Documentation of Methods and Inventory of Irrigation Data Collected for the 2000 and 2005: U.s. Geological Survey Estimated Use of Water in the United ... and Recommendations for Future Compilations

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,? which includes estimates of water withdrawals by State, sources of water withdrawals (groundwater or sur-face water), and water-use category (irrigation, public supply, industrial, thermoelectric, and so forth). This report discusses the impact of important considerations when estimating irri-gated acreage and irrigation withdrawals, including estimates of conveyance loss, irrigation-system efficiencies, pasture, horticulture, golf courses, and double cropping.