San Francisco Bay

Sniffing the Delta for Greenhouse Gases

San Francisco Estuary Partnership (SFEP) | June 16th, 2022

Global food production contributes an estimated 21% to 37% of the greenhouse gases that are warming the planet, including huge releases of carbon when vast aquatic ecosys

Global food production contributes an estimated 21% to 37% of the greenhouse gases that are warming the planet, including huge releases of carbon when vast aquatic ecosystems like the Delta are transformed for agriculture. [Dennis] Baldocchi and colleagues are now trying to figure out if bringing back tidal wetlands like the one at Dutch Slough can help reverse these processes.

Sonoma Creek Baylands Strategy

Sonoma Land Trust | May 1st, 2020

The purpose of the Strategy is to provide Sonoma Land Trust and partners with a clear and comprehensive plan that coordinates the protection, acquisition, restoration, an

The purpose of the Strategy is to provide Sonoma Land Trust and partners with a clear and comprehensive plan that coordinates the protection, acquisition, restoration, and enhancement of diverse baylands habitats (e.g., subtidal, mudflat, tidal marsh, brackish marsh, freshwater marsh, upland-wetland transition), integrates natural processes to increase climate resilience of the Sonoma Creek Baylands, identifies appropriate public access, and provides recommendations for the redesign of SR 37 and increased connectivity under and across the SMART rail line where they pass through the Sonoma Creek Baylands. 

Sonoma Valley Groundwater Sustainability Plan

Sonoma Water | January 29th, 2022

Sources, Pathways and Loadings: Multi-Year Synthesis with a Focus on PCBs and Hg

San Francisco Estuary Institute (SFEI) | December 15th, 2015

This report provides a synthesis of information gathered since 2000 on sources, pathways, and loadings of pollutants of concern in the San Francisco Bay Area with a focus

This report provides a synthesis of information gathered since 2000 on sources, pathways, and loadings of pollutants of concern in the San Francisco Bay Area with a focus on polychlorinated biphenyls (PCBs) and total mercury (Hg). Concentration and load estimates for other pollutants of concern (POC) are provided in the Appendix tables but not supported by any synthesis or discussion in the main body of the report. The PCB and Hg TMDLs for San Francisco Bay call for implementation of control measures to reduce stormwater PCB loads from 20 kg to 2 kg by 2030 and to reduce stormwater Hg loads from 160 kg to 80 kg by 2028 with an interim milestone of 120 kg by 2018. These are very challenging objectives given that the 2 kg PCB load allocation translates to a mean annual yield of 0.31 g/km2 for the free flowing areas downstream from reservoirs (6,650 km2), a mean annual concentration of 1.33 ng/L (assuming an annual average flow from small tributaries of 1.5 km3), and mean annual particle ratio of 1.4 ng/g of suspended sediment load (assuming an average annual suspended sediment load of 1.4 million metric t). Similarly for Hg, the 80 kg load allocation translates to a mean annual yield of 12 g/km2, a mean annual concentration of 53 ng/L, and mean annual particle ratio of 58 ng/g of suspended sediment load. Concentrations of these low magnitudes have been observed commonly in the Bay Area for Hg and yields of this low magnitude have been observed for PCBs and Hg. However, concentrations of PCBs at these magnitudes have only been observed in Marsh Creek (a more rural watershed) and particle ratios of PCBs and Hg as low as these have never been observed in the region.

South San Francisco Bay Salt Pond Restoration Project— A Synthesis of Phase-1 Mercury Studies

U.S. Geological Survey (USGS) | March 7th, 2023

The South Bay Salt Pond Restoration Project (SBSPRP) encompasses over 6,000 hectares of former salt production ponds along the south edge of the San Francisco Bay and rep

The South Bay Salt Pond Restoration Project (SBSPRP) encompasses over 6,000 hectares of former salt production ponds along the south edge of the San Francisco Bay and represents the largest wetland restoration effort on the west coast of North America. A series of studies associated with Phase 1 (2010–2018) restoration activities that are focused on a historically mercury contaminated slough and series of ponds within the restoration area have recently been completed. This report brings together the key findings of these loosely coordinated studies and integrates the results into a more comprehensive and holistic product that informs future restoration activities associated with the SBSPRP and elsewhere.

Southern California winter precipitation variability reflected in 100-year ocean salinity record

Nature Portfolio (Springer Nature) | April 27th, 2023

Rainfall in southern California is highly variable, with some fluctuations explainable by climate patterns. Resulting runoff and heightened streamflow from rain events in

Rainfall in southern California is highly variable, with some fluctuations explainable by climate patterns. Resulting runoff and heightened streamflow from rain events introduces freshwater plumes into the coastal ocean. Here we use a 105-year daily sea surface salinity record collected at Scripps Pier in La Jolla, California to show that El Niño Southern Oscillation and Pacific Decadal Oscillation both have signatures in coastal sea surface salinity. Averaging the freshest quantile of sea surface salinity over each year’s winter season provides a useful metric for connecting the coastal ocean to interannual winter rainfall variability, through the influence of freshwater plumes originating, at closest, 7.5 km north of Scripps Pier. This salinity metric has a clear relationship with dominant climate phases: negative Pacific Decadal Oscillation and La Niña conditions correspond consistently with lack of salinity anomaly/ dry winters. Fresh salinity anomalies (i.e., wet winters) occur during positive phase Pacific Decadal Oscillation and El Niño winters, although not consistently. This analysis emphasizes the strong influence that precipitation and consequent streamflow has on the coastal ocean, even in a region of overall low freshwater input, and provides an ocean-based metric for assessing decadal rainfall variability.

Spring 2017 Groundwater Level Data Summary

California Department of Water Resources (DWR) | October 3rd, 2022

This document presents a summary of fall 2017 groundwater level data available in the DWR groundwater level database as of February 21, 2018 and includes a discussion of

This document presents a summary of fall 2017 groundwater level data available in the DWR groundwater level database as of February 21, 2018 and includes a discussion of fall 2017, data coverage and groundwater level trends. Statewide precipitation data come from the U.S. Climate Divisional Database, which has data from January 1895 to the present.

Stacked Incentives: Co-Funding Water Customer Incentive Programs

Pacific Institute | June 1st, 2021

Water utilities throughout the United States offer customer incentives to motivate action and foster engagement. Incentive programs can take many forms, such as rebate

Water utilities throughout the United States offer customer incentives to motivate action and foster engagement. Incentive programs can take many forms, such as rebates for high-efficiency fixtures and appliances, technical assistance for installing cisterns and rain gardens, and educational programs about water reuse. In addition to providing water-related benefits, many of these programs generate additional co-benefits, including reductions in energy use for heating or treating water and wastewater, increased carbon sequestration in landscapes, enhancements to local biodiversity, and more. These co-benefits present water utilities with an opportunity to build collaborative partnerships and co-funding for customer incentive programs through “stacked incentives.”

Standardized Regulatory Impact Assessment of Proposed Making Conservation a California Way of Life Regulation

California State Water Resources Control Board (SWRCB) | June 21st, 2024

Water conservation in California overall, due to the proposed regulation and other conservation efforts by water suppliers and Californians generally, plus passive conser

Water conservation in California overall, due to the proposed regulation and other conservation efforts by water suppliers and Californians generally, plus passive conservation from prior conservation efforts, is estimated to save levels of water consistent with the goal mentioned in the Water Supply Strategy of the reduction of the water demand of towns and cities by half a million acre-feet per year. The proposed regulation serves as a backstop that is expected to cause new savings and “lock in” these other savings. As shown in the graph below, staff estimated that the proposed regulation would save approximately 30,000 acre-feet of water in 2027 (compared to the assumed 2027 baseline water use) and increased amounts in subsequent years, reaching almost 235,000 acre-feet of water in 2050 (compared to the assumed 2050 baseline water use). The total cumulative amount of water savings in the 2025-2050 period would be approximately 3.9 million acre-feet. More than half of the estimated water savings (approximately 52 percent) would come from the assumed residential water conservation measures, and the remainder (approximately 48 percent) from CII (Commercial, Industrial, and Institutional) performance measures.

State Investments in Delta Levees

Delta Stewardship Council (Delta Council) | January 1st, 2015

This 43-page Issue Paper, authored by Dustin Jones, the Council's Integrated Regional Water Management Supervising Engineer, is entitled State Investments in Delta Levees

This 43-page Issue Paper, authored by Dustin Jones, the Council's Integrated Regional Water Management Supervising Engineer, is entitled State Investments in Delta Levees, Key Issues for Updating Priorities. The Delta Reform Act requires that the Delta Plan promote strategic levee investments that attempt to reduce risks to people, property, and state interests in the Delta (Water Code section 85305) and recommend priorities for state investment in levee operation, maintenance, and improvements in the Delta (Water Code section 85306). In addition, the Delta Plan may identify actions to be taken outside of the Delta, if those actions are determined to significantly reduce flood risks in the Delta and may include local plans of flood protection (Water Code section 85307(a-b)). This paper outlines 15 issues that will need to be considered as the Council updates the Delta Plan’s provisions regarding State investment in the Delta’s levees. It summarizes background information about these issues, provides references for further information, and highlights key points to be addressed through the development of the Delta Levees Investment Strategy.