Colorado River

Small Water Systems and Rural Communities Drought and Water Shortage Contingency Planning and Risk Assessment, Part 2

California Department of Water Resources (DWR) | March 25th, 2021

This report is submitted pursuant to California Water Code (CWC) Section 10609.42 which directs California Department of Water Resources (DWR) to identify small water sup

This report is submitted pursuant to California Water Code (CWC) Section 10609.42 which directs California Department of Water Resources (DWR) to identify small water suppliers and rural communities that may be at risk of drought and water shortage vulnerability and propose recommendations and information in support of improving the drought preparedness of small water suppliers and rural communities. The report is published in two parts: Part 1 dealing with drought and water shortage contingency planning recommendations, and Part 2 presenting a methodology and results of drought and water shortage vulnerability assessment and risk scoring. Additionally, below are links for Part 2 appendices. Appendix 1: Drought and Water Shortage Risk Scoring: California’s Small Water Supplier and Self-Supplied Communities Appendix 2: Drought and Water Shortage Risk Scoring: Risk Score Results of Small Water Suppliers Appendix 3: Drought and Water Shortage Risk Scoring: Risk Score Results of Self-Supplied Communities

Snowmelt risk telecouplings for irrigated agriculture

Nature Portfolio (Springer Nature) | October 31st, 2022

Climate change is altering the timing and magnitude of snowmelt, which may either directly or indirectly via global trade affect agriculture and livelihoods dependent on

Climate change is altering the timing and magnitude of snowmelt, which may either directly or indirectly via global trade affect agriculture and livelihoods dependent on snowmelt. Here, we integrate subannual irrigation and snowmelt dynamics and a model of international trade to assess the global redistribution of snowmelt dependencies and risks under climate change. We estimate that 16% of snowmelt used for irrigation is for agricultural products traded globally, of which over 70% is from five countries. Globally, we observe a prodigious snowmelt dependence and risk diffusion, with particularly evident importing of products at risk in western Europe. In Germany and the UK, local fraction of surface-water-irrigated agriculture supply exposed to snowmelt risks could increase from negligible to 16% and 10%, respectively, under a 2 °C warming. Our results reveal the trade-exposure of agricultural supplies, highlighting regions and crops whose consumption may be vulnerable to changing snowmelt even if their domestic production is not.

Southeast California Regional Basin Study

U.S. Bureau of Reclamation (USBR) | September 1st, 2015

The United States Department of the Interior’s WaterSMART (Sustain and Manage America’s Resources for Tomorrow) Basin Study Program is a 21st Century approach to help

The United States Department of the Interior’s WaterSMART (Sustain and Manage America’s Resources for Tomorrow) Basin Study Program is a 21st Century approach to help address water supply challenges. The Southeast California Regional Basin Study (Study) takes a collaborative approach to solve local water supply and regional conveyance and storage issues. As part of this Study, the Bureau of Reclamation’s Southern California Area Office cooperated with the Borrego Water District (BWD), Coachella Valley Water District (CVWD), Imperial Irrigation District (IID) and other interested regional stakeholders to assess water supply and demand challenges in the Southeast California region. This Study’s report is comprised of seven chapters; they are: introduction, supply, demand, alternative strategies, alternative analysis, findings, and references. Three appendices provide additional details regarding climate change modeling results, engineering design and economic analysis. The Study focuses on a regional area encompassing the Coachella, Borrego and Imperial Valleys. The Study addresses current and future supply and demand imbalances, provides an assessment of existing infrastructure resources, and develops options and alternatives to solve identified issues and help plan for an uncertain water supply future. The local stakeholders provided substantial informational resources on historical and projected supply and demand, and existing infrastructure. The water districts’ background information includes numerous groundwater, urban water and integrated regional planning studies, all of which were produced and/or updated between 2010 and 2012. Extensive supply and demand studies for the Colorado River Basin and California’s Central Valley – the two imported water supply sources for the Study area – also contributed data to this Study. Reclamation’s Colorado River Basin Water Supply and Demand Study (Colorado River Basin Study) (Reclamation, 2012) and the California Department of Water Resources biennial State Water Project (SWP) report (State of California, 2012 a and b) were both completed in 2012. Reclamation’s Colorado River Basin Study included several technical analyses related to optimal water utilization, conveyance and storage alternatives relative to climate change and future water supply uncertainty. Because the Southeast California Basin Study region is dependent on both Colorado River and SWP imports, several sections of the Study reference and/or summarize both reports extensively. Existing data was used to develop structural and non-structural options to resolve supply-demand imbalances and future uncertainty. Non-structural options included governance, and regulatory or operational changes that could facilitate stakeholder processes to better conserve water or improve the use of existing facilities to convey and store water. Non-structural options were addressed qualitatively due to the complexity of interagency negotiations that would likely be involved. The structural options involved an appraisal level design effort to evaluate pipeline alignments to convey water supplies between the Study stakeholders. Both the structural and non-structural options were assessed in their capability to resolve regional water supply and demand relative to future climate uncertainties. Climate change scenarios analyzed the potential impacts increasing temperatures and changes in precipitation may have on supply and demand across the Study area. The analysis addressed both local and imported supply sources. Climate change is expected to result in increasing temperatures across the Study area and in the Colorado River and SWP basins over time. As temperatures continue to increase, annual precipitation will become more variable. Precipitation changes may affect recharge of the Study area’s local groundwater aquifers and the Colorado River and SWP snowpacks. The climate effects on imported supply have been extensively discussed in the Colorado River Basin Study and the biennial SWP report. Increasing temperatures will increase both supply and demand uncertainty. CVWD could see an increase in SWP supply deliveries under average or greater precipitation-snowpack conditions. Dry years or extended droughts could substantially decrease SWP deliveries. However, CVWD and IID receive the majority of their supply from the Colorado River. Future climate scenarios indicate an increased potential for lower basin shortages. As senior water right holders and under the Secretary of the Interior’s Colorado River Interim Guidelines for Lower Basin Shortages and Coordinated Operations for Lake Powell and Lake Mead, IID and CVWD would not be impacted by short-term shortage issues. The Colorado River Basin Study analysis indicates these shortage vulnerabilities could be mitigated by up to 50% through a variety of management actions and operational changes. Each Study option was assessed as an adaptive strategy to climate change. The structural options to convey and store water in the Borrego Valley groundwater basin are not viable at the present time. A non-structural option may be more cost-effective for the Study region, have the potential to meet the Study objectives, and may offset climate change uncertainty that is impacting available imported water supplies. Further study effort could include fostering groundwater sustainability in the Borrego Valley and promoting opportunities for additional groundwater banking between IID and CVWD in the Coachella Valley, per an October 2003 agreement. Other water and related resource options generated from discussions during the course of this Study include increasing storage opportunities at Lake Henshaw Dam, implementing best practices for flood control basins, and brackish desalination. These options may all play a greater role in diversifying the region’s water supply in the future. However, additional study is required to assess these water resource options.

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 of California Department of Natural Resources Fortieth Biennial Report of the Division of Fish and Game for the Years 1946-1948

State of California | July 1st, 1948

State of California Emergency Flood Fighting Methods

California Department of Water Resources (DWR) | August 1st, 2018

The ‘Flood Fighting Methods’ outlined in this booklet have proven effective during many years of use by DWR, United States Army Corps of Engineers, and local agencies

The ‘Flood Fighting Methods’ outlined in this booklet have proven effective during many years of use by DWR, United States Army Corps of Engineers, and local agencies on flood-related emergencies. This handbook is published by the DWR Flood Operations Branch and is designed to be used with the Flood Fighting Methods class.

State of the Salton Sea: A Science and Monitoring Meeting of Scientists for the Salton Sea

U.S. Geological Survey (USGS) | January 19th, 2017

The Salton Sea (Sea) is an ecosystem facing large systemic changes in the near future. Managers and stakeholders are seeking solutions to the decline of the Sea and have

The Salton Sea (Sea) is an ecosystem facing large systemic changes in the near future. Managers and stakeholders are seeking solutions to the decline of the Sea and have turned to the scientific community for answers. In response, scientists gathered in Irvine, California, to review existing science and propose scientific studies and monitoring needs required for understanding how to retain the Sea as a functional ecosystem. This document summarizes the proceedings of this gathering of approximately 50 scientists at a September 8–10, 2014, workshop on the State of the Salton Sea (SoSS).  In 1997, a similar gathering of nearly 100 scientists and others in Palm Springs, Calif., yielded a number of scientific proposals establishing a foundation for a program of integrated science investigations. The 1997 workshop results were combined with recommendations from a U.S. Geological Survey (USGS) Tiger Team (Shipley and others, 1999), resulting in the eventual creation of a Strategic Science Plan (SSP) for the Salton Sea (Salton Sea Science Subcommittee, 2000). The vision from the 1997 workshop of an integrated and coordinated program of scientific investigations, embraced by the SSP, was implemented through the SSC and the USGS Salton Sea Science Office (Science Office). The integrated science program, mandated by the Salton Sea Reclamation Act of 1998 (Public Law 105–372) and spelled out in the SSP, directly led to an increased scientific understanding of the Salton Sea ecosystem. The workshop concluded that “rehabilitation of the Sea is essential and requires that current ills be rectified in a manner that allows the Sea to sustain social values of importance to the human populations of the Imperial and Coachella Valleys, as well as society in general” (U.S. Fish and Wildlife Service, 1997). The 2014 SoSS workshop built upon the foundations of the 1997 workshop, with particular emphasis on changes in the condition of the Sea and its environment in the intervening years. Over the past five decades, investigations of the Salton Sea have addressed water quality, biological, recreation, and (or) economic issues at the Salton Sea (California Resources Agency, 2006, chap. 8). Many stakeholders believe that the Salton Sea has been “studied to death” (Claiborne, 1996). Although it is true that a great deal of research has been completed at the Salton Sea, much of it has been short term and focused on specific topics with little or no integration across science disciplines, time, and space. Additionally, there have been numerous attempts at resource management of the Salton Sea (previously referred to as restoration planning).  Study objectives have differed, but the main focus has generally been on methods to control the salinity and elevation of the Salton Sea (California Resources Agency, 2006, chaps. 1 and 4). Most investigations resulted in proposed plans to preserve the Salton Sea as a thriving fishery and recreational destination, and most of these plans addressed methods to preserve the “whole Sea.” More recently, however, studies have recognized that maintaining a smaller Salton Sea should be considered, owing to declining inflows to the Salton Sea (California Resources Agency, 2006).  Prior investigations considered hundreds of alternatives for managing Salton Sea salinity, nutrients, and water elevation. Some alternatives generated revenue to help pay for rehabilitating the Sea. These alternatives have been addressed in multiple studies, as summarized in chapters 1 and 4 of the “Salton Sea Ecosystem Restoration Program Draft Programmatic Environmental Impact Report” (California Resources Agency, 2006).  Although there have been multiple efforts to characterize the Salton Sea ecosystem and develop management plans, it was not until 1996 that a comprehensive and integrated research needs assessment was developed (U.S. Fish and Wildlife Service, 1997). The 1997 report captured the combined thinking of scientists and managers and identified several areas of scientific research that would be required for a fuller, more complete understanding of the Salton Sea necessary to undertake any management project. The report defined these broad categories of science as physical environment, biological environment, cultural resources, pathogens and diseases, and contaminants. These categories form the basic framework for all scientific investigations at the Salton Sea. Some science categories continue to receive greater emphasis because limited funding has required the prioritization of projects.  A Salton Sea Science Subcommittee (SSC) authorized by Public Law 105–372, representing a broad range of Federal, State, local, and other stakeholder interests, endorsed a long-range Strategic Science Plan for the Salton Sea (Salton Sea Science Subcommittee, 2000). Whereas the U.S. Fish and Wildlife Service 1997 report established the types of science needed, the SSP further established the governing processes and expectations of how this science program should be conducted. The SSP provided the framework for scientific investigations and remains the source for identifying how scientific studies should be undertaken to better understand the Salton Sea ecosystem. Based substantially on the U.S. Fish and Wildlife Service (1997) analysis of science needs, and in consultation with many stakeholders, the SSC authorized and funded a number of initial reconnaissance-level projects. The structure of this SoSS document follows the basic framework of the U.S. Fish and Wildlife Service 1997 report, placing emphasis on physical environment (air and water quality), biological environment (birds, fish, invertebrates, carbon, and algae), contaminants, and socioeconomics.  The SoSS meeting in 2014 was convened to build upon previous scientific efforts and to provide guidance to managers on what experts believe are the most critical science needs going forward. Experts were invited to participate in the SoSS meeting based on a review by the organizing committee of individuals with subject area expertise and experience working at the Salton Sea or in similar environments. The SoSS organizing committee presented a synopsis of known science to the gathered scientists, who were then tasked to evaluate the completeness of that science and make recommendations for science needs to fill information gaps. Participants were challenged to think and act independently of their organizational affiliation in order to generate conceptual proposals designed to address scientific and monitoring concerns identified by the managerial meeting participants.

Statement of E. Joaquin Esquivel, Chair, California State Water Resources Control Board Before the Water, Oceans, and Wildlife Subcommittee Hearing on Federal and State Efforts to Restore the Salton Sea

Salton Sea Authority | September 24th, 2020

Good afternoon Mr. Chairman and Members of the Committee. My name is Joaquin Esquivel and I am the Chair of the California State Water Resources Control Board. Th

Good afternoon Mr. Chairman and Members of the Committee. My name is Joaquin Esquivel and I am the Chair of the California State Water Resources Control Board. Thank you for the invitation to join you today to speak about the Salton Sea and the opportunity we all have to help bring attention to California’s largest lake.