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Title:	Upper Mississippi River Restoration Feasibility Report with Integrated Environmental Assessment : Keithsburg Division Habitat Rehabilitation and Enhancement Project, Pool 18, Upper Mississippi River Miles 428.0-431.0, Mercer County, Illinois
Authors:	United States. Army. Corps of Engineers. Rock Island District
Keywords:	Restoration ecology Environmental protection Environmental management Wetlands Mississippi River
Publisher:	United States. Army. Corps of Engineers. Rock Island District.
Abstract:	The Keithsburg Division Habitat Rehabilitation and Enhancement Project is located in Pool 18 along the left descending bank of the Upper Mississippi River (UMR), immediately north of the City of Keithsburg in Mercer County, Illinois, between river miles 428.0 and 431.0. The Project is bordered by the Edwards River to the north, Pope Creek to the south, and the Mississippi River to the west. It is separated from the Mississippi River by a 3-mile-long berm. The Project lands, part of the Port Louisa National Wildlife Refuge (NWR), are federally-owned by the U.S. Army Corps of Engineers (Corps), Rock Island District (District) and U.S. Fish and Wildlife Service (USFWS). The Corps-owned lands are out granted to the USFWS for management through a cooperative agreement dated February 14, 1963, and an amended cooperative agreement dated July 31, 2001. The Project area is a 1,400-acre backwater complex of interconnected backwaters, wetlands, and floodplain habitat. Human activity over the past two centuries within the UMR basin, floodplain, and channel has altered the hydrology, topography, and biotic communities present. Water level management capability is limited and uncontrolled flood events result in heavy sediment accumulations. Frequent inundation inhibits island forest regeneration and causes increased mortality of mature trees. All of these alterations have reduced the diversity and quality of aquatic habitat, reduced the acreage and diversity of the native floodplain forest and reduced the depth and quality of wetlands. While these stressors are likely to continue, as will the decline in quality of habitats, this Project provides an opportunity to improve the quality and diversity of critical habitats. The goals are to restore and protect off-channel aquatic, wetland, and floodplain forest habitats. The objectives identified to meet these goals are to: 1) restore mudflat and shallow water habitat for shorebird use (feeding/nesting) during the spring and fall migration periods, as measured in acres; 2) restore submergent and emergent vegetation for migratory waterfowl (feeding/nesting) use during the spring and fall migration periods, as measured in acres; 3) increase areal coverage, as measured in acres, of forest stands with hard mast-producing trees as a dominant or component species in floodplain forest areas; 4) improve the existing year-round scrub-shrub community, especially buttonbush, for feeding and roosting waterfowl and other wildlife, as measured in acres; and 5) improve year-round bottomland hardwood habitat for neotropical migrants and other woodland-dwelling species, as measures in acres. For planning purposes, the period of analysis was established as 50 years. The following enhancement measures were considered to achieve the Project goals and objectives: • excavate channels in backwater areas • construct water control structures, spillways, and pump stations, • repair existing road • construct floating treatment wetlands and islands • plant floodplain forest trees • construct elevated berms or enhance existing berms using excavated channel material • use timber stand improvement techniques Cost and habitat benefits were estimated for each measure. Habitat benefits were estimated using Habitat Evaluation Procedures. Cost-effectiveness and incremental analyses were conducted to identify cost effective plans and reveal changes in cost for increasing levels of environmental outputs. The Recommended Plan provides 750 net Average Annual Habitat Units. The Recommended Plan, shown on Figure ES-1, would restore degraded environmental conditions within the backwater and floodplain forest habitats by providing reliable water level management capabilities and implementing timber stand improvement actions. Perimeter berm enhancements such as a spillway, gated control structures, slope improvements, and a pumping station positively impacts management of water levels, while tree releases, girdling, interspersed plantings, and coppicing of buttonbush improves the overall timber stand. These actions will improve aquatic and forest diversity with a resulting improvement in vegetation response and use by migratory birds and resident wildlife. Implementation of the Recommended Plan will increase the quality and quantity of preferred habitat at this location. The Project outputs meet management goals and objectives and support the overall goals and objectives of the Upper Mississippi River Restoration (UMRR) and the Port Louisa NWR.
Description:	Feasibility Report with Integrated Environmental Assessment
Rights:	Approved for Public Release; Distribution is Unlimited
URI:	https://hdl.handle.net/11681/36575
Appears in Collections:	Environmental Documents