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Title: Upper Mississippi River System Environmental Management Program Definite Project Report and Integrated Environmental Assessment Project #114832 : Capoli Slough Habitat Rehabilitation and Enhancement Project, Pool 9, Upper Mississippi River, Crawford County, Wisconsin
Authors: United States. Army. Corps of Engineers. St. Paul District.
Keywords: Restoration ecology
Environmental protection
Environmental management
Mississippi River
Publisher: United States. Army. Corps of Engineers. St. Paul District.
Abstract: The Capoli Slough Habitat Rehabilitation and Enhancement Project is located on the Wisconsin side of the Upper Mississippi River in lower Pool 9, near Lansing, Iowa. The site lies within the Upper Mississippi River National Wildlife and Fish Refuge. The overall recommended plan is to protect 10 existing islands and construct 9 new islands at an estimated present cost of $10,093,700 (including sunk costs and Planning, Engineering, and Design and Construction Management costs). The project would protect, restore and/or create about 49 acres of islands, compared to the 74 acres of islands that were present shortly after inundation by Lock and Dam 9 in 1940. The habitat concerns within the study area center around the general degradation of habitat quality in lower Pool 9. This degradation is the result of the loss of islands, declining bathymetric diversity, and a decline in aquatic vegetation, mainly emergent vegetation, over the past few decades. Submersed vegetation has rebounded in the last 20 years but is still not optimal. The study area lies within the Upper Mississippi River National Wildlife and Fish Refuge and is considered critical habitat for migrating waterfowl and other water birds. The decline in migration habitat quality is of great concern to the U.S. Fish and Wildlife Service and State resource management agencies. The planning process focused on the protection and restoration of islands and river processes to restore habitat diversity within the 2,035-acre study area. Because it is not possible to restore or create ideal habitat conditions for all forms of fish and wildlife, measures were designed and evaluated primarily to improve conditions for State and Federal natural resource agencies’ priority communities: migratory waterfowl and native fish species. However, once the basic island layouts and designs were developed, they were modified to benefit other fish and wildlife wherever possible. Islands were positioned to maintain and/or encourage flowing channels for riverine fish and/or to provide protected deepwater habitat for overwintering Centrarchid fish such as bluegills, crappie, and largemouth bass. Measures such as emergent wetlands/mudflats were incorporated into the island designs to provide habitat for shorebirds and wading birds. To identify alternatives, measures were combined in various logical combinations and constraints were imposed to protect the endangered Higgins eye mussel. The resulting 23 identified alternatives (including the No-Action Alternative) were evaluated in detail for the Capoli Slough HREP. The U.S. Fish and Wildlife Service’s 1980 version of Habitat Evaluation Procedures was used to quantify and evaluate the potential project effects and benefits. In addition to the base project of protecting the existing island complex (Alternative A), four action alternatives were considered “Best Buy” in evaluation of cost effectiveness and incremental cost using the Institute of Water Resources economic analysis program called IWR-PLAN. Based on the incremental analysis and other factors, Alternative E4, which included additional habitat dredging, creation of emergent wetland K, and creation of two cobble liners to create a riffle/pool complex is recommended for implementation. Under Alternative E4, the acres (more than 200) of emergent and rooted floating aquatic vegetation will be maintained close to existing conditions. If the project is not completed, all emergent and rooted floating aquatic vegetation is predicted to disappear as the remaining islands disappear. The acreage of submersed aquatic vegetation is predicted to increase with the reduction of wind fetch and wave action. If Alternative E4 is implemented, substantial habitat benefits to shorebirds and wading birds are expected to accrue as a result of the creation of about 30,000 linear feet of sandy shoreline and at least one emergent wetland/mudflat totaling about 5 acres. The sand berms, pads and passing lanes of the islands will also provide a substantial amount of area available for turtle nesting. The 49 acres of islands protected or created under Alternative E4 will provide habitat for terrestrial and semi-aquatic species of wildlife. This type of habitat is nearly nonexistent in the areas where the islands would be constructed. The islands would help maintain around 41 acres of Capoli Slough secondary channel, which would contribute to aquatic habitat diversity in this area, primarily for riverine fish species and mussels. The cobble liners would also increase aquatic habitat diversity in this secondary channel. Protected deepwater habitat about 10 acres in size would be created, providing overwintering habitat for Centrarchids and other backwater fish species. This type of habitat is of critical importance in lower Pool 9 where overwintering habitat is almost nonexistent due to the loss of islands. Project construction would begin in 2012 and be completed in 2013 or 2014. The entire project lies within the Upper Mississippi River National Wildlife and Fish Refuge. Once completed, the project would be turned over to the U.S. Fish and Wildlife Service for operation and maintenance.
Description: Definite Project Report with Integrated Environmental Assessment
Rights: Approved for Public Release; Distribution is Unlimited
Size: 194 pages / 7.58 MB
Types of Materials: PDF
Appears in Collections:Environmental Documents

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