We’ve heard the talk about the sedimentation issue in Lewis & Clark Lake for years. And we’ve also heard about the discussions to address it.

Last Friday, it became clear that the former is not going away.

It was also evident that those discussions on the sedimentation issue are finally ready to be translated into a plan.

A meeting hosted by the Missouri Sedimentation Action Coalition (MSAC) and featuring several agencies and individuals with vested interests or concerns about the issue was convened in Yankton. It wasn’t the first time MSAC had held a meeting on the topic, but this one was about more than talk.

This one, as Saturday’s Press & Dakotan story noted, was a “call for action.”

Indeed, it’s time to get this ball rolling and determine what federal help is needed to address the sediment issue that is gradually devouring the Gavins Point Dam’s reservoir from west to east.

What’s being sought now is a study of the situation by the U.S. Army Corps of Engineers in order to develop a sediment management plan for the lake. It’s estimated that such a study would cost about $600,000 in federal funds. MSAC would need to raise about $250,000 to satisfy a cost-sharing mandate.

The ultimate objective recognizes the fact that the sedimentation that is encroaching on the lake is a substance that is needed elsewhere, particularly downriver, to form deltas, sandbars and other formations.

“Our goal is to move the sediment downstream, where you have the free-flowing river below Gavins Point Dam (near Yankton),” said MSAC board member Tim Cowman, who is also the state geologist with the South Dakota Geological Survey. ”We’re starting to talk about a solution and the methods that we need to use in order to reach those solutions.”

There is more at stake here than the recreational amenities on the lake. This portion of the river is also relied upon for a source of drinking water, for instance.

It would seem that the solutions would require not only moving the current sediment in Lewis & Clark Lake downriver but also addressing the main source of this sediment.

The former issue means MSAC may be reaching out to downstream states for assistance in this project. This would be politically helpful as it would build a stronger alliance that may carry more weight in Washington.

As for the latter, the main source would be the Niobrara River, whose drainage basin includes a portion of the Nebraska Sandhills. There was a suggestion in the past of implementing a means of sifting out the sediment in the Niobrara before it reaches the Missouri, and then marketing the sediment. That’s just one idea, but it would be an intriguing, proactive one.

It’s time for movement on this issue. While the surface sediment is still several miles away from Gavins Point Dam, attendees Friday pointed out there is sediment structure below the water that can’t always be seen but is already having an impact on the lake.

What’s more, what is done for the Lewis and Clark Lake sedimentation issue could also help other rivers and water bodies across the nation. This could open a new door for coping with this encroaching problem.

Friday’s summit included governing entities, which was vital. The request for a study must be made by a taxing entity, which MSAC is not. So, someone will have to take up that mantle to get this thing rolling.

There is also a legal impetus at work. The federal Water Resources Development Act (WRDA) in 2016 directs the Corps to pursue sedimentation management on the waterways it oversees. The Lewis & Clark Lake issue seemingly falls right into that arena.

So, the time for action is now.

“We have talked for years about the problem. Now, people are ready to go to work,” Cowman said. “The first step is seeing what direction we are headed and how we make things happen. We’ve done a lot of studies. Now we need to look at solutions.”


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