The huge Ogallala aquifer, the primary source of water for the agricultural high plains of West Texas and the Great Plain states, is already one-fourth depleted.
Many cities use every drop of water available locally.
Water levels in wells in Tucson, for example, have dropped as much as several hundred feet during the past 30 years. New York, San Francisco and Denver also rely on water imported from large distances. Such hugh projects are extremely expensive and are less likely to be built in the future. Hydrologists works with engineers and other scientists to provide creative solutions to finding ways of extending water supplies. Together, they may work on projects such as investigating the feasibility of increasing supplies by method such as desalting ocean water, cloud seeding to increase rainfall, or capturing storm runoff for replenishing groundwater.