Adaptability and adaptations of California’s water supply system to dry climate warming

Climactic Change (Springer) | November 27th, 2007

Economically optimal operational changes and adaptations for California’s water supply system are examined for a dry form of climate warming (GFDL CM2.1 A2) with year 2

Economically optimal operational changes and adaptations for California’s water supply system are examined for a dry form of climate warming (GFDL CM2.1 A2) with year 2050 water demands and land use. Economically adaptive water management for this climate scenario is compared to a similar scenario with the historical climate. The effects of population growth and land use alone are developed for comparison. Compared with the historic hydrology, optimized operations for the dry climate warming scenario raise water scarcity and total operation costs by $490 million/year with year 2050 demands. Actual costs might be somewhat higher where non-economic objectives prevail in water management. The paper examines the economical mix of adaptation, technologies, policies, and operational changes available to keep water supply impacts to such modest levels. Results from this screening model suggest promising alternatives and likely responses and impacts. Optimized operations of ground and surface water storage change significantly with climate. Dry-warm climate change increases the seasonal storage range of surface reservoirs and aquifers. Surface reservoir peak storage usually occurs about a month earlier under dry-warm climate change.

Addendum to the State Water Project and Central Valley Project Drought Contingency Plan

California Department of Water Resources (DWR) | July 29th, 2022

This Addendum includes current hydrologic conditions, plus updates on the following: operations status and the latest SWP and CVP (collectively referred to as Projects) o

This Addendum includes current hydrologic conditions, plus updates on the following: operations status and the latest SWP and CVP (collectively referred to as Projects) operations forecasts; species status; and known WY 2022 drought actions.

Addendum to the State Water Project and Central Valley Project Drought Contingency Plan

California Department of Water Resources (DWR) | August 31st, 2022

This Addendum includes current hydrologic conditions, plus updates on the following: operations status and the latest SWP and CVP (collectively referred to as Projects) o

This Addendum includes current hydrologic conditions, plus updates on the following: operations status and the latest SWP and CVP (collectively referred to as Projects) operations forecasts; species status; and known WY 2022 drought actions.

Addressing Institutional Vulnerabilities in California’s Drought Water Allocation, Part 1: Water Rights Administration and Oversight During Major Statewide Droughts, 1976–2016

California Natural Resources Agency (CNRA) | August 30th, 2018

Climate change has already begun to affect California’s hydrology and water resources, and droughts are likely to become more frequent, longer, and more intense

Climate change has already begun to affect California’s hydrology and water resources, and droughts are likely to become more frequent, longer, and more intense in the future (see Section 2.2.4). This project is designed to help state water governance and decision-making structures adapt to this changing climatic reality. We focus on how one of California’s primary water management institutions, the State Water Resources Control Board (Board), has responded in the past, and could better respond in the future, to droughts and their attendant challenges, including water shortage, uncertainty, and conflict. Click here for Part 2.

Addressing Institutional Vulnerabilities in California’s Drought Water Allocation, Part 2: Improving Water Rights Administration and Oversight for Future Droughts

California Natural Resources Agency (CNRA) | August 30th, 2018

 In California, droughts are likely to become more frequent, longer, and more intense in the future, posing increasing challenges for water management, and raising the s

 In California, droughts are likely to become more frequent, longer, and more intense in the future, posing increasing challenges for water management, and raising the stakes for effective drought response. This project aims to help state water governance and decision-making structures adapt to the changing climatic reality. In a companion report in this volume, we analyzed the strategies the State Water Resources Control Board (Board) used for water rights administration and oversight during the last four major statewide droughts. Our findings suggest that more proactive planning and preparation, enabling reduced reliance on in-drought improvisation, would improve the Board’s future drought responses. This report builds on that retrospective analysis with specific recommendations.  Click here for Part 1.

Addressing Stakeholder Science Needs for Integrated Drought Science in the Colorado River Basin

U.S. Geological Survey (USGS) | May 31st, 2022

Advances in Sub-seasonal to Seasonal Prediction Relevant to Water Management in the Western United States

American Meteorological Society (AMS) | July 21st, 2022

Water management in the semi-arid western United States (U.S.) is a challenging endeavor that evolves from year to year based on large-scale atmospheric and oceanic condi

Water management in the semi-arid western United States (U.S.) is a challenging endeavor that evolves from year to year based on large-scale atmospheric and oceanic conditions. This region has frequently experienced prolonged periods of drought with substantial socioeconomic impacts; the most recent instance involves California entering its third consecutive drought year. As context for the economic implications of drought, California’s enacted state budget for the Fiscal Year 2021-22 authorizes more than $600 million for the California Department of Water Resources for providing immediate drought support to local water agencies (CA State Budget 2021a); this amount is part of a package of more than $5 billion over four years for water resilience and drought preparedness (CA State Budget 2021b). For drought preparedness, state and local water managers would like to rely on skillful forecasts on timescales that span the spectrum between weather forecasts and climate predictions. Despite recent improvements in developing sub-seasonal (2- to 6-weeks lead) and seasonal (2- to 6-months lead) prediction systems that compete with and/or outperform existing dynamical and statistical models (e.g., Gibson et al. 2021, Switanek et al. 2020, DeFlorio et al. 2019), forecasting limitations have hindered crucial management decisions for western U.S. water managers, especially related to longer-lead planning, budgeting, resource allocation, and better preparedness for wet and dry extremes (DeFlorio et al. 2021). Improved understanding of physical phenomena and processes governing weather and climate extremes and utilization of emerging forecast methodologies are critical to developing skillful S2S forecast products relevant to water management.

Agricultural Irrigation in This Drought: Where is the Water and Where Is It Going?

University of California Giannini Foundation of Agricultural Economics | May 14th, 2015

In the midst of its fourth year of drought, California now faces an estimated reduction in surface-water availability of 8.8 million acre-feet (maf) out of 29 maf in agri

In the midst of its fourth year of drought, California now faces an estimated reduction in surface-water availability of 8.8 million acre-feet (maf) out of 29 maf in agricultural applied water statewide. However, groundwater, the buffer water supply during drought, is replacing about 6.2 maf of surface water via additional pumping. This increased groundwater pumping is in addition to the 1.5 maf of annual average groundwater overdraft in the Central Valley. The net reduction of 2.6 maf in the total supply in 2015 may result in about 564,000 acres fallowed statewide, or about 120,000 more acres than last year's fallowing estimates.

Allocating California’s Water: Directions for Reform

Public Policy Institute of California (PPIC) | November 11th, 2015

California’s water allocation system hampers its ability to meet the state’s needs, especially in times of drought. At its heart is an unusually complex array of wate

California’s water allocation system hampers its ability to meet the state’s needs, especially in times of drought. At its heart is an unusually complex array of water rights. This report summarizes challenges and suggests reforms to strengthen the state’s ability to weather droughts and shifting economic demands for water, while maintaining the existing seniority of water rights. Read a summary of the report’s policy recommendations.

An Assessment of Potential Severe Droughts in the Colorado River Basin

American Water Resources Association (AWRA) | September 15th, 2022