US Army Corps of Engineers
St. Paul District Website

Upper Mississippi River Restoration Program: Harpers Slough, Pool 9, Iowa Habitat Restoration

Published April 12, 2017
Updated: Nov. 24, 2020
Resident engineer Scott Baker, center, during the weekly progress meeting and site visit  Aug. 11, 2015, for the Harper’s Slough project. The Harper’s Slough Habitat Rehabilitation and Enhancement Project, located within the Upper Mississippi River National Wildlife and Fish Refuge, was planned and designed under the authority of the Upper Mississippi River Restoration Program. It will protect five existing islands and construct an additional seven islands using material from the backwater and main channel. The program emphasizes habitat rehabilitation and enhancement projects and long-term resource monitoring. Project component includes dredging backwater areas and channels, constructing dikes, creating and stabilizing islands and controlling side channel flows and water levels. Once the project is completed, the project will be turned over to the U.S. Fish and Wildlife Service, who manages the refuge.

Resident engineer Scott Baker, center, during the weekly progress meeting and site visit Aug. 11, 2015, for the Harper’s Slough project. The Harper’s Slough Habitat Rehabilitation and Enhancement Project, located within the Upper Mississippi River National Wildlife and Fish Refuge, was planned and designed under the authority of the Upper Mississippi River Restoration Program. It will protect five existing islands and construct an additional seven islands using material from the backwater and main channel.

Purpose
Assess the extent of damage of islands and habitat and determine repairs necessary for the Harpers Slough Project in Pool 9. Construction was completed in 2017; however, two consecutive years of high water (including record levels in 2019) prevented plantings from becoming established and caused significant breaches in three islands. Island loss led to material deposition in the backwaters, resulting in less productive habitat for fish and wildlife and the project not achieving the benefits originally anticipated.
 
Location
The project area is a 3,510 acre backwater located primarily on the Iowa side of the Mississippi River in Pool 9, about 3 miles upstream of Lock and Dam 9. The site is in the Upper Mississippi River National Wildlife and Fish Refuge.
 

Description

The constructed project protected five existing islands and constructed seven additional islands using material from the backwater and main channel. The project was designed to slow the loss of existing islands, reduce flow of sediment-laden water into the backwaters, reduce turbidity harmful to fish and wildlife, and increase diversity of land and shoreline habitat.
 
Status
A construction contract was awarded in September 2014; work was completed in August 2017. Island tree plantings were initiated in 2018 and will be completed in 2020. The U.S. Fish and Wildlife Service (USFWS) has requested that the repair work be addressed before formally accepting the project and assuming operation and maintenance responsibilities. In response to the flood damage, a project delivery team is completing a repair plan. The team anticipates completing a letter report and plans and specifications by fall 2020, and advertising in December.
 
Authority
Congress originally authorized the Upper Mississippi River Restoration (UMRR) Program in Section 1103 of the 1986 Water Resources Development Act (WRDA) (Public Law 99‒662), codified at 33 U.S.C. § 652. Congress reauthorized the UMRR Program in WRDA 1999 (Public Law 106‒53).
 
The project was constructed as part of a cooperative effort of the U.S. Army Corps of Engineers, USFWS, the Iowa and Wisconsin Departments of Natural Resources and local interests.
 
Funding
Project design and construction costs were 100 percent federal because the project is located on lands managed as a national wildlife refuge. Operation and maintenance costs are 100 percent federal and a responsibility of the USFWS.
 
Estimated Total Project Cost                    $14,000,000
Estimated Project Repair Cost                   $6,000,000
Funds Allocated Through FY 2020          $14,000,000