Wichita’s Primary Water Supply Source Recovering Due to City’s Efforts

One of Wichita’s primary water-supply sources is recovering because of a strategy to reduce the amount of water withdrawn, according to a new report about the Equus Beds aquifer released by the U.S. Geological Survey as part of a long-term, continuing cooperative partnership with the city of Wichita.

The Equus Beds aquifer is one of the primary water-supply sources for the city of Wichita, Kansas. Groundwater pumping for municipal and irrigation needs, and sporadic drought conditions have caused water-level declines that led to concerns about the adequacy of the future water supply for Wichita. For this reason, in 1993, the City of Wichita developed a strategy to reduce the amount of water it pumped from the Equus Beds aquifer from about 60 to 40 percent of the total usage.

Groundwater levels in the central part of the Equus Beds aquifer study area, where the City of Wichita operates municipal water supply wells, increased by three feet from 2014 to 2015. The increase is likely due to the city reducing withdrawals from the aquifer in 2014 by more than 50 percent, which is the smallest amount since 1940. Although groundwater levels did rise, the aquifer was anticipated to recharge at a faster rate. Decreased groundwater flow and recharge of the aquifer, along with an increase in agricultural pumping resulted in a slower than expected increase in the volume of water stored within the aquifer.

“Reports such as this one from USGS that include updates on the condition of the aquifer beneath and beyond our wellfield provide valuable information about natural recharge," said Scott Macey, City of Wichita Water Resource Engineer.  "These results also help confirm the benefit of measures the City has taken to sustain the aquifer.”

When groundwater levels reached a historical minimum in 1993, a large area of declines greater than 10 feet covered most of the central part of the study area and extended beyond it. The study area storage volume in 2015 has recovered more than 31 percent since 1993. The central part of the study area recovered even more with an increase of 46 percent. Groundwater-level rises since 1993 to January 2015 ranged from 10 feet in some central parts of the study area to rises of more than 20 feet within the north-central part of the study area.

“The aquifer is 96% full. However, even with the large recoveries since 1993, the overall decline volume is nearly equal to two full years of city withdrawals,” said Andy Ziegler, USGS Kansas Water Science Center Director. 

The USGS report was prepared as part of the USGS Cooperative Water Program with the city of Wichita as part of their Equus Beds Aquifer Storage and Recovery (ASR) project. The ASR project is a component of the Integrated Local Water Supply Program adopted by the City of Wichita in 1993 to ensure an adequate water supply. Additional information about the project is available online.

By decreasing the proportion of water Wichita pumps from the Equus Beds aquifer, water levels in the aquifer are recovering. However, it is anticipated that water levels in the aquifer will decline if the City and agricultural users exercise their full water rights. In 2007, the city of Wichita began to use the Equus Beds ASR facilities to artificially recharge the aquifer with storm runoff water from the Little Arkansas River. Artificial recharge is being used to increase water levels and storage volume in the aquifer and slow down the plume of chloride approaching the Wichita well field from Burrton, Kansas. The USGS will continue to work with the city of Wichita to monitor the water-level and storage-volume changes in the Equus Beds aquifer.

More information is available on USGS efforts related to defining and understanding water quantity and quality of the Equus Beds aquifer on the USGS Kansas Water Science Center website.

USGS provides information in a number of states related to preservation of water supplies in artificial recharge and aquifer storage and recovery. For more information visit the USGS artificial groundwater recharge website.