LAWRENCE—A crew from the Kansas Geological Survey, based at the University of Kansas, will be in western Kansas measuring groundwater levels the first week of January.
Weather permitting, the KGS crew will be working near Colby and Atwood on Jan. 2; Goodland and St. Francis on Jan. 3; Tribune, Syracuse and Ulysses on Jan. 4; Elkhart and Liberal on Jan. 5; and Meade and Dodge City on Jan. 6.
About 90% of the measured wells tap into the High Plains aquifer, a massive network of underground water-bearing rocks and the main source of water in the region. The rest draw from deeper aquifers or shallower alluvial aquifers along creeks and rivers.
Timing of rain and snow events influences when and how much water is pumped from the aquifer for irrigation and other purposes. In 2019, the western Kansas growing season started off very dry in April, with generous rainfall amounts in May providing some relief. By July, it was dry again over much of the region, and average precipitation rates stayed low through the rest of the year.
“Precipitation patterns were a little bit of a roller coaster this last year,” said Brownie Wilson, KGS water-data manager. “It’s been a very dry fall with virtually the entire extent of the High Plains aquifer region in Kansas under some level of drought conditions, including some areas of southwest Kansas where conditions are listed in the extreme drought category.”
Dry fall weather may lead to later-than-normal pumping that, in turn, could skew the KGS’s January 2020 water-level measurement results.
“If we run into late-season pumping, water levels could be artificially low because the aquifer hasn't had its traditional time to recover from the summer pumping season,” Wilson said. “When this happens, we usually see things balance out the following year.”
The project is coordinated with the Kansas Department of Agriculture’s Division of Water Resources (DWR). Of the 1,430 wells being monitored in 48 counties, the KGS will measure 588, and crews from the DWR's field offices in Garden City, Stafford and Stockton will measure 842. New wells are added to the program as older wells become inaccessible or to fill in spatial gaps in the monitoring network.
The Kansas portion of the High Plains aquifer is divided into three subunits—the extensive Ogallala aquifer that underlies much of western Kansas and parts of seven surrounding states, the Great Bend Prairie aquifer in west-central Kansas, and the Equus Beds aquifer north and west of Wichita.
The Ogallala aquifer groundwater levels in much of western Kansas started dropping in the 1950s as pumping increased. Declines accelerated in some areas, notably southwest Kansas, during a period of prolonged drought conditions in the early 2000s. Levels in the Great Bend Prairie and Equus Beds aquifers, which are shallower and generally receive greater precipitation than the Ogallala, are more influenced by recharge — that is, water seeping down from the surface.
“We are expecting to find traditional patterns in the water-level changes, where declines are relatively greater in the southwest than in the northwest,” Wilson said. “In the Equus Beds and Great Bend Prairie aquifers, levels should be about the same as last year or slightly higher.”
The wells are accessed with landowners’ permission, and most have been measured for years, even decades. The majority are within the boundaries of the state’s five Groundwater Management Districts (GMDs), which are organized and governed by area landowners and water users to address local water-resource issues.
The KGS and DWR measure groundwater levels in December, January, and February to avoid — as much as possible — short-term declines caused by widespread pumping during the growing season.
Historical annual measurements for each well are available at the KGS's website. Results of measurements made in January 2020 will be added in late February.