News Release, Kansas Geological Survey, March 21, 2007
LAWRENCE--Ground-water levels in central and western Kansas continued to decline in 2006, according to measurements made by the Kansas Geological Survey, based at the University of Kansas, and the Division of Water Resources of the Kansas Department of Agriculture.
While water levels continued a trend of decline in western Kansas, the water levels in central Kansas saw renewed decline after holding steady just the year before.
Strong winter storms that hit western Kansas hampered data collection this year.
"The weather delayed measurement or prevented access to many wells," said Brownie Wilson, water-data manager at the Survey. About 305 wells out of the 1428 total-well network were not measured due to ice, snow, or poor road conditions.
"We just weren't able to get into some counties this year because of the snow," said Wilson. Most of these wells were in the western portion of the state.
The Survey is planning to re-attempt measurement on the wells that were missed.
"The weather delay and missed wells may have some influence on the water-level change comparisons between 2005 and 2006, so we're going out again in early April to try to fill in the holes within our coverage area," said Wilson.
Preliminary water level data from western Kansas wells, most of them in the Ogallala aquifer, showed an average decline of about 0.94 feet since January of 2006, compared to an average decline of about 0.57 feet in 2005. However, because of the weather delay and missed wells a meaningful comparison between 2005 and 2006 may not be available until next year.
"But overall the wells that we did measure still show the declining trends that we've seen in the past," said Wilson.
Water levels in central Kansas were lower than previous years, according to the measurements. The Equus Beds and Big Bend regions showed a drop of about 2.17 feet and 1.29 feet, respectively, since January 2006. This compares to a 0.03 foot increase and a 0.11 foot decrease the year before.
"In central Kansas, the increased rate of decline in 2006 was probably due to lower annual precipitation," said Wilson. With less rainfall, irrigators generally need to pump more water to compensate, which results in a higher rate of decline. Other factors, such as changing crop patterns and energy prices, can also influence irrigation.
"In western Kansas, with the long snow-melt period, we might see some very limited ground-water recharge in a few areas, particularly in river valleys where the water table is somewhat closer to the ground surface," said Wilson. "However, it would take years before any recharge from the snow melt reaches the large majority of the aquifer. Even then, there won't be enough water to stop the overall decline of the aquifer."
The February 2007 measurements in northwestern Kansas showed a decline of 0.21 feet since January of 2006. That compares to a decline of 0.59 feet from January 2005 to January 2006, and about 0.61 foot the year before that.
Water levels in west-central Kansas declined, about 0.42 feet, compared to declines of about 0.37 feet the previous year and holding steady the year before.
In southwestern Kansas, the average well measured in February 2007 was down about 2.18 feet, compared to 1.15 feet the previous year and 0.39 feet from January 2004 to January 2005.
Water levels were down about 1.29 feet in the Big Bend area of central Kansas, compared to holding steady the previous two years.
In the Equus Beds area of central Kansas, the average well measured declined about 2.17 feet after holding steady last year and being up about a foot the previous year. With the exception of 2006, from 1996 to 2006, water levels have held relatively steady, though they have varied from year to year.
The 2006 water-level data are considered preliminary at this point and are subject to additional study and revision, say Survey scientists. Final review should be completed by the first week of April, when the 2006 measurements can be viewed and accessed online (http://www.kgs.ku.edu/Magellan/WaterLevels/index.html).