YANKTON, S.D. — Too much sediment has been a problem in South Dakota's Lewis and Clark Lake for decades, and experts say a solution will be difficult and expensive - but it has to be found soon.

The Army Corps of Engineers and others are searching for a fix to reduce the 5 million tons of sediment that pour into the lake annually from the Missouri River, and even more so from the Niobrara, which runs through Nebraska's Sandhills.

University of South Dakota Professor Mark Sweeney is a member of the Missouri River Institute. He said this has been a discussion topic for nearly 20 years, but finding a consistent sediment management plan for the lake is becoming more critical.

"All of the main-stem dams on the Missouri River do have this problem to a certain extent,” Sweeney said; “but Lewis and Clark Lake, it's the worst."

A delegation from the Yankton area met recently with federal officials in Washington to discuss potential solutions and funding possibilities. More than 1 million people visit the Lewis and Clark Lake area annually for camping, fishing and water recreation.

In 2011, the U.S. Army Corps of Engineers estimated sediment had caused Lewis and Clark to lose 27 percent of its water storage capacity. Sweeney said a delta created by the sediment is popular with recreationists on the Missouri-Niobrara River confluence, but will eventually come at the expense of boat enthusiasts.

"On one hand you could say well, we've increased the number of recreational opportunities because there's actually a lot of really interesting canoeing and kayaking in the delta itself,” he said. “But if this problem continues to progress, the reservoir will fill up and you won't be able to take a boat out on it.”

Sweeney said it's estimated Lewis and Clark Lake could lose most of its capacity by the year 2050, while the delta will grow considerably in the next 100 years.

"If we do nothing then we're going to have these impacts in the future, recreation for one,” he said. “We won't be able to produce hydro-electric power out of the Gavins Point Damn for two. It could cause additional flooding hazards along some of the margins of the lake."

Proposals for dealing with the sand and mud include lowering the lake level and flushing it father downstream, decreasing the amount of sediment entering the lake, and encouraging oil and gas industries to use it for fracking.


get more stories like this via email

A new film documents the 2018 battle between Colorado environmentalists and the oil and gas industry over proposed fracking regulations.

The film also documents a grassroots effort by Colorado Rising to pass a ballot initiative which would create a 2,500-foot setback for all hydraulic fracturing wells in the state, particularly in disadvantaged neighborhoods.

Sarah Schulte, organizing committee member of GreenFaith Boulder County, which recently previewed the film for about 100 members, said the film has a strong message.

"What probably makes the film pretty dramatic and kind of shocking is the length to which oil and natural gas industries in Colorado set out to thwart them," Schulte pointed out. "Not only with some of the tactics you might expect, but also some kind of more nefarious tactics sabotaging their signature gathering, for example."

In the end, the petroleum industry defeated the measure after a $50 million campaign opposing it. Schulte acknowledged Colorado Rising raised only $1 million for its campaign. After the election, the state adopted a 1,000-foot drilling setback from schools and residential property lines.

Hydraulic fracturing, commonly called fracking, involves drillers injecting a mixture of chemicals underground to break up the shale and free the oil. The chemicals used in the process, which are sometimes toxic, can pollute groundwater and make the surrounding land unstable.

Schulte emphasized the movie had a powerful effect on the group's members.

"I think most people were pretty angry and maybe even a little sad after seeing how these kinds of politics play out in Colorado," Schulte observed. "They asked questions like what can we do next? How do you keep going when it's so difficult to fight such a big and powerful industry?"

The film, Fracking the System: Colorado's Oil and Gas Wars, is currently being previewed by select audiences. It has won the "Spirit of Activism" award at the Colorado Environmental Film Festival
and the "Environmental Award" at the 2024 DOCUTAH International Film Festival.

As part of an effort to restore the Mississippi River delta, an organization is collaborating with nature to address environmental challenges.

The Big Muddy is the second-longest river in North America, flowing more than 2,300 miles.

Simone Maloz, campaign director for the group Restore the Mississippi River Delta, said the coalition uses nature-based solutions to help tackle some of the river's environmental problems in Louisiana and Mississippi.

"We use the power and the sediment the river provides to help us to put solutions into place," Maloz explained. "For example, we might have an area of wetlands that needs to be nourished with freshwater sediment, we can tap into that wonderful resource that we have."

Maloz pointed out some farmers are turning to nature-based solution, using cover crops like clover or other plants to protect the soil. Cover crops typically grow in between primary crops, or are planted in the offseason to help keep nutrients on the ground so they do not become toxic in the water as runoff.

Maloz emphasized nature-based solutions are key to building resilient communities, which she said are those communities thinking about how to plan for climate change, such as floods, droughts, and rising sea levels, wildfires, hurricanes and coastal threats.

"What we know about resilient communities, whether you're on the coast, or whether you're not on the coast, is about how you can brace yourself for these impacts and how you can more quickly recover," Maloz stressed. "We know that when you include nature in those plans, it helps you to better do that."

Maloz added her group is involved in various projects along the Mississippi River, using sediment to replenish marshes, rebuild ridges and barrier islands and create habitats for migratory birds.


get more stories like this via email

The Iowa Environmental Council has petitioned the Environmental Protection Agency to invoke emergency powers to protect sensitive soil and groundwater in northeast Iowa.

The council is holding a public webinar today and wants the EPA to address groundwater contamination in northeast Iowa's so-called Driftless region. The groundwater there has a well-documented history of nitrate contamination.

Alicia Vasto, director of water program for the council, said the highly porous and soluble karst soil prevalent in the region is susceptible to contamination from centralized animal feeding operations.

"We did some analyses of private well data and public water systems and found that there was a lot of contamination of nitrate in those drinking water sources," Vasto reported. "The state has really failed to take action meaningfully that would address those problems."

The state has said it is constantly working to upgrade groundwater quality standards and is in the process of taking public input on creating yet another set of rules.

Vasto emphasized since the state has failed to address the water safety concerns for decades, the council and a coalition of other environmental groups have, in effect, gone above the state's head to the EPA, asking the agency to implement an emergency stop gap on nitrate pollution the way the agency did in neighboring Minnesota last year.

"We're asking that at, at minimum, the EPA would require the state of Iowa to do what they required the state of Minnesota to do under the same petition," Vasto explained. "Because the geology of northeast Iowa is the same as of southeast Minnesota."

The council's recommendations include calling on the EPA to create a communications plan with residents whose water could be at risk, create a drinking water sampling plan, and establishing a thorough permitting process for centralized animal feeding operations.


get more stories like this via email