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GOAL OBJECTIVES POTENTIAL FEATURES Restore, to the extent practi- cal, quality, functional, flood- plain habitat and ecological processes in an Illinois River Backwater area. Restore floodplain connec- tivity from the Illinois River to a productive backwater area, which serves as fish spawn- ing grounds and a nutrient recharge to the river. a)Restore the natural hydrograph of the Emiquon Preserve/ Illinois River back- water to approximate pre-settlement conditions. b)Restore native aquatic habitat and ecological processes. c)Increase the presence of a reliable food source and quality habitat for mi- gratory waterfowl, shorebirds, and other breeding birds. d)Improve water quality through proc- essing of nutrients and sediments and reducing sediment resuspension. e)Restore hydrologic river floodplain connectivity. f)Increase IL River connectivity to quality fish spawning and nursery habi- tats g)Export biological productivity to river and maximize sustainability of aquatic habitat h)Provide recreational and educational opportunities Water control structure / Fish passage structure Levee Removal Pump Station Reinforced Levee Spillway Levee Rehabilitation Berms/islands Recreation and Education Tenatively Selected Plan ( T SP ) : The tentatively selected plan was identified through use of the Incremental Cost Analysis Software tool and input from the Product Delivery Team. The TSP is composed of a 7-ft wide Water Control Structure (WCS), a 60,000 GPM Pumping System and 10 Earthen Interior Islands. Real Estate: The Real Estate interests on the Emiquon project presented a unique set of challenges. The project site contains historic easements for the levee and drainage ditches, highway borrow pits, a high pressure natural gas pipeline, Chicago sanitary district flood inundation easement, as well as a USDA-NRCS Wetland Reserve Easement. Corps and TNC staff have worked at great length to determine a path for resolving all of these and other real estate constraints. Many of these issues have been successfully addressed, while others, TNC and Corps partners continue to work on (ex: USDA-NRCS WRP Easement). Collaborative Planning: This project utilized the TNC’s Key Ecological Attributes (KEA) that were defined by the TNC through the Emiquon Scientific Advisory Council. The KEA’s were instrumental in determining objectives and how to measure those objectives to measure success. Corps planners worked collaboratively with TNC preserve staff to develop a 6-year water level management plan to meet the ecological objectives. Developing a 6-year water level management plan allowed the Product Delivery Team to evaluate various alternatives based on how effective they are at meeting the desired water level management plan. This plan was instrumental in identifying what measures are technically feasible due to river levels and which are not. Background and Significance: The Proposed Project is located at one of the largest and most recognized bottomland lakes in the Illinois River Valley. The Illinois River’s significance was recognized by Congress in WRDA 1996 as a “nationally significant ecosystem” as part of the Upper Mississippi River System. The TNC Emiquon property is located within the area Congress authorized for USF&WS acquisition for wetland habitat restoration. Prior to Emiquon’s isolation from the river in 1920 when levee construction was completed, the Project area was a large commercial inland fishery and waterfowl hunting area. Following levee construction, the Project area was drained for agricultural production and served as productive farmland for more than 80 years. In 2000, TNC announced they had purchased the Project area along with additional adjacent lands. The Project area continued to be farmed while a restoration plan was being developed until 2006 when TNC signed into a Wetland Reserve Program (WRP) agreement with the USDA-Natural Resources Conservation Service (NRCS). In 2007, in cooperation with the WRP agreement, TNC halted pumping and the water levels began to rise, restoring fishery and wetland habitat in this backwater area. However, recent ecosystem restoration efforts at nearby Hennepin and Hopper Lakes were determined to be detrimental to the ecosystem when they ceased to manage water levels. Disturbance to the system occurred due to the high concentration of common and grass carp varieties of fish. The Nature Conservancy has identified that without a more reliable way to manage water levels at Emiquon, the ecosystem may be substantially degraded over time. Design Considerations: Due to varying river levels a managed connection would be necessary that allows for fish passage at selected times of the year while preventing fish passage during other times of the year. For cost savings the pump station outlet pipe delivers flow to the outlet apron of the water control structure. A steel grate structure allows for vehicles to drive over the water control structure opening. Further consideration need to be given to velocity of the incoming water through the structure and the resting area for river fish exiting the preserve. By Jason T. Smith, Kara N. Mitvalsky ( USACE) a nd K. Douglas Blodgett ( T he Nature Conservancy ) 2007 National Agricultural Program Aerial Photograph 2010 National Agricultural Program Aerial Photograph
