Kansas owns water storage in 14 federal reservoirs managed by the U.S. Army Corps of Engineers. But the storage capacity of those lakes is gradually diminishing, as topsoil from waterways and farms upstream washes into the reservoirs and settles to the bottom.
State officials are now trying to extend the life of the eastern Kansas reservoir where the problem is most critical, according to the KHI News Service.
In 2013, the state negotiated an agreement with the Corps of Engineers to raise the level of John Redmond Reservoir near Burlington by 2 feet.
In an effort to reclaim some of the lake’s storage capacity, state officials began a $20 million dredging project in May.
The area being dredged is only a small fraction of the lake bottom in and around the original river channel, a few hundred yards from the dam.
Project engineer Brad Hahn said that the silt that’s been deposited in that area over the 50-year life of the lake is anywhere from 5 to 20 feet deep.
“As the sediment settles to the bottom, it raises the floor. So unless you raise the water level with it to maintain that water depth and that capacity, then you run out of capacity,” he said.
This is the first large-scale dredging project to reclaim storage capacity that the Corps of Engineers has approved.
The state had to satisfy a host of environmental concerns, and the Corps of Engineers had to make sure the dredging would not jeopardize the structural integrity of the dam.
The six-month, $20 million dredging project will add enough storage capacity to offset another three to five years of sedimentation.