Colorado River flow dwindles as warming-driven loss of reflective snow energizes evaporation

American Association for the Advancement of Science (AAAS) | February 20th, 2020

The sensitivity of river discharge to climate-system warming is highly uncertain and governing processes are poorly understood, impeding climate-change adaptation. A prom

The sensitivity of river discharge to climate-system warming is highly uncertain and governing processes are poorly understood, impeding climate-change adaptation. A prominent exemplar is the Colorado River, where meteorological drought and warming have been shrinking a water resource that supports more than US$1 trillion per year of economic activity. Monte-Carlo simulation with a radiation-aware hydrologic model resolves the longstanding, wide disparity in sensitivity estimates and reveals the controlling physical processes. We estimate that annual-mean discharge has been decreasing by 9.3% per °C of warming due to increased evapotranspiration, mainly driven by snow loss and consequent decrease of reflection of solar radiation. Projected precipitation increases likely will not suffice to counter fully the robust, thermodynamically induced drying. Increasing risk of severe water shortages is expected.

Colorado River Hydrologic Region Groundwater Update

California Department of Water Resources (DWR) | April 1st, 2015

The primary goal of the Colorado River Hydrologic Region (Colorado River region) groundwater update is to expand information about region-specific groundwater conditions

The primary goal of the Colorado River Hydrologic Region (Colorado River region) groundwater update is to expand information about region-specific groundwater conditions for California Water Plan Update 2013, and to guide more informed groundwater management actions and policies. A second goal is to steadily improve the quality of groundwater information in future California Water Plan (CWP) updates to a level that will enable regional water management groups (RWMGs) to accurately evaluate their groundwater resources and implement management strategies that can meet local and regional water resource objectives within the context of broader statewide objectives. The final goal is to identify data gaps and groundwater management challenges meant to serve as a guidepost for prioritizing future data collection and funding opportunities relevant to the region. This regional groundwater update is not intended to provide a comprehensive and detailed examination of local groundwater conditions, or be a substitute for local studies and analysis. Where information is readily available, the update does report some aspects of the regional groundwater conditions in greater detail.

Colorado River Insights, 2025: Dancing with Deadpool

Colorado River Research Group | December 3rd, 2025

The Colorado River Research Group (CRRG) was formed in 2014 to bring scientific insights to Colorado River system management, inspired in part by the salient role played

The Colorado River Research Group (CRRG) was formed in 2014 to bring scientific insights to Colorado River system management, inspired in part by the salient role played by the Wentworth Group of Concerned Scientists in the Murray-Darling Basin—a similar, drought-stricken region in Australia. It was established as an independent, knowledgeable voice insulated from political constraints, sectoral alliances, and other pressures that might impede the full consideration of relevant ideas and viewpoints. Originally, the CRRG was launched with ten members, all academics with long, well-established involvement in Colorado River scholarship. In 2021 the group was expanded to 14 active members, while four original CRRG members transitioned to emeritus status. CRRG members serve as individuals, rather than as representatives of their universities or other organizations. The administrative home of the CRRG is the Getches-Wilkinson Center at the University of Colorado.

Colorado River Shortage FAQs

Arizona Department of Water Resources (ADWR) | August 1st, 2022

Colorado River Storage Project of 1956

U.S. Bureau of Reclamation (USBR) | April 11th, 1956

Colorado River water supply is predictable on multi-year timescales owing to long-term ocean memory

Nature Portfolio (Springer Nature) | October 9th, 2020

Skillful multi-year climate forecasts provide crucial information for decision-makers and resource managers to mitigate water scarcity, yet such forecasts remain challen

Skillful multi-year climate forecasts provide crucial information for decision-makers and resource managers to mitigate water scarcity, yet such forecasts remain challenging due to unpredictable weather noise and the lack of dynamical model capability. Here we demonstrate that the annual water supply of the Colorado River is predictable up to several years in advance by a drift-free decadal climate prediction system using a fully coupled climate model. Observational analyses and model experiments show that prolonged shortages of water supply in the Colorado River are significantly linked to sea surface temperature precursors including tropical Pacific cooling, North Pacific warming, and southern tropical Atlantic warming. In the Colorado River basin, the water deficits can reduce crop yield and increase wildfire potential. Thus, a multi-year prediction of severe water shortages in the Colorado River basin could be useful as an early indicator of subsequent agricultural loss and wildfire risk.

Colorado River Water: Challenges for California

Legislative Analyst's Office (LAO) | October 16th, 1997

The Secretary of the Interior has directed California to come up with a plan to live within its entitlement of 4.4 million acre-feet of water per year. We provide findin

The Secretary of the Interior has directed California to come up with a plan to live within its entitlement of 4.4 million acre-feet of water per year. We provide findings and recommendations regarding this directive.

Colusa County | Managed Aquifer Recharge: benefitting aquifers, farmers, and migratory birds

Nature Conservancy | September 3rd, 2018

In partnership with growers and the Colusa Groundwater Authority (CGA), The Nature Conservancy (TNC) is implementing a pilot multiple-benefit managed aquifer r

In partnership with growers and the Colusa Groundwater Authority (CGA), The Nature Conservancy (TNC) is implementing a pilot multiple-benefit managed aquifer recharge (MAR) program on farmland in California’s Central Valley, Colusa County. This program will benefit local groundwater users by replenishing critical domestic and agricultural groundwater supplies in a Severely Disadvanateged Community (SDAC). Participating farmers will benefit economically through incentive payments, and migratory shorebirds will benefit through the creation of critical winter habitat on farms through our specific field and water depth specificiations. MAR sites will be selected where and when it is appropriate and cost-effective to do so based on farming practices, soil suitability, water availability, basin water balances, and migratory/shorebird habitat requirements. The relevance and success of this program for Groundwater Sustainability Agencies (GSAs), Severely Disadvantaged Communities (SDACs), and Groundwater Sustainability Plans (GSPs) will require all of these stakeholders and project participants to collaborate on its design. Thus, TNC will engage growers, water managers, and other stakeholders in a variety of formal and informal ways to ensure that this program will meet the needs of all parties involved in GSP development. This program serves as a model for other GSAs and stakeholders seeking to deliver multiple benefits through on-farm recharge in the Central Valley where such a program is appropriate.

Colusa Subbasin Groundwater Sustainability Plan

Colusa Groundwater Authority | December 3rd, 2021

The purpose of this GSP is to characterize groundwater conditions in the Subbasin, evaluate and report on existing conditions relating to the six sustainability indicator

The purpose of this GSP is to characterize groundwater conditions in the Subbasin, evaluate and report on existing conditions relating to the six sustainability indicators, describe existing monitoring, 14 management programs and policies relating to groundwater resource use, document public outreach and communication, establish sustainability goals, and describe projects and management actions (PMAs) the GSAs will implement to achieve sustainable groundwater management within 20 years of implementing the GSP. Due to size, this file has been divided into 16 parts Part 1, Part 2, Part 3, Part 4, Part 5, Part 6, Part 7, Part 8, Part 9, Part 10, Part 11, Part 12, Part 13, Part 14, Part 15, Part 16

Combined Modeling of US Fluvial, Pluvial, and Coastal Flood Hazard Under Current and Future Climates

American Geophysical Union (AGU) | December 16th, 2020