San Francisco Bay

Hydropower capacity factors trending down in the United States

Nature Portfolio (Springer Nature) | June 27th, 2024

Identifying and Addressing Contaminant Sources Impacting an Urban Estuary

San Francisco Estuary Institute (SFEI) | July 1st, 2016

Identifying and Overcoming Barriers to Climate Change Adaptation in San Francisco Bay: Results from Case Studies

California Energy Commission (CEC) | July 31st, 2012

The research goals of this project were threefold: (1) to systematically identify the adaptation barriers encountered by local government entities in San Francisco Bay; (

The research goals of this project were threefold: (1) to systematically identify the adaptation barriers encountered by local government entities in San Francisco Bay; (2) to test empirically the robustness and usefulness of a diagnostic framework (previously developed by the authors) so as to modify or refine its components; and (3) to draw larger lessons about the adaptation process and the importance of adaptation barriers—even in highly developed nations—for the scientific community in terms of future research priorities and for policy-makers. To fulfill these goals, an in-depth study of five California case studies in the San Francisco Bay region (Hayward, San Francisco, Santa Clara and Marin Counties, and the regional adaptation process) was undertaken. Relevant data were collected through key informant interviews, public documents, observation of and/or participation in public meetings, and a statewide survey. The study found growing, but still very limited activities in the case studies. Institutional and attitudinal barriers dominate, but economic barriers are also important, even in wealthy locales. Leadership emerged as a critical factor in moving them forward on adaptation. Science mattered some, but policy and planning opportunities were more significant in motivating or launching the adaptation process. The study also found that communities have assets, aids, and advantages that can help them avoid barriers and that there is significant opportunity to affect and overcome the barriers that are being encountered in the “here and now.” However, local communities need outside intervention to address “legacy” and “remote” barriers. With still very little visible adaptation activity “on the ground,” the study concluded that a big portion of what communities are doing to date is working on overcoming the barriers to adaptation instead.

Identifying the Amount of Wastewater that is Available and Feasible to Recycle in California

Water Research Foundation (WRF) | July 24th, 2023

Impacts of ocean acidification on marine organisms: quantifying sensitivities and interaction with warming

Wiley | February 21st, 2013

Ocean acidification represents a threat to marine species worldwide, and forecasting the ecological impacts of acidification is a high priority for science, management, a

Ocean acidification represents a threat to marine species worldwide, and forecasting the ecological impacts of acidification is a high priority for science, management, and policy. As research on the topic expands at an exponential rate, a comprehensive understanding of the variability in organisms' responses and corresponding levels of certainty is necessary to forecast the ecological effects. Here, we perform the most comprehensive meta‐analysis to date by synthesizing the results of 228 studies examining biological responses to ocean acidification. The results reveal decreased survival, calcification, growth, development and abundance in response to acidification when the broad range of marine organisms is pooled together. However, the magnitude of these responses varies among taxonomic groups, suggesting there is some predictable trait‐based variation in sensitivity, despite the investigation of approximately 100 new species in recent research. The results also reveal an enhanced sensitivity of mollusk larvae, but suggest that an enhanced sensitivity of early life history stages is not universal across all taxonomic groups. In addition, the variability in species' responses is enhanced when they are exposed to acidification in multi‐species assemblages, suggesting that it is important to consider indirect effects and exercise caution when forecasting abundance patterns from single‐species laboratory experiments. Furthermore, the results suggest that other factors, such as nutritional status or source population, could cause substantial variation in organisms' responses. Last, the results highlight a trend towards enhanced sensitivity to acidification when taxa are concurrently exposed to elevated seawater temperature.

Impacts of Predicted Sea-Level Rise and Extreme Storm Events on the Transportation Infrastructure in the San Francisco Bay Region

California Energy Commission (CEC) | July 31st, 2012

Literature concerning the potential effect of climate change (sea‐level rise inundation and 100‐year storm events) on the San Francisco Bay region’s transportation

Literature concerning the potential effect of climate change (sea‐level rise inundation and 100‐year storm events) on the San Francisco Bay region’s transportation infrastructure is reviewed. Currently available geographical information system data is employed, and a review of how those datasets have been used in previous studies is reported. The second part of this paper presents methods. They include a higher‐resolution digital elevation model for the Bay Area; a new approach using a digital surface model is introduced to improve the surface elevations of features and better calculate the risk of over‐topping by sea level shifts and storm surges. A metric to assess change in the transportation infrastructure is introduced that calculates accessibility of first responders to the population at large. Sea level rise is incremented to the expected 1.4 meters in tandem with a 100‐year flood to analyze the extent to which transportation assets are at risk of inundation. The increased travel time from first responder locations to all neighborhoods in the region is measured for each iteration of the model. Local accessibility analysis for the entire San Francisco Bay region is performed to provide a synoptic view. Two localities are chosen to view in detail the impact on first‐responder accessibility caused by sea level rise and a 100‐year storm event. Next, the regional vulnerability of the transportation network to these events is assessed. This is accomplished by creating nodes that are the intersections of the major regional highways that surround the Bay. The loss of accessibility is measured by calculating the changes in travel time between these major nodes through iterations of our inundation model. Finally, the accessibility impacts to the hinterland from the major highway intersections for each peak water level iteration is determined, calculating the first and last 20 minutes of an origin‐destination journey.

Implementing Climate-Smart Conservation

Public Policy Institute of California (PPIC) | March 4th, 2025

In our first report, Climate-Smart Tools to Protect California’s Freshwater Biodiversity (Sommer et al. 2024), we reviewed a broad suite of tools available to a

In our first report, Climate-Smart Tools to Protect California’s Freshwater Biodiversity (Sommer et al. 2024), we reviewed a broad suite of tools available to address the urgent problem of safeguarding California’s freshwater biodiversity in the changing climate. This toolbox includes some familiar approaches—such as various ways to improve freshwater habitat—as well as approaches that may be less familiar, more experimental, and more controversial. We also recommended the adoption of a climate-smart conservation planning process, involving a broad range of stakeholders, to prioritize the selection of tools within watersheds and to adaptively implement those tools. In this follow-up report, we explore the feasibility of implementing these tools and climate-smart planning in light of legal, policy, and institutional factors.2 Our analysis draws on an extensive review of the legal literature on ecosystem and protected species management, as well as interviews and small workshops with a wide-ranging set of 45 experts from all over the state. These experts are working on the frontlines of ecosystem policy and management; they include state and federal regulators, members of the environmental conservation community, legal professionals, and representatives of many entities involved in water and land management.

Implementing Ecosystem Based Management

Duke Environmental Law & Policy Forum | June 7th, 2021

Implications of projected climate change for groundwater recharge in the western United States

Journal of Hydrology (Elsevier) | March 1st, 2016

Existing studies on the impacts of climate change on groundwater recharge are either global or basin/location-specific. The global studies lack the specificity to inform

Existing studies on the impacts of climate change on groundwater recharge are either global or basin/location-specific. The global studies lack the specificity to inform decision making, while the local studies do little to clarify potential changes over large regions (major river basins, states, or groups of states), a scale often important in the development of water policy. An analysis of the potential impact of climate change on groundwater recharge across the western United States (west of 100 longitude) is presented synthesizing existing studies and applying current knowledge of recharge processes and amounts. Eight representative aquifers located across the region were evaluated. For each aquifer published recharge budget components were converted into four standard recharge mechanisms: diffuse, focused, irrigation, and mountain-systems recharge. Future changes in individual recharge mechanisms and total recharge were then estimated for each aquifer. Model-based studies of projected climate-change effects on recharge were available and utilized for half of the aquifers. For the remainder, forecasted changes in temperature and precipitation were logically propagated through each recharge mechanism producing qualitative estimates of direction of changes in recharge only (not magnitude). Several key patterns emerge from the analysis. First, the available estimates indicate average declines of 10–20% in total recharge across the southern aquifers, but with a wide range of uncertainty that includes no change. Second, the northern set of aquifers will likely incur little change to slight increases in total recharge. Third, mountain system recharge is expected to decline across much of the region due to decreased snowpack, with that impact lessening with higher elevation and latitude. Factors contributing the greatest uncertainty in the estimates include: (1) limited studies quantitatively coupling climate projections to recharge estimation methods using detailed, process-based numerical models; (2) a generally poor understanding of hydrologic flowpaths and processes in mountain systems; (3) difficulty predicting the response of focused recharge to potential changes in the frequency and intensity of extreme precipitation events; and (4) unconstrained feedbacks between climate, irrigation practices, and recharge in highly developed aquifer systems.

Improving Groundwater Security in the United States

The White House | December 14th, 2024

The U.S. is facing a serious and unprecedented groundwater challenge. In many aquifers, groundwater withdrawal has outpaced natural recharge, which is exacerbated by the

The U.S. is facing a serious and unprecedented groundwater challenge. In many aquifers, groundwater withdrawal has outpaced natural recharge, which is exacerbated by the changing climate and precipitation variability. Much of the water in the major aquifers in the U.S. is fossil water, recharged over 10,000 years ago, and will not be replaced naturally on human timescales. In the western U.S., groundwater resources are being depleted at alarming rates, mostly from agricultural withdrawal. The depletion has caused land subsidence and earth fissures as well as permanent reduction of storage capacity. The depletion has national and global consequences as non-renewable groundwater in the west is embedded in agricultural products transported to the rest of the U. S. and in agricultural commodities exported globally. Many federal agencies have programs to measure the quality and quantity of groundwater, as well as conservation programs for sustainable use of groundwater. PCAST applauds and endorses their efforts as well as those by state governments, non-governmental organizations, professional organizations, local communities, private citizens, and others, to manage their groundwater resources. To ensure the sustainability of this indispensable resource and mitigate risks from its depletion, it is imperative that we enhance our understanding and management of groundwater resources.