Irrigation water use includes water that is applied by an irrigation system to sustain plant growth in agricultural and horticultural practices. Irrigation also includes water that is used for pre-irrigation, frost protection, chemical application, weed control, field preparation, crop cooling, harvesting, dust suppression, and leaching salts from the root zone. Estimates of irrigation withdrawals are generally accounted for at the point of diversion (wells, springs, streams, ponds) and include water that is lost in conveyance prior to application on fields, as well as water that may subsequently return to a surface-water body as runoff after application, water consumed as evapotranspiration (ET) from plants and evaporated from the ground, or water that recharges aquifers as it seeps past the root zone. This web page provides an overview of USGS's research about domestic water use. It includes related research, publications, and news (Introduction).