Petition for 2023 Drought Emergency Regulation or Other Emergency Action to Protect Nesting Birds, Water Quality, and other Public Trust Resources at Mono Lake

Mono Lake Committee | December 16th, 2022

Petition for Extension of Time to Perfect Conditional Water Rights Under the State Water Project Permits (SWP) 16478, 16479, 16481, and 16482 for Water Supply and Permits 16477 and 16480 for Hydropower Operations

California Department of Water Resources (DWR) | January 21st, 2025

Click here for DWR press release and related correspondence.

Click here for DWR press release and related correspondence.

Pilot Projects to Increase Colorado River System Water in Lake Powell and Lake Mead

U.S. Bureau of Reclamation (USBR) | January 14th, 2022

From calendar year 2015 through 2018, 64 projects were implemented in the Upper Basin resulting in an estimated 47,280 acre-feet of Colorado River System water conserved

From calendar year 2015 through 2018, 64 projects were implemented in the Upper Basin resulting in an estimated 47,280 acre-feet of Colorado River System water conserved in the Upper Basin at a cost of $8.5 million or $180.23 per acre-foot on average. From January 2015 through December 31, 2019 in the Lower Basin, 16 projects were implemented which will result in 175,347 acre-feet of Colorado River System water in Lake Mead by 2035, at a cost of approximately $29.8 million or $170.14 per acre-foot on average. The Pilot Program successfully demonstrated that voluntary, compensated water conservation projects can conserve water for Colorado River System storage to help mitigate the impacts of drought.

Planned operation of large-scale water-distribution system

American Society of Civil Engineers (ASCE) | May 1st, 1995

A water-supply-distribution-system planning model has been developed using a directed graph algorithm as its pre- and post-processors and a linear programming (LP) proced

A water-supply-distribution-system planning model has been developed using a directed graph algorithm as its pre- and post-processors and a linear programming (LP) procedure as an “intelligent” system operator at its core. The directed graph, as a preprocessor, is used to produce a mathematical representation of the distribution system in question, to check the consistency and correctness of the network topology before an input file is created for the LP procedure. In the postprocessing mode, the directed graph generates files for graphical displays of model results and performs graph analyses such as depth- and breadth-first traversals, cut-set and connectivity for evaluating water-quality blending, tracking of source-to-demand contributions, system reliability, and lifeline objectives. Unlike the conventional formulation of a resource-allocation problem, the demand requirements, storage capacities, and other system constraints are removed from the constraint set and translated into a composite objective function. This methodology was successfully applied to the Metropolitan Water District of Southern California's (MWD's) distribution system. The results indicate that the combination of using an LP procedure and graph algorithm is a very versatile tool for solving large-scale water-distribution problems. This paper documents the concept used in developing the system-planning model and the results of its application to a simplified example as well as application to four case studies involving the entire MWD's distribution system.

Planning and investing for a resilient California: A guidebook for state agencies

Governor's Office of Planning and Research (OPR) | November 17th, 2017

Executive Order (EO) B-30-15 (April 2015; Appendix A) identified three actions to advance adaptation and resilience: 1. Preparation of Implementation Action Plans to id

Executive Order (EO) B-30-15 (April 2015; Appendix A) identified three actions to advance adaptation and resilience: 1. Preparation of Implementation Action Plans to identify the steps that will be taken to realize the goals in Safeguarding California; 2. Direction to all State agencies to consider climate change in all planning and investment, including infrastructure investment; and 3. Direction to the Governor’s Office of Planning and Research (OPR) to establish a Technical Advisory Group (TAG) to provide state agencies with guidance on how to integrate climate change into planning and investment. This document is the product of the Technical Advisory Group (TAG) formed under EO B-30-15. The TAG was comprised of representatives from a majority of agencies, departments, offices and commissions of the Governor’s executive branch, and members of the public, including local and regional governments, non-governmental organizations, and the private sector (see Appendix B). This guidance document is designed to inform planning and investment processes to address the two primary elements of resilience – planning for future conditions and doing planning itself differently. This document introduces a four step process and a set of resilient decision making principles for state agencies.

Projected Changes in Precipitation, Temperature, and Drought across California’s Hydrologic Regions in the 21st Century

Climate (MDPI) | April 23rd, 2018

This study investigated potential changes in future precipitation, temperature, and drought across 10 hydrologic regions in California. The latest climate model projectio

This study investigated potential changes in future precipitation, temperature, and drought across 10 hydrologic regions in California. The latest climate model projections on these variables through 2099 representing the current state of the climate science were applied for this purpose. Changes were explored in terms of differences from a historical baseline as well as the changing trend. The results indicate that warming is expected across all regions in all temperature projections, particularly in late-century. There is no such consensus on precipitation, with projections mostly ranging from −25% to +50% different from the historical baseline. There is no statistically significant increasing or decreasing trend in historical precipitation and in the majority of the projections on precipitation. However, on average, precipitation is expected to increase slightly for most regions. The increases in late-century are expected to be more pronounced than the increases in mid-century. The study also shows that warming in summer and fall is more significant than warming in winter and spring. The study further illustrates that, compared to wet regions, dry regions are projected to become more arid. The inland eastern regions are expecting higher increases in temperature than other regions. Particularly, the coolest region, North Lahontan, tends to have the highest increases in both minimum and maximum temperature and a significant amount of increase in wet season precipitation, indicative of increasing flood risks in this region. Overall, these findings are meaningful from both scientific and practical perspectives. From a scientific perspective, these findings provide useful information that can be utilized to improve the current flood and water supply forecasting models or develop new predictive models. From a practical perspective, these findings can help decision-makers in making different adaptive strategies for different regions to address adverse impacts posed by those potential changes.

Prototyping structured decision making for water resource management in the San Francisco Bay-Delta

Environmental Science & Policy (Elsevier) | May 2nd, 2024

A structured decision making (SDM) approach can help evaluate tradeoffs between conservation and human-benefit objectives by fostering communication and knowledge transfe

A structured decision making (SDM) approach can help evaluate tradeoffs between conservation and human-benefit objectives by fostering communication and knowledge transfer among stakeholders, decision makers, and the public. However, the process is iterative and completing the full process may take years. It can be difficult to initiate an SDM effort when problems seem insurmountable. Occasionally, SDM may not even be the best or correct approach for addressing the conservation problem at hand. We describe the implementation of an SDM process to help inform difficult decisions related to competing objectives. We convened a diverse stakeholder group from the largest estuary in the western United States; the San Francisco Bay and Sacramento-San Joaquin Delta (Bay-Delta). The stakeholder group consisted of representatives from local, state, and federal agencies, non-profit organizations, and recreational fishers. The stakeholder group agreed on a problem statement and identified four priority objectives related to Chinook salmon, delta smelt, water availability and reliability, and agricultural water use. Furthermore, they proposed 14 candidate management actions to achieve their objectives. The group then used existing quantitative models and data to evaluate trade-offs in proposed management actions to identify areas of agreement of proposed candidate actions. The clear communication of the problem statement and objectives among the stakeholder group, along with evaluation of tradeoffs and uncertainty via decision-support models suggest that a full SDM approach may work in the Bay-Delta. We further communicate lessons learned during our implementation of SDM to help guide future SDM efforts in the region and elsewhere. See also: Structured Decision Making Delta Stewardship Council June 2024 meeting report.

Pure Water Southern California Volume 1 - Draft Enviornmental Impact Report

Metropolitan Water District of Southern California (MWD) | May 14th, 2025

Pure Water Southern California (Pure Water) is a proposed partnership between The Metropolitan Water District of Southern California (Metropolitan) and the Los Angeles Co

Pure Water Southern California (Pure Water) is a proposed partnership between The Metropolitan Water District of Southern California (Metropolitan) and the Los Angeles County Sanitation Districts (Sanitation Districts) to beneficially reuse cleaned wastewater that is currently being discharged to the Pacific Ocean from the Sanitation Districts’ A.K. Warren Water Resource Facility (Warren Facility) in the City of Carson. At full buildout, Pure Water would purify up to 150 million gallons per day (MGD), making it one of the largest programs of its kind in the world. Implementation of Pure Water would provide regional benefits to all Metropolitan member agencies by: (1) reducing reliance on imported water; (2) diversifying locally available supplies; (3) improving resilience to climate change and other stressors; and (4) enhancing operational reliability and flexibility.  This Environmental Impact Report (EIR) assesses the potential environmental effects of Pure Water and was prepared in accordance with the California Environmental Quality Act (CEQA) and its implementing guidelines. Metropolitan is serving as the lead agency in preparation of this EIR; the Sanitation Districts are serving as a responsible agency. The EIR is intended to inform governmental decisionmakers and the public about the potential environmental impacts associated with construction and operation of Pure Water, and to identify ways that potentially significant impacts can be avoided or reduced by making changes to the program, selecting an alternative, and/or adopting feasible mitigation measures.  Click here for appendices.

Putting People over Fish: Stopping Radical Environmentalism to Provide Water to Southern California

The White House | January 20th, 2025

Regional Governance of Flood Management in the Central Valley

California Department of Water Resources (DWR) | May 30th, 2014

California faces significant challenges in managing its highly variable water resources, particularly as climate change and a growing population exacerbate drought and fl

California faces significant challenges in managing its highly variable water resources, particularly as climate change and a growing population exacerbate drought and flood risks.  The California Department of Water Resources (DWR) and other state agencies have been encouraging integrated approaches to water management, taking into account the connections between water supply, water quality, flood protection, and ecosystem health. The recent California Water Action Plan calls for improved coordination between local, state and federal agencies and tribal governments in order to develop multi-­benefit water management strategies. Regional-­scale planning has become a crucial avenue for advancing these efforts. Initiated in 2002, the Integrated Regional Water Management Planning (IRWM) process has led to the formation of 48 water planning regions statewide, in which diverse local agencies have developed integrated plans for managing all aspects of a region’s water management. More recently, a Regional Flood Management Planning (RFMP) process was created in the context of the Central Valley Flood Protection Plan to advance integrated approaches to reducing flood risks. Six flood planning regions, overlapping with nine IRWM regions, were formed in 2012. This study analyzes the origins and functioning of the IRWM and RFMP processes, and the degree of coordination between them to address flood risks in the Central Valley. In particular, it examines how each is working to generate multi-­benefit strategies, and how they account for climate change. It also discusses opportunities for future coordination between the IRWM and RFMP processes, and DWR’s role in supporting this. This study is primarily based upon an analysis of publicly available documents related to the IRWM and RFMP processes. It is also informed by meeting observations and conversations with staff at DWR and the Central Valley Flood Protection Board, and participants in IRWM and RFMP processes. Since RFMPs were not yet completed at the time of this writing, this study’s findings are preliminary. Nonetheless, this report provides an indication of the overall functioning of these RFMP and IRWM regions, and some general considerations for DWR as it assesses next steps in supporting these programs.