Collaboration and creative thinking lead to $1 million savings on ecosystem restoration project

Published Nov. 7, 2024
An aerial view of a lake with grass and trees on the left, water on the right, and blue sky in the background.

Methodist Cove, a popular recreation spot at Harlan County Lake, was once cut off from the main reservoir due to years of erosion and sedimentation and prevented black crappie from using the cove to spawn. The Harlan County Lake ecosystem restoration project aims to reconnect Methodist Cove to the main reservoir and create new habitat for black crappie. Photo provided by Olsson, the contractor for the Harlan County Lake ecosystem restoration project.

An aerial view of a lake with grass and trees in the foreground, and water in the background.

Artificial fish habitats, called “spiders,” sit next to felled cedar trees in Methodist Cove at Harlan County Lake, Nebraska. Both the spiders and the cedar trees will be placed under the water to create fish habitat for black crappie. Years of erosion and sedimentation in Methodist Cove blocked it from the main reservoir, preventing black crappie from using the cove for spawning. The Harlan County Lake ecosystem restoration project aims to reconnect Methodist Cove to the main reservoir and create new habitat for black crappie. Photo provided by Olsson, the contractor for the Harlan County Lake ecosystem restoration project.

An aerial view of a lake with grass and trees in the foreground.

Artificial fish habitats, called “spiders,” are prepared to be placed under the water to create habitat for the black crappie at Methodist Cove at Harlan County Lake, Nebraska. Years of erosion and sedimentation in Methodist Cove blocked it from the main reservoir, preventing black crappie from using the cove for spawning. The Harlan County Lake ecosystem restoration project aims to reconnect Methodist Cove to the main reservoir and create new habitat for black crappie. Photo provided by Olsson, the contractor for the Harlan County Lake ecosystem restoration project.

An aerial view of a lake in the foreground with grass and trees to the left, right, and background.

Artificial fish habitats, called “spiders,” sit next to felled cedar trees in Methodist Cove at Harlan County Lake, Nebraska. Both the spiders and the cedar trees will be placed under the water to create fish habitat for black crappie. Photo provided by Olsson, the contractor for the Harlan County Lake ecosystem restoration project.

An aerial view of a lake in the background with grass and trees to the left, right, and foreground.

Cedar trees, an invasive species, are removed and prepared to be placed under the water to create habitat for the black crappie at Methodist Cove at Harlan County Lake, Nebraska. Years of erosion and sedimentation in Methodist Cove blocked it from the main reservoir, preventing black crappie from using the cove for spawning. The Harlan County Lake ecosystem restoration project aims to reconnect Methodist Cove to the main reservoir and create new habitat for black crappie. Photo provided by Olsson, the contractor for the Harlan County Lake ecosystem restoration project.

The past few years have seen significant increases in the cost of many things like labor, materials and supplies. Construction projects have not been immune to these rising costs. So, when federally funded construction projects can save taxpayer money, it’s worth celebrating. The government is a steward of taxpayer dollars and as such, has the responsibility to spend those dollars in the most cost-effective way. Sometimes this requires thinking outside the box.  

Through collaboration and creative thinking, the Kansas City District, U.S. Army Corps of Engineers, in partnership with the Nebraska Game and Parks Commission, was able to save about $1 million on an aquatic ecosystem restoration project at Harlan County Lake located in south central Nebraska. The construction effort, which totals over $11 million and was largely funded by the federal government under the Bipartisan Infrastructure Law, will restore vital parts of the aquatic ecosystem at the lake. In the face of rising prices, the team was able to save money while simultaneously improving the effectiveness and sustainability of the project.

One of the main problems the Harlan County Lake aquatic ecosystem restoration project seeks to fix is twofold. First, after years of erosion and sedimentation at the lake, several coves, which are popular spots for recreators, have gradually become closed off to the main lake. Second, when the coves become closed off, important fish habitat is lost. Arguably the most important habitat lost is that of the black crappie. 

“Crappie are really important to our anglers,” said Jeff Jackson, aquatic habitat program manager with the Nebraska Game and Parks Commission. “Especially when they are spawning, they’re susceptible to being caught from shore. It’s one of the top species anglers fish for.”

While the Kansas City District operates and maintains Harlan County Lake, the Nebraska Game and Parks Commission manages the fish populations found in the water and provided valuable fisheries expertise to the project. According to Jackson, the increased sedimentation found in the coves of Harlan County Lake makes it difficult for black crappie to reproduce.

“A lot of these aging reservoirs over time, their coves get closed in and get separated from the main reservoir,” said Jackson. “What we’ve found is coves are really important for crappie recruitment and spawning. Restoring some of these coves is a really important part of maintaining crappie populations.”

Methodist Cove, which is one of the most popular recreation spots at Harlan County Lake, was closed off from the main reservoir due to increased sedimentation. The project team has been working hard to dig a 200-foot channel reconnecting the cove to the main reservoir, as well as excavating the cove to a depth of about 12-feet. Not only will this provide a better recreation experience for those who enjoy fishing and boating at Methodist Cove, but it will allow black crappie to use the cove once again for spawning.

“There’s been a lot of excavation – over 100,000 cubic yards of material – to reconnect [Methodist Cove] to the lake,” said Leigh Mitchell, project manager for the Harlan County Lake aquatic ecosystem restoration project at the Kansas City District. “They excavated the cove … to create areas that could be utilized as habitat for the black crappie.”

But creating an environment suitable for black crappie to spawn requires more than just excavating silt from the cove. It also requires replacing the lost habitat. Both the Kansas City District and the Nebraska Game and Parks Commission saw this as an opportunity to get creative.

According to Mitchell, the original design of the project used only artificial habitat. The type of artificial habitat the team decided to use are often referred to as “spiders” because of the long legs jutting out of the body. However, the spiders are not cheap. The team decided to turn the project into an experimentation of sorts, using both artificial habitat and felled cedar trees to see which habitat the black crappie prefer, and which is the more sustainable option in the long-term.

The cedar trees, which are an invasive species, had already been removed as part of the larger ecosystem restoration project. By using a waste product as habitat in lieu of purchasing artificial habitat, the team was able to save close to $1 million on the project. Two-thirds of the more expensive artificial fish habitat were replaced with the cedar trees, which reduced the overall cost of the project.

“There were a lot of cedar trees that needed to be taken out as part of this project. If we hadn’t used them as habitat, they were going to get burned or taken offsite for disposal,” said Mitchell. “So, the project team thought, ‘well, instead of doing that, this stuff makes really good habitat. Let’s put it to use in the lake,’ and we were able to substitute a lot of that artificial fish habitat for what essentially was going to be a waste product.”

Sinking cedar trees to create new fish habitat is not unique to this project. Many USACE lake projects use the removal of these invasive trees as material to create natural fish habitat. What’s unique about the Harlan County Lake aquatic ecosystem restoration project is its ability to study both the artificial habitat and the cedar trees to see which is most effective in supporting the black crappie population.

“We want to know whether these habitats are successful – the artificial habitat versus the cedar trees. We want to know which one of those is a preferred habitat. It’s a multipronged approach,” said Jackson.

For Jackson and his team, this project goes beyond reconnecting Methodist Cove to the main reservoir. According to Jackson, it will likely impact species beyond the black crappie, which in turn will lead to a better recreation opportunity for those who love to fish at Harlan County Lake. 

“There are other species that will benefit from the habitat as well,” said Jackson. “There’s a decent walleye population and white bass fishery and all those other species – bluegill and crappie – that will all benefit from the habitat in the reservoir.”

The aquatic ecosystem restoration project at Harlan County Lake is expected to be complete in April 2025.