The Equus Beds Aquifer is the smallest Aquifer within the High Plains Aquifer in Kansas. It is located in south central Kansas, an area characterized by moderate precipitation, hot summers, cold winters with low average precipitation, and high rates of evaporation (Williams & Lohman, 1949).
Because much of the Equus Beds are composed of alluvial sediment (Stramel, 1966; Buchanan et al., 2015; Stullken et al., 1985), its primary source of recharge is from the precipitation that falls within its catchment area. Other than precipitation, the Equus Beds are intermittently recharged by the streams that flow over it, infiltration from other aquifers, and seepage from surface level irrigation (Stullken et al., 1985).
The three major streams that flow through the Equus Beds basin, Kisiwa Creek, Little Arkansas River, and the Arkansas river, only provide recharge during periods of high flow when the water table is low. Often when the water table is high the Equus beds will often discharge water into the Little Arkansas River (Stramel, 1966). Because of the regional climate and geology, the Equus Beds rely heavily on yearly weather conditions with low and high water levels being directly associated to low and high rainfall years respectively (Stramel, 1966).
The Equus Beds Aquifer is the primary water source of Wichita, Kansas and supplies water for both municipal and irrigation uses for roughly half a million people in south-central Kansas (USGS, 2019). The groundwater resources in Kansas are managed by five different groundwater management districts (GMD's), with GMD 2 being the district containing the Equus Beds. When it was formed in 1975, GMD 2 covered 500,480 acres and nearly all of the Equus Beds Aquifer. in 1988 GMD 2 expanded eastward and now covers 878,730 acres and now includes a portion of the Big Bend Aquifer that lies to the east. GMD 2 removes on average 187,432 acre-feet of water per year, with ~69% used for irrigation (Kansas Dept. of Agriculture, n.d.).
After a historic drought in 1993 and decades of significant pumping, the aquifer had experienced a substantial decrease in water level (Stone, 2017). The decrease in water availability created the incentive needed for action which ultimately lead to the creation of the Equus Beds Aquifer Storage and Recovery (ASR) Project. This project is separated into two phases with two goals in mind: Artificial recharge of the aquifer in order to meet 21st century water needs, and prevent the degradation of water quality as pumping has caused a large saltwater plume to begin to migrate towards the Wichita well fields from the Arkansas River. (KSWSC, 2025)
Elijah L. Ditto, University of Kansas Geology Department, May 2025