Every five years since 1950, the U.S. Geological Survey (USGS) National Water Use Information Program (NWUIP) has compiled water use information in the United States and published a circular report titled "Estimated use of water in the United States", that includes estimates of water withdrawals by State, sources of water withdrawals (groundwater or surface water), and water use category (irrigation, public supply, industrial, thermoelectric, etc.). This report discusses the impact of important considerations when estimating irrigated acreage and irrigation withdrawals, including estimates of conveyance loss, irrigation system efficiencies, pasture, horticulture, golf courses, and double cropping.
