On the Grand Prairie, rice has required irrigation. Present day economics are favoring irrigation for soybeans as well. Water needs are currently being filled primarily from three sources: rainfall, a Tertiary aquifer and a Quaternary aquifer. Rainfall and rainfall storage meet some of the total water needs. The Tertiary aquifer lies at depths of 750 to 1400 feet beneath the surface of the Grand Prairie. Some water is obtained from the formation, but the outlook for significantly increasing withdrawals is bleak because of the cost involved in drilling new wells. Roughly seventy-five percent of the irrigation water needs are met by withdrawal from the Quaternary aquifer underlying the prairie. A relatively impervious clay layer lies between the ground surface and the aquifer. Therefore recharge to the study area occurs primarily from the extended aquifer lying outside the area boundaries and from some reaches of the White River and Bayou Meto. Withdrawal of groundwater has exceeded recharge. The result is that the groundwater levels have been dropping significantly. Increasing pumping distance and escalating energy costs are creating some economic difficulties for the farmers of the area. However, the major problem is the difficulty of obtaining sufficient water.
Peralta, Richard C.; Arce, Roberto; and Skergan, Timothy M., "Grand Prairie Water Supply Project - Phase 1" (1983). Civil and Environmental Engineering Faculty Publications. Paper 1171.