• A stator in the third powerhouse at Grand Coulee.
  • The penstocks above the water at Hoover Dam
  • The top of Shasta Dam in California
  • An automated gate structure on a canal in Washington.
  • An aerial photo of the sunsetting at Ruedi Reservoir in Colorado.


An illustration that shows the temperature change in west from 1950 - 2099 An illustration that shows the precipitation change from 1950-2099.

Climate change poses a risk to western water management and Reclamation is working to ensure it is prepared to meet the growing demands in the western United States even though climate change could impact the supply in future.

In 2011, Reclamation released a report to Congress that shows several increased risks to water resources in the western United States during the 21st century. Specific projections include:

  • A temperature increase of 5-7 degrees Fahrenheit;
  • A precipitation increase over the northwestern and north-central portions of the western United States and a decrease over the southwestern and south-central areas;
  • A decrease for almost all of the April 1st snowpack, a standard benchmark measurement used to project river basin runoff; and
  • An eight to 20 percent decrease in average annual stream flow in several river basins, including the Colorado, the Rio Grande and the San Joaquin.

Reclamation has released a new online tool for western water managers and the public to help increase accessibility of science-based information and understanding of how climate variations will impact the availability of water to communities. This site provides an interface to data for 195 sites on streams and rivers throughout the West.

Climate variability involves fluctuations in weather and climatic conditions during the coming months, years and decades.  Climate change involves a shift in the envelope of climatic variations, usually measured over a span of several decades.  Incorporating information on long-term change and short-term climate variability into Reclamation's water resource management infrastructure and operations is critical. The improved ability to forecast and use climate change and variability information would greatly enhance the ability of water managers and water users to plan their short-term operations and water delivery.

Climate information influences:

  • Resource management strategies to effectively deliver water
  • Hydrologic hazard possibilities to reduce flood risk

To learn more about climate change work at the Bureau of Reclamation, please visit: www.usbr.gov/climate

Updated: October 19, 2012