Pool 11 Islands Habitat Rehabilitation and Enhancement Project
Rock Island District
Pool 11, Upper Mississippi River Miles 583.0 - 592.0, Grant County, Wisconsin and Dubuque County, Iowa, Congressional District: Wisconsin - 3; Iowa - 1
Following inundation in 1937, there has been a dramatic decrease in the island landmass in this area. This decrease has led to the loss of both terrestrial and aquatic habitats, protected littoral zones associated with the islands, and protected deep water habitats. Backwater dredging will increase habitat diversity and create off-channel fishery and over-wintering habitat.
Island construction could benefit both migratory waterfowl and the fishery by increasing bathymetric diversity, encouraging aquatic vegetation growth in shadow areas, providing nesting habitat, and reducing wind fetch and re-suspension of sediments. However, the island component of this project is deferred based on the results of the biological assessment. It has been determined that construction of the island component may affect an endangered species (Higgins' eye pearly mussels).
The Project was Federally constructed and is Federally maintained. It was designed to restore and protect backwater and aquatic habitat by reducing re-suspension of sediments, creating areas with flow and depth diversity, increasing the abundance and diversity of aquatic plants, enhancing nesting and brooding habitat for migratory birds, providing reliable food sources for migratory birds and resident wildlife and creating off-channel deep-water areas to provide year-round habitat for centrarchids and associated species.
- Approximate Acres: 10,342
- Congressional District: Wisconsin - 3; Iowa - 1
- State(s) Covered: Wisconsin, Iowa
- Land Ownership: Federal
- Management Agency: U.S. Fish and Wildlife Service
- Management Authority: Refuge
- Sunfish Lake is the southernmost part of the Project, located on the Wisconsin side of the river between RM 583 and 584, just upstream of Lock and Dam 11. The main construction features of Sunfish Lake included a deflection embankment, confined disposal facility (CDF), several channels for deep water fish habitat, a flow inlet with sediment trap and a riprap dike along the upstream portion of the embankment.
- Mud Lake is the northernmost part of the Project, located on the Iowa side of the river between RM 588 and 589. The main construction features of Mud Lake include two islands alongside the channels, dredged channels for deep water fish habitat and two flow inlets.
- The Definite Project Report was completed in May 2001.
- Stage I, Sunfish Lake, Contract DACW25-02-C-0024, was started in July 2002 and was completed in June 2004.
- Stage II, Mud Lake, Contract #W912EK-04-C-0007 was started in August 2004 and completed in July 2005.
- The Operation and Maintenance Manual was completed in 2008 with a final document issued in 2012.
- The 2014 Mud Lake Dye Study report was completed in 2016.