Over recent decades, the American Southwest has seen its population grow, its urban centers spread and its water demand increase. However, severe and frequent droughts have turned water into a major problem in the region.
The United States Interior Department has issued a new warning that these water woes are likely to worsen due to the influence of climate change. A new report warns wet areas could grow wetter and dry areas drier, with potential temperature increases of 5-7 degrees F.
Perhaps most troubling, average annual stream flow in major river basins, including the Colorado, Rio Grande and San Joaquin rivers, may decrease by 8 – 20% over the next century. This would severely impact large population centers in Las Vegas, NV, Los Angeles, CA and Phoenix, AZ, all of which depend on these rivers for water supplies.
California’s agricultural centers are an important production area for the entire country. As river flows dwindle, farmers may have fewer and less reliable water supplies to meet irrigation needs.
“Water is on the leading edge of climate change,” says Anne Castele, the Interior Department’s assistant secretary for science and water. “Many of these basins have already experienced significant… decreases to water supply.” Castle notes that some of the fastest population growth over recent years has occurred in the region’s driest parts.
Water managers in the Western U.S. must focus on the “energy-water nexus,” and heed the “alarm bells” that are sounding across the U.S. political spectrum as this issue worsens, says Secretary of the Interior Ken Salazar.