The Ogallala has been the source of substantial, large-scale irrigation development, beginning in the 1950s, when affordable technology became available for extracting groundwater and applying it to large fields of cotton, corn, winter wheat, and sorghum (Warren et al., The number of wells on the Texas High Plains increased from 48,000 in 1958 to 101,000 in 2000, as farmers increased their production of irrigated crops (Colaizzi et al., The Ogallala is largely a fossil aquifer with a very slow rate of natural recharge.