Geological Survey measures water levels in western Kansas

LAWRENCE — In early January, crews from the Kansas Geological Survey, based at the University of Kansas, will be in western Kansas measuring groundwater levels in more than 500 wells to help determine trends in the region's aquifers.

The crews will start in the vicinity of Colby on Jan. 2, Goodland on Jan. 3, Syracuse on Jan. 4 and Liberal on Jan. 5, and will cover multiple counties in those areas.

In particular, the KGS monitors the massive High Plains aquifer system, which consists largely of the Ogallala aquifer and is the primary source of municipal, industrial and irrigation water for much of western and central Kansas.

Past monitoring has shown that groundwater levels have dropped significantly in parts of the High Plains aquifer where water usage has risen substantially over the past 60 years and below-average precipitation in recent years has increased the rate of decline.

"The entire state is feeling the effects of the current drought, and this is and has been particularly true in the High Plains aquifer region of Kansas," said Brownie Wilson, KGS water-data manager. "Given that much of the aquifer normally has extremely low rates of natural recharge, the lack of precipitation increases the pumping demands, which in turn accelerates groundwater level declines in some areas."

As part of a cooperative program with the Division of Water Resources (DWR) of the Kansas Department of Agriculture, the KGS will measure 512 wells in western Kansas. The same wells are measured annually, with landowner permission, to track changes in the depth to the water table over time.

Altogether the KGS and DWR will measure 1,407 wells in 47 western and central Kansas counties. DWR staff from field offices in Stockton, Garden City and Stafford will measure 895 wells in a regional network covering parts of western and central Kansas. Most of the wells monitored in the program have been measured annually for at least two to three decades, and some since the 1960s.

"We collect data that will help us better understand the state of the aquifer and also help people make decisions about water use," said Brett Wedel, manager of the KGS's water-level-data acquisition efforts. "The data are useful to landowners, local groundwater management districts, state and federal agencies, businesses and private organizations."

Ninety percent of the measured wells draw water from the High Plains aquifer, a network of water-bearing formations that underlies parts of eight states and includes the extensive Ogallala aquifer, the Great Bend Prairie aquifer in west-central Kansas and the Equus Beds aquifer north and west of the city of Wichita. The rest of the wells are drilled into deeper systems, such as the Dakota aquifer, or shallow alluvial aquifers found along creeks and rivers.

The majority of the wells are within the boundaries of one of the state's five Groundwater Management Districts (GMDs) organized by area landowners and water users.

Results from monitoring in January 2012 indicate that between January 2011 and January 2012 water levels declined, on average, throughout all of western Kansas. For the fifth consecutive year, the greatest declines were recorded in the southwest corner, the area hardest hit by persistent drought conditions.

In southwestern Kansas GMD 3, where wells are monitored mainly in the Ogallala aquifer and selected areas of the Dakota aquifer, the average water level dropped a little more than 4 feet during 2011, more than twice the average annual rate of decline between 1996 and 2011.

Much of the district's greatest decline occurred in a triangular area from Garden City to Liberal to northeast of Dodge City. GMD 3 includes all or part of Grant, Haskell, Gray, Finney, Stanton, Ford, Morton, Stevens, Seward, Hamilton, Kearny and Meade counties.

Northwest Kansas, whose water comes mainly from the Ogallala aquifer, was the only region in the KGS assessment area where average declines did not exceed a foot in 2011. Increased levels were even recorded in some localized areas where precipitation was near normal.

Northwest Kansas GMD 4 — covering Sherman, Thomas, Sheridan and parts of Cheyenne, Rawlins, Decatur, Graham, Wallace, Logan and Gove counties — had an overall decline of 0.59 feet, close to the average of annual decline rates since 1996.

In contrast, the majority of wells measured in the area north of GMD 4, mainly in Rawlins, Decatur and Norton counties, had water-level increases up to 2.5 feet with even higher levels in a couple of locations. Most of the higher-capacity wells there are in shallow alluvial aquifers.

Western Kansas GMD 1, which includes portions of Wallace, Greeley, Wichita, Scott and Lane counties, had an average decline during 2011 of 1.49 feet, more than twice the average annual decline since 1996. Most wells in the district are drilled into the Ogallala aquifer.

The KGS measures water levels in January to try to avoid interference from the transient effects of pumping for irrigation during the growing season.

Historical measurements of individual wells are available at the Survey's website. Results of measurements made in January 2012 will be added in late February.