US Army Corps of Engineers
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District Projects

UMRR Program - Lower Pool 13 HREP

Published March 11, 2020


Pool 13, Upper Mississippi River Miles 522.5 to 529.0, Whiteside County Illinois and Clinton County, Iowa.


The Lower Pool 13 Habitat Restoration and Enhancement (HREP) project is located approximately three miles upstream of the city of Clinton, Iowa. The project features would be located entirely on federally-owned land that forms part of the Upper Mississippi River National Wildlife and Fish Refuge. The area consists of backwater lakes, sloughs, flowing channels, and impounded water residing over historically flooded islands and remnant islands. The lower section of Pool 13 is located in a valley that is 1.5 to 4.5 miles wide and contains few land masses.

The goals are to maintain, enhance, restore, and emulate natural river processes, structures and functions to promote a sustainable ecosystem; and to maintain, enhance, and create quality habitat for all native and desirable plant, animal, and fish species. The objectives identified to meet these goals are (1) enhance altered hydraulic connectivity; (2) improve water clarity, nutrient loading levels, and sediment loading/resuspension levels; (3) restore sediment transport regime for geomorphic pattern regulation, channel and floodplain features, and floodplain topography diversity; (4) restore habitat connectivity, riparian habitat, aquatic off-channel areas, terrestrial floodplain areas, and channel areas; and (5) enhance the diversity and population of native aquatic vegetation communities (Submerged Aquatic Vegetation, Emergent Aquatic Vegetation, Rooted and Floating), native floodplain forest and prairie communities, native fishes communities, native mussel communities, native bird communities, and amphibian and reptile communities.

Potential project features include the following:

• Island restoration

• Island stabilization

• Backwater dredging

• Restoring depth diversity

• Water Level Management (Pool Drawdowns)


Pre-impoundment, Pool 13 consisted of permanent and seasonal lakes, forested wetlands, bottomland forests, braided islands, wet meadows, and main channels and sloughs. Lock and Dam 13 began operation in the late 1930’s; the implementation resulted in the inundation of several thousands of acres of floodplain in lower Pool 13. Connectivity of backwater and off channel areas within the Project area changed from seasonal discharge related events to year round connectivity. The resulting constant inundation has contributed to island/landmass erosion, sedimentation, and resuspension of sediments due to wave action. Forecasted future conditions anticipate continued sedimentation and backwater sedimentation of fine materials. Wave resuspension of sediments in the Project area will continue to affect the sustainability of aquatic vegetation due to influences of the Elk River, ambient turbidity levels, and wind fetch. Fisheries resources in the Project area are expected to continue to degrade due to a lack of structure, habitat diversity, and overwintering habitat. Migratory water bird habitat will continue to be variable, primarily dependent on the stability levels of year to year aquatic plant production. A variety of physical, chemical and biological stressors individually and cumulatively affect the quantity and quality of habitat for biota in the Project area.


The feasibility report has been initiated in 2018. The report is scheduled for completion in 2022.

Additional Information

Congressional Interest

Senators: Charles Grassley (IA), Joni Ernst (IA), Richard Durbin (IL), Tammy Duckworth (IL)

Representatives: IA-2 (Dave Loebsack), IL-17 (Cheri Bustos)


CG - Construction General

Summarized Project Costs

Estimated Federal Cost $25,288,000
Estimated Non-federal Cost $0
Estimated Total Project Cost $25,288,000
Allocations Prior to FY 2020 $264,156
FY 2020 Allocation $425,000
FY 2020 President's Budget* $33,170,000

*Programmatic Amount

Major Work Item Current Year
FY 2020: 
Funds are being used to continue the feasibility report and pre-project monitoring.