April, 12, 2023
“Five Feet High and Rising” could have been the theme song for Tuesday’s Illinois River Flood Study presentation in Siloam Springs, Arkansas by the U.S Army Corps of Engineers. A large audience of stakeholders and state officials attended to learn why the Illinois River floods more often, with more rapid water reaching higher crests.
Edmund Howe, Corps chief hydrologist from Little Rock, Arkansas explained charts showing flood trends and higher stream velocity because of greater rainfall amounts and changing land use patterns.
“We are not planning on building any dams on the Illinois River. I want to make that clear,” Howe said. “What we do have is a great amount of data that can be used for planning and making data-based decisions, a divide and conquer strategy based on ideas,” he added.
Scenarios for dealing with basin flooding include stream buffers that can reduce the velocity of flood water and detention basins to hold flood water. Howe estimated riparian buffers would have to be 100-feet wide and that detention structures would have to hold one and one-half times to volume of Lake Tenkiller or 800,000 cubic feet of water.
“Detention structures are not economically viable, and we are not recommending those,” Howe said. “Riparian buffers are the most attainable and economically feasible way to reduce flood velocity,” he added.
Participating in the study were the Grand River Dam Authority and the Cherokee Nation.
The Illinois River Flood Study can be found at this web address: https://www.swl.usace.army.mil/Missions/Planning/Illinois-River-Flood-Study/
Army Corps of Engineers hydrologist Edmund Howe explains reasons for Illinois River Flooding