U.S. Interior Secretary Ken Salazar released a report to Congress that analyzes the climate change risks associated with water supplies across major river basins in the United States.
The report indicates that changes in temperature and precipitation could affect stream flows, which could cause problems downstream for hydropower, agriculture and fish and wildlife.
The report projects a general warming trend in the western United States coupled with drought in the Southwest and heavier rains in the northern Pacific coastal region. Water flowing through major rivers in the west should decline as should the snowpack, which the Interior Department said was a key indicator used to project river basin runoff.
Mike Connor, director of the Interior Department's Bureau of Reclamation, said changes in the water levels in the United States could mean long-term problems.
"Impacts to water are on the leading edge of global climate change and these changes pose a significant challenge and risk to adequate water supplies, which are critical for the health, economy, and ecology of the United States," he said in a statement.