The U.S. Department of the Interior (DOI) has released a report that assesses climate change risks and how these risks could impact water operations, hydropower, flood control, and fish and wildlife in the western U.S.
The report to Congress, prepared by the DOI's Bureau of Reclamation, represents the first consistent and coordinated assessment of risks to future water supplies across eight major reclamation river basins, including the Colorado, Rio Grande and Missouri river basins.
Specific projections in the report include the following:
– a temperature increase of 5 to 7 degrees F;
– a precipitation increase over the northwestern and north central portions of the western U.S. and a decrease over the southwestern and south central areas;
– a decrease for almost all of the April 1 snowpack, a standard benchmark measurement used to project river basin runoff; and
– an 8% to 20% decrease in average annual stream flow in several river basins, including the Colorado, Rio Grande and San Joaquin river basins.
The report notes that projected changes in temperature and precipitation are likely to impact the timing and quantity of stream flows in all western U.S. basins, which could impact water available to farms and cities, hydropower generation, fish and wildlife, and other uses such as recreation.