Please use this identifier to cite or link to this item: https://hdl.handle.net/11681/36653
Title: Upper Mississippi River System Environmental Management Program Definite Project Report (R-4) with Integrated Environmental Assessment : Andalusia Refuge Rehabilitation and Enhancement, Pool 16, Upper Mississippi River, Rock Island 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: Andalusia Refuge and adjacent Dead Slough, located in Pool 16, are a 393-acre backwater complex approximately 1 mile north of Illinois City, Illinois. The proposed site is closed to hunting and located within the Upper Mississippi River Wildlife and Fish Refuge on General Plan lands made available to Illinois through cooperative agreements between the Corps of Engineers and the Department of Interior, and between the Department of Interior and the State. The refuge is managed by the Illinois Department of Conservation in accordance with an annual program submitted to the U.S. Fish and Wildlife Service as a National Wildlife Refuge within the meaning of Section 906(e) of the 1986 Water Resources Development Act. Sedimentation from the Mississippi River and adjacent uplands has significantly impacted on the Andalusia Refuge and adjacent backwater fisheries. Migratory waterfowl already under stress due to drought conditions and loss of habitat in the Upper Midwest have been affected, and necessary deep water fish habitat off the main channel has been reduced. Duck counts by the Illinois Department of Conservation show that the duck use days at the Refuge, an important link for waterfowl using the Mississippi flyway, are exceedingly low. Food may be present in the Refuge, but there is often no available water. Present peak waterfowl use days are less than 2,000. This compares to conditions at the next nearest refuges, where water levels can be controlled, at Lake Odessa (River Mile 437) and Princeton Refuge (River Mile 507). Peak use days at these refuges are as much as 50 times higher than Andalusia Refuge. Additionally, fish are trapped in adjacent sloughs when water levels fall in the late spring and die from low levels of dissolved oxygen, and, in some years, from the high summer water temperatures or winter freeze-outs caused by the almost complete absence of water. Alternative locations in the floodplain between Lake Odessa and Princeton Refuge were considered. Pool 17 has very little potential for sites in the upper pool due to flood control levees close to each shoreline. The first suitable location is already occupied by the Big Timber Division of the Mark Twain National Wildlife Refuge (River Mile 444). In Pool 16, Andalusia Island (River Mile 467) is not feasible because of the absence of land access and significantly higher construction costs necessitated by having to levee the entire perimeter. "Milan Bottoms" (River Mile 477) is not feasible since land dedicated to new uses would involve significant loss of present wood duck and terrestrial habitat benefits. There are no suitable locations in Pool 15 due to intense development, and none in Pool 14 below the existing refuge at Princeton, Iowa. Project objectives are to: enhance migratory waterfowl habitat by providing adequate vegetation and reliable loafing and resting areas; retard the loss of fish and wildlife aquatic habitat by reducing sedimentation into the Refuge and Dead Slough; increase fish habitat in Dead Slough by channel excavation; and increase habitat available for wintering fish by providing deeper water areas. The alternatives considered to accomplish the objectives included: variously sized moist soil management units (MSMU's); diversion of four adjacent watersheds supplying flow and sediment; river bank protection of the Refuge; various access channels and slough excavation configurations for Dead Slough; varying interior and side channel drainage excavation and associated island configurations within the MSMU; and various access road configurations to permit pump station and levee maintenance access. MSMU sizes considered ranged from a 130-acre area protected by a perimeter 2-year earthen levee approximately 6 feet high with a 12-foot crown to a 265-acre MSMU protected by levees corresponding to 5- and 10-year events with average heights of 9 and 11 feet, respectively. Watershed diversions considered all four watersheds and included diversion drainage lengths of 2,200 to 2,500 feet on private land which would require permanent easements or additional fee title. River bank protection would consist of crushed stone bedding with a riprap blanket to protect approximately 85 acres of emergent and submergent vegetation from possible Mississippi River erosion. Dead Slough and access channel alternatives required locations where neither erosion nor deposition occurred and which were consistent with other project features, while allowing adequate material placement. Interior channels were necessary to facilitate drainage during drawdowns, hastening establishment of new vegetation, and to provide material for adjacent levee borrow. Interior material placement had to provide optimal island protection for waterfowl from foraging land animals. Access to the pump station alternatives required reliable all-year access, consideration of potential disruption of Refuge objectives due to unauthorized access, and clearing and ownership considerations. The selected plan for the habitat project consists of constructing a 2-year event levee averaging approximately 6 feet high, 8,600 feet long with top widths of either 12 feet or 60 feet, providing water level control on 130 acres of Refuge land. Included are a pump station capable of pumping 3,500 gallons per minute into the Refuge and 5,000 gallons per minute from the Refuge, one gated water control structure, and an armored lower section of the levee to withstand overtopping of the levee without damage during floods. Mechanical excavation in Dead Slough to a depth approximately 9 feet below flat pool (about 110,000 cubic yards) and in the interior of the MSMU (about 75,000 cubic yards) will create approximately 3.1 miles of channel (10,900 feet within the MSMU and 5,600 feet within Dead Slough). Channel width within Dead Slough adjacent to the levee will be 60 feet at the base of the cut. The configuration of the dredged channel within the MSMU will create eight or more islands, totalling about 9 acres. These channels will enable fish to leave the MSMU through a water control structure into Dead Slough and then into the main channel. The new mouth of Dead Slough will empty into Scisco Chute. The intermittent stream now depositing sediment in Refuge backwaters will be redirected to Scisco Chute, decreasing the sedimentation rate in the Refuge and Dead Slough. The new channel will be 2,430 feet long and 3 feet deep with a 30-foot bottom width. It will be located on Government-owned land and will be capable of conveying a 2-year event within bank. The other three streams have no feasible rerouting alternatives and will be left unchanged. River bank erosion was determined to be insignificant, not threatening the stability of the bank or the interior portion of the Refuge. The recommended access road consists of approximately 3,600 feet of a 12-foot-wide service road, which also will be used for placement of overhead poles for electric power supply. Illinois Department of Conservation personnel will control access to the road to minimize disturbance to the Refuge area. The habitat project will create a reliable food supply for migratory waterfowl in the fall, enabling water level manipulation on 130 acres of wetland to enhance food production. With the ability to manage water levels, water usually would be drawn down in June for the germination of natural or aerially seeded plants benefitting waterfowl, such as smartweed or Japanese millet. Water levels would be raised as the plants grow, allowing the seed heads to remain above the water level. The levee will prevent 2-year flood events (which have occurred only twice during the 22 years of record for the management period) from destroying the food crop, significantly increasing the Refuge's capacity to provide food and refuge. The channel configuration within the MSMU will create 9 acres of island suitable for the nesting of Canada geese. Improvements within Dead Slough and reopening the access will provide improved water circulation, increased levels of dissolved oxygen, and a decrease in the rapid water temperature fluctuations which now occur. The relocated drainage channel will improve water quality in Dead Slough and in the MSMU, with the decreased sediment influx prolonging project life. It is proposed that the following information be collected to evaluate performance of the project: summer and winter measurement of dissolved oxygen in Dead Slough; soundings of Dead Slough and fish access channel excavations; sedimentation measurements within the MSMU; biennial waterfowl inventories during the fall migration; biennial vegetation inventories by water level and by time of year within the MSMU; and, biennial fishery inventories in Dead Slough.
Description: Definite Project Report with Integrated Environmental Assessment
Rights: Approved for Public Release; Distribution is Unlimited
URI: https://hdl.handle.net/11681/36653
Appears in Collections:Environmental Documents

Files in This Item:
File Description SizeFormat 
AndalusiaRefugeDRP.pdf12.63 MBAdobe PDFThumbnail
View/Open