Data, Tools and Guidance

West-Wide Climate Risk Assessments were initiated by Reclamation in 2009 to complement the Basin Studies by providing a consistent, baseline assessment of climate change impacts to water supply and demand across the West, with special emphasis on how climate change impacts Reclamation's own operations through WWCRA Impact Assessments. The WWCRAs have generated important information, tools and guidance that can support the integration of climate information into planning activities, as proposed in Reclamation's Climate Change Adaptation Strategy.

Projections of Future Water Supply

Transforming General Circulation Model Information

The WWCRAs assessments of risks and impacts associated with climate change rely significantly on the information developed in partnership between Reclamation, the Department of Energy’s National Energy Technology Laboratory, Santa Clara University, Lawrence Livermore National Laboratory, and University of California’s Institute for Research on Climate Change and Its Societal Impacts provided by the Bias Corrected and Downscaled WCRP CMIP3 and CMIP5 Climate and Hydrology Projections archive. The archive serves a total of 112 unique climate projections from 16 different GCMs.

Projections of Future Water Supply

Reclamation has developed a set of projections of surface water supplies for the Western United States. The surface water supply projections build upon the 112 unique climate projections and utilize them through the use of Variable Infiltration Capacity models that were developed at the University of Washington. The product will be 112 unique projections of surface water supply for the Western United States.

Streamflow Data

The Bureau of Reclamation has made projected streamflow data available for 195 sites on streams and rivers throughout the western United States developed through its West-Wide Climate Risk Assessment effort. These projections show raw daily and monthly streamflow data that takes into account climate change impacts projected until 2099.

Interactive Map

Accessible Data Table

Projections of Future Water Demand

Irrigation Demand and Reservoir Evaporation

In 2015, the WWCRAs completed an assessment of Climate Change Impacts on Irrigation Demand and Reservoir Evaporation in the West. Using climate projections for temperature and precipitation, projected irrigation demand was evaluated in eight major river basins: Colorado, Rio Grande, Sacramento-San Joaquin, Truckee, Columbia, Missouri and Klamath. The water evaporation model was applied to 12 reservoirs in many of those major Reclamation river basins: Lake Powell, Lake Mead, American Falls Reservoir, Lake Roosevelt, Upper Klamath Lake, Canyon Ferry Reservoir, Boysen Reservoir, Elephant Butte Reservoir, Lake Shasta, Millerton Lake, Lake Tahoe and Lahontan Reservoir.

Guidance for Incorporating Climate Change Information

Technical Guidance for Incorporating Climate Change Information into Water Resources Planning Studies

This objective of this guidance is to assist study teams in navigating the range of technical methods available to account for climate change impacts in planning studies. This guidance uses a series of scoping questions to address decision relevance, information reliability, and analysis practicalities. This document is designed to be used in the existing decision making processes to understand climate change impacts on water supply, demand, and criteria that govern or guide water management.

Considerations for Selecting Climate Projections for Water Resources, Planning, and Environmental Analyses

This document provides an overview of important considerations in selecting climate projection information for use in water resources, planning, or environmental analyses. The purpose of this document is to provide an overview of how climate projections are developed, discuss key considerations in selecting climate projections for use in a given study, and briefly summarize available climate projection datasets and established methods for selecting climate projections for detailed analysis.

Fact Sheet

Last Updated: 4/17/17