Beneficial Use of Dredged Material: Section 1122, Upper Pool 4 – Lake Pepin, Bay City, Wisconsin

U.S. Army Corps of Engineers, St. Paul District
Published April 3, 2024
Updated: Sept. 25, 2023


This project utilizes dredged material generated from navigation channel to protect and restore backwater habitat; this is a win-win project for the U.S. Army Corps of Engineers, our partner agencies, and the environment. The Wisconsin Department of Natural Resources is the non-federal sponsor.


The project area is located near the head of Lake Pepin in Upper Pool 4 of the Mississippi River, between river mile 780 and 792 in the backwater complexes adjacent to the main channel. The nearest community is Bay City, Wisconsin.


Sedimentation and sediment resuspension caused a loss in water depth diversity of the backwater lakes and isolated wetlands above Lake Pepin as well as a loss in aquatic vegetation. Concerns over habitat deficiencies in Upper Pool 4 include reduced habitat diversity and quality, lack of aquatic vegetation and invertebrates, and reduced abundance of fish and wildlife.

The project utilizes dredged material generated from navigation channel dredging in Lower Pool 4 to improve the ecosystem at the head of Lake Pepin. The operations and maintenance program will pay up to the typical cost of dredged material disposal (100% federal) for any dredged material used. The project includes three peninsulas, two backwater overwintering areas, access dredging, shoreline protection and a water level management dike that create a range of habitat types for fish and wildlife.


The Lake Pepin Legacy Alliance requested a feasibility study in December 2015. The feasibility study was initiated in 2017 and completed in August 2020. The Corps and the Wisconsin Department of Natural Resources finalized the project partnership agreement in August 2021. The Corps completed final design of the project in July 2022 and awarded a construction contract in September 2022, exercising additional project options in January. A groundbreaking ceremony was held in May 2023, and construction began in August 2023. Approximately 25% of the construction was completed in 2023 including placement of sand base for several of the project features (see image). Construction will resume this spring, with construction completion planned for 2026.


The project was initiated under Section 204 of the Water Resources Development Act of 1992, as amended. The project was selected under Section 1122 of the Water Resources Development Act of 2016, which required the Corps to establish a pilot program to recommend ten projects for the beneficial use of dredged material.


The design and implementation phases of the project will be cost shared using funding from operations and maintenance, Section 1122 and the Wisconsin Department of Natural Resources.

Estimated project costs:

Feasibility 204 funds (100%)                            $938,420

Federal O&M funds (100%)                          $8,275,000

Federal CG funds (65%)                                $8,281,000

Non-federal funds (35%)                               $4,459,050

Total Project Costs                                       $21,953,470