Modified Upper Pool 4 island project available for public review

The U.S. Army Corps of Engineers, St. Paul District is seeking public comments on its draft Supplemental Environmental Assessment (EA), released May 11, for proposed modifications to the Pierce County Islands in Upper Pool 4 of the Mississippi River.

USACE officials initiated a feasibility study in 2017 to identify steps that could be taken to improve the habitat in Upper Lake Pepin, particularly in Catherine Pass.

These measures include islands, water level management structures, overwintering dredging and shoreline protection. The proposed solutions are designed to work together to reduce sediment and increase water clarity within the area.

The features include four islands, refuge dredging, a water level management dike and control structure, an access road, two backwater dredged areas, three areas of shoreline protection, a mudflat, access dredging and a partial closure of Catherine cut.

Detailed engineering and design studies conducted since the completion of the Integrated Feasibility Report and Environmental Assessment in 2020 resulted in several proposed modifications to the project.

The modifications identified since the IFR/EA include: two additional mudflats with berms and rock protection, creation of four pothole wetlands and additional access dredging.

A supplemental EA and Supplemental Clean Water Act Section 404(b)(1) evaluation have been prepared to address the potential effects associated with the proposed modifications.

The draft documents describing the project and the environmental impacts in detail are available to the public online.

The deadline for sending comments on the proposed work is June 11.