Water Supply Conditions in Southern California during 1958-1959, Volume II, Water Level Data, Central Coastal and Los Angeles Regions

California Department of Water Resources (DWR) | May 1st, 1961

Water Surplus and Drought Management Update - Conditions as of 11/29/2022

Metropolitan Water District of Southern California (MWD) | December 13th, 2022

Water transfers (Resource Management Strategy)

California Department of Water Resources (DWR) | July 29th, 2016

The California Water Code (CWC) defines a water transfer as a temporary or long-term change in the point of diversion, place of use, or purpose of use due to a transfer,

The California Water Code (CWC) defines a water transfer as a temporary or long-term change in the point of diversion, place of use, or purpose of use due to a transfer, sale, lease, or exchange of water or water rights. Temporary water transfers have a duration of one year or less (CWC Section 1725). Long-term water transfers have a duration of more than one year (CWC Section 1728). Transfers can be between water districts that are neighboring or across the state, provided there is a means to convey or store the water. A water transfer can be a temporary or permanent sale of water or a water right by the water right holder, a lease of the right to use water from the water right holder, or a sale or lease of a contractual right to water supply. Water transfers can also take the form of long-term contracts for the purpose of improving long-term supply reliability.

Water Year 2023: Weather Whiplash, from Drought to Deluge

California Department of Water Resources (DWR) | October 4th, 2023

Water Year 2023 demonstrated California’s high climate variability, ending the state’s driest consecutive three-year period with one of the snowiest years of record.

Water Year 2023 demonstrated California’s high climate variability, ending the state’s driest consecutive three-year period with one of the snowiest years of record. Even though California has been experiencing a theme of aridity in the 21st century (the statewide droughts of 2007-2009, 2012-2019, and 2020-2022), Water Year 2017 was the state’s second wettest in terms of statewide precipitation. Climate change is expected to amplify naturally occurring variability in the long term, potentially result in a shorter wet season for California but one with more extreme atmospheric river storms and hence potentially greater flood damage risk.

Water, energy and environment nexus: The California experience

International Journal of Water Resources Development (Taylor & Francis) | July 21st, 2010

The paper addresses the local and inter-state connections between water, energy and the environment. Using California and the western USA as a case study, the paper highl

The paper addresses the local and inter-state connections between water, energy and the environment. Using California and the western USA as a case study, the paper highlights the difficulties of balancing the needs of diverse stakeholders and protecting valuable resources while providing reliable and safe supplies of both water and energy to agricultural, industrial and residential customers. The investigation of these complex relationships is necessary to inform local and national policy decisions regarding the management of water, energy and the environment.

Water, environment, and socioeconomic justice in California: A multi-benefit framework

Science of the Total Environment (Elsevier) | November 5th, 2022

Low-income, rural frontline communities of California's Central Valley experience environmental and socioeconomic injustice, water insecurity, extremely poor air quality,

Low-income, rural frontline communities of California's Central Valley experience environmental and socioeconomic injustice, water insecurity, extremely poor air quality, and lack of fundamental infrastructure (sewage, green areas, health services), which makes them less resilient. Many communities depend financially on agriculture, while water scarcity and associated policy may trigger farmland retirement, further hindering socioeconomic opportunities. Here we propose a multi-benefit framework to repurpose cropland in buffers inside and around (400-m and 1600-m buffers) 154 rural disadvantaged communities of the Central Valley to promote socioeconomic opportunities, environmental benefits, and business diversification. We estimate the potential for (1) reductions in water and pesticide use, nitrogen leaching, and nitrogen gas emissions, (2) managed aquifer recharge, and (3) economic and employment impacts associated with clean industries and solar energy. Retiring cropland within 1600-m buffers can result in reductions in annual water use of 2.18 km3/year, nitrate leaching into local aquifers of 105,500 t/year, greenhouse gas emissions of 2,232,000 t CO2-equivalent/year, and 5388 t pesticides/year, with accompanying losses in agricultural revenue of US$4213 million/year and employment of 25,682 positions. Buffer repurposing investments of US$27 million/year per community for ten years show potential to generate US$101 million/year per community (total US$15,578 million/year) for 30 years and 407 new jobs/year (total 62,697 jobs/year) paying 67 % more than prior farmworker jobs. In the San Joaquin Valley (southern Central Valley), where groundwater overdraft averages 2.3 km3/year, potential water use reduction is 1.8 km3/year. We have identified 99 communities with surficial soils adequate for aquifer recharge and canals/rivers within 1600 m. This demonstrates the potential of managed aquifer recharge in buffered zones to substantially reduce overdraft. The buffers framework shows that well-planned land repurposing near disadvantaged communities can create multiple benefits for agriculture and industry stakeholders, while improving quality of life in disadvantaged communities and producing positive externalities for society.

Water/Wastewater Utilities and Extreme Climate and Weather Events: Case Studies on Community Response, Lessons Learned, Adaptation, and Planning Needs for the Future

Water Research Foundation | July 21st, 2014

This project consisted of a series of workshops that (1) examined the actions taken by water and wastewater utility practitioners who faced a recent extreme weather and c

This project consisted of a series of workshops that (1) examined the actions taken by water and wastewater utility practitioners who faced a recent extreme weather and climate-related event and documented their planning and response; (2) determined and recorded lessons learned; (3) documented and analyzed the decision process, including decision makers, organizations involved, and data needed for making decisions when faced with an extreme event; and (4) summarized communication approaches used to inform the public. The final report, published by WERF, consists of the workshop results and a series of case studies highlighting lessons learned and recommended actions. Additionally, the case studies were published separately and are available on this project page under Project Resources/Project Papers.

Waterline responses to climate forcing along the North American West Coast

Nature Portfolio (Springer Nature) | June 7th, 2025

Understanding waterline variability at seasonal to interannual timescales is crucial for predicting coastal responses to climate forcing. However, relationships between l

Understanding waterline variability at seasonal to interannual timescales is crucial for predicting coastal responses to climate forcing. However, relationships between large-scale climate variability and coastal morphodynamics remain underexplored beyond intensively monitored sites. This study leverages a newly developed 25-year (1997–2022) satellite-derived waterline dataset along the North American West Coast. Our results reveal distinct latitudinal patterns in seasonal waterline change, with excursions exceeding 25 m in the Pacific Northwest, decreasing to less than 10 m in Southern California and farther south. Waterline fluctuations strongly follow wave power in the Pacific Northwest (R = −0.78), northern California (R = −0.75), and Baja California (R = −0.62), while Baja California Sur aligns more with sea-level variations (R = −0.42). Interannually, waterline change exhibits latitudinal dependence: south of southern California, variability is low, with major erosion confined to strong El Niño-Southern Oscillation (ENSO) events, while northern regions show mixed responses. ENSO-driven storm track shifts modulate winter wave climate, resulting in enhanced (attenuated) erosion from southern California to Baja California Sur during El Niño (La Niña). However, further north, ENSO impacts are less consistent, reflecting a complex interplay of storm track displacement and intensification. These findings highlight the spatial complexity of ENSO-driven morphodynamics and provide a framework for assessing climate-induced coastal vulnerability.

WESim – The Water-Energy Simulator – Helps Water and Energy Managers Plan for Change

Pacific Institute | July 5th, 2012

The Water–Energy Simulator (WESim) is an easy-to-use analytical tool that can be used to evaluate the energy and greenhouse gas implications of water management decisio

The Water–Energy Simulator (WESim) is an easy-to-use analytical tool that can be used to evaluate the energy and greenhouse gas implications of water management decisions. The Excel-based model allows the user to explore a range of possible scenarios, such as increased demand for water resources, the development of alternative water and energy sources, and needed water treatment improvements resulting from emerging contaminants and stricter water-quality guidelines. WESim can be applied by individual water and energy utilities, groups of utilities, and policymakers and decision makers. A WESim User Manual and report, Implications of Future Water Supply Sources for Energy Demands, are provided, as well. Water provision and use require energy in all phases, from source extraction to the discharge of wastewater. Multiple factors will influence the energy intensity of the water sector in the near future: climate change will affect water supply, quality, and demand, potentially creating a need for new energy-intensive supply and treatment options; population growth, water use patterns, technology, and price all will affect water demand; and emerging contaminants may require more energy-intensive treatment technologies. These trends highlight the need for a clear and consistent methodology for evaluating the energy and greenhouse gas implications of water management decisions. WESim addresses this need, as a tool that creates a common framework in which to explore alternative scenarios. The model is designed to allow you to input actual operating data on water and energy use, allowing for an analysis that better reflects operating conditions. To facilitate use of the model, defaults for the energy requirements of various components of the water and wastewater system are provided, as well. WESim was developed by The Pacific Institute and Dr. Bob Wilkinson, with support from the WateReuse Research Foundation, the California Energy Commission, and the Canadian Mortgage and Housing Corporation.

Westside Sacramento Integrated Regional Water Management Plan Update

Westside Sacramento Regional Water Management Group | January 3rd, 2019

This Integrated Regional Water Management Plan (IRWM Plan) defines a clear vision for the management of water resources in the Westside Sacramento Region (Region) and

This Integrated Regional Water Management Plan (IRWM Plan) defines a clear vision for the management of water resources in the Westside Sacramento Region (Region) and highlights important actions needed to help accomplish that vision through the year 2040. This IRWM Plan Update complies with the 2016 Integrated Regional Water Management Grant Program Guidelines applicable to Proposition 1 IRWM grant funding published by the California Department of Water Resources (DWR) in July 2016. This IRWM Plan defines a clear vision for the management of water resources in the Region and highlights important actions needed to help accomplish that vision through the year 2040. The 2018 IRWM Plan complies with the Integrated Regional Water Management Guidelines for Proposition 1 published by DWR in November 2016.