Dredging part of the ecosystem restoration project at Harlan County Lake

The delivery of an aquatic ecosystem restoration project at Harlan County Lake, Nebraska, was initiated upon the request of Nebraska Game and Parks Commission.

The partnership project is authorized under Section 1135 of the Water Resources Development Act of 1986 and is expected to be an investment of approximately $10 million.

The U.S. Army Corps of Engineers, Kansas City District has been working with the agencies over the past several years to determine feasibility and develop of a conceptual design for this project. The agencies signed an agreement starting the detailed design stage of the project in May 2022.

The primary objectives of the project are to restore and protect degraded aquatic habitat by removing sediment that has blocked the entrance of Methodist Cove, create spawning and overwintering areas for a variety of aquatic organisms and manage invasive vegetation.

The project will involve excavation and dredging to create fish passage and spawning areas, installation of breakwaters and rock groins to control erosion and sediment deposition, removal of invasive vegetation species, such as salt cedar, and installation of artificial structures and/or vegetation to improve aquatic organism habitat.

In September 2022, USACE awarded a contract to joint venture Mead-Hunt – Olsson to develop the detailed design for the project. Mead-Hunt – Olsson is partnering with a Nebraska based firm, the Flatwater Group, that helped develop the conceptual design.

Mead-Hunt – Olsson/The Flatwater Group recently met with USACE and NGPC teammates for a kick-off meeting at the project site in mid-October. The meeting, which marked the official start to design activities, ensures that all partners are coordinating in the delivery of required tasks, and provides an opportunity for staff from each agency to connect.

While at Harlan County Lake, USACE staff conducted an assessment which identified and mapped wetlands that currently exist in the project area. This information will assist MHO/TFG in developing the detailed design.

Since the kick-off meeting, geotechnical evaluation of the project site has been conducted. A drill rig was used to drill sample bores at multiple locations across the project site.

Evaluation of the sediment cores determines the properties of soils at the project site – to a depth of up to 50 feet – and will help guide the remainder of the design effort.

Detailed design will continue into mid-2023. Once the design process is complete, the project will be ready to move into the construction stage.

Photo: USACE