Group Developing Plan To Save Silt-Laden Iowa Lake

NORTH LIBERTY, Iowa (AP) — A nonprofit is working with the U.S. Army Corps of Engineers to develop a plan to save a suburban Iowa City lake from rapid sedimentation that threatens to render it unusable in as few as 20 years.

Jon Kounkel is president of the group, Friends of Coralville Lake, The Gazette reported. He bought a house in nearby North Liberty during the winter nearly two decades ago. But when the ice melted, he discovered the lake’s dirty brown water.

“The lake was beautiful when it was frozen over and covered in snow," Kounkel recalled. When he and his family went out onto the lake for the first time, his daughter pointed out the “chocolate bubbles” in the water.

Kounkel said he has watched the lake decline ever since, as 1,300 acre-feet of additional sediment per year drops into the lake. That’s the equivalent of two Empire State Buildings a year. The Army Corps estimates it will be 20 to 30 years before the lake becomes unusable for boating and other recreation because of the silt.

“If you want your kids to enjoy the lake the way that we do, get involved,” said Derrick Parker, Friends of Coralville Lake founder and current treasurer.

The group will look at several possible solutions, including setting up a watershed management authority that would work to reduce sedimentation flow into the lake. Other possibilities include buffer strips and silt traps to slow down or catch the silt.

“You’ll never completely stop (the sedimentation), but if we can reduce it so it’s one Empire State Building worth instead of two, then that would start to extend the life of lake,” Kounkel said.

One action not being considered is dredging the lake, which is costly and dangerous for the environment, according to Jonathan Wuebker, assistant operations manager for the Corps.

A feasibility study will be one of the first steps of the group's Save the Lake campaign. Kounkel said feasibility study could be launched in 2022, with fundraising to start in 2023 or 2024 if the community is supportive. A lake restoration plan would begin around the same time as the fundraising campaign, Kounkel said.