Sacramento River

Balancing Flood Risk and Water Supply in California: Policy Search Integrating Short-Term Forecast Ensembles With Conjunctive Use

American Geophysical Union (AGU) | September 24th, 2018

Short-term weather forecasts have the potential to improve reservoir operations for both flood control and water supply objectives, especially in regions currently relyin

Short-term weather forecasts have the potential to improve reservoir operations for both flood control and water supply objectives, especially in regions currently relying on fixed seasonal flood pools to mitigate risk. The successful development of forecast-based policies should integrate uncertainty from modern forecast products to create unambiguous rules that can be tested on out-of-sample periods. This study investigates the potential for such operating policies to improve water supply efficiency while maintaining flood protection, combining state-of-the-art weather hindcasts with downstream conjunctive use to transfer surplus flood releases to groundwater storage. Because available weather hindcasts are relatively short (10–20 years), we propose a novel statistical framework to develop synthetic forecasts over longer periods of the historical record. Operating rules are trained with a recently developed policy search framework in which decision rules are structured as binary trees. Policies are developed for a range of scenarios with varying forecast skill and conjunctive use capacity, using Folsom Reservoir, California, as a case study. Results suggest that the combination of conjunctive use and short-term weather forecasts can substantially improve both water supply and flood control objectives by allowing storage to remain high until forecasts trigger a release. Further, increased conjunctive use capacity reduces the importance of forecast skill, since surface storage can be moved to groundwater during the flood season without losing water supply. This analysis serves the development of forecast-based operating policies for large, multipurpose reservoirs in California and other regions with similar flood hydroclimatology.

Base of fresh ground water (approximately 3,000 micromhos) in the San Joaquin Valley, California

U.S. Geological Survey (USGS) | June 30th, 1971

Widespread pumping of groundwater in the San Joaquin Valley began about 1900, and since 1940 pumpage has increased at an accelerated rate. In response to the heavy withdr

Widespread pumping of groundwater in the San Joaquin Valley began about 1900, and since 1940 pumpage has increased at an accelerated rate. In response to the heavy withdrawal of groundwater, water levels have declined rapidly beneath extensive areas of the valley. Consequently, it becomes necessary to delineate the base of fresh groundwater so that changes in thickness of the fresh-water zone can be monitored, and limited depths of water wells can be determined. In turn, those data will be useful in determining favorable areas for groundwater storage, and areas and depths for waste-water disposal wells. Because other agencies and the U.S. Geological Survey have collected a vast amount of well log and other data, most of the information in this report was assembled from existing files. However, for areas where data were scanty, a few hundred additional electrical logs were collected to supplement the available information.

Basic & Urgent: Realizing the Human Right to Water & Sanitation for Californians Experiencing Homelessness

University of California, Berkeley (UC Berkeley) | August 15th, 2018

The report’s three main sections follow this executive summary. The Problem Overview examines: what is driving what one source called an “explosion” in the numbe

The report’s three main sections follow this executive summary. The Problem Overview examines: what is driving what one source called an “explosion” in the number of Californians who are unsheltered; the stark reality of a severe shortfall between the number of affordable housing units needed and the number that will be available for the foreseeable future; the many problems associated with failing to ensure access to water and sanitation for homeless Californians, and how access to these basic needs compares with international minimum standards; and key barriers to progress. The Case Studies on Berkeley, Oakland, and Sacramento offer: an inventory of publicly available potable water, toilets, and showers in the three cities; discussion of how unsheltered residents struggle to meet their basic water-related needs; and an examination of municipal, non-profit, and resident-driven efforts to connect people experiencing homelessness to water and sanitation. Finally, based on the research conducted for this report, the Recommendations section offers six policies, programs, and actions that advocates can bring to State or municipal leaders responsible for upholding the human rights to water and sanitation for all Californians, particularly the State’s most vulnerable unsheltered residents.

Battling the Inland Sea

University of California Press | July 1st, 1998

Bay Area Green Infrastructure Water Quality Synthesis

San Francisco Estuary Institute (SFEI) | June 1st, 2018

San Francisco Bay is impacted by the numerous urban pollutants that flow from the surrounding landscape during storm events. In San Francisco Bay, total maximum daily lo

San Francisco Bay is impacted by the numerous urban pollutants that flow from the surrounding landscape during storm events. In San Francisco Bay, total maximum daily load (TMDL) clean-up plans are in place for polychlorinated biphenyls (PCBs) and mercury (Hg) (Davis et al., 2007; Davis et al., 2012). As municipalities strive to reach regulatory targets, green infrastructure (GI) presents a promising solution for managing stormwater pollutants while achieving additional environmental and social benefits. However, remaining data gaps including the best design layout, media composition, and vegetation and submerged zone effects on performance can prevent local managers from accurately assessing water quality benefits provided by green infrastructure as well as the maintenance needs to sustain adequate performance.

Bay Area Water Supply Resilience and the Bay-Delta Plan

Publisher not available | March 15th, 2024

Bay Delta Water Quality Control Plan (Bay Delta Plan)

California State Water Resources Control Board (SWRCB) | December 13th, 2006

"Bay Delta Plan" is short for the State Water Resources Control Board's (State Water Board) San Francisco Bay/Sacramento-San Joaquin Delta Estuary Water Quality Control P

"Bay Delta Plan" is short for the State Water Resources Control Board's (State Water Board) San Francisco Bay/Sacramento-San Joaquin Delta Estuary Water Quality Control Plan. The Bay-Delta Plan identifies the beneficial uses of the Bay-Delta, water quality objectives for the reasonable protection of those beneficial uses, and a program of implementation for achieving the objectives. The Bay-Delta Plan, when implemented, can determine the amount and timing of water entering and moving through the Delta. The State Water Board holds dual responsibilities of allocating surface water rights and protecting water quality. The State Water Board allocates water through an administrative system that is intended to maximize the beneficial uses of water while protecting the public trust, serving the public interest, and preventing the waste and unreasonable use or method of diversion of water. While most water quality control planning is done by the Regional Water Boards, the State Water Board has authority to adopt statewide water quality control plans. The State Water Board adopts the Bay-Delta Plan because of the Delta's importance as a major source of water supply for the state. The Bay-Delta Plan protects water quality in the region and includes water quality objectives to protect fish and wildlife beneficial uses through inflows to the Delta from the Sacramento and San Joaquin rivers and Delta outflows, in addition to objectives for salinity to protect agricultural beneficial uses. The State Water Resources Control Board (State Water Board) is in the process of a phased review and update of the 2006 Water Quality Control Plan for the San Francisco Bay/Sacramento-San Joaquin Delta Estuary (Bay-Delta) (referred to as the 2006 Bay-Delta Plan). To learn more about the Bay-Delta Plan, click here. In 2009, the State Water Board began the process of reviewing and likely revising the 2006 Bay Delta Plan.  At the time of the archiving of this document, that update process still continues.  For the latest information, click here to visit the State Water Resources Control Board page for the Bay-Delta Plan Update.. RELATED DOCUMENT: Water Rights Decision 1641, the document that implements the 1995 Bay Delta Plan and is still in force.

Beale Air Force Base Environmental Cleanup Program Issue 67

U.S. Air Force | October 31st, 2015

Before the Well Runs Dry: Improving the Linkage Between Groundwater and Land Use Planning

Stanford University | April 17th, 2014

There is no comprehensive regulation of groundwater use in the state of California,* and the right to withdraw groundwater is based on surface land ownership. This create

There is no comprehensive regulation of groundwater use in the state of California,* and the right to withdraw groundwater is based on surface land ownership. This creates a direct linkage between every land use that requires water and the groundwater underneath that land. Because so many aspects of groundwater use are not regulated by the state, local governments’ land use decisions become a key driver of demands on groundwater. Nonetheless, land use decisions and planning are not well coordinated with groundwater management. Understanding how land use decisions affect groundwater resources has become increasingly important in recent years, as groundwater provides approximately 30 percent of California’s water supply in average years and 40 percent of the supply in dry years. In some places, the reliance on groundwater during droughts is much higher, due to reduced supplies of surface water. Growth from housing and irrigated agriculture, among other demands, have led to chronic overdraft and declining groundwater elevations in many communities that rely heavily on groundwater. To address this problem, Water in the West convened groundwater managers, land use planners, water lawyers, consultants and academics at Stanford University for an Uncommon Dialogue in the fall of 2013. Its aim was to discuss a growing consensus that more effective integration of land use planning and groundwater management is an essential component of preserving groundwater aquifers for the future, and to share possible means of accomplishing this in California. This report, shaped in part by the Dialogue, provides the background and regulatory context for land use planning and groundwater management in California, shares case studies that highlight the intersection of groundwater and land use, and makes specific recommendations to improve the linkage between land use decisions and groundwater management in the state. *The Sustainable Groundwater Management Act (SGMA) was signed into law five months after this was published. 

Beneath the Surface: Why Reservoirs Won't Solve California's Water Woes

Center for Biological Diversity (CBD) | November 19th, 2024

Water storage and conveyance have fundamentally shaped modern California. The vast agricultural industry, as well as globally important cities like Los Angeles, were made

Water storage and conveyance have fundamentally shaped modern California. The vast agricultural industry, as well as globally important cities like Los Angeles, were made possible by storing and moving water around the state. Reservoirs are one of the primary components of California’s water storage system. There are nearly 1,500 surface storage reservoirs throughout the state, which together can store a year’s supply of water for farms and cities. But reservoirs come with high costs. They destroy and degrade habitats and alter flows in rivers and streams, harming native fish and wildlife. They emit significant amounts of greenhouse gases, worsening climate change. They cost taxpayers billions of dollars to build and maintain. And as the climate continues to warm, reservoirs will become less efficient, losing more and more of the water they hold to evaporation.  This report examines reservoirs’ environmental harms and explains why new reservoirs are not the solution to our 21st century water problems.