Climate Change

Since the Industrial Revolution in the early 1800s, human activities have led to continual increases in the concentrations of carbon dioxide and other greenhouse gases in Earth’s atmosphere. These increases are driving widespread changes in our planet’s climate, including the atmospheric, oceanic, and hydrologic processes that support water resources and water quality in California. Observed and anticipated changes in temperatures and precipitation could significantly affect water supplies and water quality in our region by increasing the frequency, severity, and duration of floods and droughts, depleting groundwater supplies, and increasing the risk of catastrophic wildfires. These changes can increase pollution, sedimentation, temperatures/salinities, the risk of harmful algal blooms, and other factors that impact the quantity and quality of aquatic habitats such as streams, lakes, and wetlands.

Climate change is also driving observed and projected increases in local sea levels, which threaten the integrity and health of the natural and built communities along the Bay’s shoreline. Sea level rise threatens to drown the tidal marshes that sustain the health of the Bay, increase the risk of catastrophic floods in low-lying neighborhoods, inundate crucial shoreline infrastructure such as highways, railroads, airports, and wastewater treatment plants, and increase erosion and beach/land loss along the Pacific Coast. Rising atmospheric carbon dioxide also drives ocean acidification, which threatens the Bay Area’s fragile aquatic food webs as well as its robust commercial fisheries. 

The combined impacts of climate change will affect water quality and many beneficial uses of our waters, including those supporting ecological habitats, rare and endangered species and recreational uses. Addressing climate change and its ramifications in the region are high priorities for the Water Board.

For more information about San Francisco Bay Regional Water Board Climate Change activities, please contact Christina Toms, 510-622-2506,


Adaptation Atlas. 

The Bay Area’s varying landscape characteristics (geology, hydrology, climate, etc.), land use, and demographics make different parts of the Bay shoreline vulnerable to climate change and sea level rise in different ways. Effective adaptation requires an approach that is coordinated, place-based, and cross-jurisdictional. The Water Board is therefore funding the San Francisco Estuary Institute (SFEI) to develop an Adaptation Atlas for San Francisco Bay based on the science of Operational Landscape Units, or OLUs. The Atlas classifies the Bay’s shoreline into practical OLUs based on the natural and developed characteristics of the shoreline and pairs each unit with a suite of appropriate nature-based and non-structural sea level rise adaptation strategies that support the resilience of the built and natural environment. An article in the San Francisco Chronicle and an article in the San Jose Mercury News describe the atlas and how it can be used to aid local governments in planning for sea-level rise. SFEI completed the first phase of the Adaptation Atlas in May 2019, and entities including Marin County, San Mateo County, the Metropolitan Transportation Commission, and the Bay Conservation and Development Commission are already applying the Atlas within their planning frameworks. The Water Board is funding SFEI to develop a second phase of the Adaptation Atlas project that will address data gaps identified in Phase 1, refine the criteria for certain nature-based adaptation approaches (e.g. beaches), and develop case studies of phased adaptation strategies for representative Operational Landscape Units. This second phase of work is scheduled to begin in summer 2019.



Wetland Policies Update.

The Water Board is reviewing and, where necessary, updating its policies and procedures related to wetland fill, the beneficial re-use of dredged sediment and use of treated wastewater in wetlands, and treatment wetlands to address climate change resilience. Review partners include the San Francisco Estuary Partnership, the UC Berkeley Department of Civil and Environmental Engineering, and the National Science Foundation’s Re-Inventing the Nation's Urban Water Infrastructure (ReNUWIt) program.


Wetlands Regional Monitoring Program Planning.

Understanding and adapting to the impacts of climate change on the Bay’s tidal wetlands requires a regional approach to monitoring. Extensive planned tidal marsh restoration for the Bay will change the Bay’s landscape and dynamically impact water quality. Together with partners including the U.S. Environmental Protection Agency, San Francisco Estuary Partnership, San Francisco Estuary Institute, and San Francisco Bay National Estuarine Research Reserve, the Water Board is collaborating on the development of a Wetland Regional Monitoring Program (WRMP) plan for regional tidal wetland monitoring. The program plan will focus on cost-effective monitoring strategies that build upon existing programs and leverage ongoing innovation in remote sensing techniques.

The Water Board is reviewing its policies and procedures related to addressing the regulatory challenges posed by baylands multi-benefit wetland restoration projects proposed to address climate change resilience.

Proposed Basin Plan Amendment on Climate Change and Aquatic Habitat Protection, Management, and Restoration

The San Francisco Bay Regional Water Quality Control Board (Water Board) is accepting public comments on a proposed amendment to the Water Quality Control Plan for the San Francisco Bay Basin (Basin Plan). The proposed Basin Plan amendment provides information related to the challenge of climate change in the region, including to its aquatic habitats, and the Water Board’s participation in various regional efforts to address climate change. The amendment also provides information to assist in the planning and development of climate adaptation and other shoreline projects, based on the Water Board’s review of the evolving climate change science and its knowledge and expertise in coastal and estuarine management and permitting. The amendment also updates references, corrects errors, and makes minor, non-substantive edits for clarity. The amendment is informational and contains no new regulations.

The Water Board approved a previous version of this amendment in July 2022. The State Water Resources Control Board (State Board) did not decline to approve this previous version. After discussing with the State Board, the Water Board jointly decided to revise the Basin Plan Amendment to refine the language. The revisions do not substantively change the Basin Plan Amendment. Instead, they provide further clarity on the amendment, including its non-regulatory nature.

At its June 12, 2024 meeting, the Water Board approved the updated amendment; please see the materials linked below for more information:

Climate Change Preparedness Questionnaires

The Water Board has requested or required several facilities to prepare and submit vulnerability assessments. See the links here for the distributed questionnaires.

Sea Level Rise Adaptation Financing Workshop held July 8, 2020

Climate Change Priority Setting

April 10, 2019 Board Meeting Item on Wetlands and Climate Change

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