Paying it Forward: The Path Toward Climate-Safe Infrastructure in California

Climate-Safe Infrastructure Working Group | September 1st, 2018

Post‐Fire Sediment Yield from a Western Sierra Nevada Watershed Burned by the 2021 Caldor Fire

American Geophysical Union (AGU) | January 7th, 2025

Potential for Using the Upper Coachella Valley Ground-Water Basin, California, for Storage of Artificially Recharged Water

U.S. Geological Survey (USGS) | September 15th, 1980

The California Department of Water Resources, through the Future Water Supply Program, is investigating the use of ground-water basins for storage of State Wate

The California Department of Water Resources, through the Future Water Supply Program, is investigating the use of ground-water basins for storage of State Water Project water in order to help meet maximum annual entitlements to water project contractors. This report presents a preliminary evaluation of the geohydrologic fac- tors affecting storage of water by artificial recharge in the upper Coachella Valley, Calif. The ground-water basin of the upper Coachella Valley seems to be geologically suitable for large-scale artificial recharge. A minimum of 900,000 acre-feet of water could probably be stored in the basin without raising basinwide water levels above those that existed in 1945. Preliminary tests indicate that a long-term artificial recharge rate of 5 feet per day may be feasible for spreading grounds in the basin if such factors as sediment and bacterial clogging can be controlled.

Projected increases and shifts in rain-on-snow flood risk over western North America

Nature Portfolio (Springer Nature) | August 6th, 2018

Destructive and costly flooding can occur when warm storm systems deposit substantial rain on extensive snowcover, as observed in February 2017 with the Oroville

Destructive and costly flooding can occur when warm storm systems deposit substantial rain on extensive snowcover, as observed in February 2017 with the Oroville Dam crisis in California. However, decision-makers lack guidance on how such rain-on-snow (ROS) flood risk may respond to climate change. Here, daily ROS events with flood-generating potential are simulated over western North America for a historical (2000–2013) and future (forced under Representative Concentration Pathway 8.5) period with the Weather Research and Forecasting model; 4 km resolution allows the basin-scale ROS flood risk to be assessed. In the warmer climate, we show that ROS becomes less frequent at lower elevations due to snowpack declines, particularly in warmer areas (for example, the Pacific maritime region). By contrast, at higher elevations where seasonal snowcover persists, ROS becomes more frequent due to a shift from snowfall to rain. Accordingly, the water available for runoff increases for 55% of western North American river basins, with corresponding increases in flood risk of 20–200%, the greatest changes of which are projected for the Sierra Nevada, the Colorado River headwaters and the Canadian Rocky Mountains. Thus, flood control and water resource planning must consider ROS to fully quantify changes in flood risk with anthropogenic warming.

Projecting groundwater storage changes in California’s Central Valley

Nature Portfolio (Springer Nature) | August 27th, 2018

Accurate and detailed knowledge of California’s groundwater is of paramount importance for statewide water resources planning and management, and to sustain a

Accurate and detailed knowledge of California’s groundwater is of paramount importance for statewide water resources planning and management, and to sustain a multi-billion-dollar agriculture industry during prolonged droughts. In this study, we use water supply and demand information from California’s Department of Water Resources to develop an aggregate groundwater storage model for California’s Central Valley. The model is evaluated against 34 years of historic estimates of changes in groundwater storage derived from the United States Geological Survey’s Central Valley Hydrologic Model (USGS CVHM) and NASA’s Gravity Recovery and Climate Experiment (NASA GRACE) satellites. The calibrated model is then applied to predict future changes in groundwater storage for the years 2015–2050 under various precipitation scenarios from downscaled climate projections. We also discuss and project potential management strategies across different annual supply and demand variables and how they affect changes in groundwater storage. All simulations support the need for collective statewide management intervention to prevent continued depletion of groundwater availability.

Pulse Flows Component of the Water Storage Investment Program Groundwater Projects Supplemental Environmental Impact Report

California Department of Water Resources (DWR) | July 30th, 2024

This final supplemental environmental impact report (Final SEIR) has been prepared for the Pulse Flows Component of the Water Storage Investment Program (WSIP) Groundwate

This final supplemental environmental impact report (Final SEIR) has been prepared for the Pulse Flows Component of the Water Storage Investment Program (WSIP) Groundwater Projects (Pulse Flows Component). The Final SEIR is a supplement to three certified environmental impact reports (EIRs) prepared pursuant to the California Environmental Quality Act (CEQA) for three independent WSIP projects (referred to herein as the “WSIP Groundwater Projects”): (1) the Chino Basin Program, (2) the Kern Fan Groundwater Storage Project (Kern Fan), and (3) the Willow Springs Water Bank Project (Willow Springs).

Pumping for the masses: evolution of groundwater management in metropolitan Los Angeles

Geo Journal (Springer) | August 7th, 2015

Groundwater supports many aspects of human life. In cities, groundwater can provide a cost-effective source of water for drinking and industrial uses, while groundwater b

Groundwater supports many aspects of human life. In cities, groundwater can provide a cost-effective source of water for drinking and industrial uses, while groundwater basins provide storage. The role of groundwater in a city’s water supply tends to change over time. In the Los Angeles metropolitan area, groundwater is critical. Over decades, users in the region’s many basins allocated annual pumping rights to groundwater among users through adjudications. These rights were determined through collective processes over decades, which contributed to the complex array of public and private organizations involved in water management. The rights also continue to evolve. We analyzed changes in the distribution of groundwater rights over time for adjudicated basins in Southern Los Angeles County. Results indicate that groundwater rights are increasingly: (1) controlled or regulated by public institutions and municipalities, and (2) consolidated among larger users. Yet, both the percentage of total supplies provided by groundwater, as well as the distribution of groundwater rights, varies widely among cities and communities throughout Los Angeles. As metropolitan Los Angeles faces reduced water imports and emphasizes local water reliance, access to pumping rights and storage capacity in groundwater basins will become even more vital. We discuss implications of our results for future urban water management.

Recent decreases in snow water storage in western North America

Nature Portfolio (Springer Nature) | May 22nd, 2023

Mountain snowpacks act as natural water towers, storing winter precipitation until summer months when downstream water demand is greatest. We introduce a Snow Storage Ind

Mountain snowpacks act as natural water towers, storing winter precipitation until summer months when downstream water demand is greatest. We introduce a Snow Storage Index (SSI), representing the temporal phase difference between daily precipitation and surface water inputs—sum of rainfall and snowmelt into terrestrial systems—weighted by relative magnitudes. Different from snow water equivalent or snow fraction, the SSI represents the degree to which the snowpack delays the timing and magnitude of surface water inputs relative to precipitation, a fundamental component of how snow water storage influences the hydrologic cycle. In western North America, annual SSI has decreased (p 

Recharge Roundtable Call to Action: Key Steps for Replenishing California Groundwater

Groundwater Resources Association of California (GRA) | September 24th, 2018

The age of tacitly treating groundwater as primarily an extractive resource is over, both for California and the rest of the world. This will require vastly more

The age of tacitly treating groundwater as primarily an extractive resource is over, both for California and the rest of the world. This will require vastly more managed aquifer recharge than ever previously imagined. It was in this spirit of profound concern for the future of not only groundwater resources, but also for water security and sustainability in general, that on October 2, 2017 the Groundwater Resources Association of California (GRA) and the University of California Water Security and Sustainability Research Initiative (UC Water) convened the Recharge Roundtable in Sacramento. The Recharge Roundtable consisted of 50 attendees with a diverse cross-section of disciplines and professions, including water managers, consultants, academics, hydrologists, and social scientists. The strong experience and expertise assembled in this group, together with the sincere interest in solving a daunting water challenge, made the meeting very productive and led to the proposed actions included in this document.

Report Card for California's Infrastructure 2019

American Society of Civil Engineers (ASCE) | May 9th, 2019