One in Ten U.S. Watersheds Are Stressed
Almost one-tenth of water supplies in the U.S. are stressed, meaning demand outweighs supply, according to a new study published in Environmental Research Letters. The authors used a water supply stress index model to examine supply and demand in over 2100 watersheds across the U.S. In almost all of the country, agriculture is the main driver of water stress. In southern California, however, the main driver is from municipal sources. Another substantial demand on water and driver of water stress in the U.S. is cooling water for power plants, “indicating that a single power plant has the potential to stress water supplies at the watershed scale.” The region most sensitive, especially to changes in water supply, is the western U.S. due to the potential for low flow events and long-term shifts in flow from climate change. However, other sectors also exhibit potential vulnerabilities including the ‘water-rich’ southeast.