Irrigation in the texas high plains: A brief history and potential reductions in demand

Abstract

Irrigation for crop production in the semi-arid Texas High Plains is dependent on groundwater withdrawals from the Ogallala Aquifer, which is declining because withdrawals exceed natural recharge. Irrigation development in the region accelerated during the 1950s. Both irrigated area and volume pumped peaked in 1974 and steadily declined during 1974-1989. By 2004, however, irrigated area was nearly the same as it was in 1958, and volume pumped had increased slightly. Several strategies to reduce groundwater withdrawals were reviewed without any reductions in irrigated land area or crop productivity. The most promising evaluated were: (1) increasing weather-based irrigation scheduling using the Texas High Plains Evapotranspiration Network (TXHPET); (2) converting gravity-irrigated land (27% of total) to centre pivot irrigation; and (3) replacing high-water to lower-water demand crops (i.e., corn to cotton). If the land area using the TXHPET network was doubled, and if gravity-irrigated lands were reduced to 10%, groundwater withdrawals could be reduced by 14%. An additional reduction of 8% may be possible by converting half of the irrigated corn area to cotton. © 2008 John Wiley & Sons, Ltd.