Progress Report on the Ground-Water Hydrology of the Equus Beds Area, Kansas

Abstract

This report describes an investigation of the availability of ground water in the well field of the city of Wichita within the area known as the Equus beds in south-central Kansas, and the general hydrology of the Equus beds area.

By January 1, 1955, the City of Wichita had pumped 330,000 acre-feet of water from the well field. As of January 1955, the water level had declined a maximum of 32 feet in the well field. The decline of the water table is small, however, compared to the thickness of the saturated deposits. In January 1955, the depth to water in the well field ranged from 5 to 47 feet. The water table is affected by the city's pumping in an area of about 100 square miles, As of January 1955, about 67 percent of the water pumped from the well field by the city of Wichita had come from recharge by precipitation. The primary source of water for recharge to the well field is local precipitation falling on the land surface, and the seasonal rise of the water levels correlates closely with precipitation.

The water-bearing materials consist of unconsolidated deposits of sand, gravel, silt, and clay of Pleistocene age. The hydraulic gradient of the water table in the well field is toward Little Arkansas River, and some water is being discharged into it, although most of the water moving across the well field is intercepted by pumping.

If the Wichita well field is expanded, a larger area will be influenced by pumping, and the perennial yield will be correspondingly larger. If the well field were expanded to include all the Equus beds area, the perennial yield would be many times larger than the amount of water pumped in 1955 by the city of Wichita.

The hydrology and geology may be favorable in parts of the well field for artificial recharge. Additional data must be collected before the best method and the economic feasibility of artificially recharging the well field can be determined.

A map of the generalized geology of the Equus beds area and figures showing the water-table contours, changes in water levels during specific periods, cross sections, pumpage charts, precipitation graphs, and hydrographs of water-level fluctuations are given in this report,