Posted on May 16, 2017
By Nick Hytrek, Sioux City Journal
Federal, state and local officials have spent years studying ways to clear out the sediment that’s slowly filling in Lewis and Clark Lake.
With all the time spent seeking solutions to either removing the sediment or reducing the amount flowing into the lake, one would think just about every avenue had been explored.
That wasn’t the case.
After a meeting of the Missouri Sedimentation Action Coalition last summer, executive director Sandy Stockholm received a phone call from a businessman who had a potential solution that no one in this area had heard of.
That idea — trap sediment on the Niobrara River and pump it out before it can reach Lewis and Clark Lake — caught Stockholm by surprise.
“You just don’t expect to hear of something out of the blue,” she said.
That businessman, Jason Ziss, of Kurtz Bros. Inc., of Independence, Ohio, says that the amount of sediment flowing into the lake from the Niobrara River, a major source of lake sediment, could be reduced by 60 percent.
He’s submitted a preliminary project overview and in March spoke at the annual meeting of MSAC, a Springfield, South Dakota-based organization committed to educating the public and seeking solutions to Missouri River reservoir sedimentation.
“It really injected a lot of optimism into the discussion,” Stockholm said. “The technology offers a good start to the solution to sediment in the lake.”
The idea is far from coming to fruition. Cost estimates run as high as $16 million, and a market must be found for the tons of sand that would be removed from the Niobrara River.
Those are issues that Stockholm said her group is happy to explore if it means keeping sand out of the lake.
“There are a lot of questions yet, but they are questions that are exciting to ask,” she said.
Finding answers to those questions is a growing concern, especially for those who live near the confluence of the Niobrara and Missouri rivers near the lake’s west end. The sand delta accumulating there has raised ground water levels, increasing flooding threats near Niobrara, Nebraska, and Springfield and affecting water supplies. It’s also becoming harder for recreational boaters to navigate the waters around the sediment delta.
Each year, 5.1 tons of sediment enters Lewis and Clark Lake, said Mark Sweeney, a University of South Dakota associate professor of earth sciences and member of USD’s Missouri River Institute.
The Niobrara River, which runs through the sandy soils of northern Nebraska, contributes 60 percent, or 3.1 tons of that total. Much of the rest comes from the Missouri River, with a small portion from the small creeks that empty into the lake and shore erosion.
The U.S. Army Corps of Engineers estimated in 2011 that Lewis and Clark Lake had lost 27 percent of its water storage capacity to sediment since the reservoir began filling in August 1955. At the current rate, the lake would be filled with sediment in 125-175 years.
“Any action that could reduce the rate at which Lewis and Clark Lake is filling with sediment would be beneficial to the future of the reservoir,” said Paul Boyd, a hydraulic engineer in the Corps of Engineers’ Omaha office.
Ziss is offering one of those actions.
Kurtz Bros., a waste resource company with an emphasis on recycling and sediment management projects, has teamed with Ohio-based Streamside Technology, which has developed sediment collectors that remove sand and other materials from rivers.
In simplified terms, collectors that look similar to speed bumps are placed on the river bed. As the sand is carried by the water, it hits the ramp, tumbles into a grate system and is pumped on shore.
Ziss said he saw a newspaper story online about the sediment issue in Lewis and Clark Lake last fall and called Stockholm for more information. He visited the area last fall and determined that Niobrara River conditions are conducive to sediment collection.
“The flow rates are perfect. The sand type is great,” he said.
Ziss identified two potential sites on the river for sediment collection.
Ziss said the collectors, which have been used in Colorado, Texas and Louisiana, could reduce Niobrara River sediment by 60 percent. Depending on the site chosen, the estimated cost of the project ranges from $14 to $16 million.
In addition to funding, a private developer would need to market and sell the tons of sand pumped from the river. Ziss said the sand could be used for fill in road construction and beach restoration projects across the country. It is also increasingly needed for fracking, a method of extracting oil and natural gas from the earth through high-pressure injection of water, sand and chemicals into the ground, Ziss said.
Stockholm and Ziss said they are exploring government and private funding sources. Stockholm said turning sand into a marketable commodity could provide new local business opportunities.
“Another big part of this whole idea is it could create another economic development opportunity,” she said.
The idea deserves consideration, Sweeney said.
“I like the idea and think it’s important to test these things,” Sweeney said. “I think to prolong the reservoir, a combination of some sediment removal and best management practices to reduce bank erosion would go a long way to reducing sediment.”
Any project likely would face a review by the Corps of Engineers’ regulatory division, Boyd said. The corps is familiar with the process Ziss is proposing, but it’s hard to say what types of permits might be required without seeing a final proposal and plan to remove the sand that’s extracted from the river.
“Certainly in any type of proposal, you would have an impact to the floodway by putting a facility to harvest sand by the river,” said Boyd, who attended the MSAC meeting at which Ziss spoke.
The corps currently has ongoing studies into flushing sediment through Gavins Point Dam near Yankton, South Dakota, or dredging the growing sand delta and pumping the sediment past the dam and back into the Missouri River 15 miles to the east.
Boyd said the corps believes a multi-faceted solution to reduce sediment in Lewis and Clark Lake will be needed. This new possibility could be one of many pieces to that solution.
“We’re looking at better, more efficient, less expensive ways to reduce sediment,” Boyd said.
Ziss said further engineering is needed and a site on the Niobrara chosen so developers can quote more accurate costs when seeking funding. He’s also open to starting the operation on a smaller scale in order to demonstrate the process and, hopefully, spur more interest and investment.
“I do believe there are options,” Ziss said. “I really do believe this could be a great public/private opportunity to preserve the lake.”
Source: Sioux City Journal
