Vermillion, S.D. – Mark Sweeney, associate professor of sustainability and environment, discusses the effect of accumulating sediment on the Missouri River during the latest episode of Credit Hour, the University of South Dakota’s official podcast.
Sweeney addresses how sediment issues can cause problems in downstream areas like the Lewis and Clark Lake near Yankton. Because the Gavin’s Point Dam blocks the natural flow of the river, sediment builds up behind the dam, which will, in time, cause the lake to fill in.
“If you fill in that reservoir with sediment, you’re going to eventually reduce the hydroelectric capacity of the dam and reduce boating and other recreational opportunities on the lake, which could potentially have devastating economic impact to the surrounding towns,” Sweeney said.
To better understand the problems with sediment, Sweeney studies the river’s tributaries to learn where the sediment is coming from. The largest tributary, the Niobrara River in Nebraska, contributes the most sediment into the reservoir. The Missouri River itself also carries a significant amount of sediment with it in its flow.
A solution Sweeney discussed is to plant vegetation along the banks of the river to prolong the life of the reservoir.
“Mark does an excellent job explaining how lakes like Lewis and Clark near Yankton are affected by years of downstream sediment accumulation,” said Michael Ewald, host of Credit Hour. “While the problem may take years to grow, it has the potential to impact hydroelectric power generation, recreation and natural river environments and habitat."
Credit Hour is available on Apple podcasts, Stitcher, Google Play and usd.edu/podcast.