YANKTON, S.D. (WNAX) – A cooperative effort to come up with a plan to manage sediment flowing into Lewis & Clark Lake is moving slower than backers had hoped.

Sandy Stockholm, Executive Director of the Missouri Sediment Action Coalition, gave an update to the Yankton City Commission last week. She says studies of the problem are continuing.

Sand and sediment, mostly from the Niobrara River, continues to move into the lake creating more shallows and slowing the flow of the Missouri River.

Stockholm says they have been working with the Corps of Engineers on expanding the scope of the study.

Stockholm says sedimentation of reservoirs is a universal problem.

The coalition is hoping to start a demonstration project next year.