In many parts of the country, competing demands for water create stress in local and regional watersheds. Map shows a “water supply stress index” for the U.S. based on observations, with widespread stress in much of the Southwest, western Great Plains, and parts of the Northwest. Watersheds are considered stressed when water demand (from power plants, agriculture, and municipalities) exceeds 40% (water supply stress index of 0.4) of available supply. (Figure source: Averyt et al. 20116c050821-4d0f-452a-9fb3-6576a5cc1c2e).