An underground reservoir called the Ogallala Aquifer supplies all the water necessary to irrigate thousands of square miles of corn, grain sorghum, and wheat. That is twice the capacity of all existing and proposed surface reservoirs in Texas. Water from the underground reservoir, however, is not as abundant nor as available as it once was. A nagging problem for the High Plains has been that there is less water each year than the year before. The water level near Plainview, for instance, dropped from 70 feet below the surface in 1956 to 110 feet below the surface in 1974.
Less water means deeper wells and higher pumping costs.
Less water also means once prolific wells declining in production, and many drying up completely. This water has remained trapped in porous sand and rock simply because it has nowhere else to go. These same geological features also prevent ground water from flowing into the isolated Ogallala. The only method of recharging the aquifer, then is the slow percolation of water through the soil. It became obvious to many living in the High Plains as early as 1940 that the water table of the ground water formation was being lowered by irrigation pumpage, that waste was occurring, that competition between closely-spaced wells was reducing their efficiency, and that the water was being mined because withdrawals greatly exceeded the recharge.