Corps outlines first-in-the-world Tuttle Creek dredging test, hydrosuction study planned for John Redmond

John Shelley, a representative of the U.S. Army Corps of Engineers, told the Kansas House Agriculture and Natural Resources Budget Committee on March 6 that reservoir sedimentation is reducing water-storage capacity across eastern Kansas and described two demonstration approaches — water-injection dredging at Tuttle Creek Lake and hydro-suction at John Redmond Lake — intended to move sediment downstream and extend reservoir life.

Shelley told the committee the issue is urgent for eastern Kansas because about two-thirds of state residents rely on reservoir storage for water supplies. "Reservoir sedimentation is really the number 1 water supply threat for Eastern Kansas," he said, noting that some reservoirs have lost roughly half their original storage and that continued infill threatens water security for cities including Manhattan, Topeka, Lawrence and parts of Johnson County.

The Corps’ demonstration at Tuttle Creek Lake will use a method called water-injection dredging to fluidize and move fine sediment toward the dam and through the outlet gates instead of removing solids to land. The Corps plans to begin test operations on Aug. 14, with an initial 10-day run in summer and another 10-day run in early October; additional test days in 2026 are being considered. The Tuttle test is funded with a mix of congressional directed funds and a $2 million contribution from the State of Kansas, Shelley said. The Corps has awarded construction and fabrication contracts to Michael’s (contractor) and Custom Dredge Works (fabricator).

Shelley described how the injection method differs from conventional cutterhead dredging: rather than pumping a sediment slurry long distances to confined disposal, water-injection dredging injects clear water near the bed to create a denser, sediment-laden bottom layer that moves under its own weight to the dam, allowing discharge through existing gates. "Instead of pumping a sediment slurry thousands of feet, you're pumping clear water tens of feet," Shelley said, arguing this can lower energy and disposal costs.

The Corps will treat the Tuttle test as a technology demonstration rather than a project to remove a fixed volume of sediment. Key questions include production rate, cost per cubic yard and downstream effects on channel morphology, water quality and ecology. The Corps will monitor the test with multibeam sonar, instrumented buoys and other measures and has partnered with the University of Kansas, Kansas State University, USGS, Bureau of Reclamation and Corps research units.

John Redmond Lake presents different engineering constraints: outlet gates sit about 21 feet above the bottom, limiting direct passage of bed sediment through the gates. For Redmond, the Corps is pursuing a hydro-suction approach (a siphon-like system) that uses gravity and an existing conduit crossing the dam to move sediment downstream without continuous diesel pumping. The Kansas Water Office contracted Setekon to develop a 35% design and cost estimate for John Redmond; the Tulsa District has requested $4 million for a hydro-suction demonstration under the Corps’ flood risk management account. During the hearing, committee staff later noted the Senate had placed $3 million for John Redmond in the pending budget, but Shelley said a longer lead time will likely be required to coordinate downstream channels and interstate regulatory questions because sediment leaving Redmond can affect a downstream Oklahoma impoundment.

Committee members pressed on ecological and drinking-water risks. Representative Roth asked whether stirred-up sediment would harm fish; Shelley said the sediment-laden layer will hug the bottom and that fish "are just gonna get out of the way," adding that removing sediment generally slows eutrophication. Representatives also asked how far an injection could move sediment and whether the material might settle and re-accumulate; Shelley said the demonstration is designed to answer how far sediment will travel, noting laboratory flume tests suggested transport could be on the order of thousands of feet, but real-world results are an open question. He stressed monitoring downstream concentrations during tests so drinking-water systems can react if required.

Shelley summarized program-level next steps: engineering and environmental permitting (especially for John Redmond), long-term funding to operate these treatments repeatedly over years, and coordination with downstream stakeholders and federal regulators. The Corps has requested major-rehabilitation and general-investigation study status for Tuttle and Kanopolis in the Corps’ FY27 work plan; those avenues could enable longer-term, cost-shared projects with state and federal partners. "Without intentional significant action, the lakes will fill in with mud," Shelley said.

Ending: The Corps will proceed with the Tuttle Creek demonstration this summer and continue design and planning for John Redmond, but long-term implementation will require sustained funding, multi-jurisdiction coordination and additional environmental and engineering study. The hearing record shows the committee and multiple downstream water suppliers, including Johnson County entities, are watching the demonstrations for impacts and potential future costs.