BAY DELTA PLAN UPDATE: A deep dive into the staff report for the for the Sacramento Delta update: How do the voluntary agreements stack up?

On Friday, the State Water Resources Control Board will hold the first day of a three day public hearing on the draft staff report for the Sacramento Delta update to the Bay Delta Water Quality Control Plan.  The Board is accepting public comments on the report through December 15  January 19, 2024.

The report examines the potential economic, environmental, and other impacts of various options for updating the Bay Delta Plan, including the proposed voluntary agreements.  Curious to know how the staff proposal and voluntary agreements compare? In a workshop held on October 19 workshop, the State Water Board staff delved into the details of the report, discussing the background, key components, and modeling results for both the staff proposal and the voluntary agreements. This is essentially a transcript of the staff presentation.

Background on the State Water Board and the Regional Water Quality Control Boards

Diane Riddle, Assistant Deputy Director, began the presentation.  The State Water Board and the nine Regional Water Quality Control Boards have regulatory responsibility for protecting the water quality of California streams, rivers, lakes, bays, estuaries, and California’s coastline. The State Water Board is also responsible for allocating surface water rights, protecting the public trust and public interest, and preventing the waste and unreasonable use of water. These responsibilities are reflected in the board’s mission statement, which is to preserve, enhance, and restore the quality of California’s water resources and drinking water for the protection of the environment, public health, and all beneficial uses and to ensure the proper water resource allocation and efficient use for the benefit of present and future generations. These responsibilities all converge in the Bay-Delta, where the State Water Board must balance many responsibilities and interests.

Water quality control plans

State law requires that the State Water Board and the Regional Water Quality Control Boards adopt Water Quality Control Plans that include measures to protect water quality in the state’s streams, rivers, and lakes.  The State Water Board protects water quality in the Bay-Delta in part through its Bay-Delta Water Quality Control Plan, or Bay-Delta Plan for short. The Bay-Delta Plan identifies beneficial uses of water to be protected in the Bay-Delta, including municipal and industrial, agricultural and fish and wildlife, water quality and flow objectives to reasonably protect the beneficial uses, and a program of implementation to achieve the objectives, including actions that State Water Board will take, such as implementation of flow requirements, and actions the State Water Board will take with others or recommendations for others for actions they should take, such as habitat restoration. The Bay-Delta Plan also identifies monitoring and assessment measures to evaluate compliance and effectiveness of implementation actions.

The Bay-Delta Plan contains water quality objectives that are both narrative and numeric.  Narrative objectives describe the general water quality and flow conditions that must be attained through watershed management. They also serve as a basis for detailed numerical objectives. Numeric objectives are specific numbers, for example, cubic feet per second flow or percentage of unimpaired flow.

The Regional Water Quality Control boards adopt Water Quality Control Plans or basin plans to protect beneficial uses of water pursuant to state and federal law.  Two Regional Water Quality Control Board basin plans include water bodies in the Bay-Delta watershed. These basin plans are the Central Valley Regional Water Board’s Water Quality Control Plan for the Sacramento and San Joaquin River basins and the San Francisco Bay Regional Water Quality Control Board’s Water Quality Control Plan for the San Francisco Bay region. For water subject to the Clean Water Act, the beneficial use designations in these two basin plans serve as designated uses under the Clean Water Act, and the water quality objectives to protect those uses serve as criteria under the Clean Water Act.

The water quality standards for the Bay-Delta watershed are largely established in these two basin plans. The two regional water board basin plans serve as the water quality standard setting function of the Porter Cologne Act and the Federal Clean Water Act.

The State Water Board’s Bay-Delta Plan is a recognition that discharges of waste, including discharges regulated through National Pollution Discharge Elimination System (NPDES) permits and Waste Discharge Requirements for nonpoint source discharges, are not the only source of pollution affecting the Bay-Delta. The State Water Board is responsible for adopting and updating the Bay-Delta Plan to protect beneficial uses of water in the Bay-Delta watershed related to water diversions and operations.

Together, the Bay-Delta Plan and the two regional water board basin plans are intended to be complementary to one another and address the range of water quality and water diversion activities within the state and regional water boards implementation authorities that may impact beneficial uses of water, as well as identifying and including recommendations and actions by others to protect beneficial uses of water.  The state and regional water boards are required under California law and federal law to periodically review Water Quality Control Plans and to update these plans as needed.

Bay-Delta Plan

The map on the slide provides an overview map of the Bay-Delta watershed and the areas covered by the State Water Board’s Bay-Delta planning and implementation processes. The term Delta watershed includes the Sacramento and San Joaquin River systems, the Delta Suisun Marsh, and San Francisco Bay. The Sacramento and San Joaquin River systems, including their tributaries, drain water from about 40% of California’s land area, supporting a variety of beneficial uses of water.

The Bay-Delta is one of the most important ecosystems in California. As the largest tidal estuary on the west coast of the Americas, it supports a vast array of fish and wildlife in the Delta, San Francisco Bay, and near shore ocean, as well as a diverse assemblage of species upstream of the Delta. The Bay-Delta watershed is also an integral component of California’s water supply system for people and farms, as well as an essential part of the culture, religion, and way of life for numerous California Native American Tribes.

In response to the decline of several aquatic species since the Bay-Delta Plan was last comprehensively updated, the State Water Board is in the process of updating and implementing the Bay-Delta Plan to provide for the reasonable protection of native fish and wildlife. The Bay-Delta Plan is being updated and implemented, implemented through separate processes.

Lower San Joaquin River flow and Southern Delta salinity objectives

The State Water Board updated the Bay-Delta Plan’s lower San Joaquin River tributary flow and southern Delta salinity components in 2018. Efforts are currently underway to implement these updates and to consider a voluntary agreement on the Tuolumne River.

The blue oval on the slide identifies the general geographic scope of the Bay-Delta plan’s Lower San Joaquin River tributary flows and southern Delta salinity components. This geographic area generally covers the lower San Joaquin River, its three main tributaries, including the Stanislaus, Tuolumne, and Merced rivers, and the southern Delta.

Sacramento Delta watershed objectives

The State Water Board is currently in the process of considering updates to the portions of the Bay-Delta Plan covering the Sacramento River and the Delta. The blue oval on the slide identifies the general geographic scope of these updates, including the Sacramento River and its tributaries, the Delta east side tributaries, including the Cosumnes, Mokelumne, and Calaveras Rivers, and the Delta. This area is referred to as the Sacramento Delta watershed.

As documented in the State Water Board’s 2017 Scientific Basis Report in support of possible Sacramento Delta updates to the Bay-Delta Plan and the 2023 Scientific Basis Report Supplement in support of possible Voluntary Agreements, native aquatic species have undergone substantial population declines due to a variety of aquatic ecosystems stressors, including flow alterations, habitat loss, degradation of water quality, and prolonged droughts. The scientific basis report further documents that the existing provisions of the Bay-Delta Plan are not adequate to provide for the reasonable protection of Fish and Wildlife beneficial uses.

The Bay-Delta Plan update is intended to help address aquatic ecosystem stressors within the State Water Board’s responsibilities and improve environmental conditions to provide for the reasonable protection of Fish and Wildlife beneficial uses.

To give context for the existing provisions of the Bay-Delta Plan and what may be updated, the current provisions of the Bay-Delta Plan do not include inflow or cold water habitat requirements for most Sacramento Delta tributaries to ensure that adequate flow and outflows are provided in those tributaries and that those flows contribute to Delta outflows to provide for a connected and functioning ecosystem while ensuring that cold water habitat is protected. Where there are inflow requirements on the Sacramento River, they only apply in the fall.

In addition, existing Delta outflows are often significantly higher than the Minimum Required Delta Outflow, or MRDO. This is pursuant to the existing Bay-Delta Plan as implemented under Decision 1641.  While there are additional biological opinions and incidental take permit requirements that affect Delta outflows under current conditions, those requirements are largely not specific Delta outflow requirements but instead limits on exports by the State Water Project and Central Valley Project diversions in the interior Delta that only apply to those diversions. As such, flows could be diminished by other diversions in the future; they are not constrained by these restrictions.

The graphs on the slide show minimum required Delta outflows in orange, the baseline or existing flows in black, and observed flows in other colors. The difference between the MRDO line in the figure and the baseline flows represents existing flows that are not required under the Bay-Delta Plan that could be diminished in the future as a result of additional diversions in the absence of additional constraints.

The significant difference between these flow levels indicates that the Bay-Delta Plan flow requirements are not adequate to project existing Delta outflows during the critical winter and spring periods for native fish and wildlife species, except during the driest conditions. The State Water Board’s 2017 Scientific Basis report documents science that indicates that these minimum required Delta outflows are not protective of native fish species and that additional Delta outflows above these blue levels are needed to recover native fish species along with habitat restoration and other provisions. The draft staff report evaluates alternatives that would provide for varying levels of increased inflow, outflow, and related provisions.

Supporting documents for draft staff report

Nicole Williamson, Environmental Program Manager, then presented the draft staff report.  First, she provided background on previous activities that have been completed, leading to the development of the draft staff report for the Sacramento Delta update to the Bay-Delta plan.

Scientific Basis Report to support possible Sacramento Delta updates

The State Water Board issued a supplemental notice of preparation for updating the Sacramento River and Delta components of the Bay-Delta Plan in 2012. Between 2012 and 2016, the State Water Board conducted several activities to support and inform the Sacramento River and Delta updates to the Bay-Delta Plan, including several public technical meetings and workshops, undertaking a major process to develop the Sacramento Water Allocation Model (SACWAM) used to evaluate possible Sacramento Delta updates to the Bay-Delta Plan and developing the draft scientific basis report to document the science supporting possible Sacramento Delta updates.

The scientific basis report was released for public comment and reviewed by the Delta Independent Science Board. The report was revised in light of the input the State Water Board received. Then, it was independently peer-reviewed pursuant to the Public Health and Safety Code, which requires that the scientific basis of any statewide plan, basin plan, plan amendment, guideline, policy, or regulation undergo external peer review before adoption.

The final scientific basis report was released in 2017. The report identified the science supporting possible year-round inflows and temperature management measures for the Sacramento River, its tributaries, and Delta eastside tributaries; associated Delta outflows that would provide for required inflows in the Bay-Delta Plan to be provided as outflow; and interior Delta flows to prevent impacts to native fish from Delta water export operations.

Framework for the Sacramento Delta update

Following the development of the scientific basis report, in 2018, in advance of consideration of the lower San Joaquin River and southern Delta salinity updates to the Bay-Delta Plan, the State Water Board released a framework for the Sacramento Delta update that identified a staff proposal at that time for possible Sacramento Delta updates to the Bay-Delta Plan.

The framework identified a possible inflow objective for the Sacramento River and its salmon-bearing tributaries and Delta eastside tributaries, including the Calaveras, Cosumnes, and Mokelumne Rivers, calling for 55% of unimpaired flow with an adaptive range from 45 to 65% of unimpaired flow. Unimpaired flow is the flow that would accumulate in surface waters in response to rainfall and snow melt and flow downstream if there were no reservoirs or diversions to change the quantity, timing, and magnitude of flows.  Effectively, an unimpaired flow requirement would provide for a portion or percentage of the inflow to a river or stream, for example, 55%, to be left instream to support Fish and Wildlife, allowing remaining flows to be stored or diverted for consumptive uses for agriculture, municipal and other uses.

The framework includes flexibility to address specific tributary needs as well as possible voluntary implementation methods and a default implementation absent voluntary methods.  The identified flow levels would provide flows more often that meet flow thresholds indicated to support the recovery of key ecological indicator species as documented in the 2017 scientific basis report.

The adaptive range would allow for higher or lower flows based on specific tributary considerations. Specifically, higher flows may be required on tributaries that are already at higher levels, and these flows are needed to protect native fish and wildlife. Lower flows could be required if flows needed to be maintained in storage for temperature management. The range would also provide for lower flows in the event voluntary measures are implemented to restore habitat that achieves equivalent benefits.

In addition to inflows consistent with the scientific basis report, the framework identified cold water habitat provisions that would require tailored measures based on the specific needs within each individual tributary to ensure that reservoirs are operated in a manner that provides needed cold water habitat for salmonid or other measures to provide cold water habitat; inflow-based Delta outflows that would provide for required inflows in the Bay-Delta Plan from the Sacramento Delta tributaries and San Joaquin River to be provided as outflows; and Interior Delta flows to establish conditions in the interior Delta to reasonably protect native fish populations migrating through and rearing in the Delta, and science, monitoring, assessment, reporting, and other provisions.

The staff proposal identified in the 2018 framework is referred to in the draft staff report as the proposed plan amendments. While identified as the proposed plan amendments, all other alternatives evaluated in the draft stock report are also under consideration by the State Water Board, and the State Water Board has not made a decision on the actual changes to the Bay-Delta Plan. That decision will be informed by comments on the draft staff report and other information, as will be discussed later in this presentation.

Draft Scientific Basis Report Supplement in support of the Voluntary Agreements

Following the release of the 2018 framework in late 2022, during the completion of the draft staff report, the State Water Board received a memorandum of understanding or MOU signed by state and federal agencies and water users proposing voluntary agreements or VAs as a proposed means for updating and implementing the Bay-Delta Plan. The MOU is referred to as the VA term sheet in the draft staff report.

The VAs proposed flow and habitat restoration on several tributaries to the Delta and in the Delta that are intended to contribute to achieving a new narrative ecosystem protection objective proposed by the VA parties in the Bay-Delta Plan’s existing narrative salmon protection objective calling for the doubling of salmon populations which the VA proposes to contribute to achieving by 2050.

The State Water Board is not a signatory to the VA term sheet and has made no decision regarding whether to approve the proposed VAs, as will be discussed later. That decision will be informed by comments on the draft staff report and other information.

In January of 2023, State Water Board staff released a draft Scientific Basis Report Supplement in support of the proposed VAs for public review and comment. This report documents the science supporting the Sacramento Delta provisions included in the proposed VAs and supplements the 2017 scientific basis report. The scientific basis report supplement was developed in collaboration with staff from the California Department of Fish and Wildlife and the California Department of Water Resources. Following receipt of public comments, the draft was revised, and the final draft scientific basis report supplement is undergoing external scientific peer review pursuant to the requirements of the California Public Health and Safety Code, similar to the process that was taken for the 2017 scientific basis report.

Draft staff report

In September 2023, the State Water Board released the draft staff report. The draft staff report evaluates the potential benefits and environmental, economic, and other impacts and associated mitigation measures for possible alternatives for updating the Sacramento Delta portions of the Beta Delta Plan, including the proposed plan amendments and proposed VAs. The draft staff report also assesses other standalone and modular alternatives that may be considered by the State Water Board.

The proposed VAs include a combination of flow and non-flow habitat restoration measures on the Sacramento, Feather, American, Yuba, and Mokelumne Rivers, and Putah Creek and in the Delta proposed by water users in the watershed. The VAs also include a proposal for the Tuolumne River, which is being considered separately and is not being considered for approval in this draft staff report. However, the possible additive benefits to Delta outflows from the Tuolumne River VA are analyzed in the draft staff report and VA scientific basis report supplement.

If approved by the State Water Board, the State Water Board would take action to protect the VA flows from diversion by others consistent with applicable water rights provisions.

As indicated previously, the VAs propose that the flow and non-flow habitat restoration measures would be implementation measures for a proposed new narrative objective to achieve the viability of native fish populations and implementation of the participating parties’ share during the term of the VAs to contribute to the existing narrative objective to double salmon populations by 2050.

The proposed VAs also include governance and science programs to direct flows and habitat restoration, conduct assessments, and develop strategic plans and annual reports. By the end of the year, the VA parties also plan to submit to the State Water Board drafts of flow accounting procedures, a global agreement, enforcement and implementing agreements, and a governance charter.

The VAs propose an initial eight-year term. If approved by the board and shown to be effective, the term could be extended or modified. If the proposed VAs are not found to be effective, through a process laid out in the VA documents, a regulatory pathway could apply after the board takes certain steps.

The draft staff report identifies a staff-proposed regulatory pathway consistent with the flows identified in the 2018 framework and proposed plan amendments. The draft staff report also assumes the regulatory pathway would apply to non-VA regions.

The draft staff report includes scientific information and environmental and economic analyses to support Sacramento Delta updates to the Bay-Delta Plan, including impact and benefit assessments. The report assesses a range of alternatives, including the proposed plan amendments based on the 2018 framework document, identifying a 55% of unimpaired flow level, with an adaptive range from 45 to 65% for Sacramento Delta tributaries and associated Delta outflows and a proposed VAs alternative that includes voluntary water contributions and physical habitat restoration on major tributaries to the Delta, as well as other project alternatives. The other alternatives being considered are described in more detail in subsequent slides.

In addition, based on input from California Native American Tribes, the draft staff report identifies the proposed incorporation of Tribal and subsistence fishing beneficial uses of water to the Bay-Delta Plan. As described in chapter 11 of the draft staff report, incorporation of the Tribal beneficial uses into the Bay-Delta Plan is not proposed as a formal designation of the uses as applying to specific water bodies or water body segments within the Bay-Delta watershed.  California’s Porter-Cologne Water Quality Control Act envisions that most Water Quality Control Planning will be accomplished on a regional hydrologic basis by the regional water boards. Additional work and collaboration are needed among the Tribes, the State Water Board, and the regional water boards to define the proper scope and identify the effects of formal designations as applicable to the geographical area of the Bay-Delta watershed, which the state and regional boards are working to expedite.

CEQA compliance

The draft staff report is also a substitute environmental document that fulfills the requirements of the California Environmental Quality Act, or CEQA. Under the State Water Board’s CEQA regulations, the Board’s public release of the draft staff report provides interested parties the opportunity to make oral and written comments on the analyses to inform any needed additions or changes to those analyses. Public input on the draft staff report, peer review of the scientific basis report supplement for the VAs, and the additional VA documents will inform the State Water Board’s planning processes and eventual consideration of the adoption of potential Sacramento Delta updates to the Bay-Delta Plan.

When approving a discretionary project, state agencies must comply with CEQA. CEQA’s basic purposes are to inform governmental decision-makers and the public about the potentially significant environmental effects of proposed activities, identify ways that environmental damage can be avoided or significantly reduced, and prevent significant avoidable damage to the environment by requiring changes in projects through the use of alternatives or mitigation measures when the government agency finds the changes to be feasible.

The State Water Board adopts Water Quality Control Plans as part of a certified or regulatory program under CEQA. Certified regulatory programs are exempt from CEQA’s requirements for preparing an environmental impact report, negative declaration, or initial study. Accordingly, the State Water Board may prepare a substitute environmental document that meets the requirements of CEQA. The entire staff report can be considered a substitute environmental document that fulfills the requirements of CEQA and the State Water Board CEQA regulations to analyze the environmental effects of the proposed regulatory activity as well as other applicable requirements.

Other requirements

In addition to CEQA’s requirements, the State Water Board’s amendments to the Bay-Delta Plan must be prepared in accordance with applicable water quality planning provisions of the Porter-Cologne Water Quality Control Act or Porter-Cologne Act, water code, and other applicable laws. Section 13241 of the Porter-Cologne Act identifies certain factors that must be considered when establishing water quality objectives. These factors include past, present, and probable future beneficial uses of water, environmental characteristics of the hydrographic unit under consideration, including the quality of water available, water quality conditions that could reasonably be achieved through the coordinated control of all factors that affect water quality in the area, economic considerations, the need to develop housing within the region and the need to develop and use recycled water. The draft staff report discusses these factors with respect to the Sacramento Delta updates to the Bay-Delta Plan, including under the proposed plan amendments, proposed VAs, and other project alternatives.

The executive summary, which is Chapter 1 of the staff report, provides a list of the locations within the draft staff report where these discussions are primarily located. The factors are an inherent part of the analysis presented for decision-makers to understand the effects not only on the environment but also on other beneficial uses of water, economics, and other important considerations like the human right to water. Climate change is another relevant factor that is also considered, though it is not specifically identified in water code section 13241.

Watershed, plan area, and study area

The State Water Board is considering amendments to the Bay-Delta plan focused on flow and related measures in the Sacramento River and its tributaries, Delta eastside tributaries, including the Cosumnes, Mokelumne, and Calaveras Rivers, Delta, and interior Delta in order to reasonably protect fish and wildlife beneficial uses. This area is referred to as the Sacramento Delta watershed or Sacramento Delta.

The draft staff report also identifies a plan area and a study area.

The plan area includes the Sacramento Delta watershed and continues west as water flows through the Delta and downstream through Suisun Marsh and adjoining bays, marking the brackish transition from freshwater to saltwater and out to the Pacific Ocean.  The plan area encompasses the areas where the possible Sacramento Delta Plan amendments may apply and the ecosystem that the plan is intended to protect.

The study area: Water from the Sacramento Delta watershed is used in the Sacramento Delta and is also delivered and used in portions of the San Francisco Bay Area, San Joaquin Valley, Central Coast, and Southern California regions. Therefore, a larger study area is also defined to ensure that environmental impacts and economic effects are evaluated comprehensively.

The study area is divided into seven regions based on geography and water supply.  The geographic regions in the study area include the Sacramento River watershed, Delta, Eastside tributaries, Delta, San Francisco Bay Area, San Joaquin Valley, Central Coast, and Southern California.

The organization of the draft staff report

• Chapter 1, Executive Summary, explains the draft staff report’s purpose and organization and provides a summary of its major findings.
• Chapter 2, Hydrology and Water Supply, describes the flow regime within the Sacramento Delta watershed, including how the magnitude, frequency, duration, timing, and rate of change of flows have been altered, and presents an overview of California’s water rights system and water supply portfolios.
• Chapter 3, Scientific Knowledge to Inform Fish and Wildlife Flow Recommendations, provides a review and summary of the best available science on flow needs for the protection of fish and wildlife beneficial uses.
• Chapter 4, Other Aquatic Ecosystem Stressors, summarizes other aquatic ecosystem stressors, such as loss of habitat, invasive species, and water quality pollutants in the Bay-Delta watershed, and how those stressors interact in the ecosystem.
• Chapter 5, Proposed Changes to the Bay-Delta Plan for the Sacramento Delta, includes a description and discussion of proposed changes to the Beta Delta Plan that were largely identified in the 2018 framework document. These changes are referred to as the proposed plan amendments.
• Chapter 6, Changes in Hydrology and Water Supply, includes a summary of the Sacramento Water Allocation Model, or SACWAM, used to evaluate the potential changes to flows, reservoir levels, and water supplies in the draft staff report. This chapter includes SACWAM results for a range of unimpaired flow levels from 35% to 75% and describes other water management actions, including groundwater storage and recovery, water transfers, water recycling, and water conservation measures.
• Chapter 7, Environmental Analysis, presents the environmental analysis for the proposed plan amendments, as well as several other project alternatives.
• Chapter 8, Economic Analysis and Other Considerations, evaluates the economic effects associated with proposed plan amendments and other alternatives.
• Chapter 9, Proposed Voluntary Agreements, includes analyses of the proposed VAs. These analyses are included together in Chapter 9 because the VAs were received after much of the draft staff report was prepared. Chapter 9 provides model results and an evaluation of the potential environmental impacts of the proposed VAs. This chapter relies on the environmental analyses presented in Chapter 7, where possible, for efficiency and to avoid redundancy. The economic effects of the proposed VAs are also evaluated in this chapter, which relies on analyses included in Chapter 8 where possible.
• Chapter 10, Economically Disadvantaged Communities, provides an overview of economically disadvantaged communities, or DACs, and their water supplies, discusses the potential effects of the project on DACs and small public water systems, and incorporates information from several other sections and chapters to identify potential effects on DACs. This chapter also discusses relevant State Water Board financial and technical assistance programs to provide safe, clean, and reliable water supplies to DACs.
• Chapter 11, Tribal Engagement, summarizes Tribal engagement activities related to the Sacramento Delta updates to the Bay-Delta Plan, including Tribal input requesting the incorporation of traditional ecological knowledge and incorporation of Tribal beneficial uses into the Bay-Delta Plan.
• Chapter 12, Public Participation, summarizes the public participation activities that were held during the pre-scoping and scoping phases of the environmental review process for the Sacramento Delta update to the Bay-Delta Plan.
• Appendices: The draft staff report also includes several appendices that present additional information, including detailed modeling results, the scientific basis report, and the final draft scientific basis report supplement in support of proposed VAs and supporting documents describing the proposed VAs developed by the VA parties discussed previously.

Alternatives

This slide identifies the alternatives that are evaluated in the draft staff report. These include both standalone alternatives and modular alternatives that could modify the standalone alternatives.

The standalone alternatives include the proposed plan amendments, which are based on the 2018 framework; the proposed VAs, which are based on the VA term sheet; high flow and low flow alternatives, which are similar to the proposed plan amendments but would require lower or higher amounts of inflow and delta outflow, and a no-project alternative. The no-project alternative is included to compare the impacts of approving a proposed project with the impacts of not approving a project. The no-project alternative assumes the continued implementation of the State Water Board’s 2006 Bay-Delta Plan as implemented by State Water Board decision 1641.

Note that the southern Delta salinity and Lower San Joaquin River flow provisions of the Bay-Delta Plan were updated in 2018. However, the updates have not yet been implemented, which the State Water Board is currently in the process of completing.  With the 2018 updates, the State Water Board did not amend elements of the Bay-Delta Plan that are now being considered for revision in the draft staff report.

The modular alternatives include three interior Delta Flow and fall Delta outflow variations, including an alternative that would remove the interior Delta Flow and fall Delta outflow provisions from the flow alternatives and two alternatives that would add to the interior Delta Flow provisions of these alternatives. The modular alternatives also include a conceptual drought alternative with two variations that could help to address limited water supplies during drought. Lastly, the modular alternatives include a conceptual alternative that would apply to the VA alternatives and would protect VA flows and the base upon which they are added from future diversions.

The modular alternatives are not currently specifically proposed or incorporated into the standalone alternatives. In the event any of these alternatives is proposed to be carried forward in actual updates to the Bay-Delta Plan, they would be further developed and subject to public review and input during the process to develop specific proposed changes to the Bay-Delta Plan that will be discussed later in this presentation.

A description of each of the alternatives is included in Section 7.2: Description of alternatives.

Environmental analyses

This slide summarizes the organization of the environmental analyses presented in chapters seven and nine of the draft staff report.  As mentioned previously, Chapter 7 includes a broad environmental analysis of the proposed plan amendments, as well as several other alternatives. Chapter 9 includes the environmental analysis for the proposed VAs.  Due to the size and complexity of the Sacramento Delta water supply and use, the environmental analyses are necessarily broad and conservative to cover the wide range of foreseeable possible compliance measures and responses that may result from the Sacramento Delta update to the Bay-Delta Plan.

To organize the environmental analysis, the evaluation of reasonably foreseeable methods of compliance and response actions that may be taken in response to the project are organized into the following categories:

• Changes in hydrology, including changes in the magnitude and timing of Sacramento Delta tributary inflows, Delta inflows, interior Delta flows, and Delta outflows, as well as changes in reservoir levels.
• Changes in water supply include reduced Sacramento Delta surface water supplies. The draft staff report evaluates the effects of changes in Sacramento Delta water supplies by sector, which includes agricultural supplies, municipal supplies, and wildlife refuge supplies. Changes in water supply also include possible increases in groundwater pumping that could occur in response to reduced Sacramento Delta surface water supplies. Changes in supply also include other water management actions, such as groundwater storage and recovery or conjunctive management efforts, water transfers, water recycling, and water conservation that could be undertaken in response to reduced Sacramento Delta surface water supplies, utilizing existing infrastructure and not involving construction.
• Habitat restoration and other ecosystem projects, and
• New or modified facilities: These types of projects are evaluated separately in sections 7.21 and 7.22 and would apply to all of the standalone alternatives.

The impacts of changes in hydrology and changes in the water supply that could result from the alternatives for updating the Bay-Delta Plan are presented in Chapters 7 and 9 of the draft staff report. The environmental analyses are organized by environmental resource category, following the State Water Board’s environmental checklist. The environmental checklist categories are identified on the slide.

The CEQA environmental checklist questions are listed in the same order as they are addressed in Chapters 7 and 9. Some impact questions are sufficiently related and are addressed together. Impacts on physical habitat restoration and other ecosystem projects and new and modified facilities are evaluated in sections 7.21 and 7.22 for these same resource areas, following the State Water Board’s environmental checklist. Common construction impacts are identified together to avoid redundancy where possible.

Impact conclusions

Chapters 7 and 9 describe the potential significant environmental impacts, less than significant impacts, and beneficial environmental effects of the alternatives. The impact summary tables can be found in Tables 1-1, 1-2, 7.21-1, 7.22-1, and Appendix F of the report.

The environmental analysis often considers a range of potential outcomes, including the most conservative for evaluating potentially significant effects on the physical environment. In many cases, there may be no impact.

However, for each resource area, the analysis assumes a worst-case scenario for evaluating effects on the physical environment. Some impacts are inversely proportional, such as impacts on groundwater levels and impacts on agricultural resources, so it is not possible for the worst-case scenario to occur for every environmental resource area. For example, assuming lower groundwater replacement pumping by farmers and ranchers in response to decreased surface water supplies will result in lower impact conclusions for groundwater resources but will increase the severity of impacts to agricultural resources, including potential permanent conversion of important farmland. Conversely, assuming higher groundwater replacement pumping by farmers and ranchers increases the severity of impact conclusions for groundwater resources but assumes that more water is available for agriculture, which reduces the severity of impact conclusions for agricultural resources.

There cannot be maximum potential impacts on groundwater resources from replacement, pumping, and maximum potential impacts on agricultural resources. Because groundwater pumping increases supply, the actual impact would likely fall somewhere in the middle of the range evaluated in the draft staff report. It’s important that the CEQA impact conclusions be understood in the context of the nature of the project, which is intended to be a restoration action.

The Bay-Delta Plan identifies various beneficial uses of water in the Bay-Delta watershed and establishes water quality objectives designed to reasonably protect those uses. The impacts that could potentially result from implementation occur in a system that has been highly altered, and the project would be expected to improve conditions for native fish and wildlife in the Sacramento Delta watershed over time. However, changes in hydrology and changes in water supply could result in some environmental impacts at certain times and locations that must be analyzed under CEQA. These potential environmental impacts should be viewed in light of the overall purpose and goals of the Sacramento Delta update to the Bay-Delta plan.

Mitigation measures

Chapters 7 and 9 of the draft staff report identify mitigation measures that could avoid or reduce potentially significant environmental impacts that the updates to the Bay-Delta Plan may have. Mitigation measures are likely to reduce many of the potential impacts to less than significant levels. Because the State Water Board has the authority to ensure that mitigation is completed for certain actions, these impacts could be reduced to a less than significant level with mitigation Incorporated.

However, due to the large scope of the project and the wide range of possible response actions, sufficient information is not available to conclude with certainty that mitigation measures will reduce all impacts to less than significant levels under all circumstances. Some mitigation measures are largely within the jurisdiction and control of other agencies or depend on how water users respond to the project.  Accordingly, the State Water Board cannot guarantee that measures will always be adopted or applied fully to mitigate potentially significant impacts. For these reasons, many impact conclusions acknowledge the potential for significant impacts that cannot be mitigated to less than significant levels. As such, unless and until the mitigation is fully implemented, the impacts would remain potentially significant.

The impact summary tables in Tables 1-1, 1-2, 7.21-1, 7.22-1, and Appendix F of the report summarize mitigation measures that can avoid or reduce potentially significant impacts.

Modeling Tools to Support Environmental Analysis

Matt Holland, Environmental Program Manager with the State Water Board, then discussed the modeling tools and some of the results.

Models used

• The Sacramento Water Allocation Model or SACWAM is used to model changes in hydrology and changes in water supply and to inform other models in the draft staff report.
• The Delta Simulation Model 2 or DSM 2 was used to model Delta hydrodynamics and water quality.
• The Statewide Agricultural Production Model or SWAP was used to model agricultural production in the Sacramento and San Joaquin valleys.
• HEC 5Q was used to evaluate temperature changes on the Sacramento, Feather, and American Rivers.
• Other models are used to evaluate habitat benefits, changes in hydropower production and to further evaluate economic effects.

It is important to note that all of these models are intended to be used in a comparative sense for assessing the incremental effects between scenarios. Similar to other modeling tools used for assessing actions in the Bay-Delta watershed, like Cal Sim 2 and Cal Sim 3, SACWAM and other models are not intended to be used in a specific predictive manner.

Draft staff report baseline

CEQA provides for comparing a project’s impact against the baseline derived from historical conditions. The environmental analyses use both quantitative and qualitative approaches to compare the potential impacts relative to baseline conditions. The draft staff report baseline is intended to be reflective of existing conditions.

The process for updating the Sacramento Delta portions of the Bay-Delta Plan has been ongoing since 2012. Since that time, there have been changes to regulations that affect reservoir operations, stream flows, and Delta operations. Updates to the biological opinions for the long-term operation of the Central Valley Project and State Water Project and Incidental Take Permit for the State Water Project have changed requirements for the operation of these major water infrastructure projects in the Sacramento Delta watershed. However, the most recent changes to biological opinions have not been fully implemented due to litigation and associated court orders.

The project baseline includes requirements as they have been implemented in recent years in an attempt to represent the existing conditions. These regulatory assumptions are listed in Table 6.2-1 in chapter six of the draft staff report.

Changes in hydrology

Chapter 6, Changes in Hydrology and Water Supply, summarizes the changes in hydrology, including changes in stream flows, reservoir levels, Delta inflows, and Delta outflows expected as a result of these flow scenarios. Modeling results are presented in ranges of potential instream flow in increments of 10% from 35 to 75% of unimpaired flow.

Overall, changes in hydrology under flow scenarios would be expected to result in increases in flows at some times in some locations. In particular, stream flows on regulated tributaries, which are tributaries with a major flow-regulating reservoir, would be expected to generally increase over baseline during the late winter through spring months as a result of the unimpaired flow requirements. Changes in hydrology would also be expected to result in decreases in flows at times in some locations, including during the late summer months on regulated tributaries where flows are artificially high under baseline conditions.

Changes in hydrology would be expected to result in changes in reservoir levels, including lower reservoir storage at some times and an increase in fluctuations in reservoir levels at some locations. Delta inflows would also increase with increasing flow requirements during January through June and decrease in July through October. The increase in winter and spring Delta inflows is from bypassing reservoirs and diversions to meet increased flow requirements throughout the watershed. The decrease during summer and fall results from a decrease in stored water available for export. Greater spring outflows also push the salinity field downstream, reducing the volume of water needed to maintain salinity control during the following months, largely the summer.

Reductions during fall can also be caused by a reduced need to create flood space and reservoirs to reduce carryover storage under wetter conditions. Although the timing of Delta inflow is altered in the flow scenarios, the average annual Delta inflow is generally higher in the flow alternatives for all water year types.

In contrast to Delta inflow, Delta outflow generally increases during all months under the flow alternatives.

Changes in Hydrology Example: Feather River Above the Sacramento River

Box plots are used in the draft staff report to broadly characterize the distributions of monthly or annualized numerical streamflow results under baseline and flow scenarios. The slide below provides an example of the format of these model results. In these plots, the box encompasses the middle 50% of observations. The line in the middle of each box represents the median value, and the whiskers show the full range of the data between the minimum and maximum values.

SACWAM results are shown on the slide for the Feather River above the confluence with the Sacramento River. Overall, these results show the flows generally increase compared to baseline conditions during the late winter and spring months and decrease during the summer and fall months.  Similar patterns are seen on other regulated tributaries in the Sacramento Delta watershed.

Changes in Hydrology Example: Shasta Reservoir (Sacramento River)

Exceedance curves are generally used in the draft staff report to characterize the distribution of reservoir storage volumes. The slide provides an example of the format of these model results. The exceedance curves presented in the staff report and this presentation show the value of interest on the y-axis and the percentage values that exceed a given observation on the x-axis.

SACWAM results are shown on this slide for Shasta Reservoir storage levels at the end of April and September. Overall, these results show that Shasta Reservoir storage levels could generally be lower for these months under the flow alternatives compared to the baseline. Other storage reservoirs also show similar results.

Operations of the rim reservoirs are increasingly constrained under the higher flow scenarios because new instream flow requirements when the ability to store water in spring and cold water pool requirements limit how far reservoirs can be drawn down in the drier years. In general, this results in lower storage at the end of April entering the irrigation season and less water being released in the summer months. The actual level of a given reservoir could differ from that modeled as operations are refined with an increased understanding of actions needed to protect cold water habitat.

Monthly Exceedance Frequency Distribution of Old and Middle River Net Flow for December through June

The slide below presents SACWAM results for changes in Old and Middle River Net Flow across the flow scenarios. This slide shows the monthly exceedance frequency distribution of old and Middle River NetFlow for December through June. SACWAM results indicate that OMR reverse flows are less negative than baseline and the flow of alternatives because exports are reduced to meet the higher Delta outflow requirements.

Changes in Delta Outflow Across the Flow Scenarios

SACWAM results are shown on the slide below for Delta outflow across the flow scenarios. These results show that Delta outflow generally increases across all months and water year types under 35 to 75% of unimpaired flow scenarios, with larger increases under the higher flow scenarios.

Change in Annual Total Delta Outflow by Water Year Type (TAF)

The slide provides a summary table that shows the change in annual total delta outflow by water year type under the flow scenarios compared to the baseline. These results show the annual total Delta outflow would increase under the flood scenarios compared to baseline, with the largest increases under the higher flow scenarios.

Median of January – June Average X2 Position for Baseline and Flow Scenarios

The location where lighter freshwater from the rivers mixes with heavy seawater from the ocean and estuary is referred to as the low salinity zone. It’s correlated with the survival and abundance of many species. The location of the low salinity zone is where the tidally averaged salinity is 2 parts per thousand (or X2) as measured in kilometers from the Golden Gate Bridge.

Generally, the further X2 is located downstream of the confluence of the confined channels in the Sacramento San Joaquin rivers, and the effects of project export facilities and downstream into the broad, shallow cool channels of Suisun Marsh and Suisun Bay, the better fish and other species respond. While the exact mechanisms behind these relationships are not fully understood, the more westerly X2 positions generally provide significantly improved habitat conditions for native species.

The figure below shows the January through June median position of X2 during critical water years and across all water year types under baseline conditions and the flow scenarios.

The figure shows that the January through June median X2 position under all water year types combined and during critical water years specifically would be expected to shift downstream under the flow scenarios compared to baseline conditions.

Proposed Voluntary Agreements

The slide shows a summary of the proposed VA assets. Details regarding when and how these assets are proposed to be provided are described in the VA proposal included in Appendix G-1 of the draft staff report. As discussed previously, the VAs include a combination of flow and non-flow habitat restoration measures on the Sacramento, Feather, American, Yuba, and Mokelumne Rivers, Putah Creek, and the Delta proposed by water users in the watershed.  The assets for which there are specific existing commitments included in the VA term sheet are summarized in the table shown on the slide and described in more detail in Chapter 9 of the draft staff report.

The draft staff report identifies that there was uncertainty about Friant commitments to reduce the recapture of San Joaquin River Restoration Program flows in the Delta. Friant has confirmed and intends to participate in the VAs.  The Tuolumne River component of the VAs identified on the slide has been considered separately, but the benefits to Delta outflows are evaluated in this draft staff report.

Flow assets are expected to be concentrated in January through June with some flexibility outside of this period, with more limited flow assets also planned for fall months, for example, in the Mokelumne and Putah Creek systems. Priority months include April through May, and priority water year types include dry, below normal, and above normal years.  Flows during these time periods and water year types are intended to benefit spawning and rearing habitats for salmonids in the VA tributaries and provide benefits for native estuarine species such as longfin smelt.

The proposed VAs include flow assets that would be provided through water purchases, including a permanent state water purchase program, Public Water Agency or PWA water purchase fixed price program, and PWA water purchase market price program.

The sources of the flow assets for the PWA water market price program and the permanent state water purchases are not fully known at this time and are termed unspecified water purchases. Because the sources of the unspecified water purchases are not known, two different scenarios are evaluated, assuming these flows are derived from either inflow or from CVP/SWP export reductions. These scenarios represent the range of possible effects of these water purchases. Both of these methods would have the same effects on Delta outflows; accordingly, different scenarios for evaluating the effects of unspecified water purchases on Delta outflows are not needed.

In addition to the project baseline, other points of comparison are used in the draft staff report that are relevant in describing and analyzing the effects of the proposed VAs:

• First, as described in the VA term sheet, the VA flows are represented as additive to flow conditions resulting from decision 1641 and the 2019 biological opinions, not including provisions of the State Water Project’s Incidental Take Permit or recent court orders that precluded full implementation of the 2019 biological opinions for the Central Valley Project. For the purposes of evaluating the impacts, the proposed VAs are compared to the baseline described previously.
• In addition to the impact analysis, the benefits of the VAs are assessed in the draft staff report relative to the point of reference used in the 2017 scientific basis report based on the 2008 and 2009 biological opinions. This scenario is similar to the baseline. The differences between the scenarios are described in detail in Chapter 6 and Chapter 9. The major differences are changes in fall Delta outflow requirements, with some minor differences and export constraints in wetter years and other minor differences that have limited effects on the modeling.
• The VA analysis also includes a number of scenarios to fully assess the range of possible outcomes under the proposed VAs, including evaluation of the different ways that the unspecified water purchases may be provided and different assumptions for contributions from San Joaquin River tributaries. Because the unspecified water purchases under the proposed VAs could be provided from reductions in exports or increases in inflows, both scenarios are evaluated. The scenarios are referred to as VA high export cuts and VA high inflow, respectively. Under both scenarios, the unspecified water purchases are assumed to occur during April and May to the extent possible, though those purchases could also result in flows at other times.
• Finally, the staff report includes evaluations of scenarios with and without flow contributions from San Joaquin sources, including potential Tuolumne and Friant VAs, as well as flows that may result from VAs on the Merced and Stanislaus Rivers or implementation of the 40% of unimpaired flow requirements in the 2018 Delta Plan.

Changes in Hydrology Example: Feather River Above the Sacramento River with the VAs

SACWAM results are shown on the slide for flows on the Feather River above the Sacramento River for the baseline on the proposed VA.  As discussed in Chapter 9 of the draft staff report, January through June monthly average flows on the Feather River above the Sacramento River would be expected to increase compared to the baseline in all water types under the VAs.

The largest increase in flows on the Feather River above the confluence of the Sacramento River would be expected in dry and below-normal years, where there is a modeled increase of about 135,000 acre-feet over the January through June period. The majority of these increases in flow originate from the Thermalito complex into the Feather River High flow channel. However, additional increases in flow are also provided from the Yuba watershed under the Yuba VA. Other VA tributaries show similar results.

Changes in Hydrology Example: Shasta Reservoir (Sacramento River) with the VAs

SACWAM results are shown on the slide below for Shasta Reservoir’s end of April and end of September storage levels for baseline and the proposed VAs.  Overall, SACWAM results indicate slightly lower Shasta Reservoir storage in all but the wettest years under the VAs. The SACWAM results indicate that by the end of September, storage in Shasta Reservoir under the VA scenario would be closer to baseline than at the end of spring. Other reservoirs on VA tributaries show similar results as well.

Monthly Exceedance Frequency Distribution of Old and Middle River Net Flow for December – June under Baseline, 2008 – 2009 BiOps Condition, VA, and VA High Export Cuts Scenarios

The proposed VAs would not result in changes to requirements for interior Delta flows in the Bay-Delta Plan, but the VAs do contemplate changes to biological opinion and incidental take permit requirements. In addition, changes to inflows and Delta exports can change interior Delta flows.

On the slide below, results for net OMR flows under the VAs, and December through June are presented as an exceedance frequency distribution plot. Overall net negative OMR flows between zero and minus 2500 CFS could occur with greater frequency under the VA scenario compared with baseline and the 2008-09 biops condition. However, the frequency of net flows more negative than minus 5000 CFS would not increase under the VA scenario.

In addition, the VA high export cuts scenario would likely result in a lower frequency of net negative OMR flows from the VA scenario and a similar frequency of net negative flows compared with baseline and the 2008-09 biops condition. However, these changes in OMR flows would not be the result of adding VAs to the Bay-Delta Plan but instead due to differences in biological opinion and ITP requirements under the VAs compared to the baseline.

Delta outflows with proposed VAs

SACWAM results are shown on this slide for Delta outflow for baseline, the 2008-09 biops condition, the VA scenario, and the VA without San Joaquin contribution scenario.

Under the VAs, Delta outflow would be expected to increase from January through June compared to both baseline and the 2008-09 biops condition, except in wet years. Increases in January to June Delta outflow would be greater for the VA scenario than the VA scenario without San Joaquin contributions and increases in Delta outflow under both VA scenarios would be greater when compared to the 2008-09 biops condition than compared to baseline. The largest expected January through June increase would occur in dry years.

The table shows the modeled changes in outflow during January through June under the VA and VA without San Joaquin contributions relative to the 2008-09 biops condition, along with two additional bookend scenarios that account for potential additional flows from the VAs or implementation of 40% of the unimpaired flow on the Merced and Stanislaus rivers, as well as a bias correction to account for different estimates of the incremental effect of the 2019 biops Delta outflow as modeled by SACWAM.  The largest increase under either of these additional scenarios would be expected under above-normal years.

This figure shows the expected January through June median position of X2 during critical water years and across all water types under baseline conditions, the VA scenario, and the VA without San Joaquin contribution scenario.

This figure shows that the January through June median position of X2 under all water years types combined and during critical water years specifically should shift downstream under the VA scenarios compared to baseline conditions.

A summary of the environmental effects that would be expected to occur as a result of changes in hydrology under the flow conditions in proposed VAs:

• Changes in hydrology would be expected to provide environmental benefits to native aquatic and aquatic-dependent species, aquatic and riparian habitats and natural communities, and ecosystem functions in the Sacramento Delta watershed. In addition, the project would be expected to provide certain water quality benefits, particularly during periods when stream flows would increase compared to baseline conditions. Many of these benefits would be a result of higher winter and spring flows.
• Providing higher flows could benefit native fish in the Sacramento Delta, restore and maintain natural processes, such as sediment deposition, marsh creation, nutrient transport, seed dispersal, and flow-related disturbance, which would benefit riverine and associated wetland and riparian habitat, and benefit native resident and migratory wildlife that use riverine and associated wetland and riparian habitat as migratory corridors or nursery sites.
• However, changes in hydrology would also be expected to result in decreased flows during the summer and fall in some locations due to reduced water deliveries and Delta exports, particularly at the higher flow levels.
• Changes in hydrology could also result in reduced reservoir levels and increased reservoir level fluctuations in some locations, particularly at higher flow levels. These changes could result in potentially significant environmental impacts to environmental resource areas but must be evaluated under CEQA.
• Impact mechanisms are expected to be similar across all alternatives. However, with increases in instream flow levels, larger effects in terms of magnitude, frequency, and geographic scope would be expected.

We do not have time today to discuss all of the environmental impacts identified in the draft staff report that could occur due to changes in hydrology, but we will highlight a few of the impacts in the following slides. As discussed previously, the draft staff report contains several impact summary tables that provide a summary of the potentially significant impacts, less than significant impacts, and beneficial environmental effects of the alternatives.

Water temperature

Elevated water temperatures are an existing concern in the Bay-Delta watershed, particularly downstream of reservoirs that are now the upper extent of habitat for anadromous fish. Existing temperature protections are in place for some stream reaches and reservoirs, but temperature requirements are applied unevenly and, in some cases, not at all.

The flow alternatives and VAs would generally result in higher spring flows compared to baseline conditions on regulated tributaries. While higher spring flows that more closely resemble the natural hydrologic regime would benefit native anadromous salmonids and other native species, higher spring flows could also result in a reduction in reservoir storage at the end of spring and a smaller cold water pool volume in the summer and fall months under the high flow alternatives. Streams with reservoirs with limited cold water supplies preventing greater volumes of cold water earlier in the year could reduce the cold water supply available later in the year.

In addition, the existing flow regime on regulated tributaries can include substantially elevated flows above required flow levels and above unimpaired conditions that are greater than 100% of unimpaired flow in summer and fall to supply downstream water diversions or when flood control releases are made. Summer flows can be reduced from existing conditions, which could reduce flows on some tributaries at times and could affect water temperatures, particularly under the higher flow scenarios.

The draft staff report identifies several mitigation measures that could be implemented to reduce or avoid temperature-related impacts on aquatic biological resources. Under the proposed plan amendments, implementation of the narrative cold water habitat objective and the flexibility provided in the inflow requirements would be expected to mitigate potential temperature impacts and improve water temperature conditions for native cold water fish. For reservoirs in the Sacramento River watershed and Delta eastside tributaries regions, the new narrative cold water habitat objective would be intended to ensure that salmonids have access to cold water habitat at critical times and to ensure that adequate water is available for minimum instream flow purposes downstream of the reservoirs.

However, while the specific cold water habitat implementation measures are refined, there may be some challenges with meeting suitable temperatures at all times on all tributaries while meeting flow requirements and water deliveries, particularly those with significant water diversions at smaller storage capacity. In some cases, improving temperature conditions can be achieved through operational and structural measures in reservoirs. Key non-flow actions for managing water temperatures released from dams include the installation or modification of temperature control devices. These actions are evaluated in Section 7.21 of the draft staff report.

Overall, the changes in instream flows and reservoir levels would be expected to be less under the proposed VAs compared to the proposed plan amendments, so temperature-related impacts would likely be less than under the proposed plan amendments.  However, the draft staff report acknowledges that all the project alternatives could result in potentially significant temperature-related impacts. While changes in hydrology would be less, it is also possible that there could be some instances in some streams where temperatures could increase under the proposed VAs. Although the proposed VAs do not include a cold water habitat objective, the proposed VAs include flexibility in the timing of flow assets and other attributes that could reduce or avoid possible temperature-related impacts.

Contaminants

Changes in hydrology, specifically increased flows, could affect the movement of contaminants such as pathogens, trace metals and metabolites, current use pesticides, legacy contaminants, contaminants of emerging concern, and mercury and methylmercury. When flows increase the movement of sediment, any adhered contaminants may increase.

The long-term water quality impacts on movement and deposition, sediment, and adhered contaminants will generally be minimal because contaminants are likely already present in areas where sediment deposition occurs.  In addition, while higher flows may cause more sediment to enter the water column, higher flows can also help move sediment and contaminants out of the system. Some of these impacts are incremental impacts associated with existing degraded conditions. When flows increase, the movement of sediment and any adhered contaminants may increase. Increases in flow would be expected to help dilute local sources of dissolved contaminants, thus improving water quality. However, reductions in flow could concentrate dissolved contaminants and could negatively impact water quality. These impacts are discussed further in Section 712.1 and 9.7.12.1 in the draft staff report.

Mercury and methylmercury

Mercury is a statewide problem, and the amount of mercury moved from one area to another is of concern under existing conditions, as is the conversion of mercury to more harmful methylmercury. Clean Water Act Section 303 D requires all states to identify waters that are not attaining water quality standards and include a priority ranking of such waters. The list identifies water bodies and their impairments and is referred to as the 303 D list.

Many water bodies in California are identified as impaired by mercury levels and are included in the 303 D list. Due to high levels of methylmercury found in fish tissue, consumption of contaminated fish is of greater concern for human health than is mercury in drinking water. High levels of methylmercury in the environment also pose a threat to fish and wildlife because of methylmercury toxicity and the ability to accumulate in aquatic food webs.

The draft staff report identifies potentially significant mercury and methylmercury water quality-related impacts under the flow alternatives and proposed VAs. Mercury impacts could be associated with downstream mercury transport and inundation of floodplains. Given mercury’s high affinity for particles, increased suspended sediments and higher and greater streamflow from changes in hydrology could increase the transport of mercury, potentially affecting the achievement of water quality standards and tributaries with known mercury impairments. The negative consequences of this effect could be exacerbated if the receiving water forms intermittent wetlands that are conducive to converting mercury into methylmercury.

The Yolo Bypass is a specific location where the combination of increased mercury input and transformation to methyl mercury could occur due to the existing concentration of mercury in the tributaries and large wetland acreage.  Increased flows in the Yolo Bypass could affect the transformation of mercury into methylmercury due to floodplain inundation.

The State Water Board recognizes in the draft staff report that wetlands and floodplain inundation provide valuable water quality, wildlife habitat, and flood control functions and should not necessarily be disincentivized due to mercury concerns. Methylmercury production from physical habitat restoration projects is also evaluated in Section 7.2.1, habitat restoration, and other ecosystem projects. Mercury impacts could also occur due to increases in water level fluctuations in reservoirs. The draft staff report identifies mitigation measures that could reduce or avoid mercury and methylmercury-related impacts.

Harmful algal blooms (HABs)

The Sacramento Delta update to the Bay-Delta Plan could also affect the production of harmful algal blooms or Habs.  Similar to temperature and mercury issues, HABs are an existing condition in the Sacramento Delta watershed. HABs have been reported in multiple locations within the Sacramento Delta watersheds, such as Clear Lake, Black Butte Lake, Sacramento River, Folsom Reservoir, Lake Berryessa, Oroville Reservoir, and Shasta Reservoir. Generally, HABs form at lower elevations, but HABs have also been reported in some upper watershed reservoirs.

Since 1999, HABs have also occurred annually in varying levels throughout the Delta in locations including the Stockton waterfront, Discovery Bay, and Franks tract. Several studies indicate that low flows through the Delta are associated with increased HAB formation. HABs are also more frequent and severe in dry years.

The flow alternatives and VAs would be expected to result in an increase in flows in the spring that could lead to reduced HAB formation and invasive aquatic vegetation in the Delta to varying degrees based on the increased level of flow. However, reduced Delta inflows in summer and fall could result in increased production of HABs and invasive aquatic vegetation in some Delta channels at some times. Lower reservoir levels can also lead to shallower, warmer, more stable water and calm conditions in some reservoirs, which could increase the production of HABs. These effects would be greater at higher flow levels and lesser at lower flow levels.

The draft staff report identifies several mitigation measures that could be implemented to reduce or avoid HAB-related water quality impacts.

Uncertainty in the specific drivers of HABs in the Delta has resulted in uncertainty in the potential impacts or benefits of the proposed plan amendments or the proposed VAs. We need better information on the drivers of HABs, including the effects of flow and water project operations, to reduce this uncertainty. To address this knowledge gap, the program of implementation is proposed to identify commitments by the State Water Board in coordination with other agencies and stakeholders to undertake actions to better understand HABs and possible control mechanisms. The board has already started these efforts by funding research into HAB drivers and the development of an HAB monitoring design. Related to these efforts, the Delta HABs monitoring strategy facilitated by the Delta Stewardship Council will be available for public review next year.

Changes in water supply summary: Flow scenarios

In addition to the changes in hydrology just discussed, implementation of the proposed plan amendments or other flow scenarios would be expected to result in changes in the Sacramento Delta water supply, including to agricultural, municipal, and wildlife refuges. Sacramento Delta water is defined as the surface water supply that originates in or is diverted from water bodies in the Sacramento River watershed, Delta eastside tributaries, and Delta regions. Sacramento Delta surface water supplies are used both within and outside of the Sacramento Delta watershed.

Reductions in the Sacramento Delta water supply would be expected to occur in all of the geographic regions in the study area. Reductions in the Sacramento Delta supplies are not expected to be uniform across the various tributaries, and some water users would be affected more by reduced Sacramento Delta supplies. However, the Sacramento Delta supply is only one portion of this water supply portfolio for each of these regions. Therefore, a reduction in Sacramento Delta supply results in a reduction in only one of the sources of supply to users in each region. The reductions in water supply and the scenarios as a percent of the total water supply available to users in any given region can be much smaller than the percent reduction in the Sacramento Delta supply.

In response to reductions in water supply, individual water users could choose to increase groundwater pumping as a substitute supply were available and not locally restricted. In addition, water users may choose to modify their water supply portfolios by increasing the use of other sources of water and maximizing the use of existing water supplies. These and other water management actions include groundwater storage and recovery, water transfers, water recycling, and water conservation.

The table on this slide shows the annual average water supply to each region in the study area by type of use: agriculture, urban, and refuge. Total water supply, including surface water supplies, groundwater, and other sources, is estimated using historical water delivery data. Baseline Sacramento Delta supply is estimated using SACWAM results. Reduction in Sacramento Delta supply is obtained from SACWAM flow results for the flow scenarios.

Overall, the slide shows that reductions in water supply and the scenarios as a percent of the water total water supply available to users in any given region is smaller than the percent reduction in the Sacramento Delta supply.

For example, the annual average reduction in Sacramento Delta supply to the Central Coast region for 55% of the unimpaired flow scenario is 22%. However, that reduction as a percentage of the total water supply to the Central Coast is only 1%.  This table is available in chapter six in table 6.4-1. It contains more details about the sources and interpretation of the results.

The slide below shows the annual Sacramento Delta supply to all regions in the study area under baseline conditions and under flow scenarios ranging from 35 to 75% of the unimpaired flow. As the box plots show, the total Sacramento Delta supply decreases with increasing flow requirements by the smallest change from baseline under the 35% unimpaired flow scenario and the largest change from baseline under the 75% unimpaired flow scenario. Additional details and additional locations are provided in chapter six of the draft staff report.

Implementation of the proposed VAs could also result in changes in the Sacramento Delta water supply, including both within and outside of the Sacramento Delta watershed. Under the proposed VAs, reductions in Sacramento Delta supply would be expected to primarily affect agricultural uses. SACWAM results show that there could be a small reduction in water supply for municipal use, and there would be no expected change in water supply to wildlife refuge areas.

Although the source of the unspecified water purchases is not known, as discussed in Chapter 9,  unspecified water purchases would be expected to be provided primarily or entirely by agricultural water users. The VA proposal identifies that some flow assets can be provided through groundwater substitution, including in basins subject to the Sustainable Groundwater Management Act. Where that action is consistent with local management under SGMA, including the American River watershed consistent with a VA proposal, flow assets in other watersheds could also be provided through groundwater substitution, but sufficient information is not available at this time to include groundwater substitution in the modeling. If additional flow assets are made available through groundwater substitution, water supply reductions would be less than indicated by the modeling results.

Changes in Sacramento Delta water supply from baseline and associated changes in water management actions would be smaller in magnitude under the proposed VAs than the changes that would occur under the proposed plan amendments. However, the water supply-related impact mechanisms and significance determinations would be similar.

The slide below shows the SACWAM modeled annual total Sacramento Delta surface water supply under baseline and the change under the proposed VAs. Overall, the proposed VAs would be expected to result in an annual average reduction of water for the entire study area across all water year types. The reductions would be greatest during dry water years.

The proposed VAs involve voluntary contributions of water that could be implemented in different ways that would affect hydrology and water supply, including reservoir operations, fallowing of agricultural lands, and groundwater substitution. The VA modeling includes assumptions that are generally reflective of how the proposed VAs are expected to be implemented but cannot reflect all of the numerous specific ways that can be implemented.

Modeling results should not be taken as indicating the exact changes in water supply and changes in hydrology from the implementation of the proposed VAs but rather should be used to indicate the general timing and trends that may occur.

Effects of Changes in Water Supply

Nicole Williamson then returned to discuss the environmental analysis for changes in the water supply.

Overall, the environmental analysis presented in the draft staff report finds that changes in water supply could result in potentially significant impacts to multiple environmental resource areas. As we discussed previously, the environmental analysis often considers a range of potential outcomes, including the most conservative for evaluating potentially significant effects on the physical environment. In many cases, there may be no impact; however, for each resource area, the analysis assumes a worst-case scenario for evaluating effects on the physical environment.

Some impacts are inversely proportional, such as impacts to groundwater levels and impacts to groundwater resources. And it’s not possible for the worst-case scenario to occur for every environmental resource area.

In response to reductions in the Sacramento Delta surface water supply, individual water users may choose to increase groundwater pumping where available and not locally restricted. Importantly, this is not a directive that farmers and ranchers should or would replace Sacramento Delta water supply reductions with groundwater pumping, especially in light of requirements to achieve sustainability in basins subject to the Sustainable Groundwater Management Act. But this is a good faith attempt to capture the potential maximum impacts on the groundwater basin from replacement pumping.

Water users could also choose to use other water management actions, including groundwater storage and recovery, water transfers, and water conservation in response to reduced Sacramento Delta supplies, while other water management actions help to mitigate impacts from reduced Sacramento Delta supply.  These actions may also result in potentially significant impacts that must be evaluated under CEQA.

For evaluating impacts on agricultural resources, the analysis presented in the draft staff report uses a conservative threshold of significance for land conversion that assumes that any reduction in irrigated crop acreage would result in permanent conversion of important farmland to non-agricultural use, which would be a significant impact. In response to reductions in Sacramento Delta supplies, as we discussed previously, some individual growers could choose to replace some of the reduced Sacramento Delta supplies by increasing groundwater pumping where available and not locally restricted.

Because of uncertainties about water users’ response, the environmental analysis considers two bounds or bookends: no replacement groundwater pumping, in which it was assumed that groundwater would not be available to replace reductions in surface water availability beyond current use under baseline conditions, and maximum replacement groundwater pumping, in which it was assumed that growers could use groundwater to replace Sacramento Delta surface water supply reductions when economically feasible to do so and subject to existing groundwater infrastructure limits.

The likely response would be somewhere in between, meaning that water users would likely increase groundwater pumping to replace some amount of reduced surface water supplies but not at a volume sufficient to replace all of the reduced surface water supplies. Water Users could also choose to plant lower water use crops, engage in deficit irrigation, or fallow land in response to reduced Sacramento Delta supplies.

The draft staff report identifies several mitigation measures that could be implemented to reduce or avoid impacts to agriculture. For example, water users can and should diversify their water supply portfolios to the extent possible in an environmentally responsible manner and in accordance with the law. Diversification includes sustainable conjunctive use of groundwater and surface water, water transfers, water conservation and efficiency upgrades, and increased use of recycled water. Farmers are likely to implement efficiency and conservation measures on their own initiative in response to reduced supplies. But unless and until the mitigation measures are fully implemented, the impacts remain potentially significant.

The slide above presents SWAP model results for changes in crop acreage in the Sacramento Delta watershed under the 35 to 75% unimpaired flow scenarios. These results show that the reduction in irrigated crop acreage compared to baseline would be largest under the 75% unimpaired flow scenario and smallest under the 35% unimpaired flow scenario.

Again, it’s uncertain how water users may respond to reduced Sacramento Delta supplies regarding groundwater pumping. Accordingly, the SWAP modeling for the flow scenarios considered both maximum replacement groundwater pumping conditions, shown in blue, and no replacement groundwater pumping conditions, shown in grey. Modeling higher groundwater replacement pumping assumes more water is available for agriculture, which reduces effects on crop acreage. The model results for the flow scenarios with no replacement groundwater pumping show a greater effect on crop production. Because the availability of groundwater to replace reduced surface water supply would be limited, the likely response would be somewhere in between.

Chapter 9 of the draft staff report presents SWAP results for changes in crop acreage under the proposed VAs. Overall, the modeling results suggest that effects on crop acreage would be less under the proposed VAs than the proposed plan amendments.

There is some uncertainty regarding the effects of the proposed VAs on crop acreage. First, equating reductions in irrigated acreage to cropland conversions likely overestimates potential acreage reductions because not all land acreage estimated to be removed from irrigation would be permanently converted to non-agricultural uses. In addition, the sources of the unspecified water purchases are not fully known at this time. SWAP estimates the possible sources and effects of unspecified water purchases based on economic criteria, and the actual effects of unspecified water purchases under the proposed VAs on crop acreage could differ from those indicated by the SWAP model results. Finally, to capture a conservative estimate of changes in crop acreage under the proposed VAs, the SWAP modeling for the proposed VAs assumes that agricultural water users would not increase groundwater pumping in response to reductions in Sacramento Delta water supplies. If groundwater substitution is used to supplement reductions in surface water supplies, the change in crop acreage could be less than indicated by the SWAP modeling results.

Although there’s some uncertainty regarding the effects of the proposed VAs on crop acreage, the SWAP model results suggest that reductions in the Sacramento Delta water supply under the proposed VAs could result in changes in crop acreage in the Sacramento Delta watershed and San Joaquin Valley that would be considered a potentially significant impact on agriculture.

Municipal use

As discussed above, alternatives evaluated in the draft staff report could result in a reduction in Sacramento Delta surface water supply to municipal users described in sections 7.20 and 9.7.20 of the draft staff report, with some additional discussion in the surface and groundwater quality sections.

Under the proposed plan amendments, impacts of reduction in Sacramento Delta supply to municipal suppliers can vary across regions. As the Sacramento Delta supply represents only a portion of the municipal supply portfolios, the overall impact depends on what portion of the total municipal supply is Sacramento Delta supply compared to other water supplies.

Many municipal suppliers are well prepared to address a supply reduction of up to 10%. However, agencies that rely primarily on Sacramento Delta surface water and have limited water supply portfolios, and agencies that already have demand that outpaces supply, could experience impacts with reductions in the Sacramento Delta supply. Municipal water agencies, on their own or with others, may develop new supplies through additional groundwater wells, water recycling, desalination, groundwater storage, and recovery, or surface storage projects to address reduced supplies. These are the types of projects that the draft staff report considers to be likely responses to the proposed plan amendments.

The reductions in Sacramento Delta supply to municipal users under the proposed VAs would be smaller compared to the proposed plan amendments. Sacramento Delta water supply reductions under the proposed VAs would be based on voluntary measures, and any water supply reductions to municipal water users would be small and would not result in the need to obtain new water supplies. The draft staff report identifies that under the proposed VAs, reductions in Sacramento Delta water supplies to municipalities would represent a less than significant impact.

Under the proposed plan amendments, the draft staff report identifies that changes in water supply, including reduced Sacramento Delta supply for municipal use and increased water conservation and the use of other lower quality water supply sources, could affect wastewater treatment plants (or WWTP) influent and effluent. The construction to modify or expand existing treatment facilities as a result of changes in supply and hydrology and as a possible response action to increase water recycling is evaluated in Section 7.22 of the staff report.

Groundwater

Many communities in the study area rely on groundwater as their primary source of supply, either as municipal supply or supply from private domestic wells. Although the proposed plan amendments and proposed VAs would not directly affect these supplies, there could be indirect effects on groundwater supply and quality. Communities that rely on groundwater for drinking water supplies in the San Joaquin Valley region have been facing challenges from declining groundwater levels under existing conditions, with critical shortages or dry wells occurring in some areas during prolonged drought periods.

Economically disadvantaged communities that rely solely on groundwater often disproportionately experience impacts on their drinking water supplies. Their groundwater wells are often shallow and thus more susceptible to water quality issues or the risk of going dry if the groundwater level is lowered. The frequency and severity of these challenges could increase in localized areas as a result.

The draft staff report identifies several mitigation measures that could be implemented to reduce or avoid impacts on municipal water supplies.

Reduced Sacramento Delta supply could also result in potentially significant impacts related to lower groundwater levels and groundwater quality from increased groundwater pumping as a substitute supply and reductions in applied irrigation water, including from increased water use efficiencies, which would reduce incidental groundwater recharge.  Potentially significant environmental impacts on groundwater levels and groundwater quality are discussed in sections 7.12.2 and 9.7.12.2.

The slide presents a brief summary of the impact mechanisms that could result in lower groundwater levels. As discussed previously, in response to reductions in the Sacramento Delta surface water supply, individual water users may choose to increase groundwater pumping where available and not locally restricted. The VA proposal also identifies that some flow assets could be provided through groundwater substitution. Lower groundwater levels could result in secondary impacts, including reduced water supplies for agriculture and communities that rely on groundwater as their primary municipal water source, including economically disadvantaged communities. Lower groundwater levels could have localized effects on groundwater quality by concentrating pollutants where groundwater contamination already exists. Secondary impacts from lower groundwater levels are evaluated in the related resource categories, such as utilities.

The draft staff report identifies mitigation measures that could reduce or avoid groundwater-related impacts. For example, local groundwater management under the Sustainable Groundwater Management Act could reduce or eliminate impacts, particularly in medium and high-priority groundwater basins.

Other water management actions

The evaluation of actions that may be taken in response to changes in water supply include other water management actions, including groundwater storage and recovery or consumptive use efforts, water transfers, water recycling, and water conservation measures that are already being implemented throughout the state. While the Sacramento Delta update to the Beta Delta Plan cannot be considered the driving impetus for sustainable management and water supply diversification efforts, the project may accelerate and increase the need for such efforts.

Other water management actions affect the overall analysis in two ways. First, environmental impacts and economic effects from reduced Sacramento Delta surface water supplies likely would be less, given these efforts. Second, other water management actions may result in their own environmental impacts that must be disclosed and analyzed.

The approach to the environmental analyses of other water management actions assumes the use of existing infrastructure, such as existing groundwater wells, existing water delivery systems, and existing storage systems, as well as existing conservation measures. The potential impacts of other water management actions are described in sections 7.3 through 7.20 for each environmental resource area.

Physical Habitat Restoration and Other Ecosystem Projects

The other two main categories of reasonably foreseeable methods of compliance and response actions are physical habitat restoration and other complementary ecosystem projects and new and modified facilities that involve construction.

The environmental impacts of physical habitat restoration and other ecosystem projects are evaluated in Section 7.21 of the staff report. This section evaluates the environmental impacts of non-flow ecosystem projects, including physical habitat restoration, fish passage projects, predation, and aquatic invasive species control.

The proposed plan amendments provide a framework that would allow stakeholders to implement complementary ecosystem projects in addition to flow requirements and actions that other entities could take that would contribute towards achieving the overall goal of improving conditions for fish and wildlife in the Sacramento Delta watershed. In addition, the narrative cold water habitat objective could be implemented in part through certain construction projects such as reservoir temperature management facilities or fish passage facilities.

In addition, the proposed VAs include physical habitat restoration on a portion of the Sacramento Delta tributaries and in the Delta. These types of projects are evaluated in Section 7.21.

New and modified facilities

The Sacramento Delta update to the Bay-Delta Plan would result in reduced Sacramento Delta surface water supplies at certain times and locations. In response, water users could increase efforts to prioritize limited available water supplies or develop other water supply sources. Other water sources are already being developed and utilized in response to water shortages that occur as a result of many factors.

Section 7.22 addresses actions that entities may take that would involve construction to modify or build new facilities and infrastructure to supplement or conserve surface water supplies and other construction projects that may result from the Sacramento Delta update to the Bay-Delta Plan.  Projects include newer modified dams and reservoirs and points of diversion, groundwater wells and groundwater storage and recovery projects, and new or modified drinking water treatment plants, including desalination plants and wastewater treatment plants.

Section 7.22 also evaluates other construction projects that entities may take in response to changes in hydrology and water supply, including new or modified boat ramps, streamflow or temperature monitoring devices, and water conservation projects such as canal lining.

Many of the actions evaluated in sections 7.21 and 7.22 would involve construction and, in some cases, large construction projects that would require site-specific environmental impact analyses. Common construction impacts are consolidated where possible to avoid redundancy. Note that operational impacts from increased groundwater pumping and other water management actions are already addressed in the main resource sections 7.3 through 7.20.

Economic effects

Under the Porter-Cologne Water Quality Control Act, the State Water Board is required to consider several factors, including economic considerations, when establishing water quality objectives for the reasonable protection of beneficial uses.

The economic effects of the proposed plan amendments are evaluated in Chapter 8 of the draft staff report. The economic effects of the proposed VAs are evaluated in Chapter 9 and specifically Section 9.8 of the draft staff report.

These chapters analyze the potential economic effects on California’s agricultural economy from changes in water supply. The direct economic effects of potential changes in water supply on the production of irrigated crops are estimated using the SWAP model. In addition, the analysis estimates how changes in agricultural production could affect total industry output or sales, income, and employment throughout the regional economy. The analysis of regional economic effects is primarily conducted using the INPLAN model.

In addition, the analysis in Chapter 8 estimates the potential costs to affected municipal service providers of securing reliable water supplies with a focus on increased costs of meeting the same demand through the development of other water supplies, as well as the opportunity cost of lost supply if no other supply sources are available, or costs of meeting the same demand using other water supplies already being used by municipalities within existing water portfolios.

Tribal engagement

Rob McCarthy, Senior Environmental Scientist with the State Water Board and the Tribal coordinator for the Bay-Delta Plan update and implementation processes, discussed Tribal engagement and public participation.

The State Water Board has been engaging with California Native American Tribes through listening sessions, meetings, and individual discussions to understand Tribal perspectives and interests in the Board’s effort to update and implement the Bay-Delta Plan.

Chapter 11 summarizes these Tribal outreach and engagement activities related to the Sacramento Delta updates. The Bay-Delta Plan documents Traditional Ecological Knowledge to inform the update of the Bay-Delta Plan and discusses the inclusion of Tribal and subsistence fishing beneficial uses (or TBUs) into the plan.

The State Water Board is committed to ongoing engagement with California Native American Tribes to incorporate Traditional Ecological Knowledge, Tribal feedback, and Tribal perspectives into the Bay-Delta Plan to inform the reasonable protection of beneficial uses of water.

Earlier this year, the State Water Board mailed letters offering formal consultation to California Native American Tribes on the update and implementation of the Bay-Delta Plan. The board continues to actively seek input and engagement with Tribes, and Tribal representatives interested in further engagement may contact me at Robert.McCarthy@WaterBoards.ca.gov.

In addition, State Water Board staff held Tribal listening sessions earlier this year to gather input from Tribal leaders on the State Water Board’s efforts to update and implement the Bay-Delta plan. Through that outreach, Tribal representatives requested the specific recognition of Tribal beneficial uses in the plan. At its meeting on June 7, 2023, the State Water Board held an informational item on consideration of the addition of Tribal beneficial uses to the Bay-Delta Plan in response to comments from California Native American Tribes within the watershed. The State Water Board is now considering the incorporation of Tribal and subsistence fishing beneficial uses of water, including Tribal tradition and culture, Tribal subsistence fishing, and subsistence fishing.

In addition, State Water Board staff have engaged in efforts to document traditional ecological knowledge to help inform technical and policy considerations of the Bay-Delta Plan, including improving adaptive management decisions, monitoring, evaluation for plan effectiveness at protecting fish and wildlife, and Tribal beneficial uses in future updates and implementation.

Public participation

The State Water Board has also received valuable input from many members of the public that has informed the development of the draft staff report. Chapter 12 describes the public participation activities that have occurred during the development of the draft staff report. These public participation activities included CEQA scoping meetings and public comment periods in 2009 and 2012, informational workshops on the scientific and technical basis for potential changes to the Bay-Delta Plan from 2012 through 2016, informational items, workshops, and comment periods on the scientific basis report and scientific basis reports supplement.

More recently, the State Water Board held informational items on upcoming actions to update and implement the Bay-Delta plan in December 2021 and January 2023. During January 2023, the State Water Board held a public workshop on the draft scientific basis report supplement in support of proposed voluntary agreements and an associated comment period to receive public comments. In March and June of 2023, the State Water Board hosted public listening sessions focused on environmental justice issues in the plan. During these listening sessions, the State Water Board considered input from environmental interests, representatives of economically disadvantaged communities, and representatives of black Indigenous and People of Color organizations on the State Water Board’s current efforts to update and implement the Bay-Delta Plan.

The State Water Board appreciates input provided by stakeholders through these discussions and in general comments and encourages interested parties to remain engaged in the process to update the Bay-Delta plan. State Water Board staff will continue to meet with interested parties to discuss information pertinent to the Bay-Delta Plan updates and will continue to consider new information provided by stakeholders during the planning process.

Opportunities for public participation

The release of the draft staff report initiates a public comment period.  The public comment period is the public’s opportunity to review and comment on the analysis described in the draft staff report. Written comments on the draft staff report are due December 15, 2023. Detailed information on how to submit written comments on the draft staff report and how to participate in the upcoming workshops and hearings is in the notice.

A multi-day public hearing beginning November 17 and continuing on December 1 and December 11 before the State Water Board to receive oral comments. The public hearing will be held during regular business hours on November 17 and December 1.  To provide an opportunity for interested parties to provide oral comments outside of regular business hours, the hearing will continue during evening hours only on December 11.

Next steps

The board has initiated an independent scientific peer review of the final draft scientific basis report supplement for the Sacramento Delta VAs. Following the peer review, the scientific basis report supplement may be further revised.

The specific regulatory text for changes to the Bay-Delta Plan has not been developed yet. Those changes will be developed based on public comments on the draft staff report, the remaining VA products expected at the end of this year, and peer review comments on the VA scientific basis report supplement.

The draft changes will be subject to public review and oral and written public comment anticipated to occur in early to mid-2024. In addition, responses to public comments on the draft staff report will be provided in early to mid-2024, along with any needed changes to the draft staff report.

The input received on the draft staff report, and the draft Bay-Delta Plan amendments will inform the final staff report and final proposed plan amendments, which will be brought before the board for consideration at a future meeting as part of a full public process. It is anticipated that the State Water Board may consider adoption of the Sacramento Delta updates as early as late 2024.

Statement by Brooke Jacobs with the California Department of Fish and Wildlife

The voluntary agreements are the proposed alternative for updating the Water Quality Control Plan for the San Francisco Bay-Sacramento-San Joaquin Delta to achieve reasonable protection of Fish and Wildlife beneficial uses in the regions covered by the voluntary agreement.

The parties seek to take a comprehensive approach to integrate flow and non-flow measures, including habitat restoration and landscape reactivation, targeted at improving spawning and rearing capacity for salmonids, estuarine species, and other native fish and wildlife.  The California Natural Resources Agency is investing in voluntary agreements for the potential to provide a collaborative and adaptive structure that can guide flow and habitat management at a landscape scale.

Collaboration is key to reversing the pattern of deterioration of the ecosystem. This approach is different from how the watershed is traditionally managed, with each tributary and the Delta previously managing and making decisions by themselves. The voluntary agreements include proposed governance and science programs to direct flows and habitat restoration, conduct assessments, and develop strategic plans and annual reports.

The primary purposes of voluntary agreement governance and science activities are to maximize the benefits of the flow and non-flow measures for the narrative objectives and to provide accountability and transparency for the voluntary agreement program to regulatory agencies and the public.

Implementation of a watershed scale program for flows and restoration would require extensive collaboration. For example, there’s flexibility contained in the proposed voluntary agreements for how much and when environmental flows could be deployed and within a range. These are the types of decisions that are envisioned in governance discussions. So now I’m going to turn it over to my colleague DWR to talk more about the documents associated with the voluntary agreements.

Erik Loboschefsky with the Department of Water Resources

Here is a very quick overview of the draft documents that are included as part of the water board staff report on the voluntary agreements.

Chapter 9 of the staff report includes a general description of the proposed voluntary agreements and the environmental and economic analyses, including changes to hydrology and water supply heard a lot about that over the last few minutes. Additional details regarding the voluntary agreement proposal are in Appendix G of the staff report.

This includes five different elements:

• The MOU and term sheet that has been previously circulated and is available in Appendix G.
• Draft strategic plan of the voluntary agreements: The draft strategic plan provides an overview of the proposed voluntary agreement program, as well as additional details on the flow and non-flow measures or habitat restoration measures included in the March 29, 2022, memorandum of understanding to advance the term sheet for voluntary agreements. The strategic plan also includes more details as to when and how those flow and habitat measures will be implemented, as well as an overview of their county.
• Draft governance program: The draft Governance Program describes how VA entities or voluntary agreement entities will be engaged in the planning and decision-making related to the flow and non-flow measures. This includes an overview of system-wide governance and tributary and delta governance entities. The governance program is envisioned to direct system-wide measures, make recommendations regarding the deployment of tributary and delta measures, conduct assessments, update the strategic plan, develop annual reports, and implement a system-wide science and monitoring program.
• Draft science plan: The draft science plan provides a framework and approach, including hypotheses and associated monitoring for evaluating the outcomes of the voluntary agreement flow and non-flow measures, as well as addressing several important and broad-scale ecosystem management questions. This document provides guidance to the voluntary agreement Science Committee as it develops recommendations for priority areas to focus additional monitoring, conduct active experiments, provide decision support modeling and data analysis needed to fill knowledge gaps, assess outcomes of those VA measures, and inform ongoing and future decision making.  As the Science Committee continues to work, this group welcomes the inclusion of relevant expertise from additional parties, including from Tribes and non-governmental organizations.
• A final draft scientific basis report that includes the voluntary agreements which is being submitted for independent peer review.

Lastly, over $2.9 billion of funding commitments have been identified to support this voluntary agreement program. This is generated from many sources and over the term of the entire proposed agreement, including CNRA, Reclamation, state, other federal agencies, and public water agencies, as well as other sources. This funding largely supports the dedication of water to instream flows, support science, as well as habitat projects.