(Commercial/Industrial) Water and Power Rates Request, 2016-2020

Los Angeles Department of Water and Power (LADWP) | July 1st, 2015

2020 Water Resilience Portfolio (draft)

California Natural Resources Agency | January 2nd, 2020

2022 Annual Review of the Construction and Operation of the State Water Project

California Water Commission (CWC) | January 18th, 2023

2022 Annual Water Supply and Demand Assessment Summary Report

California Department of Water Resources (DWR) | November 22nd, 2022

This summary report contains projected water shortage information at the urban water supplier level as well as regional and statewide analyses of water supply conditions

This summary report contains projected water shortage information at the urban water supplier level as well as regional and statewide analyses of water supply conditions and is intended to inform the State Water Resources Control Board (State Water Board). Additionally, the report includes information on water shortage response actions taken by urban water suppliers as a result of their Annual Water Supply and Demand Assessments (Annual Assessments), and urban water suppliers’ compliance statistics with respect to their Annual Water Shortage Assessment Report (Annual Shortage Report) submittals. The purpose of this Annual Water Supply and Demand Assessment Summary Report (Summary Report) is to fulfill the California Water Code (CWC) §10644(c)(1)(B) requirements and it is due on or before September 30, 2022, and every year thereafter. The full text of the CWC section regarding the Department of Water Resources’ (DWR) Summary Report to the State Water Board is presented below for reference.

21st century California drought risk linked to model fidelity of the El Niño teleconnection

Nature Climate and Atmospheric Science | September 3rd, 2018

Greenhouse gas-induced climate change is expected to lead to negative hydrological impacts for southwestern North America, including California (CA). This includes a decr

Greenhouse gas-induced climate change is expected to lead to negative hydrological impacts for southwestern North America, including California (CA). This includes a decrease in the amount and frequency of precipitation, reductions in Sierra snow pack, and an increase in evapotranspiration, all of which imply a decline in surface water availability, and an increase in drought and stress on water resources. However, a recent study showed the importance of tropical Pacific sea surface temperature (SST) warming and an El Niño Southern Oscillation (ENSO)-like teleconnection in driving an increase in CA precipitation through the 21st century, particularly during winter (DJF). Here, we extend this prior work and show wetter (drier) CA conditions, based on several drought metrics, are associated with an El Niño (La Niña)-like SST pattern. Models that better simulate the observed ENSO-CA precipitation teleconnection also better simulate the ENSO-CA drought relationships, and yield negligible change in the risk of 21st century CA drought, primarily due to wetting during winter. Seasonally, however, CA drought risk is projected to increase during the non-winter months, particularly in the models that poorly simulate the observed teleconnection. Thus, future projections of CA drought are dependent on model fidelity of the El Niño teleconnection. As opposed to focusing on adapting to less water, models that better simulate the teleconnection imply adaptation measures focused on smoothing seasonal differences for affected agricultural, terrestrial, and aquatic systems, as well as effectively capturing enhanced winter runoff.

A 10 per cent increase in global land evapotranspiration from 2003 to 2019

Nature | May 26th, 2021

Accurate quantification of global land evapotranspiration is necessary for understanding variability in the global water cycle, which is expected to intensify und

Accurate quantification of global land evapotranspiration is necessary for understanding variability in the global water cycle, which is expected to intensify under climate change. Current global evapotranspiration products are derived from a variety of sources, including models, remote sensing and in situ observations. However, existing approaches contain extensive uncertainties; for example, relating to model structure or the upscaling of observations to a global level. As a result, variability and trends in global evapotranspiration remain unclear. Here we show that global land evapotranspiration increased by 10 ± 2 per cent between 2003 and 2019, and that land precipitation is increasingly partitioned into evapotranspiration rather than runoff. Our results are based on an independent water-balance ensemble time series of global land evapotranspiration and the corresponding uncertainty distribution, using data from the Gravity Recovery and Climate Experiment (GRACE) and GRACE-Follow On (GRACE-FO) satellites. Variability in global land evapotranspiration is positively correlated with El Niño–Southern Oscillation. The main driver of the trend, however, is increasing land temperature. Our findings provide an observational constraint on global land evapotranspiration, and are consistent with the hypothesis that global evapotranspiration should increase in a warming climate.

A changing framework for urban water systems

American Chemical Society (ACS) | May 8th, 2013

Urban water infrastructure and the institutions responsible for its management have gradually evolved over the past two centuries. Today, they are under increas

Urban water infrastructure and the institutions responsible for its management have gradually evolved over the past two centuries. Today, they are under increasing stress as water scarcity and a growing recognition of the importance of factors other than the cost of service provision are forcing a reexamination of long-held ideas. Research and development that supports new technological approaches and more effective management strategies are needed to ensure that the emerging framework for urban water systems will meet future societal needs

A hydrological simulation dataset of the Upper Colorado River Basin from 1983 to 2019

Scientific Data | January 20th, 2022

The Upper Colorado River Basin (UCRB) is one of the most over-allocated basins in the world. It provides water for 40 million people in Colorado and downstream states of

The Upper Colorado River Basin (UCRB) is one of the most over-allocated basins in the world. It provides water for 40 million people in Colorado and downstream states of Arizona, California, Nevada, and Utah. However, the UCRB water capacity is decreasing as a combined result of climate change and anthropogenic activities. Understanding the dynamic of the UCRB water cycle is crucial for long-term and short-term water resources management.

A Perspective on the Drought in California

Legislative Analyst's Office | November 21st, 1991

Despite heavy rains in March 1991, California continues to face a serious near-term water problem resulting from five years of drought. In fact, the amount of water in st

Despite heavy rains in March 1991, California continues to face a serious near-term water problem resulting from five years of drought. In fact, the amount of water in storage on October 1, 1991 was about equal to the amount in storage one year ago—a year in which strict conservation measures were imposed in some areas and there were significant reductions in water supplies for many agricultural users. In this paper, we provide background information on California's water system, the impact of the drought, water needs in the future, and legislative options for coping with water supply limitations.

A simmering revolt against groundwater cutbacks in California

Stanford University Bill Lane Center for the American West | December 14th, 2022

In 2014, California legislators, focused on groundwater’s accelerating decline during a prolonged drought, passed the Sustainable Groundwater Management Act. Its impera

In 2014, California legislators, focused on groundwater’s accelerating decline during a prolonged drought, passed the Sustainable Groundwater Management Act. Its imperatives: keeping groundwater levels sustainable by 2040 and keeping control of groundwater in local hands. Both goals are now in limbo. As the state endures yet another prolonged drought and state water managers have balked at approving plans covering the basins at greatest risk – the vast majority in the San Joaquin Valley – more growers in a few of the new local groundwater agencies are in revolt at the new rules that will curtail access to the water they once took for granted.