An integrated framework for stormwater management and life cycle assessment of rainwater harvesting: A comparative study of two underserved communities

Science of the Total Environment (Elsevier) | November 4th, 2024

Annual Report Clean Water State Revolving Fund and the Water Quality, Supply, and Infrastructure Improvement Act of 2014 State Fiscal Year 2017-2018

California State Water Resources Control Board (SWRCB) | December 30th, 2018

The California State Water Resources Control Board (State Water Board), Division of Financial Assistance (DFA) presents the Clean Water State Revolving Fund (CWSRF) annua

The California State Water Resources Control Board (State Water Board), Division of Financial Assistance (DFA) presents the Clean Water State Revolving Fund (CWSRF) annual report for State Fiscal Year (SFY) 2017-18. The State Water Board provided approximately $707 million in new CWSRF financing to 44 projects in SFY 2017-18, which represent a wide variety of projects eligible under the CWSRF. This report describes how the State Water Board met the objectives identified in the SFY 2017-18 CWSRF Intended Use Plan (IUP). 

Assessing Early Implementation of Urban Water Use Efficiency Requirements

Legislative Analyst's Office (LAO) | January 4th, 2024

Legislation approved in 2018 established a long‑term urban water use efficiency framework to “Make Conservation a California Way of Life.” This framework—which is

Legislation approved in 2018 established a long‑term urban water use efficiency framework to “Make Conservation a California Way of Life.” This framework—which is one component of the state’s overall water management strategy—creates new requirements for about 405 urban retail water suppliers that supply water to nearly 95 percent of state residents. This report responds to a requirement contained in the 2018 legislation for our office to assess implementation of the framework. (Our report is not able to address every aspect requested in the legislation due to framework implementation delays.)

Assessment of California's Water Footprint

Pacific Institute | December 11th, 2012

The Pacific Institute has released the first comprehensive assessment of California’s water footprint, providing an important perspective on the interconnections betwee

The Pacific Institute has released the first comprehensive assessment of California’s water footprint, providing an important perspective on the interconnections between everyday activities and impacts to water resources – both at home and around the world. The new report, California’s Water Footprint, analyzes the state’s water footprint – that is the amount of water required to produce the food we eat, the clothes we wear, the beverages we drink, and the other goods on which we rely. The water footprint of the average Californian is 1,500 gallons per day, slightly less than the average American but considerably more than the average resident in other developed countries or in the rest of the world.

Bulletin 132-77 The California State Water Project -- 1976 Activities and Future Management Plans

California Department of Water Resources (DWR) | November 30th, 1977

The 1975-76 and 1976-77 water years (a water year begins October 1 and extends through September 30) were the first years of critical water shortage since operation of th

The 1975-76 and 1976-77 water years (a water year begins October 1 and extends through September 30) were the first years of critical water shortage since operation of the State Water Project began in 1962. The shortage of new water supplies, which are far below the quantities normally expected during the winter and early spring seasons, has had far-reaching effects. The management of available State Water Project supplies on a day-to-day basis is critical during these times, for we must make most efficient use of available water supplies including the maintenance of water quality in the Delta as required by law. Although we don't know what next year may bring, we must prepare for another season of minimum precipitation. A public awareness program has been a part of the Department's responsibilities during the current drought, and we have done everything possible to inform the public of the critical situation at hand. The drought program has kept our water contractors and the people of California current with evaluations of what can be expected from the State Water Project during 1976 and within the foreseeable future.

Bulletin 132-78 The California State Water Project -- 1977 Activities and Future Management Plans

California Department of Water Resources (DWR) | October 31st, 1978

1977 was a bittersweet year for the State Water Project. The worst drought in our State's history limited our ability to serve our 31 water service contractors; yet at th

1977 was a bittersweet year for the State Water Project. The worst drought in our State's history limited our ability to serve our 31 water service contractors; yet at the same time the largest water exchange in the history of the State took place between urban users in the San Francisco Bay area, agricultural users in the San Joaquin Valley, and The Metropolitan Water District of Southern California with San Bernardino Valley Municipal Water District, Coachella Valley County Water District, and Desert Water Agency. This greatly helped to significantly reduce the magnitude of the shortage.

California Simulation of Evapotranspiration of Applied Water and Agricultural Energy Use in California

Journal of Integrative Agriculture (Elsevier) | August 5th, 2013

The California Simulation of Evapotranspiration of Applied Water (Cal-SIMETAW) model is a new tool developed by the California Department of Water Resources and t

The California Simulation of Evapotranspiration of Applied Water (Cal-SIMETAW) model is a new tool developed by the California Department of Water Resources and the University of California, Davis to perform daily soil water balance and determine crop evapotranspiration (ETc), evapotranspiration of applied water (ETaw), and applied water (AW) for use in California water resources planning. ETaw is a seasonal estimate of the water needed to irrigate a crop assuming 100% irrigation efficiency. The model accounts for soils, crop coefficients, rooting depths, seepage, etc. that influence crop water balance. It provides spatial soil and climate information and it uses historical crop and land-use category information to provide seasonal water balance estimates by combinations of detailed analysis unit and county (DAU/County) over California. The result is a large data base of ETc and ETaw that will be used to update information in the new California Water Plan (CWP). The application uses the daily climate data, i.e., maximum (Tx) and minimum (Tn) temperature and precipitation (Pcp), which were derived from monthly USDA-NRCS PRISM data (PRISM Group 2011) and daily US National Climate Data Center (NCDC) climate station data to cover California on a 4 km×4 km change grid spacing. The application uses daily weather data to determine reference evapotranspiration (ETo), using the Hargreaves-Samani (HS) equation (Hargreaves and Samani 1982, 1985). Because the HS equation is based on temperature only, ETo from the HS equation were compared with CIMIS ETo at the same locations using available CIMIS data to determine correction factors to estimate CIMIS ETo from the HS ETo to account for spatial climate differences. Cal-SIMETAW also employs near real-time reference evapotranspiration (ETo) information from Spatial CIMIS, which is a model that combines weather station data and remote sensing to provide a grid of ETo information. A second database containing the available soil water holding capacity and soil depth information for all of California was also developed from the USDA-NRCS SSURGO database. The Cal-SIMETAW program also has the ability to generate daily weather data from monthly mean values for use in studying climate change scenarios and their possible impacts on water demand in the state. The key objective of this project is to improve the accuracy of water use estimates for the California Water Plan (CWP), which provides a comprehensive report on water supply, demand, and management in California. In this paper, we will discuss the model and how it determines ETaw for use in water resources planning.

California Single Family Water Use Efficiency Study

California Department of Water Resources (DWR) | April 20th, 2011

The California Single Family Home Water Use Efficiency Study includes data from many traditional sources such as billing data, survey data, weather data and aerial photo

The California Single Family Home Water Use Efficiency Study includes data from many traditional sources such as billing data, survey data, weather data and aerial photo information to analyze the water use patterns of a sample of over 700 single-family homes across ten water agencies throughout the State of California. Detailed flow trace data was obtained from portable data loggers which were attached to the water meters of each of the study homes. These flow traces provided flow readings at ten second intervals from the magnetic pickup, which generate 80-100 pulses per gallon. These highly detailed flow data make it possible to identify individual water use events and to categorize them by their end-use. The flow trace data tell not just how many gallons per day the home used, but how many gallons per day were used for individual end uses such as toilet flushing, clothes washing, dishwashers, showers, irrigation, faucets and leaks. Detailed use information can be pulled from the trace, giving for example, a count of toilet flushes and toilet flush volumes during a logging period. Researchers used flow trace data to determine levels of daily use in the homes and the efficiency of that use. Although the flow trace technique contains marginal error, such as from the mis-categorization of some events, it provides information on end uses-that is not available from any other source. This report summarizes the results of the study which began in 2005 and was completed in 2010. Water use patterns found during the 2007 logging period were analyzed to show how much potential remains for conservation savings from both indoor and outdoor efforts. 

California Water Resilience Portfolio

State of California | July 28th, 2020

California’s Next Million Acre-Feet: Saving Water, Energy, and Money

Pacific Institute | September 26th, 2010

A new analysis from the Pacific Institute recommends specific actions that can annually save a million acre-feet of water quickly and at a lower economic and ecological c

A new analysis from the Pacific Institute recommends specific actions that can annually save a million acre-feet of water quickly and at a lower economic and ecological cost than developing new supplies. The assessment notes that new actions are immediately needed to reduce the growing tensions over the state’s water resources and to address California’s persistent water supply challenges. This is a key time for California water: the California Water Bond has been tabled for at least two years and may be scrapped altogether. New reviews from around the state are calling for prompt efforts to use technology, economics, and institutional reform to address the state’s water crisis. All parties seem to agree that the state will need a diverse portfolio of solutions – but it makes the most sense to do the most effective things first. The Pacific Institute’s new report, California’s Next Million Acre-Feet: Saving Water, Energy, and Money, quantifies more than one million acre-feet of water that can be conserved through improved efficiency, with savings coming from the urban and industrial sectors and improvements in agriculture. “There is vast untapped potential to reduce our demand for water without affecting the services and benefits that water provides,” said Heather Cooley, co-director of the Pacific Institute’s Water Program and lead author of the report. “We identified how the next million acre-feet of water can be conserved in California, with approximately 30% of the savings from the urban sector and 70% from the agricultural sector. Both sectors have savings potential far exceeding this amount, and while we could have identified one million acre-feet of water savings annually in either sector alone, we’re showing how all sectors can benefit from these improvements.” In the urban sector, the report identifies water savings from replacing old, inefficient water-using devices with high-efficiency models in our homes and businesses, as well as replacing some lawns with low-water-use plants. In the agricultural sector, best water management practices include weather-based irrigation scheduling, regulated deficit irrigation, and switching from gravity or flood irrigation to sprinkler or drip irrigation systems. The efficiency improvements identified in California’s Next Million Acre-Feet require an upfront investment of less than $1.9 billion, costs that could be borne by a mix of state, federal, and local agencies and individuals – all at a small fraction of the cost of the proposed water bond. The cost of the conserved water is $185 per acre-foot for the agricultural sector and a net savings of $99 per acre-foot for the urban sector, over the lifetime of the efficiency improvement. Conserving water also conserves energy, saves money, and reduces the need for new water and energy projects.