WASHINGTON — What's being praised as the first coordinated and comprehensive look at climate change impacts to eight major basins in the West shows how they could play out in Utah, most notably the Colorado River Basin area.
The new report, released Monday by Interior Secretary Ken Salazar to Congress, assesses climate change risks and how those risks have the potential to jeopardize water operations, hydro power, flood control and even fish and wildlife in the Western United States.
The Interior Department's Bureau of Reclamation's 2011 SECURE Water Report says the upper Colorado River Basin (which includes Utah, New Mexico and Colorado) could likely face:
"Slightly" larger increases in temperature by 5 or 6 degrees Fahrenheit during the 21st century
Projected increases of precipitation by 2.1 percent by 2050
A mean annual runoff decrease of 8.5 percent by 2050
Warmer conditions transitioning snowfall to rainfall, producing more December-March runoff and less April-July runoff
"Water is the lifeblood of our communities, rural and urban economies, and our environment," Salazar said, "and small changes in water supplies or the timing of precipitation can have a big impact on all of us. This report provides the foundation for understanding the long-term impacts of climate change on Western water supplies and will help us identify and implement appropriate mitigation and adaptation strategies for sustainable water resource management."
The report says that such increased water runoff will likely require modifications be made to infrastructure and flood control plans, which could correspondingly reduce water supplies during the summer months.
Additionally, warmer conditions may result in more stresses to fisheries and specific aquatic species and facilitate an acceleration in the growth of nonnative or invasive species. Such warming would also pose substantial risks to farmers because reservoirs would be subject to "significant" evaporation, decreasing water supplies to farm fields and pasture lands.
Even in advance of the report's release Monday, the reclamation bureau has been trying to make adjustments were it can.
At Hoover Dam, new wide head range turbines are being installed that will allow for more efficient power generation over a wider range of lake levels than the existing turbines.
In Arizona, a yearlong pilot run of the Yuma Desalting Plant successfully converted return irrigation water — enough to supply 116,000 people with their water needs for a year.
The project not only helped boost water supplies, but helped meet U.S. treaty obligations with Mexico over supplies of Colorado River water.
Salazar said the water report will serve as a blueprint for Colorado River water users on steps that need to be taken in light of changing climates and increased demands.