is 23% lower than the 244.1 mgd of demand used in the AWS plan.

These two 2045 demand projections may still be high.
3) Demand Forecasting Accuracy
There’s precedence that the SFPUC and BAWSCA have been consistently overestimating demand. The chart below compares 2020 water demand for both the SFPUC and BAWSCA against what they projected 2020 water demand to be 5, 10, 15 and 20 years prior. In their 2015 UWMP’s, 5 years earlier, they projected 2020 demand to be 19% higher than it was. In their 2000 UWMP’s, 20 years earlier, they expected demand to be 47% higher than it was. 2020 Service
area
population
2045 AWS
projected
population
25 year
growth
Population
Growth
based on CA
Dept of
Finance
estimates
Revised
population
projections
Percent of
AWS 2045
projected
population
AWS demand
(mgd)
Population
adjusted
demand
projection
(mgd)
BAWSCA 1,868,090 2,456,566 31.5% 5.9% 1,978,424 81% 170.6 137.4 SF Retail 899,732 1,251,214 39.1% -5.8% 847,256 68% 73.5 49.8 Total 2,767,822 3,707,780 34.0% 2,825,680 76% 244.1 187.2 2020-2045 Demand Projections Based on CA Department of Finance July 2023 Population Projections E-2
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In 2000, 20 years earlier, demand for 2020 was projected to be 292 mgd. People likely would have been laughed out of the room if they said that demand would be under 200 mgd in 2020. “There was no way demand could be that low.”
If the 2045 AWS projections turn out to also be overstated by 47%, that would mean demand on the RWS in 2045 would be 166 mgd. This would mean the water supply gap would be only 14 mgd, and after adjusting for the rationing benefit AWS needed would come to 12-13 mgd. 4) Improving a Key Table in the Executive Summary
The executive summary of the AWS plan makes it appear that demands on the RWS in 2045 are expected to be 244 mgd as shown in this table from page xii: But as you know from the above analysis, level of demand in 2045 is highly uncertain. Readers should understand this. 5 years prior
10 years
prior
15 years
prior
20 years
prior
Water demand (mgd)
San Francisco 17% 19% 38% 38%
BAWSCA from RWS 20% 36% 50% 52%
Combined 19% 30% 46% 47%
Variances in the Projections to 2020
Projected as a Percent of Actual: Over/(under) estimated

Table from the executive summary where a reader could infer that demand of 244 mgd is highly likely and 92 mgd of AWS is needed.

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A second problem is that the table leadsthe reader to infer that the 92 mgd would all come from AWS.

This isn’t the case, as shown in figure 3-3 on page 34:

Two changes should be made to the table in the executive summary (and the text of the executive summary should change accordingly):
1) A column should be added with one of the above demand scenarios, or one similar in order to give the reader a better understanding of the uncertainty associated with projecting 2045 demand.
2) Rows should be added at the bottom of the table to take the reader from the water supply gap to the AWS impact of each scenario. As the report is about AWS, the executive summary should reflect potential AWS needs.

Figure 3-3 from page 34 showing that at water supply gap of 92 mgd translates to AWS of 81 mgd. This information should have been included in the executive summary.

The table below proposes how these two changes might be made.

Being prudent about our AWS investment is important because of our already very high water rates that are projected to increase further without substantial investments in AWS.

If the gap were to turn out to be 31 mgd, there are a number of other ways to cover that gap without having to invest in AWS. But that’s another topic.

Improving the executive summary to better show the uncertainty of demand projections benefits of all retail and wholesale ratepayers. Please consider making this a part of your recommendations.

Recommended changes to the table in the executive summary -

Response to Comment Letter E
Dave Warner, Member of the Public
August 31, 2023
E-1 See Global Response 1. There is a new corresponding Recommendation 5 in Chapter 6 of the AWS Plan that includes considering the inclusion of additional demand scenario(s) in future AWS Plan updates.

E-2 Sensitivity to economic factors in the demand forecasting model will be considered as part of a new Recommendation 5 in Chapter 6. It is also described in Global Response 1. However, as consumer behavior and water efficiency measures continue to drive demands down throughout the service area, there is less flexibility in water use. Therefore, SFPUC staff consider the LOS goal of no greater than 20% rationing to be prudent. Achieving greater sustained reductions is unlikely outside of an extreme drought emergency.

E-3 Rate impacts are briefly addressed in Section 5.2.3, AWS Cost Considerations, of the AWS Plan.

The AWS team will continue to coordinate with SFPUC rate analysts to understand the impact of fixed and variable costs of implementing AWS Projects under updated demand scenario(s) as they are developed (see Recommendation 5 in Chapter 6) and project planning progresses.

Staff agree that this kind of analysis will be important to support future investment decisions.

E-4 See response to comment E-3. Recommendation 5 in Chapter 6 directs the SFPUC to prepare additional demand scenarios that will be used to support future investment decisions.

E-5 While the statement that climate change “is not the single most important driver of vulnerability” for the RWS is true (from Section 3.2.3 in the AWS Plan) , the LTVA did not find that “there is no significant climate change exposure to the RWS” (from commentor). The statement in Section 3.2.3 that reads “climate change exacerbates impacts from other drivers of change such as increased instream flow requirements and increased demands on the system” combines the first and fifth key findings of the LTVA. The SFPUC is aware that climate change studies need to be a continuous process when new information and data are available and the last sentences of paragraph 1 and 3 of Section 3.2.3 of the AWS Plan reflect this commitment.

E-6 See Global Response 2.

E-7 See Global Response 3. Furthermore, refer to response to Comment E -2 regarding customer response to droughts. The SFPUC does not consider a long -term reduction in water supply beyond 20% to be sustainable outside a drought emergency.

E-8 The water supply gap described in the AWS Plan is defined as the difference between projected dry year supply availability and anticipated demands, or 92 mgd as shown in Table 3.4 and the corresponding table in the Executive Summary. Rationing can fill some of that gap, as detailed in Section 3.1.1 and shown visually in Figure 3-3. To provide greater clarity, a footnote has been added both Table 3-4 and the corresponding table in the Executive Summary to clarify that up to 11 mgd of the 92 mgd gap can b e filled by rationing. As rationing is a function of water supply availability, it does not definitively make up for 11 mgd of supply unless the full 81 mgd

of new supplies are developed. Regarding the additional request to add a column with new demand scenarios, that comment has been noted and can be considered once SFPUC staff have completed an evaluation of appropriate demand scenario(s) to include in futur e AWS Plan updates.

E-9 Environmental stewardship is embedded in several SFPUC policies and practices, especially with respect to the protection of watersheds and water quality; it is not exclusive to the Tuolumne River. The purpose of Voluntary Agreement negotiations in concert with th e Irrigation Districts is to address the environmental needs in the lower Tuolumne River. The statement cited in the comment is a reflection of the importance the SFPUC places broadly in the protection of all of its watersheds.

155 Bovet Road, Suite 650 ⚫ San Mateo, CA 94402 ⚫ ph 650 349 3000 ⚫ fx 650 349 8395 ⚫ www.bawsca.org
19798123.6
August 31, 2023
Via email

Steven Ritchie
Assistant General Manager, Water Enterprise
San Francisco Public Utilities Commission
525 Golden Gate Avenue, 13th Floor
San Francisco, CA 94102

RE: BAWSCA’s Review of the SFPUC’s Draft Alternative Water Supply (AWS) Plan

Dear Mr. Ritchie,

BAWSCA has reviewed the SFPUC’s Draft Alternative Water Supply (AWS) Plan made available for public review on June 28, 2023. BAWSCA commented on earlier versions of key sections of the AWS Plan and appreciates that most of these earlier comments have been incorporated or adequately considered by the SFPUC. This letter focuses on significant comments BAWSCA views as meriting further attention by the SFPUC.

General Comments
BAWSCA strongly supports both the AWS Plan and the overall AWS Program. The SFPUC must be prepared to face potential future reductions to its existing water supply that could require the development of new supplemental sources to improve long-term water supply reliability in order to meet its legal and contractual obligations to the BAWSCA Member Agencies as well as the water needs of its Retail Customers in San Francisco. Climate change and future regulatory uncertainties could exacerbate the need for new diversified and distributed water supply sources. The AWS Plan meets these critical planning needs.

Components of the AWS Plan provide the roadmap for the development of projects needed to address the water supply shortfall (gap) that is calculated to be present through the planning horizon (2045). That gap is acutely related to shortage of supply during times of drought.

The AWS Plan presents detailed information regarding estimated project costs and development times and estimated rate impacts to both SFPUC Retail and Wholesale Customers for the AWS planning work estimated to take place within the SFPUC’s 10- year Capital Improvement Plan (CIP). While BAWSCA agrees that the presented rate impacts are correct for the purposes of the SFPUC's 10-year CIP, the full rate impact of the implementation of the suite of AWS Plan projects has not been estimated at this time as more details are needed that can only be provided following further planning work.

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August 31, 2023

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This complete cost and rate impact information will be necessary for the SFPUC and BAWSCA to support future decision making.

The AWS Plan includes recommendations for the Commission to consider that, if embraced, will work to: 1) Avoid widening the water supply gap; 2) Fill the water supply gap; and 3) Reduce the water supply gap. BAWSCA supports those recommendations, particularly those that call for additional staffing as needed to better implement the AWS Program.

There remains uncertainty related to how regulatory and other pressures can widen the supply shortfall. The AWS Plan is clear that, although implementing the projects listed can contribute substantially to lessening that gap, additional projects beyond those documented in the Plan will be necessary to fill the water supply gap.

BAWSCA recognizes that efforts by both the SFPUC and BAWSCA's Member Agencies have and can continue to result in lowered water demands. It also must be recognized that demand hardening is not simply a concept, but a reality that must be addressed as part of long-term water supply planning. Our respective agencies continue to be committed to water use efficiency, and the fundamentals of continued population growth coupled with realistic expectations as to what level of per capita water use can be achieved, further support the need for the AWS Plan.

The AWS Plan better positions San Francisco to fulfill its contractual obligation under the 2021 Amended and Restated Water Supply Agreement between San Francisco and the Wholesale Customers (WSA) to decide, by December 31, 2028, whether to make the cities of San Jose and Santa Clara permanent Wholesale Customers of the SFPUC. It is appropriate for the AWS Plan to acknowledge and be informed by the requirement that the SFPUC make this decision.

Specific Comments

1. Section 1.3.2 – Role of Wholesale Customers and BAWSCA in the AWS Program Development and Implementation

The SFPUC's responsibility to inform the Wholesale Customers of the actions and progress of the AWS Program stems not only from the SFPUC's role as a regional supplier (as the first paragraph of Section 1.3.2 notes), but also from the SFPUC's contractual obligations under the Amended and Restated 2021 Water Supply Agreement between San Francisco and the Wholesale Customers (WSA). BAWSCA requests the first paragraph of Section 1.3.2 be revised to emphasis this point.

2. Section 2.2.4 – RWS Infrastructure and WSIP

The second paragraph of Section 2.2.4 mentions that the SFPUC will use Level of Service (LOS) Goals and Objectives to inform the SFPUC’s approach to future water supply planning and the AWS Program. San Francisco’s perpetual obligation to provide the Supply Assurance to the Wholesale Customers is another critical factor F-4
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Steven Ritchie
August 31, 2023

19798123.6
that must inform the SFPUC’s approach to future water supply planning and the AWS Program, and should be acknowledged in this specific discussion. BAWSCA requests that Section 2.2.4 be revised to acknowledge that San Francisco's perpetual obligation to provide the Supply Assurance to the Wholesale Customers will also inform the SFPUC's approach to future water supply planning and the AWS Program's efforts.

3. Section 2.4.3 – Current and Historical Demands

While BAWSCA acknowledges that the AWS Plan is focused on the SFPUC’s obligations through the 2045 planning horizon (which may or may not include the City of San Jose and the City of Santa Clara as permanent Wholesale Customers), it is important that the AWS Plan captures the SFPUC's existing contractual obligations to San Jose and Santa Clara under the WSA, including but not limited to, (i) SFPUC's contractual obligation to supply San Jose and Santa Clara with a combined annual average of 9 mgd through 2028, and (ii) the 10-year notice requirement to terminate San Jose and Santa Clara if such a decision regarding their status is reached.

BAWSCA requests that the following sentence be added to the end of the first paragraph in Section 2.4.3 to clarify the SFPUC's contractual obligation to San Jose and Santa Clara: "Additionally, the AWS Program must account for the SFPUC's contractual obligation to supply San Jose and Santa Clara with a combined annual average of 9 mgd through 2028."

4. Section 5.2.2 - AWS Staff Considerations

BAWSCA supports the SFPUC’s identification of additional staffing needs as required for the implementation of the AWS Plan, including at both the project level and programmatic level. As AWS Projects move toward implementation, BAWSCA anticipates that additional staffing, beyond that included in the AWS Plan’s Recommendations, may be needed.

5. Section 5.2.3 - AWS Cost Considerations

BAWSCA understands that the development of project cost estimates are based on the stage of the planning and development cycle that a particular project is in, and further understands that greater detail on how those estimates were developed has been provided in Appendix C of the AWS Plan. BAWSCA notes, however, that the SFPUC will continue to refine these costs as more project information is developed.

With respect to the Rate Impacts discussion in Section 5.2.3, BAWSCA understands that the rate impacts in the AWS Plan provide a planning level assessment and are only representative of the portion of the AWS Plan’s total project costs that will be expended during the SFPUC 10-year CIP term. Rate impacts are of great interest to BAWSCA's Member Agencies and their water customers. As more cost information is developed as part of the implementation of the AWS Plan, BAWSCA will expect the SFPUC to provide the necessary additional clarity on total costs and potential rate impacts.

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Steven Ritchie
August 31, 2023

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6. Section 6.1.1 - Recommendation 1

The Regional Groundwater Storage and Recovery (RGSR) Project’s yield of 6.2 mgd listed in the Recommendation 1 in Section 6.1.1 is less than the project yield in the adopted Water System Improvement Program. This difference needs to be reconciled by the SFPUC. If and when the SFPUC proposes to adjust the RGSR Project’s yield, the SFPUC will need to comply with AB 1823 and BAWSCA recommends the SFPUC provide a formal process involving BAWSCA, stakeholders, and the public to evaluate alternatives for treatment, infrastructure, and staffing needed to achieve the RGSR Project's proposed dry-year supply by 2045.

7. Section 6.1.2 - Recommendation 3
BAWSCA requests Recommendation 3 be revised to specifically mention groundwater banking and conjunctive use opportunities. In particular, BAWSCA requests that the first sentence of Recommendation 3 be revised as follows: “Continue reporting progress on negotiations related to the Proposed Voluntary Agreement, a possible groundwater banking and conjunctive use project in partnership with Groundwater Sustainability Agencies in the San Joaquin Valley, and other potential transfers and projects in the area that could contribute to instream flow releases.”

8. Section 6.1.3 - Local Projects – Wholesale Service Area

Section 6.1.3 notes that in 2008, when the SFPUC Commission adopted WSIP by Resolution 08-0200, the Commission directed the SFPUC to offset demand by 10 mgd in the retail service area through additional conservation or the development of new recycled water or groundwater sources. The Commission also asked the same of the Wholesale Customers. To illustrate the Wholesale Customers' compliance with this request, BAWSCA asks that a table (or Figure) be added to Section 6.1.3 documenting that, since FY 2008-09, Wholesale Customer SFPUC purchases have been reduced by 35.6 mgd or 22%. The table would include the following data:

• FY 2008-09 SFPUC purchases – 80,034,009 Ccf (164.01 mgd) • FY 2021- 22 SFPUC purchases – 62,647,759 Ccf (128.38 mgd) • Increase/Decrease in 2021-22 purchases compared to 2008-09 – 22% reduction

9. Glossary – Bay Area Water Supply and Conservation Agency (BAWSCA)

The text incorrectly states that BAWCA is an “entity”. BAWSCA is a public agency, and the term “entity” should be replaced as such.

10. Appendix C – AWS Program Cost Development Approach

BAWSCA appreciates the inclusion of Appendix C in the AWS Plan. However, as noted in Appendix C, the SFPUC is still in the process of developing program costs, and in particular preparing a Proforma Model to more fully assess program costs.

BAWSCA will reserve comments on individual project costs until the Proforma Model is completed and its results are shared with BAWSCA.

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Steven Ritchie
August 31, 2023

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BAWSCA appreciates this opportunity to provide comments on the SFPUC’s AWS Plan and looks forward to continuing to work with the SFPUC as the AWS Plan is finalized and the AWS Program is implemented.

Sincerely,

Nicole Sandkulla
CEO / General Manager

NS/tf:le

cc: SFPUC Commission
SFPUC Citizens’ Advisory Committee
Manisha Kothari, SFPUC, Manager, Alternative Water Supply (AWS) Program Alison Kastama, SFPUC, BAWSCA Liaison
Board of Directors
Water Management Representatives
Allison Schutte, Hanson Bridgett, LLP, Legal Counsel

Response to Comment Letter F
Bay Area Water Supply & Conservation Agency (BAWSCA)
Nicole Sandkulla, CEO/ General Manager
August 31, 2023
F-1 This comment expresses support for the AWS Plan and overall AWS Program. The SFPUC recognizes this comment.

F-2 This comment describes the water supply gap and how the AWS Plan and AWS Projects can address the water supply gap. The SFPUC recognizes this comment.

F-3 The AWS Plan incorporates preliminary capital costs, as they are known as of the drafting of this document (May 2023). Based on proposed budgeting recommendations at that time, the SFPUC analyzed potential rate impacts over the next 10 -year period. Updated budget information as of December 2023 is included in Chapter 6. Because the December budget numbers are still in draft form and lower than what was analyzed, no changes were made to the rate analysis. As additional cost information is developed, associated rate impacts will continue to be evaluated. Results will be shared with BAWSCA and included in future updates to the AWS Plan.

F-4 This comment expresses support for recommendations made in Chapter 6 of the AWS Plan.

The SFPUC recognizes this comment.

F-5 The SFPUC recognizes the uncertainty around regulatory and other drivers that may impact the water supply gap. Changes to either water availability or demand will affect the water supply gap and future planning goals. SFPUC staff continue to identify new p roject opportunities while also tracking developments that could change the gap through the completion of WSIP projects, Voluntary Agreement negotiations, and/or demand updates.

F-6 The SFPUC recognizes the commitment of both retail and wholesale customers to water use efficiency and agrees that demand forecasting should consider feasible scenario(s) and demand elasticity. SFPUC staff will work with BAWSCA as it considers updates to i ts demand modeling as part of a new Recommendation 5 presented in Chapter 6 of the AWS Plan.

F-7 Comment noted. The policy decision of whether to make the cities of San Jose and Santa Clara permanent customers is one of the drivers affecting future potential obligations, as described in Section 3.3.2.

F-8 Section 1.3.2 of the AWS Plan has been revised to include SFPUC's contractual obligations to underscore its responsibility to keep Wholesale Customers informed of progress on the AWS Program.

The language has been updated as follows: “As a regional supplier and owing to its contractual obligation, the SFPUC has a responsibility to keep its wholesale customers informed of the actions and progress of the AWS Program.”

F-9 Section 2.2.4 of the AWS Plan has been revised to acknowledge SFPUC's obligations to Wholesale Customers in informing the SFPUC's approach to future water supply planning.

Revised text now reads: "Consistent with the SFPUC’s contractual obligations to the Wholesale Customers, estimated demands, and long range planning processes , the LOS Goals and Objectives continue to inform the SFPUC’s approach to future water supply planning and the AWS Program’s efforts.”

F-10 The SFPUC is committed to delivering up to 9 mgd to San Jose and Santa Clara through 2028 and acknowledges that a 10-year notice is required to terminate supplies, if such a decision is made by the SFPUC.

The following sentence has been added to the end of the first paragraph of Section 2.4.3:
"Additionally, the AWS Program accounts for the requirement in the WSA to supply San Jose and Santa Clara with up to 9 mgd through 2028."
F-11 This comment expresses support for the SFPUC's identification of additional staffing needs as required for the implementation of the AWS Plan, as described in Chapter 6 of the AWS Plan.

The SFPUC recognizes this comment.

F-12 The SFPUC agrees that it will continue to refine costs as project planning progresses. As information is updated, the SFPUC will share that information in future AWS Plan updates.

F-13 See response to comment F-3.

F-14 The AWS Plan identifies that a yield of 6.2 mgd by 2045 is assumed for the RGSR project as part of the baseline that has been included in the calculation of the future water supply gap.

Reporting for the project will continue through the WSIP reporting pro cess, including any changes to the project. Furthermore, the SFPUC will comply with AB 1823, as needed.

F-15 The SFPUC will continue to report on the progress of the Proposed Voluntary Agreement and any groundwater banking and conjunctive use opportunities.

Language for Recommendation 3 has been updated to incorporate the suggested text:
"Continue reporting progress on negotiations related to the Proposed Voluntary Agreement and potential transfers and projects in the San Joaquin Valley that could contribute to instream flow releases. Identify resource and funding needs, as and when appropriate. No new funding or additional resources are needed to support this recommendation at this time." F-16 Section 6.1.3 of the AWS Plan has been revised to acknowledge that both retail and wholesale customers achieved the targets outlined in Resolution 08-0200. New text in this section states:
"Both the San Francisco retail and wholesale service areas have achieved the targets outlined in Resolution 08-0200."

Additionally, a new table (Table 6-1) has been added to the Plan, which presents the Wholesale Customer RWS purchase data identified in this comment. New text has been added: "Table 6- 1 shows Wholesale Customer purchases from the RWS in FY 2008 -09, when the SFPUC

Commission adopted WSIP by Resolution 08-0200, compared to RWS purchases in FY 2021 -22, representing a reduction of 35.6 mgd or 22% since FY 2008-09.” F-17 The glossary of the AWS Plan has been updated to refer to BAWSCA as a "public agency." F-18 See response to comment F-3.

1 August 31, 2023

President Newsha Ajami and Commissioners
San Francisco Public Utilities Commission
525 Golden Gate Ave.

San Francisco, CA 94102
Via Email

Re: Comments on the SFPUC’s Draft Alternative Water Supply Plan.

Dear President Ajami and Commissioners:

The Sierra Club, Tuolumne River Trust, Golden State Salmon Association, San Francisco League of Conservation Voters and California Sportfishing Protection Alliance appreciate the opportunity to comment on the SFPUC’s draft Alternative Water Supply Plan (AWS Plan). While we appreciate that the SFPUC is undertaking this exercise, we think the Plan has a lot of room for improvement. Of utmost concern is the lack of a robust assessment of how much alternative water supply the SFPUC might reasonably need to develop.

I. The Plan Must Include a Sensitivity Analysis, and Model Alternative Scenarios

The AWS Plan states, “Identifying future demand is critical to planning for long-term supply reliability of the RWS.” (p. 30) Yet it fails to include alternative scenarios that consider a more realistic drought planning horizon and reasonable demand projections.

It goes on to say:

Successful implementation of the AWS Program requires a balance between securing future reliability and maintaining affordability, both of which are critical SFPUC goals.

The AWS Program must focus on implementing water supply projects that will address long-term customer demands and obligations without over-building or overcommitting capital funding. (p. 57)

This comment emphasizes the importance of not overinvesting in AWS that will not be needed, but the Plan fails to accurately identify future water supply needs. The Plan acknowledges that changes in assumptions related to the Design Drought and projected water demand would have a profound impact on the SFPUC’s water supply deficit, yet there is no modeling of how such changes would affect “Demands.” It states:

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2 The SFPUC relies on planning assumptions and modeling to project future water availability in dry-year conditions. The SFPUC design drought and adopted rationing policy…are assumptions that affect the estimates of water availability during dry-year conditions. Changes to the assumptions around the design drought or rationing would change total system yield estimates. For the purposes of this AWS Plan, these planning assumptions are being held constant as part of the SFPUC planning methodology for projecting future water supplies. This allows a direct comparison to the planning that was done for the WSIP program. (p. 39)

In BAWSCA’s 2022 “Regional Water Demand and Conservation Projections Update,”1 a sensitivity analysis was included that looked at slower population growth.2 The SFPUC should include a similar sensitivity analysis in the AWS Plan, especially considering that the California Department of Finance (CDOF) recently reduced its population growth projections, predicting population declines in both San Francisco and San Mateo Counties.3

Despite raising concerns about overinvesting in expensive alternative water supplies, the AWS Plan fails to consider alternative scenarios, such as reducing the length of the Design Drought or using CDOF population growth projections, both of which would reduce “Demands” significantly. The Commission should be informed on how these changes would impact the perceived water supply deficit.

Recommendations:

1) Direct staff to model “Demands” (water supply deficit) using a 7.5-year Design Drought. 2) Direct staff to model “Demands” using CDOF population growth projections, similar to BAWSCA’s sensitivity analysis (see Attachment A).
3) Direct staff to model “Demands” using a combination of a 7.5-year Design Drought and CDOF population growth projections.
4) Amend Figure 3-4 (Obligations and Demands) to include a third column titled “Lower Demands” that is based on a 7.5-year Design Drought and CDOF population growth projections. Rename the current “Demands” column “Upper Demands.”

II. Why It’s Important To Do This Right?

Alternative water supplies can be expensive, so investing wisely is important. According to the AWS Plan:

1 BAWSCA Regional Water Demand and Conservation Projects Update, December 5, 2022 – https://bawsca.org/uploads/userfiles/files/BAWSCA%202022%20Demand%20Study%20Update%20Final%20Repor t(1).pdf
2 Please see Attachment A.
3 San Francisco exodus: City may never recover population loss as other parts of the Bay Area grow, San Francisco Chronicle, August 9, 2023.

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3 Based on preliminary estimates, the capital investment associated with the suite of regional AWS Projects could be on the order of $4 billion to $10 billion (escalated to the mid-point of construction) over the planning horizon, varying largely based on the size of the expansion of Calaveras Reservoir and the preferred conveyance facilities.4 (p. 124)

The amount of alternative water supplies the AWS Plan cites as needed – 92 million gallons per day (mgd) – is inflated and would be extremely expensive. On the low end, at $3,000 per acre foot, developing 92 mgd would cost $300 million per year, which would have to be passed on to ratepayers. As you know, ratepayers (especially low income) are already heavily stressed by water and wastewater rates.

Even without these AWS investments, water and wastewater rates are expected to increase substantially in coming years, as demonstrated by the following slide presented at the February 14, 2023 budget hearing.

The AWS Plan would increase rates further. The first phase alone (2% to 5% of the full implementation cost)5 would raise rates as follows:

AWS staff have worked with the Finance team to evaluate the rate impact of adding the AWS Project and Programmatic recommendations in this Plan, which would add

4 Note that the $4 billion to $10 billion range is for capital investments only, and does not include operations and maintenance. Table 5-1 should include at least a range of O&M costs to give a better sense of the full cost of the projects.
5 The first phase of the AWS Plan would cost $209 million. Full implementation would cost $4 billion to $10 billion.

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4 approximately $209 million in capital and operating expenses between FY 2025 and 2034…The financial modeling showed that retail rates would need to increase by about

0.9% above the current projected rate plan by FY 2033 and wholesale rates would increase by 7.6% in the same time period…Rate impacts would also extend past the 10- year timeframe analyzed. (pp. 124 & 125)
Higher rates will continue to send a strong price signal to consumers, leading them to use water more efficiently in order to reduce their bills. At the July 16, 2021 SFPUC workshop, staff stated that in response to a 10% rate increase, single-family demand decreases 1.4%, multi-family demand decreases 2%, and commercial demand decreases between 1.4% and 3%.6 It should be of great concern to the Commission that if the AWS Plan is implemented, water rates will skyrocket, driving a dramatic increase in conservation. There would be more water infrastructure to pay for, but less demand to cover the costs. This would exacerbate the “death spiral” – rates increase to cover fixed costs, consumers use less water, rates increase again, and the economic situation continues to worsen.

III. Impacts on Water Supply
The AWS Plan erroneously states:

The most pronounced driver affecting water availability is the potential implementation of the 2018 Amendment to the State Water Resources Control Board’s San Francisco Bay/Sacramento-San Joaquin Delta Estuary Water Quality Control Plan. (p. XII) According to the SFPUC’s $743,000 Long-Term Vulnerability Assessment (LTVA), this statement is incorrect. The LTVA states:

Climate change is not the single most important driver of vulnerability for the RWS.

Under current RWS infrastructure conditions, either state-amended WQCP [Bay Delta Plan] for additional IFR [instream flow requirement] on the Tuolumne River or an increase in demand by 15% have significant impacts on the RWS performance that are equivalent to a decrease in mean annual precipitation of around 15%. (LTVA, p. 250) In other words, the Bay Delta Plan instream flow requirement is equivalent to either a 15% increase in demand, or a 15% decrease in precipitation.

RWS demand has been under 200 mgd for the past nine years. Assuming demand remains flat at around 200 mgd, the 244 mgd projection for 2045 in the AWS Plan would increase demand 6 SFPUC workshop on Water Demand Projections and Demand Management, July 16, 2021 – https://sanfrancisco.granicus.com/player/clip/38991?view_id=22&redirect=true&h=28ea534dd1acf1e58ebb0321a 7db1492 (22:40).

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5 by 22%. This inflated demand projection is the most pronounced driver affecting water availability.

The baseline demand figure used in the LTVA is 227 mgd, which is 15% greater than what RWS demand has been for the past nine years. This means that results included in the LTVA based on the baseline demand figure are essentially incorporating the Bay Delta Plan instream flow requirement into actual current demand. Furthermore, most of the analysis in the LTVA is based on 240 mgd demand, which is 20% greater than 200 mgd demand. The LTVA suggests there is an extremely small chance the SFPUC would run out of water unless water demand grows substantially, which is very unlikely to happen (see comments on demand projections below).

IV. The AWS Plan Needs to Address the Design Drought
Despite numerous references to “climate uncertainty,” the AWS Plan dedicates a mere three paragraphs to the LTVA, with no citations to justify the Design Drought. The AWS states, “Impacts related to climate change are not currently quantified in the AWS planning efforts;” (p. 39)
Removing one year from the Design Drought, which is justified by the LTVA, would have a big impact on the perceived need to invest in expensive alternative water supplies. Removing the final year from the Design Drought would reduce “Demands” in the AWS Plan by about 25 mgd.

This would reduce costs (passed on to ratepayers) by at least $90 million per year – an opportunity that is certainly worth exploring.

The LTVA found that the Design Drought is extremely unlikely to occur, yet the SFPUC continues to use it as its primary planning tool. The LTVA included return periods (likelihood of occurrence) for the known droughts, but inexplicably did not include a return period for the Design Drought. A Public Records Act request uncovered a document revealing that the study authors had produced a return period for the Design Drought of once-in-25,000 years,7 but this information was not included in the final report. Information that was included in the final report suggests the Design Drought is even less likely to occur. We addressed this at the August 23, 2022 SFPUC workshop, and SFPUC staff had no response. Please review the workshop video.

The Design Drought was conceived following the 1987-92 drought of record. It was arbitrary and has never been backed up by supporting evidence. Much has changed since the 1987-92 drought. For example:
• Heading into the drought, water demand was at an all-time high of 293 mgd. It has been under 200 mgd for the past nine years.
• The SFPUC adopted its Water First Policy, prioritizing water supply over hydropower generation. According to an SFPUC presentation, precipitation in 1976/77 was 39.14 7Hydrological Drought Frequency Analysis for the Upper Tuolumne River, December 8, 2020.

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6 inches, and was similar in 2020/21 at 39.28 inches. Yet, while total system storage was 563,298 acre feet on June 10, 1977, it was substantially higher at 917,455 acre feet on the same date in 2021.
• Cherry Lake, the SFPUC’s second largest reservoir in the Tuolumne watershed (3/4 the capacity of Hetch Hetchy) was drained for maintenance in 1989, and that storage was lost.

The LTVA states, “According to climate projections and expert elicitations, there is a central tendency of warming of +2°C and +4°C by 2040 and 2070 (Representative Concentration Pathway [RCP] 8.5), respectively, with no clear direction of change in mean annual precipitation over the planning horizon.” (LTVA, p. xxii)
In other words, we might expect wetter years and drier years, but on average precipitation isn’t expected to change much. In fact, the report suggests that the Hetch Hetchy watershed is more likely to experience slightly more precipitation in the future. Interestingly, earlier runoff projected by the study would likely benefit the SFPUC’s water entitlements based on how water rights were established on the Tuolumne River under the Raker Act. Based on the study’s projection that runoff will likely come three weeks earlier by 2070, if the Design Drought were to occur, the SFPUC would pick up an additional year’s-worth of water over the course of the

8.5-year drought. We explained this at the August 23, 2022 workshop.

V. The AWS Plan Needs to Address Inflated Water Demand Projections The issue of inflated water demand projections has been raised many times, and was addressed at the July 16, 2021 workshop. AGM Steve Ritchie stated:

I want to make sure it’s clear that the Urban Water Management Plan is not intended to be an actual projection of demands, because plan developments may or may not occur or may be delayed for a variety of reasons…and the projections presented in the 2020 Urban Water Management Plan are closer to an outside envelope of what the demands may be in 2045 rather than actual demands.

The accuracy of water demand projections was again addressed in an SFPUC report titled “Water Enterprise and Finance Bureau Water Demand Projections,” dated July 5, 2022. The report stated:

It [UWMP Act] was not intended to establish the projected water demands that would be used for all operational and planning purposes…the projections represent an outside bound of whatever demand will occur in the next 25 years...These demands will likely always be greater than actual demands because not all developments materialize, or they materialize slower than projected.

And:

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7 By contrast, for the purpose of financial planning and for short term water system management, we estimate the demand that we are likely to experience. For budgeting and rate setting we use demand projections that are as close to actual as we can make them.

The report included graphs showing that both the SFPUC Water Enterprise and Finance Bureau have historically over-projected demand, but Finance has always been closer to the actuals. The Finance Bureau currently projects sales will remain flat for at least the next decade.

The primary driver for current inflated water demand projections is inflated population growth projections. This issue came up at the July 16, 2021 workshop, to which then SFPUC President Anson Moran gave the following directive:
…we be given information about the differences between Department of Finance and the Plan Bay Area and what those differences really are, and within that, what portion of that reflects legal mandates such as affordable housing targets and what is more aspirational.

After a ninth month delay, staff finally provided two paragraphs explaining how the CDOF and ABAG (Plan Bay Area) determine population growth projections, but ignored the question raised by President Moran.8
The latest CDOF projections (July 2023) suggest that the populations of San Francisco and San Mateo Counties will likely decline over the coming decades.

VI. SFPUC “Rationing Methodology” Vs. “Rationing Policy” The AWS Plan should explain the difference between the SFPUC’s “rationing methodology” and “rationing policy.” The rationing methodology is explained in Appendix K of the 2020 Urban Water Management Plan as follows:

In applying its water supply planning methodology, the SFPUC performs an initial model simulation of the system for the design drought sequence and then reviews the ability of the system to deliver water to the service area through the entire design drought sequence. If the projected water supply runs out before the end of the design drought sequence in the initial model run, system-wide water use reduction is added and the scenario is re-run. This process continues iteratively until a model simulation of the system is achieved in which the water supply in storage at the end of the design drought sequence is brought to the system “dead pool,” where no additional storage is available for delivery (currently simulated as 96,775 acre-feet). Drawing system storage down to 8 Department of Finance and Plan Bay Area Projections, email from AGM Steve Ritchie to Anson Moran dated April 14, 2022 (included in the April 26, 2022 SFPUC correspondence log).

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8 the dead pool without going below it indicates that water supply delivery, including the adjusted amount of water use, is maintained through the design drought sequence.

The rationing methodology was not used to produce the 122 mgd of “Obligations” nor the 92 mgd of “Demands” cited in the AWS Plan. Instead, the SFPUC used rationing figures produced in 2008 for the WSIP using the rationing methodology. Back then, what staff now refers to as the “rationing policy” conformed with the rationing methodology. Now that the State Water Board adopted the Bay Delta Plan, it no longer does. Staff should have rerun the numbers using the rationing methodology, which is the SFPUC’s true rationing policy. Doing so would require rationing to begin earlier in the Design Drought and increase more rapidly.

SFPUC staff explained the “rationing policy” as follows:

The estimate of SFPUC water supply without Bay Delta Plan contributions is 257 MGD of total yield, which is the sum of the system firm yield of 227 MGD and the volume associated with the rationing policy established for the WSIP program. That rationing policy includes 3 years of 10% rationing and 3.5 years of 20% rationing over the 8.5-year design drought. The volume associated with the rationing policy changes as the firm yield changes, as noted above. In this case, the volume of the rationing policy is 30 MGD. That gives a total yield (firm yield + rationing) equal to 227+30 or 257 MGD.9 In other words, the rationing figures used to determine “Demands” in the AWS Plan assume no rationing in Years 1 and 2 of the Design Drought, 10% rationing in Years 3 to 5, and 20% rationing in Years 6 to 8.5.

The rationing numbers and timing that was determined necessary to manage the Design Drought at the time the WSIP was approved would fail to enable the SFPUC to manage the Design Drought under the Bay Delta Plan. In fact, the SFPUC has argued it could not manage the Bay Delta Plan flows without exceeding its Level of Service Goal of limiting rationing to no more than 20%.

It is clear that starting rationing at 10% in Year 3, and not increasing it to 20% until Year 6 is not how the SFPUC would impose rationing if the Bay Delta Plan is implemented. Imposing rationing earlier and at higher levels would reduce “Demands” substantially. Starting 20% rationing in Year 3 rather than Year 6 would have an incremental favorable impact on water available in storage, which should be factored when considering alternative water supplies.

The AWS Plan acknowledges this in a hidden way. Figure 3-3 includes “Estimated Contribution of Rationing,” which is another way of saying “using the SFPUC’s rationing methodology.” The 81 mgd “Demands” cited in Figure 3-3 should be the upper demand used in the AWS Plan, saving at least $36 million per year in unnecessary investments. 9 Email from Matt Moses (SFPUC) to Peter Drekmeier (TRT), October 26, 2022.

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9 VII. Alternative Water Supply Investments
As discussed above, we believe that, particularly with a modest adjustment to the Design Drought and the use of realistic demand projections, even with full implementation of the Bay Delta Plan, the SFPUC could maintain a highly reliable water supply. Under this approach, the SFPUC would not face the need for a large scale investment in alternative water supplies.

The AWS Plan, however, follows a different path with regard to the Design Drought and demand projections. We recommend that the SFPUC develop multiple scenarios for analysis in this document. At one end, this should include the assumptions we have suggested regarding the Design Drought and demand projections. At the other end, if the SFPUC choses to use higher demand projections, that assumption should be paired with a greater investment in alternative water supplies. For example:

Denitrification and Direct Potable Reuse
It is likely that in coming years Bay Area wastewater treatment plants will be required to reduce nutrient discharges into the Bay through investments in denitrification. At the same time, the State Water Board is developing regulations for direct potable reuse. We believe water agencies, particularly the SFPUC, are presented with an important opportunity to develop a cost-effective solution to two problems – excessive nutrient discharges and ensuring long-term reliable water supplies. We urge the SFPUC to include, as needed in the scenario approach discussed above, significant investments in purified water and denitrification.

On August 21, 2023, the San Jose Mercury News published an article titled “Fighting Future ‘Red Tides’ in San Francisco Bay.” San Francisco Bay suffered a significant harmful algal bloom (HAB) in August 2022, killing thousands of fish and endangering people and their pets. A second less severe bloom occurred in July 2023.

In response, Eileen White, Executive Director of the San Francisco Bay Water Quality Control Board (SF Bay Water Board), is quoted, “The science is telling us that we need to reduce nutrient loads as quickly as possible. What has happened is a game changer.” San Francisco’s discharges into San Francisco Bay are responsible for 20% of the nutrient loading. The Mercury News article states that San Francisco and the East Bay Municipal Utilities District (EBMUD) are running behind other municipalities in dealing with this problem. The article also states that some of the South Bay agencies have reduced nitrogen releases by about 85% from previous levels. As a major contributor of nutrient pollution, the SFPUC should take the lead in solving this problem. The AWS Plan should be amended to specifically make this a priority goal.

As noted in the Mercury News article, some of the newer technologies for reducing nutrients do not always result in available water. The SFPUC should avoid using those technologies unless G-21
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10 they are proven to be very cost-effective on a short-term basis. The long-term plan should be a combination of reducing nutrient loading and water recycling and reuse.

An SFPUC presentation on the “San Francisco Purified Water Opportunities Study” (Carollo, May 2022) included the following slide. Despite mentioning that staff were preparing a recommendation, it is not included in the AWS Plan. This is a lost opportunity.

Collaboration with the Irrigation Districts on Groundwater Banking Implementation of the Sustainable Groundwater Management Act (SGMA) is leading Central Valley water agencies to invest in significant groundwater recharge programs. Implementing these programs on a large scale will be expensive, and may lead the Modesto and Turlock Irrigation Districts to be receptive to collaborating with the SFPUC. We continue to urge the SFPUC to explore a conjunctive use partnership in Stanislaus County that could assist with SGMA implementation while providing the SFPUC with additional storage and reliability benefits.

Collaboration with the Irrigation Districts on More Efficient Water Delivery Similar to groundwater banking, the SFPUC could partner with the Irrigation Districts on developing pressurized water systems that enable more efficient delivery of water to farms.

The SFPUC could fund the infrastructure for a share in the savings. Conserving agricultural irrigation water is far less expensive than developing alternative water supplies in the Bay Area, and the opportunity is huge. For example, a pilot project implemented by the South San Joaquin Irrigation District installed a pressurized water system on 2,000 acres of farmland that decreased water use by 30% while increasing crop yield by 30%.

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11 For the above water supply scenarios, we recommend the following:
• The document’s scenarios should explicitly pair higher growth assumptions with higher investments in alternative water supplies.
• The document should include a scenario that would include ambitious direct potable reuse and denitrification of wastewater effluent in the service area. • The document should include the potential for a conjunctive use program partnership between the SFPUC and the Irrigation Districts, as well as an analysis of the potential to partner on water efficient delivery to farms.

VIII. Conclusion
In order to greatly improve the AWS Plan, we recommend the following:
1) Direct staff to model “Demands” using a 7.5-year Design Drought. 2) Direct staff to model “Demands” using CDOF population growth projections. 3) Direct staff to model “Demands” using a combination of a 7.5-year Design Drought and CDOF population growth projections.
4) Amend Figure 3-4 (Obligations and Demands) to include a third column titled “Lower Demands” that is based on a 7.5-year Design Drought and CDOF population growth projections. Rename the current “Demands” column “Upper Demands.” 5) Pair higher growth assumptions with higher investments in alternative water supplies, specifically direct potable reuse and denitrification, groundwater banking in Stanislaus County, and collaboration with the Irrigation Districts on water delivery efficiency.

Thank you for the opportunity to share our thoughts and recommendations.

Sincerely,
Molly Culton Peter Drekmeier
Chapter Organizing Manager Policy Director
Sierra Club California Tuolumne River Trust
Scott Artis Chris Shutes
Executive Director Executive Director
Golden State Salmon Association California Sportfishing Protection Alliance G-29
G-30

12 Chance Cutrano Kristina Pappas
Chapter Chair President
Sierra Club, SF Bay Chapter San Francisco League of Conservation Voters CC: San Francisco Board of Supervisors
San Francisco Capital Planning Committee
BAWSCA Board of Directors
SFPUC Citizens Advisory Committee
Please scroll down for Attachment A.

13 Attachment A – BAWSCA’s Water Demand Sensitivity Analysis

BAWSCA’s 2022 Regional Water Demand and Conservation Projections Update10 assessed how different factors affect demand projections. The study looked at alternative future scenarios based on:
• Population and jobs growth
• Housing density
• Water rates
• Water conservation
• Climate change

Scenarios A through E are summarized in the following table.

Among other assumptions, Scenario E used California Department of Finance population growth projections (prior to the recently released numbers). Scenario E is presented in the following table.

10 BAWSCA Regional Water Demand and Conservation Projections Update, December 2022 – https://bawsca.org/uploads/userfiles/files/BAWSCA%202022%20Demand%20Study%20Update %20Final%20Report(1).pdf

14 The table below shows projected water demand for Scenarios A through E. Note that under Scenario E, BAWSCA’s total water demand in 2045 is projected to be 204 million gallons per day (mgd). To put this in perspective, BAWSCA’s total water use in FY 2020/21 was 205.4 mgd.11 Note that these figures are for total BAWSCA demand, including water provided by sources other than the SFPUC.

11 BAWSCA Annual Survey, March 2023, Table 3B: Historical Total Water Use among BAWUA/BAWSCA Agencies, 1975-76 to Present. -- https://bawsca.org/uploads/userfiles/files/Annual%20Survey_FY21-22_FINAL.pdf

15

Response to Comment Letter G
Sierra Club, California; Tuolumne River Trust; San Francisco League of Conservation Voters; Golden State Salmon Association; California Sportfishing Protection Alliance; Sierra Club, San Francisco Bay
Molly Culton, Chapter Organizing Manager; Peter Drekmeier, Policy Director; Kristina Pappas, President; Scott Artis, Executive Director; Chris Shutes, Executive Director; Chance Cutrano, Chapter Chair
August 31, 2023
G-1 The AWS Plan was developed based on the latest available information as of May 2023. The AWS Plan acknowledges that information continues to evolve on water availability, demand projections, and AWS Projects. As such, Recommendation 4 of the AWS Plan is to provide periodic updates to the Plan beginning in FY 2026-2027. Investment decisions related to planning and development of AWS Projects are also staggered to reflect a need to take a stepwise approach to implementation.

G-2 A new Recommendation 5 has been added to the AWS Plan to include a process to refine demand forecasting, which will include additional scenario(s) to capture a range of potential futures. See Global Response 1 for additional discussion on demand forecasting.

G-3 Recommendation 5 includes reviewing demand forecasting model assumptions and the sensitivity of inputs, as well as coordinating with BAWSCA . See Global Responses 2 and 3 for more information on the design drought and rationing, respectively.

G-4 As outlined in Recommendation 5, the SFPUC is planning to consider developing additional water demand scenario(s) prior to making large future investment decisions on projects identified in the AWS Plan. The AWS Plan, along with the water supply gap and recommendations, will be updated periodically and provided to the Commission to keep them informed ahead of critical decision milestones. Refer to Global Response 1 for more information on demands and Global Response 2 for more information on the design drought.

G-5 For recommendations 1 and 3 in the comment, see Global Response 2. For recommendation 2 in the comment, see Global Response 1.

G-6 Any additional demand scenario(s) resulting from the implementation of Recommendation 5 will be included in future updates to the AWS Plan, beginning in FY 2026-2027.

G-7 The cost of the AWS Program is an important part of ongoing planning. The AWS Program will continue refining costs as more project information becomes available and will be undertaking rate analys es to determine customer impacts . Because the AWS Projects are in their early planning phases, low interest loans, grants, and cost shares have not yet been factored in, which have the potential to significantly reduce costs and ratepayer impacts. The methodology used to calculate the future water supply gap is described in further detail in Appendix B.

G-8 The AWS Program recognizes that planning and implementing alternative water supplies is expensive and acknowledges the need for continued analysis of rate impacts in conjunction with future investment recommendations. The cost of AWS projects has been and will continue to be an important factor in decision -making as the SFPUC moves forward. The SFPUC will continue to share information in public documents as project costs develop and alternatives for financing are identified.

G-9 The SFPUC recognizes this comment. The language in the AWS Plan has been updated as follows to reflect the intended meaning: “ One of the most pronounced drivers affecting water availability is the potential implementation of the 2018 Amendment to the State Water Resources Control Board’s San Francisco Bay/Sacramento-San Joaquin Delta Estuary Water Quality Control Plan (Bay-Delta Amendment). Unlike other factors that could affect SFPUC water supply, such as climate change, the effect of implementing the Water Quality Control Plan update would be immediate.”
G-10 Retail demand projections are based on the SFPUC’s econometric demand forecasting model and the Wholesale Customer demand projections are based on their projected purchase requests, as provided most recently in the BAWSCA’s 2022 Annual Survey. The new Recommendation 5 in Chapter 6 will enable staff to rev iew modeling assumptions to refine future demand projections. See Global Response 1 for additional information on demand projections.

G-11 See Global Response 1 for the rationale behind the AWS demands forecast involving retail and wholesale customers. LTVA is a modeling exercise focused on assessing the extent of climate change threat to the Regional Water System which involves many assumptions and model limitations including uncertainties around climate change projections. Please also see the response to comment G -14 to understand the nature of such limitations. While SFPUC’s demand has reduced in recent years primarily due to various actions (such as voluntary or mandatory rationing) taken during two droughts covering 2014 to 2016 and 2019 to 2022, SFPUC’s long-term planning cannot rely on such short -term changes influenced by drought management actions. Forecasting water demand is highly uncertain and is influenced by macro-level socioeconomic and climatic factors, as well as the local behavior of consumers.

Understanding the changing long -term demand is crucial in AWS planning along with the adaptation of a reasonable conservative planning approach to safeguard the SFPUC’s water supply. SFPUC has invested significantly in tracking the demand as accurately as possible an d will continue to put effort into continuously improving such measurements.

G-12 The SFPUC recognizes that climate change and other changes to external conditions may jeopardize the future ability of the RWS to meet the desired levels of service, hence the preparation of the LTVA. However, evaluating the design drought was not the purp ose nor objective of the LTVA. Thus, the LTVA is agnostic to its use and does not make any such justifications (see Global Response 2 for more information on using the design drought as a planning tool). The SFPUC is aware that climate change studies need to be updated periodically as part of a continuous process when new information and data are available. The last sentences of paragraph 1 and 3 in Section 3.2.3 of the AWS Plan reflect this commitment.

G-13 Evaluating the design drought was not the purpose nor objective of the LTVA. Thus, the LTVA is agnostic to any changes to the design drought and does not make any such

recommendations or justifications. Future water supply planning cannot solely rely on historical events, it must also consider scenarios outside of those already experienced. See Global Response 2 for more information on using the design drought as a planning tool.

G-14 The SFPUC provided a memo to the Tuolumne River Trust describing issues with return period calculation (and why it was not included in the final LTVA report) in response to public records requested by the Tuolumne River Trust on 5/3/2022. These issues were related to (1) an error in Upcountry hydrologic models, and 2) a large uncertainty in drought frequency analysis for extreme drought events. The portions of the memo describing these two issues, clarifying the calculation related to the design drought, are included below. See Global Response 2 for more information on the design drought and its use.

Issue 1: Error in Upcountry hydrologic models
Description: The PRMS hydrologic models for the Tuolumne River show underprediction of annual volume in wet years and overprediction in dry years. The simulated flows do not have distributional properties that mimic those of the observed flows. This is illustrated in the figure below for annual flow volume of the Tuolumne River at La Grange. This discrepancy has repercussions for the Water Available to the City (WAC) and therefore on drought operation in the reservoir system model SFWSM.

Resolution: Given the importance of a good reproduction of the WAC for the RWS, UMASS HRG collaborated with SFPUC to correct the PRMS simulations across the Upcountry region. A post - processing model was developed by SFPUC to correct the PRMS daily streamflow. The con sidered method attends to correct the residual model errors using meteorological indices. More details about the post-processing model, including calibration and validation, are provided in the Technical Report 2 on hydrology.

Updated resolution: As shown in the final report, even after the post-processing correction, the PRMS hydrologic model used to simulate the streamflow on the Tuolumne watershed in response to

precipitation and temperature overestimates streamflow during dry years. For example, the flow computed at the Tuolumne River at La Grange is overestimated, and therefore San Francisco’s allocation is also overestimated by about 482,000 acre-feet during the drought sequence 1987-1992 (observed is 813,000 acre -feet versus simulated is 1,295,000 acre -feet). This volume of water is significant and is about equal to the volume of rationing that was required by customers during the six-year period, and so overst ating the RWS water supply reliability. An effort of re -building and re- calibration of hydrologic models for the Upcountry watersheds is underway by HHWP.

Issue 2: Large uncertainty in drought frequency analysis for extreme drought events Description: Droughts, even more than floods, are rare events. As such, long time series are crucial for inferring model parameters to model drought frequency. Three sources of hydrological data are available for this analysis:
• 95-year-long historical natural flow at La Grange (1921-2015) • paleo record at La Grange reconstructed from tree rings for the period 900-2012 • 9 representative climate realizations of 50-year long streamflow simulated using PRMS model plus 500 other stochastic realizations using PRMS.

For the flow at La Grange, about 100 years of reconstructed historical is available, which is rather small since droughts are rare and last multiple years. For that reason, we attempted to use the tree - ring reconstructed flow record and the simulated flow time series from the LTVA stochastic rainfall simulations. The advantage of the stochastic datasets is that a very long time series of simulated hydrologic flows is available to extract drought events. However, the PRMS hydrologic model used to simulate the streamflow on the Tuolumne watershed in response to precipitation and temperature overestimates streamflow during dry years (see issue 1). The drought events identified in the working draft final report are represented below using the severity (cumulati ve flow deficit) and duration (number of years). The largest ensemble of drought events is created using the stochastic flow time series from PRMS. Since the model overestimates flows in dry years, the number of drought events in the figure below is biased and underestimated. The small sample of events with duration greater or equal to 6 years results in large uncertainty bounds around the frequency curve, which means a poor confidence in the frequency estimate (i.e. the return period). This is shown in the working copy of return period estimates of historical drought and the design drought. The uncertainty bounds represent about 100% of the estimated return period, which means that the “real” value could be the estimate divided by 2 or multiplied by 2. Such a large uncertainty bound renders the estimate unusable. If the error is too large, what good is the estimate. The uncertainty bounds on historical droughts (76-77, 87-92, 2012-16) are significantly smaller.

Resolution: The drought frequency analysis was redone using the post -processed PRMS simulated flows (Issue 1). We found that the estimated frequency curve is sensitive to the considered dataset.

Therefore, the estimates for the return period for the historical drought events depends on the chosen dataset for the analysis. We also found that we still had very large uncertainty bounds around the frequency curve (see the following figure). This means that we still have very large uncertainty around the estimated return period of extremely rare drought events.

As hypothesized, when reducing the overprediction of flow in dry years using PRMS, the number of drought events increased. More long and very severe drought events were extracted from the stochastic realizations. This is represented in the figure below with more events with duration greater or equal to 6 years and higher severity (cumulative deficit). However, as shown in the previous figure, the large uncertainty bounds around the frequency curve remains, which means a poor confidence in the frequency estimate (i.e. the return period).

We updated the return period estimates for severity and duration of historical droughts (figure below) and attempted to extrapolate to the Design Drought. However, we decided to abandon the idea due to the extremely large uncertainty bounds on the estimate (as aforementioned). Even after improving the PRMS hydrologic model outputs with post-processing, we did not carry forward to the final report the return periods for Design Drought, because the extrapolation was extreme for the level of confidence on the frequency curve. If the error bound is too large on the estimate, what good is the estimate itself. However, the error bound is much smaller for the historical droughts and therefore we published these estimates in the report.

Updated resolution: The drought frequency analysis can be updated after the hydrologic modeling errors are corrected.

G-15 The detailed hydrologic analysis conducted in the LTVA does not find that a warmer climate “would likely benefit the SFPUC’s water entitlements” (from commentor) due to earlier runoff.

The LTVA finds that the annual average water available to the city (WA C) decreases with warming (Section 5.1.1.2 and Figure 5 -4(a) of the LTVA). Importantly, the LTVA finds that the variability in WAC does increase with warming, and estimated reductions in WAC can be much larger than the increases in WAC (Figure 5 -6 of the L TVA). Understanding the changing variability in water available to the city with warming is crucial in water supply planning to safeguard the SFPUC’s water supply. The LTVA also finds that annual average water available to the SFPUC changes linearly with a nnual precipitation. Because climate models are not as equivocal on precipitation changes in the region as compared to changes in temperature, understanding more about these changes is also important. The SFPUC is committed to continued efforts of investi gating climate change effects on water supply as new climatic information and data are available.

G-16 The SFPUC will consider new water demand scenario(s) prior to making large future investment decisions on projects identified in the AWS Plan as part of Recommendation 5 . See Global Response 1 for more information on demand forecasting.

G-17 Consistent with the WSIP Program, planning staff continue to use 12% of total system yield over the design drought as the basis for water supply planning. See Global Response 3 for more information on how rationing is used in AWS planning.

G-18 See Global Response 3 for more information on how rationing is used in AWS planning.

G-19 See Global Response 3 for more information on how rationing is used in AWS planning , including how the Bay-Delta Plan factors into its use.

G-20 The AWS Plan defines the water supply gap as the difference between water available in dry years and cumulative 2045 customer demands. Based on this definition, the resulting water supply gap is 92 mgd. As the comment notes, Figure 3-3 shows that of the 92 mgd gap, up to 11 mgd can be filled by rationing, if 81 mgd of new supplies are developed. For clarity, a footnote has been added to Figure 3-4 repeating this breakdown. This figure is also shown in the Executive Summary of the AWS Plan.

G-21 At this time, the SFPUC will not modify its design drought as part of the AWS planning process.

More information on the design drought is included in Global Response 2 . Information on demand projections is included in Global Response 1.

G-22 At this time, the SFPUC will not modify its design drought as part of the AWS planning process.

More information on the design drought is included in Global Response 2. A new Recommendation 5 is being added to the AWS Plan to evaluate potential modifications to its retail demand forecasting model, including the consideration of a range of possible future demand scenarios to support future AWS planning and recommendations.

G-23 The SFPUC’s Wastewater Enterprise, as well as wastewater agencies around the Bay Area, are working with State regulators to address water quality issues including nutrient loading.

Purified and recycled water projects described in the AWS Plan would reduce total wastewater discharges. While not an explicit goal of the Plan, project-specific impacts to nutrient flows can be included in the considerations for each project as they are evaluated in the future.

G-24 The stated goal of the AWS Plan (pg. 7) is to "identify water supply projects that increase the dry-year reliability of RWS supplies and address the long-term water supply gap in alignment with the LOS Goals and Objectives." Of the six AWS Projects highlighted in the AWS Plan, three purified water projects and one recycled water project include partnerships with wastewater agencies around the San Francisco Bay. While not an explicit goal of the Plan, project -specific impacts to nutrient flows can be i ncluded in the considerations for each project as they are evaluated in the future.

G-25 The selection of technologies for purified water treatment will be based on a number of factors including effectiveness, regulatory and permitting requirements, cost, and other factors.

Performance criteria for purified water projects will be developed pri or to completing alternatives’ analyses.

G-26 The SFPUC serves as both a retail and wholesale water supplier. As discussed in Section 1.3.1, the SFPUC is undertaking the development of the AWS Program with a regional focus and in its role as the operator and steward of the RWS. The presentation refere nced by the commentor was given in the context of SFPUC as a retail supplier. Section 4.2 describes the role that retail and local projects can play in reducing demands on the AWS. It is in this context that the purified water project is described. While additional details for this project are outside the scope of the AWS Plan, the project is continuing to move forward in planning through San Francisco’s local water program.

G-27 The SFPUC is open to exploring a conjunctive use partnership with Stanislaus County. See Global Response 4 for more information on the SFPUC’s coordination with agencies in the Central Valley.

G-28 The SFPUC is open to exploring other alternatives with irrigation districts to increase supply reliability and fishery protection in the Tuolumne River . See Global Response 4 for more information on the SFPUC’s coordination with agencies in the Central Valley.

G-29 The SFPUC is committed to revisiting its retail demand forecasting and to coordinating with BAWSCA in the review of wholesale demand projections. As new demand scenario(s) are developed, the projected water supply gap would likely be affected. New informat ion, once available, will be used to provide future recommendations in updates to the AWS Plan, beginning in FY 2026-2027.

Regarding inclusion of ambitious potable reuse in AWS planning, three of the six proposed AWS Projects are potable reuse projects. The SFPUC remains committed to developing sustainable water supply options that would provide water supply in dry years.

Similarly, the SFPUC will continue to work with its partners in the San Joaquin basin to reach the shared goals of supply reliability and fishery protection through the creation of additional water resources. See Global Response 4 for additional detail on partnerships in the Central Valley.

G-30 At this time, the SFPUC will not modify its design drought as part of the AWS planning process.

A new Recommendation 5 is being added to the AWS Plan to evaluate potential modifications to its retail demand forecasting model, including the consideration of a range of possible future demand scenarios to support future AWS planning and recommendations. Once the SFPUC has completed its review of demand forecasting, additional scenario(s) may be developed that can be analyzed in future AWS Plan updates, beginning in FY 2026-2027. More information on demand projections and the design drought is included in Global Responses 1 and 2, respectively. See response to Comment G-23 for a response to the denitrification component of the comment and Global Response 4 for a response to the groundwater banking and irrigation district collaboration components of the comment.

From: David Happs
To: Commission
Cc: Alternative Water Supply; [email protected]; [email protected]; [email protected]; [email protected]; [email protected]; White, Eileen@Waterboards; Solutions Not Sandbags; [email protected]; [email protected]
Subject: SFPUC Alternative Water Supply Comments
Date: Thursday, August 31, 2023 12:22:11 PM
CAUTION: This email originated from outside of the organization. Do not click links or open attachments unless you recognize the sender and know the content is safe.

SF Public Utilities Commissioners:

Thank you for the chance to comment on SFPUC's current plans to expand the water usage from the Tuolumne River and Delta instead of cooperating with the Bay-Delta Water Quality Control Plan. We find the approach SFPUC has had in many different legal areas confusing and harmful, not only to the environment, which SFPUC provides lip service to, but also to the pocket books of its ratepayers and wholesale customers as SFPUC's strategy of constantly fighting meaningful
environmental regulations has backfired many times, leading to more legal requirements placed on the ratepayers by courts then might have been achieved with reasonable negotiation, and collaboration. We also feel there have been many opportunities to provide more meaningful water recycling and groundwater improvements with SFPUC has not only ignored, but shown outright hostility to which should be a concern to the regulators, other bay area agencies, the citizens of California and most importantly, to the ratepayers who end up ultimately footing the bill for excessive and in some cases unwarranted infrastructure.

This overly litigious
approach is problematic not only on the water supply side, but also on the sewer side. SFPUC has been given many opportunities to incrementally improve its combined sewer system but instead fights for the right to discharge untreated sewage into SF Bay. Please note that although the SFPUC claims the combined sewer overflows are "treatment" this is clearly not the case at some of the larger sewage outfalls around SF where discharges contain large floatable sanitary
sewage debris as well as sediment which was supposed to be trapped in its system. But instead of finding ways to incrementally improve, it has spent $10 millions of dollars on attorneys to fight the US EPA and Regional Board attempting to avoid even marginal improvements. SFPUC has similarly
been spending $10millions on attorneys to fight
statewide collaboration on the Delta, which is likely to cause judges to eventually decide SFPUC should be penalized for its intransigence.

When looking at SFPUC's demands to expand its water supply and attempts to provide for "Alternatives", Californian's should be shocked to learn that SFPUC refuses to provide anything other then token "green" projects to redirect stormwater away from its combined sewer system and back into the ground to recharge the water table. SF has also avoided using it's existing infrastructure to distribute recycled water and instead continues to use Hetch Hetchy where even simply replumbing can greatly reduce it's reliance on water imports. Here is a quick list of low hanging fruit throughout SF that SFPUC has refused to deal with or outright ignored:

1. Downspout disconnect: Currently, San Francisco buildings are required by SF's plumbing code to channel their roof downspouts directly into the combined sewer, from which it is sent to the sewage treatment plant and in many storms a year get discharged into the Bay and ocean without any treatment other then token sedimentation. This is especially infuriating on the H-1
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City's westside where any water that returns to the ground can help recharge the Westside Basin and help both SF and its neighbors use local groundwater. Removing the requirement from the building code, at least throughout the westside, should be a first step in improving not only the ocean's water quality but also improving our groundwater supplies. Simply channelizing the storm water from roofs and pavement areas such as the large concrete patios throughout the sunset into the roadway gutters and then providing simple infiltration chambers ahead of the sewer catch basins could be a simple starting point. Even if the water does end up back into the combined sewer system from the gutter, just the change in the timing of the flow due to the decreased speed would help improve both flooding and combined sewage discharges. SF's plumbing code requirement to directly connect roof drains is something that is very rare in the United States, in fact in the world. One of the "Only in San Francisco" things that SF officials have taken for granted instead of working out strategies to overcome.

2. Disconnect large areas specifically to recharge groundwater and replace SFPUC's use of Hetch Hetchy Water:

A. Lake Merced Area: Throughout the westside of SF, there are many opportunities to directly disconnect large facilities and paved areas from the combined sewer system and have the storm water return to the water table. For example, the area from Brotherhood Way to Eucalyptus Drive between 19th Ave and Lake Merced is approx. 960 acres covered mostly by parking lots and large institutional buildings (churches, shopping mall, schools, apt. complexes). Currently most of the water from these areas all drain directly into the combined sewer system. Although there was some effort by the developer of Park Merced to remove that area from combined sewage
and SFSU has also attempted to improve, mostly these are only token "green infrastructure" and do not incorporate the potential for large scale disconnect from the combined sewage system. Roadway drains surrounding Lake Merced could be retrofitted to allow decanted water to flow towards the lake during storms as Daly City's Vista Grande canal is (partially) doing today.

This is an incredible opportunity first brought up in
the 2008 Sewer System Master Plan but has since been ignored by SFPUC.

B. West Portal, down Trocadero Creek to Pine Lake: This area was identified to have a substantial green infrastructure project to address flooding but SFPUC chose to replumb the combined sewers there instead. Currently the Wawona and 15th area is prone to flooding due to the lack of adequate roadway conveyance to handle the flows that exceed the combined sewer system capacity. The project could have done a substantial roadway and rooftop disconnect upstream and allowed the rain to flow into the low areas of Tocadero Creek, with smaller storms infiltrating in the creek bed and larger overflow events eventually leading to Pine Lake.

Currently, when local groundwater tables are lower, Hetch Hetchy water is used to supplement Pine Lake. Pine Lake suffers because the primary source of water has historically been springs immediately east of 19th Ave. When 19th Ave was built in the early 1900s, the roadway embankment blocked the flows from that spring. Instead of putting a culvert to maintain the historical source of Pine Lake, the spring flows were routed to a sewer catchbasin at the bottom of the sump created east of 19th Ave. This means that for the last 120 years, SF has been dumping the source of Pine Lake out the sewers and instead filling Pine Lake with Hetch Hetchy water.

C. Laguna Honda/Twin Peaks: the Mid Town Terrace, Forest Knolls and Laguna Honda Hospital areas are all upstream of the Laguna Honda reservoir. These areas could have the downspouts easily disconnected (most are external), and along with flows from the roadways, sent into the low sump area south of Clarendon and then infiltrating and overflowing into the old Laguna Honda Reservoir which would be used as a buffer for larger storms, allowing the water to slowly infiltrate back into the ground. It is likely this area is actually upstream of the Lobos Creek ground water basin in which case it would benefit the Presidio water supply as H-8
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well as reduce SFPUC reliance on Hetch Hetchy.

D. Various other local opportunities: Probably the easiest opportunity which has been ignored by SFPUC is to disconnect most of the street drains along the sides of Golden Gate Park and redirect the surface water into the Park.

3. Recycled Water:

Recycling waste water not only reduces reliance on supplies from Hetch Hetchy, but also reduces the impacts of sewage discharges into the bay, which are currently the major contributor to the harmful algal blooms killing fish and wildlife in the Bay. Opportunites include:

A. Provide recycled water to Mission Bay properties: SF required the Mission Bay developers to install "purple pipe" to use recycled water for flushing and irrigation but has never actually provided them with water. This has lead to frustration by the excessive costs and lawsuits by the builders. One of the interesting points about this is there already is an existing, unused 10" force main that goes from the Southeast Sewer Treatment Plant(SEP) along 7th St, right next to Mission Bay. This pipe used to carry sewage sludge from the North Point Plant near Pier 39, down to the digesters at the SEP in Bayview. Along with Mission Bay users, there are numerous other potential recycled water uses nearby the force main alignment including the SF Downtown Steam loop, parks, etc. Instead of repurposing that pipe, SF has chosen to fight the developers even though SF itself was the one requiring "purple pipes".

B. AWSS System: SF is one of the few cities in the world that have are "double plumbed" with a separate water distribution network for high pressure fire fighting. This system runs throughout much of the northern and eastern parts of SF and there are plans to expand more into the southwest neighborhoods. with modest changes and institutional controls such as advising firemen to not drink from their hoses (which they probably shouldn't do anyway) this system could be using "title 22" reclaimed water instead of Hetch Hetchy. With simple pressure regulators at the various users, water from this system could be provided for irrigation and other reclaimed waste water uses.
https://sfpuc.org/programs/future-water-supply-planning/alternative-water-supplies https://water.ca.gov/-/media/DWR-Website/Web-Pages/Programs/Groundwater- Management/Bulletin-118/Files/2003-Basin-Descriptions/2_035_Westside.pdf H-12
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Response to Comment Letter H
David Happs, Member of the Public
August 31, 2023
H-1 This comment is noted. Legal actions related to the Bay Delta Plan Amendment are outside the scope of the AWS Plan.

H-2 The SFPUC has made significant investments in local groundwater and recycling projects, including the San Francisco Groundwater Supply Project and numerous projects under its Recycled Water Program. While these local projects are beyond the scope of the AW S Plan, the SFPUC is also committed to regional collaboration. See project details presented in Chapter 5 and Gobal Response 4.

H-3 This comment is noted. Sewer system improvements in San Francisco are outside the scope of the AWS Plan.

H-4 See response to Comment H -1. While outside the scope of the AWS Program, the SFPUC is working collaboratively with partners and the State on the Voluntary Agreement.

H-5 Local water supply projects provide many benefits, including reducing demands on the RWS.

As a result of a requirement in the WSIP Phased Variant, both San Francisco and the Wholesale Customers have each developed 10 mgd of local supplies to offset demands on the RWS. The AWS Plan continues to encourage additional local water supply development, as discussed in Section 6.3.1.

H-6 Note that the AWS Plan is prepared from the perspective of the SFPUC as a regional water provider to both wholesale and retail customers of the RWS. Therefore, the discussion of local retail projects is limited to how these projects can play a role in reducing reliance on the RWS and increase local reliability. Note that regulation prohibits the use of potable water pipelines for non -potable recycled water. Purified water would be able to use the existing potable distribution system and there are several purified water projects in planning phase as described in the AWS Plan.

H-7 Local groundwater projects are part of how San Francisco, as a customer of the Regional Water System, can lower its demands on the Regional Water System. Those projects and strategies are a focus of SFPUC's Water Resource Division but are outside of the scope of the AWS Plan.

H-8 This comment is outside the scope of the AWS Plan. SFPUC is working with Daly City on the Vista Grande Project.

H-9 Flooding is a challenge in several areas of San Francisco. Solutions are location -specific and may range from installing green infrastructure to addressing capacity issues. While the SFPUC continues to look at ways to address high-risk flooding areas in the City, this comment pertains to areas outside the scope of the AWS Plan.

H-10 Pine Lake is fed by the same underground spring that feeds Lake Merced; water from the Regional Water System is not stored in Pine Lake. The SFPUC does not currently anticipate storing water from the Regional Water System in Pine Lake.

H-11 Local groundwater projects are part of how San Francisco, as a customer of the Regional Water System, can lower its demands on the Regional Water System. The SFPUC continues to encourage these projects and strategies as a way to reduce in -city demand as di scussed in Section 6.1.3; their development and implementation are a focus of the SFPUC's Water Resource Division but are outside of the scope of the AWS Plan.

H-12 In 2005, San Francisco's plumbing code was amended via Ordinance 137-05, making it possible for residents to disconnect downspouts from the combined sewer system and direct rainwater to alternative locations such as rain gardens, rain barrels, and cisterns . The SFPUC currently offers grants for such activities through its Green Infrastructure Grant Program. Downspout disconnection remains a viable option for San Francisco residents to use alternative water supplies for non-potable uses, thereby reducing the ir potable demand. The SFPUC continues to encourage these types of projects as a way to reduce in-city demand, as discussed in Section

6.1.3; their development and implementation are a focus of the SFPUC's Water Resource Division but are outside of the scope of the AWS Plan.

H-13 The SFPUC agrees that purified water has great potential to address the water supply gap.

Three of the six projects included in the AWS Plan involve purified water. While outside the scope of the AWS Program, the SFPUC is also looking at opportunities for purified water in San Francisco, in its capacity as San Francisco's water supplier.

H-14 The SFPUC is planning a purified water project in San Francisco that could serve dual-plumbed buildings on the east side of San Francisco.

H-15 Local recycled water projects are part of how San Francisco, as a customer of the Regional Water System, can lower its demands on the Regional Water System. The SFPUC continues to encourage these projects and strategies as a way to reduce in -city demand as discussed in Section 6.1.3; their development and implementation are a focus of the SFPUC's Water Resource Division but are outside of the scope of the AWS Plan.

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Response to Comment Letter I
Alameda County Water District (ACWD)
Ed Stevenson, General Manager
August 31, 2023
I-1 A footnote has been added to Figure 2-1 to reflect this comment.

I-2 This linework on the map was a result of waterbodies on the GIS basemap file and has been removed from the figure.

I-3 The SFPUC acknowledges that the cost estimates reported in the AWS Plan are based on the SFPUC's own economic analysis and may differ from the estimates reported in the draft Purified Water Feasibility Evaluation (PWFE).

I-4 The "Staffing & Workforce Development” Section of the ACWD -USD Purified Water Project Description in Chapter 5 has been revised to reflect this comment.

I-5 The "Operations Considerations” Section of the ACWD-USD Purified Water Project Description in Chapter 5 has been revised to reflect this comment.

I-6 The SFPUC recognizes that ACWD continues to assess the ACWD-USD Purified Water Project’s needs and timing and is conducting an integrated resources planning update.

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CALIFORNIA WATER SERVICE
I
Water Resource Sustainability Department 1720 North First Street San Jose, CA 95112
August 31, 2023
Mr. Steven Ritchie
Assistant General Manager, Water Enterprise
San Francisco Public Utilities Commission
525 Golden Gate Avenue, 13th Floor
San Francisco, CA 94102
RE: SFPUC's Draft Alternative Water Supply (AWS) Plan - Cal Water Comments Dear Mr. Ritchie:

Cal Water has reviewed the SFPUC's Draft Alternative Water Supply Plan (AWS Plan) made available for public review on June 28, 2023. We appreciate the efforts and details of the AWS Plan and support additional alternative water supply. The Bay-Delta Plan changes represent significant potential changes to water supply to the region, and alternative supplies are needed.

This letter provides our comments on the AWS Plan.

Executive Summary page x, Chapter 1: Introduction page 1, and Section 2.2 Regional Water System Overview page 15
All three sections reference that the RWS draws an average of 85% of its water from the Tuolumne River, and the remaining 15% from local surface water. In all three cases wells are not mentioned, even though the Regional Groundwater Storage and Recovery project is mentioned in the document. Perhaps these wells are not included for a specific reason, but it seems that they are or will be part of the water supply mix and should be referenced more clearly.

Section 2.3.1 page 22
Section 2.3.1 outlines the total system yield of 257 mgd for dry year supply. There is no discussion or detail of normal year supply, and adding this as a baseline would better show the magnitude of potential water supply shortages.

Additionally the continuation of this section on page 23 describes the simulated design drought sequence. This model output could be used to develop probability of exceedance curves to add a discussion of Level of Service that will be achieved through the implementation of the AWS Plan projects.

Figure 2-6: Historical Retail and Wholesale Water Purchased from the RWS (2000-2022) page 28 The Wholesale Historical values bar chart upper limit values shown in blue, do not seem to match the corresponding purchase number shown in white. As an example, the blue bar chart Quality. Service. Value:
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upper value shown in 2017-2018 with a value of 128.1 mgd, seems to be larger than the blue bar chart upper values shown in 2019-20 and 2020-21 where the values are 132.2 and 134.5 mgd respectively. There seems to be an error in how the blue bar chart values are shown in this graphic.

3.2.3 Climate Uncertainty page 39
The third paragraph of this section starts with the statement that "impacts related to climate change are not currently quantified in the AWS planning efforts." It is concerning that not even an initial value of climate change impacts is included in this AWS Plan, as many climate change models are now showing a need for additional water supplies which would only add to the deficits shown in this plan.

Section 3.3.4 Customer Reliance on RS Supplies page 41, Section 4.2 Reducing Demands on the RWS through Local Water Projects page 47, and Recommendation 14 on page 127 There is discussion in these areas on the changes in dependence on SFPUC supplies and th e consideration of a regional fund for local supplies. It would be valuable to clarify in one or all of these sections if there is a want just to reduce demands on SF PUC supplies, or to also reduce percent dependence on SFPUC supplies.

Section 4.2 Reducing Demands on the RWS through Local Water, San Francisco Groundwater Supply Project page 47
The last sentence states that "pumping can be gradually increased in order to blend up to 4 mgd of treated groundwater ... " It would be valuable to clarify this statement and why that pumping is unable to be implemented immediately, or in the near-term, to help with regional water supplies.

Table 4-1 on page 58
The Planning Principle to Diversify supplies mentions desalinated water. Though Alternative SA has the potential of desalination, desalination projects as alternative water supplies are largely missing from this Plan. It is understood that there is a high cost to desalination, but it is recomm ended that additional detail be added explaining why additional desalination projects are not being pursued.

The projects referenced in this section largely include local projects, and do not include projects that connect with State Water Project Contractors, or other Irrigation Districts for water banking or transfer opportunities that could help with dry year supply needs.

If the Bay-Delta Plan is implemented as adopted, there were discussions related to a project to recapture the by-pass flows in the Tuolumne River once the instream flow requirements have been met. Though costly, including a discussion on this proj ect and potential costs would help Quality. Service. Value.
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show the true cost of the adoption of the Bay-Delta Plan, and the added value of the six proposed projects.

1. Daly City Recycled Water Expansion after page 76
The Project Location map seems to indicate that the Colma Cemeteries are outside of Cal Water's service territory, and that the new storage tank is to the northwest of this green cemetery area. It is recommend that the map be revised to better indicate that the Colma cemeteries are within Cal Water's service territory, and that the most likely new storage tank location is to the southeast corner of the green cemetery area.

The third page of the project description shows that the O&M costs are estimated to be $12million. Though stated elsewhere, it would be valuable to state in this section that the O&M costs are not included in the $4,203 cost per acre-foot. Including these costs will have a direct increase to the cost per foot. Additionally it could also be mentioned that the full 0.7 mgd capacity is included in the $4,203 cost per acre-foot cost.

2. San Francisco-Peninsula Regional PureWater
The Project location map shows the Cal Water Bear Gulch service territory shaded, but this project will likely go through San Carlos within the Cal Water Mid-Peninsula service territory. It is recommended to make this correction and to the Agencies where the likely alignment would go through.

The second page of this section shows an Estimated Capital Cost per Acre-Foot value of $1,868 value. This cost per acre-foot still appears low compared to the high cost of the project even with the relatively high supply it would include. There is risk of additional costs depending on which alignment is selected to complete the project.

Page A-6 (160 of 197) California Water Service
The City of San Carlos is shown with the Redwood City label over it. Redwood City is denoted on most of the maps, but it is requested that the Redwood City label be removed and the City of San Carlos label be added to properly show the Cal Water service territory.

Finally, the assumptions in this AWS Plan are directly connected to the final decision on the Bay Delta Plan. It is not clear in this document if it will be revised once that decision is made, or when a revision to this AWS Plan will be made.

Thank you again for considering these comments regarding the Alternative Water Supply Plan.

We look forward to working with you to further increase supply reliability.

Quality. Service. Value.
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Sincere ly,
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Scott Wagner ~
Director of Water Resources
Cc: Alison Kastama, SFPUC, BAWSCA Liaison
Manisha Kothari, SFPUC, Manager, Alternative Water Supply (AWS) Program Nicole Sandkulla, BAWSCA, CEO/ Genera l Manager
Quality. Service. Value.
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Response to Comment Letter J
California Water Service (Cal Water)
Scott Wagner, Director of Water Resources
August 31, 2023
J-1 The description in the introduction of the RWS is intended to provide an overview of normal year deliveries from the RWS. Groundwater is a source of supply for the RWS in dry years and therefore not included in the overview description.

J-2 The second paragraph of Section 2.3.1 discusses normal year supply, stating that "in normal or wet years, the SFPUC watersheds produce enough supply to meet current and projected future demands, and existing obligations." Because there is no shortage of su pply in normal years, the focus of the AWS Plan is on identifying and addressing potential water supply shortfalls in dry years. Therefore, the baseline is described as the dry year water available with WSIP projects completed (Chapter 2) and it is com pared to the potential water supply shortages with the Bay-Delta Plan Amendment implemented (Chapter 3). Table 3 -1 provides a side -by-side comparison.

J-3 A new Recommendation 5 is being added to the AWS Plan to review the SFPUC’s demand forecasting model and coordinate with BAWSCA to update demands and possibly create additional demand scenario(s). This will likely affect future analysis of the projected water supply gap. The SFPUC acknowledges this comment and can review it in the context of future planning updates. See Global Responses 1 and 2 for more information on demand projections and the design drought, respectively.

J-4 Figure 2-6 has been revised to reflect this comment.

J-5 The SFPUC understands that climate change and other changes to external conditions may jeopardize the future ability of the RWS to meet the desired levels of service. To better understand the potential vulnerability of the RWS to uncertain future conditions, the SFPUC recently partnered with the Water Research Foundation to pr oduce the Long -Term Vulnerability Assessment (LTVA). The LTVA final report, published in December 2021, found that climate change exacerbates impacts from other drivers of potential change such as increased instream flow requirements and increased demands on the system. The SFPUC is aware that climate change studies need to be updated periodically as part of a continuous process when new information and data are available. The last sentences of paragraph 1 and 3 in Section 3.2.3 of the AWS Plan reflect this commitment.

J-6 The stated goal of the AWS Program is "to identify water supply projects that increase dry - year reliability of AWS supplies and address the long -term water supply gap." The extent to which individual customers reduce their reliance on the RWS is part of their individual planning processes. Recommendation 15 is aimed at reducing the gap by incentivizing the development of local supplies and thereby reducing the demand on the RWS.

J-7 The SF Groundwater Supply Project has completed construction of six new wells on the westside of San Francisco. However, three wells (two on the westside and one in the central portion of Golden Gate Park) cannot be used until the Westside Recycled Water project is operational so that Golden Gate Park can stop pumping from these wells for irrigation and the SFPUC can start operating the new wells for potable use. Additional treatment is also potentially required at three project wells, which is currently being evaluated. Finally, the SFGW EIR mitigation measures requires that the SFGW Project ramp up production in increments of about 1 mgd to ensure the project does not lead to adverse impacts and undesirable environmental conditions such as subsidence, impacts to Lake Merced, or seawater intrusion.

J-8 The SFPUC remains open to exploring opportunities for additional desalination projects through partnership with other agencies. However, given the demands associated with land and energy requirements as well as potential entrainment and impingement impacts for desalination projects compared to purified water projects, the SFPUC has focused resources on pursuing purified water projects for local, in-city development.

J-9 The SFPUC is exploring water supply projects that would leverage State Water Project facilities to convey water to the SFPUC in the context of the Los Vaqueros Reservoir Expansion Project.

This is described in Project 5C in Chapter 5. For a discussion of p otential opportunities with Irrigation Districts, see Global Response 4.

J-10 The Daly City Recycled Water Expansion Project map has been revised to reflect the edits suggested in this comment.

J-11 The SFPUC acknowledges this comment requesting additional clarification. As mentioned in the comment, other parts of the document (see section 5.2.3) note that the O&M costs are not included, and the header of the metric is explicitly labeled "Capital cost per acre -foot." In an effort to maintain consistency in how the costs of each project are described, additional language is not explicitly provided for the Daly City Project.

J-12 The SFPUC acknowledges this comment. The capacity used as a basis for the calculation of the cost per acre-foot is consistent for all projects. No additional changes were made.

J-13 The San Francisco-Peninsula Regional PureWater Project map has been revised to reflect the edits suggested in this comment.

J-14 The project is in the early planning phases and the cost estimate provided represents planning to feasibility-level information with an estimated accuracy range between -30 percent and +50 percent.

J-15 This change has been made to Cal Water wholesale service area map in Appendix A. This change was also made to the San Francisco -Peninsula Regional PureWater project map in Chapter 5.

J-16 Recommendations 3 and 4 in Chapter 6 provide for periodic updates to the AWS Plan as negotiations progress and more information becomes available, beginning in FY 2026-2027.

City of
Santa Clara
The Center of What's Possible
August 31, 2023
Steven Ritchie
Assistant General Manager, Water Enterprise
San Francisco Public Utilities Commission
525 Golden Gate Avenue, 13th Floor
San Francisco, CA 94102
Water and Sewer Utilities
RE: BAWSCA's Review of the SFPUC's Draft Alternative Water Supply (AWS) Plan
Dear Mr. Ritchie,
The City of Santa Clara joins BAWSCA in its strong support of both the Draft Alternative Water Supply (AWS) Plan and the overall AWS Program. The SFPUC must be prepared to face potential future reductions to its existing water supply that could require the development of new supplemental sources to improve long-term water supply reliability in order to meet its legal and contractual obligations to the BAWSCA Member Agencies as well as the water needs of its Retail Customers in San Francisco. Climate change and future regulatory uncertainties could exacerbate the need for new diversified and distributed water supply sources. Santa Clara joins BAWSCA in the assertion that the AWS Plan meets these critical planning needs.

Components of the AWS Plan provide the roadmap for the development of projects needed to address the water supply shortfall (gap) that is calculated to be present through the planning horizon (2045). That gap is acutely related to shortage of supply during times of drought.

The AWS Plan presents detailed information regarding estimated project costs and development times and estimated rate impacts to both SFPUC Retail and Wholesale Customers for the AWS planning work estimated to take place within the SFPUC's 10- year Capital Improvement Plan (CIP). While Santa Clara joins BAWSCA in agreement that the presented rate impacts are correct for the purposes of the SFPUC's 10-year CIP, it further agrees that the full rate impact of the implementation of the suite of AWS Plan projects has not been estimated at this time as more details are needed that can only be provided following further planning work.

This complete cost and rate impact information will be necessary for the City of Santa Clara to support future decision making.

The AWS Plan includes recommendations for the Commission to consider that, if embraced, will work to 1) Avoid widening the water supply gap; 2) Fill the water supply gap; and 3) Reduce the water supply gap.
1500 Warburton Avenue • Santa Clara , CA 95050 • Phone: ( 408) 615-2000 • Fax: ( 408) 24 7-0784 • www.santaclaraca.gov K-1
K-2
K-3

Steven Ritchie
August 31, 2023

There remains uncertainty related to how regulatory and other pressures can widen the supply shortfall. The AWS Plan is clear that, although implementing the projects listed can contribute substantially to lessening that gap, additional projects beyond those documented in the Plan will be necessary to fill the water supply gap.

Santa Clara is among the BAWSCA Member Agencies that has committed to a level of conservation that will continue to result in lowered water demands . Santa Clara believes that demand hardening should be taken into consideration as part of long-term water supply planning. Santa Clara continues to be committed to water use efficiency, recycled water expansion and reducing per capita water use while underscoring the realities of population growth and housing requirements, thus highlighting the need for the AWS Plan.

Santa Clara joins BAWSCA in the sincere hope that the AWS Plan better positions San Francisco to fulfill its contractual obligation under the 2021 Amended and Restated Water Supply Agreement between San Francisco and the Wholesale Customers (WSA) to decide, by December 31, 2028, whether to make the cities of San Jose and Santa Clara permanent Wholesale Customers of the SFPUC. It is appropriate for the AWS Plan to acknowledge and be informed by the requirement that the SFPUC make this decision.

It is important to note that the AWS Plan must incorporate the SFPUC's existing contractual obligations to Santa Clara under the WSA as identified by BAWSCA's August 21, 2023 comment letter (under specific comments, Item #3), however, the City supports the goals of the AWS and joins BAWCA in support of it.

Sincerely,
~- ~r cJ»v/;qv
Gary ~elling
Director, Water nd Sewer Utilities
City of Santa Clara
cc: Nicole Sandkulla, CEO/General Manager, BAWSCA
Tom Francis, Water Resources Manager, BAWSCA
K-6
K-4
K-5
K-7

Response to Comment Letter K
City of Santa Clara
Gary Welling, Director, Water and Sewer Utilities
August 31, 2023
K-1 As stated in Section 2.3.1, the SFPUC watersheds produce enough supply in normal or wet years to meet current and projected future demands, and existing obligations. Drought and climate uncertainty are drivers affecting the future water supply gap, as disc ussed in Section

3.2.3. K-2 The AWS Plan incorporates preliminary capital costs, as they are known as of the drafting of this document (May 2023). Based on proposed budgeting recommendations at the time, the SFPUC analyzed potential rate impacts over the next 10 -year period. Recommendations in Chapter 6 include the most recent changes based on evolving budget developments. As additional cost information is developed, associated rate impacts will continue to be evaluated.

Results will be included in future updates to the AWS Plan.

K-3 This comment provides a summary of objectives that the AWS Plan aims to achieve through the recommendations presented in Chapter 6. The SFPUC recognizes this comment.

K-4 The SFPUC recognizes the uncertainty around regulatory and other drivers that may impact the water supply gap. Changes to either water availability or demand will affect the water supply gap and future planning goals.

K-5 The SFPUC agrees that demand hardening must be taken into consideration as part of its long- term water supply planning.

K-6 Comment noted. The decision of whether to make the cities of San Jose and Santa Clara permanent customers is one of the drivers of the AWS Program.

K-7 The SFPUC is committed to delivering up to 9 mgd to San Jose and Santa Clara through 2028 and acknowledges that a 10-year notice is required to terminate supplies, if such a decision is made by the SFPUC. See response to Comment F-10. 3025 Tuers Road, San Jose, CA 95121 tel Administration (408) 277-4218, Engineering (408) 277-3671 Operations & Maintenance (408) 277-5180, Customer Service (408) 363-4742 August 31, 2023
Steven Ritchie
A
ssistant General Manager, Water Enterprise
San Francisco Public Utilities Commission
525 Golden Gate Avenue, 13th Floor
San Francisco, CA 94102
[email protected]
Re: Comment
Letter – SFPUC’s Draft Alternative Water Supply Plan
Dear Mr. Ritchie:

San José Municipal
Water System (SJMWS) has reviewed the SFPUC’s Draft
Alternative Water Supply (AWS) Plan and appreciates the opportunity to provide comment.

SJMWS would like t
o express overall support for SFPUC’s efforts to plan for and address potential water supply shortfalls through the 2045 planning horizon, thereby improving water supply reliability for the 2.7 million residents and businesses within the Bay Area that rely on SFPUC’s Regional Water System.

As discussed i
n the Draft AWS, staff from SFPUC, San José, and Santa Clara have been coordinating to assess feasibility of one of the Draft AWS’ identified projects, the South Bay Purified Water Project. SJMWS is appreciative of SFPUC staff’s collaborative efforts throughout the initial assessment of this project.

We look forward to conti
nued collaboration now and in the future to evaluate the viability of the South Bay Purified Water Project, and any other water supply projects or transfers that may be an option to inform the SFPUC Commission’s 2028 policy decision to formally recognize San José and Santa Clara as permanent wholesale customers.

Sincerely,
Jeff Provenzano
D
eputy Director
Environmental Services Department
Environmental Services Department

MUNICIPAL WATER SYSTEM
L-1
L-2
L-3

Response to Comment Letter L
San José Municipal Water System (SJMWS)
Jeff Provenzano, Deputy Director, Environmental Services Department August 31, 2023
L-1 This comment expresses support for SFPUC’s efforts to plan for and address potential water supply shortfalls through the 2045 planning horizon. The SFPUC recognizes this comment.

L-2 This comment expresses support for the SFPUC staff's collaborative efforts in coordinating to assess the feasibility and complete an initial assessment of the South Bay Purified Water Project. The SFPUC also appreciates the collaborative work with San Jose and Santa Clara, and recognizes this comment.

L-3 This comment expresses support for continued collaboration regarding the evaluation of the South Bay Purified Water Project and any other projects that may inform the SFPUC’s decision to make the cities of San Jose and Santa Clara permanent wholesale customers. The SFPUC recognizes this comment.

OUR MISSION: To provide our customers with high-quality, efficient, and reliable water, power and sewer services in a manner that values environmental and community interests and sustains the resources entrusted to our care.
525 Golden Gate Avenue, 13th Floor
San Francisco, CA 94102
T 415.554.3155
F 415.554.3161
TTY 415.554.3488
San Francisco Public Utilities Commission
Citizens’ Advisory Committee
Water Subcommittee

MEETING MINUTES
Tuesday, August 22, 2023
5:30 p.m. – 7:00 p.m.
525 Golden Gate Ave., 3rd Floor Tuolumne Conference Room

MEMBERS OF THE PUBLIC MAY OBSERVE AND PARTICIPATE VIA ZOOM

VIRTUAL CONFERENCE SOFTWARE
Meeting URL
https://sfwater.zoom.us/j/84852774253?pwd=YWJicDlFZjZBNjYyakRad2l1TytRdz09 Phone Dial-in
669 219 2599
Find your local number: https://sfwater.zoom.us/u/kbzVJuPz8b Meeting ID / Passcode
848 5277 4253 / 189833
Mission: The Water Subcommittee reviews water supply system reliability, water conservation, recycling, regional cooperation efforts and other relevant plans and policies. (Admin Code 5.140-142)
Members:

Jennifer Clary (Chair) (D11) Suki Kott (D2) Amy Nagengast (D8) Nicole Sandkulla (M-Reg’l
Water Customers)
Eliahu Perszyk (M-Large
Water User)
Douglas Jacuzzi (D4)
D = District Supervisor appointed, M = Mayor Appointed, B = Board President appointed
Staff Liaisons: Mayara Ruski Augusto Sa, Lexus Moncrease, and Jotti Aulakh Staff Email for Public Comment: [email protected]

ORDER OF BUSINESS

1. Call to Order and Roll Call at 5:35 pm
Members present at roll call: (4) Perszyk, Kott, Jacuzzi, and Nagengast Members Absent: (2) Sandkulla and Clary
Staff: Manisha Kothari
Members of the Public: Dave Warner and Peter Drekmeier

*Chair Clary joined at 5:45 pm. Quorum maintained.

2. Approval of the June 27, 2023 Minutes
Motion was made (Jacuzzi) and seconded (Perszyk) to approve the June 27, 2023, Minutes as amended.

AYES: (4) Perszyk, Kott, Jacuzzi, and Nagengast
NOES: (0)
ABSENT: (2) Sandkulla and Clary
Public Comment: None

3. Report from the Chair
• Chair welcomes committee members, staff, and the public Public Comment: None

4. Public Comment: Members of the public may address the Committee on matters that are within the committee’s jurisdiction and are not on today’s agenda
• Dave Warner commented that the water and sewer rate projections are based on a certain level of demand. He noted that if demand comes in below the assumed level, water rates must increase to cover all the fixed costs, including the $8.8 billion in the 10-year Capital Plan.

Warner added that water and sewer rates would have to increase even more than projected as water demand declines. He commented that as a chief financial officer by trade, he is concerned about the lack of financial expertise within the SFPUC’s leadership, especially considering the $10 billion debt the SFPUC will be in once the 10-year Capital Plan is put in place.
• Peter Drekmeier commented that the SFPUC was entitled to 2.77- million-acre feet and demand has been under 200 million gallons per day (mgd), which is 225,000-acre feet per year, for the past nine years.

He noted that the SFPUC was entitled to enough water to last 12 years, but because there was no place to store it, the unimpaired flow between February and June in the lower Tuolumne River was 81%, while the Bay Delta Plan calls for 40%. Drekmeier added that demand was down and was 221 mgd in the middle of summer, which is the peak of demand.

5. Discussion: SFPUC Draft Alternative Water Supply Plan, Water CAC Subcommittee
Discussion
• Member Jacuzzi commented that he did not see any mention of the Westside Basin Aquifer in the Alternative Water Supply Plan (AWSP).

M-1

Staff Kothari responded that the AWSP is focused on additional alternative water supply projects that the SFPUC is considering beyond what is already in planning, so the only reference to WSIP (Water System Improvement Program) is that the SFPUC has ongoing WSIP projects. She commented that the Future Planning List touches on the Westside Basin with its’ Daly City Recycled Water Expansion Project, which proposes recycled water delivery to the cemeteries in Colma that then alleviate some of the pumping in the Westside Groundwater Basin and provide additional assurance for the dry year supply. Staff Kothari noted that the pie charts and graphs are baseline with implemented WSIP projects, and the focus is on the additional needs that the SFPUC can fill.

Chair Clary commented that the AWSP was about the regional water system, so the Westside Basin would not be mentioned. She noted that there was a difference between in-city supply and the supply that was a part of the regional water system.
• Member Nagengast asked for key takeaways on the Urban Water Management Plan to better understand how the AWSP built on it.

Staff Kothari responded that the AWSP takes in-city retail demand from the Urban Water Management Plan, and the adjustment made in the AWSP relative to the Urban Water Management Plan is the expansion of the non-potable ordinance because the SFPUC lowered the threshold for what would trigger the onsite water reuse development. She noted that there was 0.2 mgd less demand in 2040 from retail. Staff Kothari added that for all the other customers except for San Francisco and suburban retail, the SFPUC relies on BAWSCA’s (Bay Area Water Supply and Conservation Agency) annual survey
• Chair Clary commented that she would like to see a ranking of potential projects to see what their sensitivity is to potential drivers.

She noted that the SFPUC has a storage heavy system, so extra storage does not have as much weight because it will likely be impacted in a similar way during a drought. A decision by the regional board to require denitrification of the City’s effluent into SF Bay could make east side recycling more feasible. Chair Clary added that she would also like to understand how the SFPUC responds to various stressors.
• Member Perszyk asked if the AWSP explicitly discussed the relationship between the ability to increase a supply of alternative water sources and the ability to increase in-stream flows.

Staff Kothari responded that each project would be looked at differently, and the location of the project would matter. • Member Perszyk asked if a dry year would be more of an issue.

Staff Kothari responded affirmatively and commented that the projects in a dry year are intended to provide water that was not available upstream from the Tuolumne.

M-2
M-3
M-4
M-5

• Chair Clary commented that it would be helpful to add a table that identified how much water was left in the river for various wet and dry years.
o Resource: Tuolumne River Flows and Diversions
Staff Kothari responded that the yield of the projects is how much the SFPUC can receive without taking water from the Tuolumne in dry years.
• Member Perszyk asked if that could be visually demonstrated.

Member Kott responded that it would help weigh how much impact a project has.

Chair Clary responded that it would help show which projects are more helpful in a drought.
• Member Jacuzzi asked about knocking off one year from the design drought.

Chair Clary responded that the discussion of whether a design drought should be seven or eight years is unprofessional, and instead, they should look at what the triggers are for a five-year plan. She noted that, despite the 20-year drought we’ve been having, the SFPUC was never in danger of having a water supply issue, which is progress that the SFPUC has made. They should be thinking of how they can share their good fortune with the species that are overstressed in the Tuolumne River. Chair Clary then asked about the 244 mgd demand in 2045 and whether all the different systems are expecting a 30% increase in water use even though there has been a 30% decrease in water use over the last two decades. She also asked if the SFPUC could think about differential pricing where people who were giving big demand increases to the SFPUC are required to pay for the projects identified in the AWSP that are needed to meet that increased demand. Lastly, Chair Clary asked if Brisbane was going to increase their water use by 50%.

Staff Kothari responded affirmatively but noted that the Baylands Development was not included in their demand number.
• Member Perszyk asked what BAWSCA’s position would be on that idea.

Chair Clary responded that they would be opposed to it because they would be the ones paying for it.
• Staff Kothari commented that for the AWSP, the SFPUC wants to incentivize all customers to develop local supplies and reduce demand on the regional water system, which would benefit everybody. She noted that part of the proposal in the AWSP is for the SFPUC to work with BAWSCA to help develop that approach.
• Member Jacuzzi asked what local supplies would look like.

M-6
M-7
M-8
M-9

Staff Kothari responded that there is potential for potable water because people are relying on potable supply from the regional water system.
• Chair Clary asked if potable water production was being limited to 10% of the supply.

Staff Kothari responded that the 10% rule has to do with mixing and only applies over a 24-hour period.
• Member Jacuzzi asked if there were other sources besides purified water.

Staff Kothari responded that the geography would dictate what potential there is in different places and noted that the SPFUC is looking for a new water supply that has not been tapped enough. • Chair Clary asked what the yield of the Westside Basin was.

Member Jacuzzi responded that the Westside Basin is overburdened. • Chair Clary commented that the Basin is too small for indirect potable reuse but that should not apply to direct potable reuse. She noted that recycled water that cannot be put in the system can be put in the ground.

Staff Kothari responded that the SFPUC did a study for the Daly City Recycled Water Project to look at indirect potable reuse potential from that project. She commented that an issue was that Daly City did not have space for the additional treatment that was required, and they did not have sufficient well sites to put that water in. Staff Kothari added that if these issues can be resolved then there would be potential for purified water injection in indirect potable reuse for the Westside Basin. • Member Perszyk commented that there should be language added to include the modularity of being able to add capacity in the future. • Chair Clary asked what the maximum potential to produce direct potable reuse at the Westside Basin was.

Staff Kothari responded that it is 38 mgd on the east side and between 4 and 5 mgd on the west side with more room to expand on the east side.
• Member Nagengast asked what the ratio was between what the SFPUC purchased and what the demand was for any given year.

Staff Kothari responded that she does not have those numbers, but it is a fact that their use has been lower than the projections. She noted that the SFPUC is trying to do a better job of calibrating that, but a large portion of their overall demand does rely on their wholesale customers to provide them with their demand.
• Member Nagengast commented that she appreciated the graphic that depicted the six projects, but she would like to see them in the context M-10
M-11
M-12
M-13
M-14
M-15
M-16

of the year they could get implemented to better understand where things have been uncertain historically. She noted that she would like to see demand projections versus purchases from a customer perspective, and to visually understand things better, she would like to see things on a time-based scale.

Staff Kothari clarified if that meant seeing the demand projections and potential supply together and how that gap is changing with the implementation of the projects in five-year increments. • Member Perszyk commented that alternative water supply projects are expensive and asked if there will be a return on investment for water supply from the grant programs.

Staff Kothari responded that the first three years of working on the AWSP was focused on procuring and the feasibility of the projects but now they are looking into hiring somebody who prioritizes financial analysis because affordability is a key issue.

Public Comment:
• Dave Warner commented that the SFPUC should consider the general public as the audience for the AWSP. He noted that the executive summary makes it sound like future demand is fixed but that is far from the case. Warner added that Commissioner Ajami had pointed out how the SFPUC has an old school centralized approach to water and how she hoped for a decentralized approach in the future where households would use SFPUC water just for drinking, cooking, showering, and the rest of the water would be recycled in-house. He commented that the executive summary needs to show that demand is more uncertain than what is shown in the AWSP because demand uncertainty is the biggest challenge to making alternative water supply decisions, particularly when the cost structure is so high. • Peter Drekmeier commented that a big issue is that the SFPUC does not want to run out of water, but they also do not want to over-invest in expensive alternative water supplies. He noted that if the SFPUC did build out the 92 mgd of perceived demand, that would cost about $300 million per year, which would be spread out amongst the rate payers. Drekmeier added that the Urban Water Management Plan used Plan Bay Area while BAWSCA included a sensitivity analysis with their demand study at the end of 2022, which looked at population growth by using the California Department of Finance projections. He commented that the projections showed that BAWSCA’s demand would remain flat for the next 25 years while Plan Bay Area projected that San Francisco will grow twice as fast in the next 15 years after 2020 than it did in the 15 years before 2020.

Drekmeier noted that San Francisco was investing in infrastructure storage at a time when demand projections were suggesting that they would be using 400 mgd, which is twice the amount being used today.

He added that alternative water supplies are like water conservation because the idea is that they will benefit the environment, but that water does not end up in the environment if the reservoirs have storage capacity.

M-17
M-18
M-19

6. Discussion: Water CAC FY 2023-2024 Priorities, Jennifer Clary, Water CAC Chair
• Resource: Citizens Advisory Committee Annual Report FY 21-22 Discussion
• Member Perszyk asked whether the tribal land management issue should be a part of the Water Subcommittee or if it should go to the Full CAC.

Chair Clary responded that she would check with the Full CAC Chair. • Chair Clary commented that the CAC does not focus on water rates because that is a topic for the Rate Fairness Board.
• Member Perszyk commented that for the SF Groundwater Project, the Water Subcommittee should investigate the San Francisco Groundwater Feasibility Study.
• Chair Clary commented that the Water Subcommittee, excluding herself and Sandkulla, should watch the Bay Delta Plan hearings to come up questions/comments.

Member Kott responded that it was a great idea and noted that it would be a public meeting to make sure the rules of quorum are met. • Chair Clary commented that the Alternative Water Supply should not be included in the list of priorities for the upcoming year because they just covered that. She noted that the Emergency Firefighting Water System topic should stay on the list because there was an ordinance passed to discuss that every year. Chair Clary added that Commissioner Ajami did not seem interested in the diversity and inclusion topic when it was brought up to her attention at the recent Full CAC meeting.

Member Perszyk responded that she seemed interested but perhaps SFPUC staff was not making her aware of all the problems. • Member Kott commented that the SFPUC now has a DEI (Diversity, Equity, and Inclusion) Director who oversees everything.

Chair Clary responded that it was hard to know where Diversity, Equity, and Inclusion fit in the budget, so she would check with the Full CAC Chair about that topic.
• Member Nagengast asked when should demand projections be discussed.

Chair Clary responded that the Urban Water Management is done every five years, so the next iteration of it would be in 2025. She then noted the priorities for the 2023-2024 fiscal year. Chair Clary commented that Jacuzzi will oversee the SF Groundwater Project, Perszyk will oversee Infrastructure and the Water Capital Plan, Kott will oversee Hiring Practices/Labor Force Turnover, Nagengast will oversee Demand Projections, and all the Water Subcommittee members except for Chair Clary and Sandkulla will focus on the Bay Delta Plan and Voluntary Settlement. Lastly, Chair Clary noted that it should be a priority to have Assistant General Manager Steve Ritchie

present to the Water Subcommittee on budget and the Water Enterprise’s priorities.

Public Comment:
• Dave Warner commented that the sensitivity analysis with the BAWSCA Demand Study is fascinating, and it would be great to have the SFPUC do it as well. He noted that it is a big ask for Water Subcommittee members to watch the Bay Delta Plan hearings and recommended having the SFPUC and the NGOs (non-governmental organization) present to the Water Subcommittee instead.

7. Staff Report
• No report from Staff
Public Comment: None

8. Future Agenda Items and Resolutions
Standing Subjects
• Groundwater
• Water Quality
Specific Subjects
• Tribal Land Acknowledgment Resolution – tentatively October • AGM Steve Ritchie Visit – tentatively October
• BAWSCA Demand Projections – tentatively October
• Emergency Firefighting Water System Update - Sept. Full CAC Topic • Affordability – Tentatively Full CAC topic
• Green Infrastructure - Tentatively WW Topic
• Integrating Tribal Leaders into SFPUC Land Management Decisions • State Board Water Rights
• Water Enterprise Environmental Stewardship Policy Implementation Report
• Debate about Bay Delta – Member Sandkulla suggested everyone watch the February 5, 2021, Commission workshop about the Voluntary Agreement
• COVID and Long-term Affordability Program
• Implementation if the Bay Delta Plan Flow Requirement • Hetch Hetchy Water and Power Division Update
• State Policy and Programs on Affordability or Low-Income Rate Assistance (LIRA)
• Bay Delta Plan and voluntary settlement agreement
• Legislative Update
• State of the Regional Water System Report – Bi-annual report • Drought resilience: 3-year water supply update
• Water Equity and Homelessness
• State of Local Water Report
• Retail Conservation Report
• Harry Tracy Water Treatment Plant tour
Adopted Resolutions for Follow Up
• Resolution in Support of a Resilient Water Supply adopted August 17, 2021
• Resolution in Support of the Southern Skyline Boulevard Ridge Trail Extension Project adopted April 20, 2021

• Resolution in Support of Interim Emergency Rate Assistance Program and Revised Community Assistance Program adopted July 21, 2020 • Resolution in Support of Improved Communications Related to the San Francisco Groundwater Supply Project adopted August 21, 2018 • Resolution in Supporting Stewardship and Public Access in the Redeveloped Lake Merced West Property adopted in March 15, 2016 • Resolution on Impacts of Drought on System Maintenance and Improvements adopted January 19, 2016
Public Comment: None

9. Announcements/Comments Please visit www.sfpuc.org/cac for final confirmation of the next scheduled meeting, agenda, and materials. • Member Jacuzzi commented that the SFPUC website should list specific dates for when CAC meetings are held.
• Chair Clary commented that the CAC should consider a different location to hold their meetings.

Public Comment:
• Peter Drekmeier commented that at the recent Commission meeting, Commissioner Ajami recommended moving general public comment back to the beginning of the meeting.

10. Adjournment
Motion was made (Kott) and seconded (Jacuzzi) to adjourn the meeting.

Meeting was adjourned at 7:18 pm.

Response to Comment Letter M
SFPUC Citizens’ Advisory Committee Water Subcommittee
August 29, 2023
M-1 The AWS Plan has a regional focus and assumes that WSIP projects are completed as part of the baseline scenario. Recommendations 1 and 6 in Chapter 6 are aimed at ensuring the completion of groundwater projects that were initiated under WSIP, to avoid wide ning the future supply gap. The focus of the AWS Plan is on how to address the resulting supply shortfall in future dry years if the Bay -Delta Plan Amendment is implemented. Of the six regional projects described in detail in Chapter 5 of the AWS Plan, the Daly City Recycled Water Expansion project provides dry year groundwater supply in the Westside Basin.

M-2 During the meeting, SFPUC staff responded that the AWS Plan primarily uses in -city retail demand from the SFPUC’s 2020 UWMP.

M-3 Projects included in the AWS Plan are largely in the early planning stages. Rather than providing a subjective ranking without comparable level of detail, the AWS Plan aims to present the information as it is known in Chapter 5. While there isn’t a ranking, several criteria are described for each project including: infrastructure needs, water supply availability and distribution, institutional complexity, operational considerations, staffing and workforce development, alternatives, and cost. Pros and cons are included for each project, along with a project schedule and recommendation.

There are two storage projects included in the list of AWS Projects. One provides water in an area where the SFPUC doesn’t currently have supply or delivery infrastructure and the other is the expansion of one of our reservoirs to hold more drought supply. In both cases, more storage provides incremental dry year supply. However, the majority of projects are purified water projects. In parallel to the regional purified water projects, the SFPUC is also pursuing a purified water project in San Francisco. Fro m a purified water standpoint, denitrification provides better feed water quality for advanced treatment in San Francisco and for regional projects.

Regarding the role of stressors in water supply planning, a new Recommendation 5 has been added to Chapter 6 that will enable the SFPUC to explore revisiting its retail demand modeling.

In that process, the SFPUC will consider a sensitivity analysis. Results of this analysis would be included in an AWS Plan update in 2026.

M-4 The yield of each project shown in Table 5 -1 is the dry year water supply that the SFPUC can expect from that project. The yield is intended to fill a gap that results from less water available to customers in dry years and is a 1:1 ratio.

M-5 During the meeting, the SFPUC responded that projects in the AWS Plan are intended to provide water that is not available from the Tuolumne watershed in dry years.

M-6 The yield of the projects or “SFPUC Supply Assumed” shown in Table 5 -1 represents the estimated volume of water that the SFPUC can receive from AWS Projects to help fill the water

supply gap. The gap assumes an estimated volume of water that is released for fishery and environmental purposes.

M-7 See response to Comment M-6.

M-8 The SFPUC is not currently considering changes to the design drought. See Global Response 2 for additional information.

M-9 Local water supplies would be projects that can replace RWS deliveries, particularly in dry years.

Examples include local purified water, desalination, or groundwater banking projects.

M-10 Staff responded that the 10% rule in the draft Direct Potable Reuse regulations has to do with mixing and only applies over a 24-hour period.

M-11 Staff responded that location would dictate what potential there could be for local water supply development and noted that the SFPUC continues to explore new dry year water supply opportunities that are feasible.

M-12 Staff responded that the SFPUC did a study for the Daly City Recycled Water Project to look at indirect potable reuse potential from that project. This work found that there was not sufficient space for the required additional treatment and that there were not sufficient well sites. If these items can be resolved, IPR potential from that project can be reconsidered.

M-13 The future opportunity to reconsider purified water is included under “Project Alternatives” for the Daly City Recycled Water Expansion project in Chapter 5.

M-14 The SFPUC’s production capacity for purified water on the west side of San Francisco is limited by available source water and permit regulations from the Oceanside Treatment Plant and is approximately 5 mgd. Staff noted that the Southeast Treatment Plant, while not connected to the Westside Basin, has a larger purified water potential of up to 38 mgd according to the SF Purified Water Opportunities Study in San Francisco.

M-15 Comparing past deliveries with previously projected demands is a task that will be undertaken as part of a new demand forecasting analysis that is included as Recommendation 5 in Chapter 6 of the AWS Plan. Tracking that data, potentially recalibrating the retail demand model, and coordinating with BAWSCA to analyze wholesale demand projections will help inform future AWS investment decisions and will be included in updates to the AWS Plan in 2026.

M-16 See response to Comment M -15. A comparison of demand projections versus purchases will be considered in the recommended demand modeling update for the AWS Plan.

M-17 Affordability and financial analysis of the AWS Projects will be a key planning issue as more project information becomes available. The AWS Plan identifies this as a priority area of focus in the next three years of program development.

M-18 The SFPUC has included a new Recommendation 5 in Chapter 6 of the AWS Plan to review and explore ways to revise its retail demand forecasting. Further, the SFPUC is committed to working with BAWSCA to also review demand projections for Wholesale Customers. While some demand uncertainty is inevitable, developing likely scenario(s) can help account for a range of potential outcomes in planning. Under the heading “Project and Programmatic

Recommendations” in the Executive Summary, the AWS Plan notes the need to continue to update water availability and demand projections and take a stepwise approach to recommending investments in AWS Projects.

M-19 Comment noted.

San Francisco Public Utilities Commission
August 31, 2023
Re: Comments on the Draft Alternative Water Supply Plan

BOARD OF DIRECTORS
Roger Williams, Chair
Virginia Johannessen, Vice- Chair
Peter Van Kuran, Treasurer
Mark Palley, Secretary
Kathy Bowler
Mark Cederborg
James Fousekis
Ann Hayden
Lance Olson
Craig Reynolds
Lucho Rivera
Mecia Serafino
Melanie Webber
STAFF
Spreck Rosekrans
Executive Director
Julene Freitas
Office Manager
Marissa Leonard
Engagement and Development
Director
3286 Adeline St. Suite 7
Berkeley, California 94703
510.893.3400
Tax ID # 77-0551533
San Francisco Public Utilities Commission
August 31, 2023
Re: Comments on the Draft Alternative Water Supply Plan Restore Hetch Hetchy appreciates the opportunity to provide comments on the San Francisco Public Utilities Commission’s Draft Alternative Water Supply Plan.

Moreover, Restore Hetch Hetchy respects and honors the work of both the Commission and staff in providing reliable water to customers in San Francisco and other cities in the Bay Area.

Fundamentally, the Draft Alternative Water Supply Plan, with the exception of Calaveras Reservoir, considers only modest additional supplies. Additional elements should be added to ensure the SFPUC will be able to meet customer needs in the years and decades to come.

The Alternative Water Supply Plan should consider both groundwater banking and recycling. These are alternatives that water agencies throughout California have been pursuing successfully in recent years, but are inexcusably missing in the Draft Alternative Water Supply Plan.

Groundwater banking is by far the most cost-effective large-scale alternative.

SFPUC staff knows this. BAWSCA staff knows this. There are willing partners in Stanislaus County. What is missing is the prospective cooperation of the Turlock and Modesto Irrigation Districts. SFPUC Commissioners and staff should both reach out to the Districts and determine together how to work cooperatively on a groundwater banking program. Failure to do so will result in the inability to capture water in wet years, as well as contribute to California’s long-term groundwater over- draft problem.

Recycling, especially converting wastewater at the San Francisco Public Utilities Commission’s Southeast Treatment plant, also has the potential to produce significant “droughtproof” supplies far in excess of other alternatives. While recycling is an expensive alternative, it would improve water quality in San Franciso Bay, helping to avoid catastrophes like the 2022 “fish kill” caused by an algae bloom in the Bay.

N-1
N-2
N-3

San Francisco Public Utilities Commission
August 31, 2023
Re: Comments on the Draft Alternative Water Supply Plan

The San Francisco Public Utilities Commission’s own analysis shows that the projects presently included in the will not mitigate the projected shortfall if the Bay-Delta Plan is implemented as adopted by the State Water Board. The analysis appears to assume that the final form of the Bay- Delta Plan will impose lesser challenges to its system – an assumption that has obvious inherent risks.

Furthermore, the San Francisco Public Utilities Commission should consider that public support for restoring Hetch Hetchy Valley may well require the water supply function of Hetch Hetchy Reservoir to be replaced. While that outcome is by no means certain, prudent planning should consider the prospect and how the system would operate without storing water in Yosemite National Park.

Failure to consider potential substantial changes to system operations, whether initiated by environmental interests or other factors, carries inherent risks. The San Francisco Public Utilities Commission should expand the elements of the Draft Alternative Water Supply Plan, at a minimum, to include groundwater banking in Stanislaus County and recycling at the Southeast Treatment Plant.

For a short summary of recent and ongoing groundwater banking and recycling projects, see Yosemite's Opportunity: Options For Replacing Hetch Hetchy Reservoir – attached to this letter.

Restore Hetch Hetchy is prepared to assist the San Francisco Public Utilities Commission in these endeavors.

Sincerely,

Spreck Rosekrans
Executive Director

N-4
N-5
N-6

Yosemite's Opportunity
Options For Replacing Hetch Hetchy Reservoir
“The ultimate removal of the reservoir would
make possible the restoration of the Valley a few
miles from Yosemite Valley and, amazingly, a
near twin of that extraordinary gift of nature.

In the case of Hetch Hetchy, it isn’t that San
Francisco’s water supply now stored at the
O’Shaughnessy Dam will be lost. Rather,
it would be stored at existing dams
downstream and perhaps off-stream or
in groundwater basins.”
— Carl Boronkay
Former General manaGer oF the
metropolitan Water DistriCt oF southern CaliFornia
O’ShaughneSSy Dam anD
hetch hetchy ReSeRvOiR
Hetch Hetchy Reservoir is a storage tank — one of four reservoirs on the Tuolumne River and one of nine in San Francisco’s Regional Water System. Hetch Hetchy is not a source of water.

The reservoir can be replaced and Hetch Hetchy Valley restored while continuing to meet 100% of the water and power needs of every community that depends on the Tuolumne River.

California water agencies have found many ways to reverse environmental damage, restoring ecosystems and wildlife populations on rivers and in wetlands — in the Central Valley, at Mono Lake, in the Bay-Delta and on the Trinity River. The same can be done for Yosemite’s Hetch Hetchy Valley.

The recent investments that California’s cities have made in groundwater, recycling and local surface storage would replace Hetch Hetchy Reservoir more than 15 times over . The San Francisco Public Utilities Commission has the opportunity to pursue any or all of these technologies.

Customer Demand
Annual Supply
(Average)
Annual Supply
(Drought)
Storage
Photo: Level Par
Photo: Tim Connor
YOSEMITE'S OPPORTUNITY Options For Replacing Hetch Hetchy Reservoir 1 The San Francisco Public Utilities Commission delivers about 250,000 acre-feet1 of water annually. Flows in the Tuolumne River are more than adequate to meet that demand in
most years.2
In dry years, water is withdrawn from storage. The driest period on record for San Francisco’s Regional Water System is the 6-year drought from 1987–1992, when the Tuolumne River provided only 151,000 acre-feet per year.

To make up the shortage in a repeat of that drought lasting six years, or even a worse one, the SFPUC has invested in multiple storage projects to meet customer needs (see Figure 1).

The San Francisco Public Utilities Commission (SFPUC) performs an essential public service by delivering water to homes and businesses in San Francisco as well as to other Bay Area communities. Hetch Hetchy Reservoir is an important component of San Francisco’s Regional Water System — but it can be fully replaced, and then some, with alternative investments.

The San Francisco
Regional Water System
Customer Demand
Annual Supply
(Average)
Annual Supply
(Drought)
Storage
0 500,000 1,000,000 2,000,0001,500,000
Don Pedro Water Bank Bay AreaCherry-Eleanor Tuolumne RiverHetch Hetchy Bay Area Watersheds 1 One acre-foot equals 325,851 gallons, roughly enough to supply two households for a year. 2 References for this document can be found at hetchhetchy.org/yosemites-opportunity/ 3 Like all water agencies, the SFPUC also increases reliability with demand-side programs — by encouraging conservation and efficient use through a variety of regulations and incentives.

FIGURE 1
San Francisco Regional Water System: Demand, Annual Supply & Storage (acre-feet) Replacing Hetch Hetchy Reservoir requires additional
investments.3 Other urban water agencies throughout
California are actively continuing to invest in groundwater storage, local surface storage, and recycling. The SFPUC can and should do the same.
2 YOSEMITE'S OPPORTUNITY Options For Replacing Hetch Hetchy Reservoir -5

RiveR anD WetlanD ReStORatiOn
Californians have supported ecosystem and wildlife renewal throughout the state, including restoration of rivers and wetlands in the Central Valley, at Mono Lake, in the Bay-Delta and on the Trinity River. Affected water agencies have found ways to invest in additional supplies and/or use water more efficiently.

Restoration of Hetch Hetchy Valley in Yosemite National Park would require system improvements to replace 360,000 acre-feet of storage (or 60,000 acre-feet each year over a 6-year drought). Water flowing through Hetch Hetchy Valley would be used or captured downstream — it would not go to waste.

Mono Lake
Trinity &
Lower Klamath Rivers
Upper
Sacramento River
Gray Lodge
Wildlife Area
San Luis
National Wildlife
Refuge Complex
Los Banos
Wildlife Area
Kern National
Wildlife Refuge
Volta
Wildlife Area
Grassland Resource
Conservation District
Merced National
Wildlife Refuge
Pixley National
Wildlife Refuge
Mendota Wildlife Area
North Grasslands
Wildlife Area
Sacramento
National Wildlife
Refuge Complex
Sacramento NWR
Delevan NWR
Colusa NWR
Sutter NWR
San Luis Unit
West Bear Creek Unit
East Bear Creek Unit
Kesterson Unit
Freitas Unit
China Island Unit
Salt Slough Unit
Bay Delta
The Central Valley Project Improvement
Act, enacted by Congress in 1992, added
250,000 acre-feet per year to wildlife
refuges in the Central Valley.

The 1994 Bay-Delta Accord, an agreement
to protect endangered estuarine /f_ish
including long/f_in smelt, reduces
diversions to cities and farms by 316,000
acre-feet per year below previous levels.

The Trinity River Restoration program,
jointly developed by the federal
government and the Hoopa Valley Tribe,
restores /f_low to the river, reducing
diversions to cities and farms by 83,000
acre-feet per year.

Court rulings in 2007 and 2008 to protect
endangered salmon and other species
have reduced diversions to cities and
farms by 980,000 acre-feet per year.

In 1994, the State Water Board ruled
that the Public Trust Doctrine required
additional in/f_low to Mono Lake,
resulting in reduced diversions to Los
Angeles by 46,000 acre-feet per year.

San Jose
Sacramento
Los Angeles
San Diego
Y osemite National Park
Hetch Hetchy
San Francisco
YOSEMITE'S OPPORTUNITY Options For Replacing Hetch Hetchy Reservoir 3 califORnia gROunDWateR inveStmentS
Many California cities have agreements with agricultural water agencies to recharge and manage groundwater, allowing aquifers to be used as "banks" to exchange supplies using California's vast network of canals. California’s “Sustainable Groundwater Management Act”, passed in 2014, requires long-term sustainability throughout the state and provides incentives for additional agreements.

Banking San Francisco’s excess water in aquifers in the eastern portions of the Turlock and Modesto Irrigation Districts and in the Eastside Water District would replace the storage function of Hetch Hetchy Reservoir.

California
Aqueduct
Santa Clara Valley
Water District
Alameda County
Water District
Modesto
Irrigation District
Turlock
Irrigation District
Eastside
Water District
EBMUD
Metropolitan Water District of
Southern California
Mojave Water Agency
Antelope Valley
Water District
Semitropic
Water Storage District
Arvin-Edison
Water Storage District
Kern Delta
Water District
The Metropolitan Water District of
Southern California, serving most of
urban southern California, manages
212,000 acre-feet of groundwater
storage within its service territory, and
banks 350,000 acre-feet in Semitropic,
350,000 acre-feet in Arvin Edison,
250,000 acre-feet in Kern Delta, 330,000
acre-feet in Mojave and 30,000
acre-feet in Antelope Valley.

Examples of similar programs abound.

Several Bay Area water districts bank
groundwater in Semitropic, including
Santa Clara Valley (350,000 acre-feet),
Alameda County (150,000 acre-feet)
and Zone 7 (65,000 acre-feet).

Operating a groundwater bank in
Stanislaus County in conjunction with San
Francisco’s surface storage facilities
would eliminate the need for Hetch
Hetchy Reservoir and allow Hetch Hetchy
Valley in Yosemite National Park to be
restored. Groundwater plans in these
areas show unsustainable pumping rates
that limit farm production over time. Wet
year recharge with San Francisco’s water
would provide bene/f_its to all parties.

Geology and proximity to the California
Aqueduct make Kern County an ideal site
for groundwater recharge. Urban water
agencies bank groundwater in Semitropic
(970,500 acre-feet), Arvin Edison
(350,000 acre-feet), Kern Delta (250,000
acre-feet) and other aquifers.

Option available to the San Francisco
Public Utilities Commission
San Francisco
San Jose
Sacramento
Los Angeles
San Diego
Y osemite
National Park
San Francisco
4 YOSEMITE'S OPPORTUNITY Options For Replacing Hetch Hetchy Reservoir Recycling WateR in califORnia
Increases in demand, limits on groundwater pumping and worries of drought have led to a boom in wastewater recycling projects — in California as well as other states and countries.

While Orange County has long been a recycling leader, others are catching up quickly. Most of California’s large urban agencies have initiated robust recycling plans, but so far San Francisco has not. Recycled water provides a reliable, drought-proof supply, and the enhanced treatment process reduces pollution to rivers, bays and beaches.

Replacing the water storage function of Hetch Hetchy Reservoir could be accomplished by recycling 60,000 acre-feet per year (360,000 acre-feet over a 6-year drought).

San Diego’s PureWater program is
scheduled to provide a third of its total
supply (83,000 acre-feet per year, or
498,000 acre-feet over a 6-year
drought), and will also reduce pollution
along its famous beaches. San Diego will
store its recycled water locally in
Miramar and San Vicente Reservoirs.

The Orange County Water District
recycling plant is the largest in the world.

It presently recycles 100,000,000 gallons
per day — soon to be increased to
130,000,000 gallons per day (146,000
acre-feet per year or 876,000 acre-feet
over a 6-year drought). After a multi-step
treatment process which includes
nano/f_iltration (shown above), the water
is stored underground.

The San Francisco Public Utilities
Commission reports a capacity to recycle
49,000 acre-feet per year ( 294,000
acre-feet over a 6-year drought) at its water
treatment plants but has no plans to move
forward at this time. San Francisco’s
wholesale customers, who use 2/3 of the
system’s water, operate their own treatment
plants and have similar opportunities.

The Santa Clara Valley Water District plans
to recycle 40,000 acre-feet per year
(240,000 acre-feet over a 6-year drought)
by 2035, about 10% of its supply.

Governor Newsom praises the Los
Angeles County Sanitation District’s
recycling plan, describing it as a model
for others to follow. When completed, the
plant will produce 168,000 acre-feet per
year of recycled water (1,008,000
acre-feet over a 6-year drought).

Option available to the San Francisco
Public Utilities Commission
Orange County
Water District
Sanitation District of
Los Angeles
San Diego
Water Agency
Santa Clara Valley
Water District
San Diego
Water Agency
Sacramento
Los Angeles
San Diego
San Jose
Y osemite
National Park
San Francisco
San Francisco
YOSEMITE'S OPPORTUNITY Options For Replacing Hetch Hetchy Reservoir 5 DevelOping lOcal StORage in califORnia
Today, most of California's major rivers are either already dammed, protected by law, or too remote to be economically developed.

Many water agencies have, however, found advantage in building “off stream” reservoirs close to their service areas to assure supply reliability during dry years. These reservoirs are built in canyons with little natural flow, avoiding the damage of damming a large river.

San Francisco has long-term plans to enlarge Calaveras Reservoir, allowing it to hold imported Tuolumne River supplies as well as local runoff. Enlarging Calaveras would replace 90% of the 360,000 acre-feet of water storage that Hetch Hetchy Reservoir provides.

In 2009, San Diego enlarged San
Vicente Reservoir to 242,000 acre-feet.

It not only holds runoff from San
Vicente Creek, but also water supplies
diverted from the Colorado River.

Diamond Valley Reservoir, /f_irst /f_illed in
2003, holds up to 800,000 acre-feet of
water for customers of the Metropolitan
Water District of Southern California.

Above, Metropolitan General Manager
Jeff Kightlinger dedicates a dam at
Diamond Valley in honor of his visionary
predecessor, Carl Boronkay. Boronkay
called Hetch Hetchy Valley a “national
treasure” and, after retirement, joined the
Restore Hetch Hetchy Board of Advisors.

Calaveras Reservoir, the largest of the San
Francisco Public Utilities Commission’s Bay
Area reservoirs, was rebuilt in 2019 and
presently holds 97,000 acre-feet. The
SFPUC has plans to increase its capacity by
323,000 acre-feet (almost the volume of
Hetch Hetchy Reservoir). Some of the
foundation work to support this larger
project has already been accomplished.

Los Vaqueros Reservoir, initially
constructed by the Contra Costa Water
District in 1998, was expanded in 2012 to
hold 160,0000 acre-feet of water. It will
be expanded further, and San Francisco
should consider taking part in the project.

Option available to the San Francisco
Public Utilities Commission
Metropolitan Water District of
Southern California
Diamond Valley
Reservoir
San Diego County
Water Authority
San Vicente
Reservoir
Contra Costa
Water District
Los Vaqueros
Reservoir
Calaveras
Reservoir
San Jose
Sacramento
Los Angeles
San Diego
Y osemite
National Park
San Francisco
San Francisco
6 YOSEMITE'S OPPORTUNITY Options For Replacing Hetch Hetchy Reservoir FIGURE 2
Summary of Recent and Ongoing Water Storage and Supply Projects for Cities in California

AVAILABLE WATER SUPPLY OVER A SIX-YEAR DROUGHT (ACRE-FEET) Surface Storage
Recycling
Groundwater
Needed to Replace
Hetch Hetchy Reservoir
0 Contra Costa
San Francisco
San Diego
Southern California
Southern California
Orange County
Valley Water
San Diego
Los Angeles
Bay Area
200,000 400,000 600,000 800,000 1,000,000 1,200,000
Recent investments by California’s cities in groundwater, recycling and local surface storage would replace Hetch Hetchy Reservoir more than 15 times over. The San Francisco Public Utilities Commission has the opportunity to pursue any or all of these technologies. aDDitiOnal neceSSaRy impROvementS
While water storage and/or supply are the most obvious system improvements necessary to restore Hetch Hetchy Valley in Yosemite National Park, other steps must be taken as well. • Replace 350 gigawatt-hours of electricity that will be lost when water from Hetch Hetchy Reservoir will no longer
generate hydropower at the Kirkwood Powerhouse in
summer and fall;
• Expand the Sunol Water Treatment Plant so the San
Francisco Regional Water System has capacity to filter all system supplies; and
• Build new interties to connect Cherry and/or Don
Pedro Reservoir to existing pipelines crossing the San
Joaquin Valley.

Plans to remove the reservoir while maintaining water and power supplies have been proposed in a variety of reports by government agencies, environmental groups and academics.

The estimated costs in the various reports of restoring Hetch Hetchy Valley without loss of water or power have been the subject of public disagreement but have never been independently reviewed.

Restore Hetch Hetchy’s most recent cost estimate, published in a 2015 Superior Court filing, projects a cost of 2 billion dollars over a fifty year period, including 199 million dollars for additional interties, 372 million dollars for water supply, 387 million dollars for water treatment, 669 million dollars for renewable electric power, and 374 million dollars for modifying O’Shaughnessy Dam.
cRitical StakehOlDeRS
The Turlock and Modesto Irrigation Districts are intertwined with the SFPUC on the Tuolumne River and at Don Pedro Reservoir. A restoration plan must guarantee, at a minimum, that the Districts suffer no loss of water supply or hydropower production.

Tribal communities were the original inhabitants of Hetch Hetchy. Indigenous peoples must be consulted in all stages of restoration and, if they desire, should be involved in the future management of the valley.

Rafters and kayakers flock to the Tuolumne River for its world-class whitewater. A restoration plan should assure recreational flows are protected.

The Bay-Delta Plan — Restore Hetch Hetchy supports the State’s ongoing effort to improve flows and habitat for fish and wildlife on the Tuolumne River below Don Pedro Reservoir, as well as downstream into the Bay-Delta.

Photo: Sierra Mac River Trips
YOSEMITE'S OPPORTUNITY Options For Replacing Hetch Hetchy Reservoir 7 Restore Hetch Hetchy urges the
San Francisco Public Utilities Commission
to pursue system improvements so
Hetch Hetchy Reservoir can be replaced
without any loss of water supply or electric
power production.

Hetch Hetchy, Yosemite Valley's lost twin, can be returned to its natural splendor; a majestic glacier-carved valley with towering cliffs and waterfalls where river and wildlife run free.

Hetch Hetchy can be a new kind of national park, with limited development, an improved visitor experience, shared stewardship with Native peoples, and permanent protection of its natural and cultural heritage for future generations.

RESTORE HETCH HETCHY

BOARD OF DIRECTORS
Roger Williams, Chairman
Virginia Johannessen, Vice-Chairman
Peter Van Kuran, Treasurer
Mark Palley, Secretary
Kathy Bowler | Mark Cederborg | James Fousekis
Ann Hayden | Rex Hime | Lance Olson | Craig Reynolds
Lucho Rivera | Mecia Serafino | Melanie Webber
STAFF
Spreck Rosekrans, Executive Director
Julene Freitas, Office Manager
Mike Gaffney, Community Outreach Liaison
3286 Adeline St., Suite 7, Berkeley, CA 94703 | 510.893.3400 | Tax ID # 77-0551533 HetchHetchy.org
Yosemite's Opportunity
Options For Replacing Hetch Hetchy Reservoir
Restore Hetch Hetchy urges
San Francisco, the State of California and
the United States Congress to return
Hetch Hetchy Valley to all people.
“The Bay Area does not need Hetch Hetchy
reservoir to continue delivery of high-quality
water from the Tuolumne River.”
— Jay lunD
proFessor oF Civil anD environmental enGineerinG anD
Co-DireCtor oF the Center For WatersheD sCienCes at uC Davis Painting: Tom Coyle
8 YOSEMITE'S OPPORTUNITY Options For Replacing Hetch Hetchy Reservoir

Response to Comment Letter N
Restore Hetch Hetchy
Spreck Rosekrans, Executive Director
August 31, 2023
N-1 The SFPUC agrees that groundwater banking as well as recycled and purified water can be critical components of the AWS Program. The AWS Plan includes three purified water projects and one recycled water that provides an opportunity to increase groundwater storage for dry year supply. Additionally, Recommendation 3 has been updated to specifically refer to groundwater banking in the San Joaquin Valley.

N-2 See Global Response 4 for information related to partnering efforts with irrigation districts in the Central Valley.

N-3 The SFPUC agrees that purified water has great potential to address the water supply gap.

Three of the six projects included in the AWS Plan involve purified water. While outside the scope of the AWS Plan, the SFPUC is also looking at opportunities for pur ified water in San Francisco, including at SFPUC's Southeast Treatment Plant, in its capacity as San Francisco's water supplier.

N-4 The comment correctly notes that the AWS Projects presented in the AWS Plan do not fully resolve the projected supply gap in future dry years. In addition to tracking and reporting on developments of the Voluntary Agreement negotiations in Recommendation 3 , Recommendation 15 aims to incentivize local supplies to reduce demands on the RWS.

Additionally, the SFPUC remains open to other water supply projects and continues to pursue opportunities as they arise.

N-5 Comment noted. The SFPUC is not considering the loss of water supply from Hetch Hetchy Reservoir at this time.

N-6 See Global Response 4 for more information related to partnering efforts with irrigation districts in the Central Valley . Purified water with water from the Southeast Treatment Plant and Oceanside Treatment Plant is currently being planned through the SFPUC’s local water program.