News Release, Kansas Geological Survey, Dec. 27, 2011
LAWRENCE--In early January crews from the Kansas Geological Survey based at the University of Kansas will be in western Kansas measuring ground-water levels as part of a program to track changes in the depth-to-water in the region's aquifers over time.
KGS crews will start in the vicinity of Colby on January 3, Goodland on January 4, Syracuse on January 5, and Liberal on January 6 and will cover multiple counties in those areas.
Working cooperatively with the Division of Water Resources (DWR) of the Kansas Department of Agriculture, the KGS monitors approximately 500 water wells each year. DWR staff from field offices in Stockton, Garden City, and Stafford measures about 900 more wells in a regional well network.
Measurements are made with the cooperation of landowners.
"The landowners and operators we work with are outstanding," says Brett Wedel, manager of the KGS's water-level-data acquisition efforts. "They support what we are doing and provide us invaluable access to their wells."
Landowners, state and federal agencies, local groundwater management districts, private entities, and the general public use the collected data in a variety of ways.
"They use it for many purposes ranging from reviewing management activities and computing storage estimates to making local water-use decisions," said Brownie Wilson, KGS water-data manager. "We get inquiries from producers to tax accountants to engineers."
Altogether, 1,393 wells in 47 western and central Kansas counties are being measured this year by the KGS and DWR. Most have been monitored every year for at least two to three decades.
"Annual readings on some of the wells date back to the 1960s," Wilson said. "Having decades of data from individual wells helps us see where the High Plains aquifer is changing over the long term and how water levels are affected by climatic conditions and pumping."
Ninety percent of the measured wells draw water from the High Plains aquifer, a massive 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 Wichita.
The rest of the wells are drilled into deeper aquifer systems, such as the Dakota, or shallower aquifers along creeks and rivers.
The High Plains aquifer is the primary source of municipal, industrial, and irrigation water for much of western and central Kansas. Ground-water levels have dropped in parts of the aquifer as usage increased over the past 60 years.
Most of the wells measured by the KGS and DWR are within the boundaries of one of the state's five Groundwater Management Districts (GMDs), organized by area landowners and large-scale water users and governed by local boards to help define and address water-resource issues.
Between January 2010 and January 2011 ground-water levels declined, on average, nearly 3 feet in wells located in Southwest Kansas GMD 3, while average levels within Western Kansas GMD 1 and Northwest Kansas GMD 4 dropped less than a foot. Measurements at individual wells may differ from regional averages, mainly due to localized rain and snowfall.
In GMD 3, the greatest declines occurred from the Arkansas River south into Grant, Haskell, and Gray counties. The district also includes all or part of Finney, Stanton, Ford, Morton, Stevens, Seward, Hamilton, Kearny, and Meade counties. Most wells measured in the area are drilled into the Ogallala aquifer with a few in the deeper Dakota aquifer.
Precipitation during the growing season has been well below average for the past several years throughout much of southwestern Kansas, accelerating the declines.
In Western Kansas GMD 1, which includes portions of Wallace, Greeley, Wichita, Scott, and Lane counties, the decline averaged 0.71 feet from 2010 to 2011. Most of the area's wells, whose levels have dropped 12 of the last 15 years, are drilled into the Ogallala aquifer.
Measurements for 2011 in Northwest Kansas GMD 4, covering Sherman, Thomas, Sheridan, and parts of Cheyenne, Rawlins, Decatur, Graham, Wallace, Logan, and Gove counties, were down 0.5 feet overall, although levels in some localized areas actually rose 2.5 feet or higher. In this district the Ogallala aquifer is generally less productive so most of the higher capacity wells are in alluvial river valleys.
An aquifer will decline over time if more water is pumped out than is replenished through precipitation and other recharge events, Wilson said. Historically, declines in western Kansas have been most prevalent in the Ogallala portion of the High Plains aquifer.
Water levels are measured in January when irrigation wells aren't in use because that is when levels are least likely to fluctuate.
"At this time of year we are also least likely to interfere with activities at or around the wells," Wedel said.
Historical measurements of individual wells are available at the Survey's web site (http://www.kgs.ku.edu/Magellan/WaterLevels/index.html). Results of measurements made in January 2012 will be added in late February.
Story by Cathy Evans, (785) 864-2195.
For more information, contact Brownie Wilson, (785) 864-2118
Kansas Geological Survey, Public Outreach