Upper Mississippi River Restoration Project Big Lake, Pool 4, Wisconsin

U.S. Army Corps of Engineers, St. Paul District
Published April 4, 2022
Updated: April 15, 2024

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The upper Mississippi River, sedimentation of backwater areas is an ongoing issue. The project area is greatly influenced by the input of sand from the Chippewa River that enters Pool 4 at about river mile 764. Other potential sources of sand are the historic channel maintenance dredging side-cast islands and the four active temporary placement sites within the study area. Big Lake has lost much of its island complex and bottomland forest to wind and wave erosion. The barrier islands between the lake and Catfish Slough have been degraded and/or eliminated over the past several years.


The project area consists of open backwater, meandered side channels, main channel border, and island formations in the Mississippi River in lower Pool 4. The site is in the Upper Mississippi River National Wildlife and Fish Refuge near Wabasha, Minnesota. Sedimentation of the backwaters is an ongoing issue in this study area.


The proposed project goal is to maintain, enhance, and create habitat suitable for native and desirable aquatic and terrestrial plants and animals.

The project seeks to protect, enhance, restore, or create naturally regenerating, resilient, and diverse bottomland forest that will benefit migratory and resident birds and other species. The project seeks the same for backwater and flowing channel habitats that provide flow conditions and sediment dynamics that will benefit native fish (including migratory species) and mussel populations. The project seeks same of submerged, emergent, and rooted floating leaved vegetation.


Project planning began in the fiscal year 2022 as part of a cooperative effort with the U.S. Fish and Wildlife Service (USFWS), the Wisconsin and Minnesota Departments of Natural Resources and local interests.

A public meeting was held in Wabasha, Minnesota, in August 2022. The Corps identified a Tentatively Selected Plan in July 2023 and held a public meeting on the draft report in Wabasha, Minnesota, in November 2023. The Corps will complete the final report in spring 2024.


Congress originally authorized the Upper Mississippi River Restoration (UMRR) Program in Section 1103 of the Water Resources Development Act (WRDA) of 1986, Pub L. No. 99-662 (codified as amended at 33 U.S.C. § 652). Section 8345 of WRDA 2022, Pub. L. No. 117-263, increased the authorized program funding to a combined $90 million annually.


Project design and construction costs will be 100% federally funded because the project is located on lands managed as a national wildlife refuge. Operation and maintenance costs are 100% federal and a responsibility of the USFWS.

Federal Funds Allocated to Date        $1,296,000