Not only is there a sediment accumulation problem going on up in the reservoir, there is also a sediment deficit problem going on below the dam. Listen to Tim Cowman, of the South Dakota Geological Survey, explain what is happening. It’s a problem in slow motion, that will not stop unless something changes. As Cowman, an MSAC Board of Director member says – one of MSAC’s goals is to produce a groundswell of support to help solve the problem.