Location
Pool 18, Upper Mississippi River Miles 425.4 - 421.2, Des Moines County, Iowa.
Description
The Huron Island Complex Project (Project) is located along the left descending bank of the Upper Mississippi River (UMR), approximately 20 miles upstream of Burlington in Des Moines County, Iowa. The Project lands, part of the National Wildlife Refuge System, are federally-owned.
The Project area is 2,600 acres of interconnected backwaters, secondary channels, wetlands and floodplain forest habitat. The Project includes both Huron Island and Huron Chute located 9 river miles downstream from where the Iowa River enters the Mississippi River. Huron Island is heavily forested and dissected by a series of backwaters, secondary channels and wetlands. Huron Chute separates Huron Island from the main land.
The goals are to manage for a diverse and dynamic pattern of habitats to support native biota; manage for viable populations of native species within diverse plant and animal communities; and mange for processes that shape a physically diverse and dynamic river floodplain system. The objects identified to meet these goals are (1) increase the areal coverage as measured in acres of emergent and submersed aquatic vegetation in backwater areas during the growing season; (2) increase diversification of year round floodplain forest and scrub-shrub habitat on Huron Island, (3) increase the structure and function of year-around aquatic habitat diversity and native fish use of spawning, rearing, and overwintering habitat; (4) maintain side channel riverine hydrodynamic, sediment transport and geomorphic processes in Huron Chute.
Project Features:
- Construct bathymetric and topographic diversity adjacent to and in backwater areas;
- Construct topographic diversity in non-diverse forested areas;
- Establish native aquatic and floodplain forest vegetation;
- Construct a closure structure in Garner Chute; and
- Protect small side channel island and bankline protection in Huron Chute from erosion.
The Recommended Plan will restore backwater habitat by excavating backwater channels to a depth of 8 feet below flat pool to provide overwintering and year-round habitat for fish. Excavated material will be used to construct land areas to enhance bathymetric and increase topographic diversity. These areas will be planted with native aquatic and floodplain forest vegetation and trees. A rock closure structure will be constructed in Garner Chute to reduce overwinter water velocities while maintaining necessary levels of dissolved oxygen. Rock will be constructed at the head of two small islands in Huron Chute to protect them from erosion. Theses project features will enhance and increase the quality and quantity of preferred habitat in a major backwater complex in Pool 18.
Background
Existing habitat on the Project is of moderate to poor quality. Current stressors include sedimentation and increased water levels due to construction of the lock and dam system in the 1930’s. These stressors are likely to continue and the quality of aquatic and floodplain habitat will continue to decline.
The bottomland forest are dominated by even aged soft mast tree species of silver maple, ash and cottonwood. The sloughs and wetlands within Complex have lost much of their fish and wildlife habitat value due to silt deposition. Huron Chute is experiencing bankline sloughing in the upper portion, which has degraded the near-shore habitat.
Status
The Stage II construction contract was awarded in August 2016 and completed in June 2020. Stage III – US Army Engineer Research and Development Center planted a test plot in August 2020, additional plantings took place in July 2021 and they continue to monitor the progress.
Additional Information
Authority
CG - Construction General
Summarized Project Costs
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Estimated Federal Cost
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$ 15,773,000
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Estimated Non-Federal Cost
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$ 0
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Estimated Total Project Cost
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$ 15,773,000
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Allocations Prior to FY 2022
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$ 11,321,601
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FY 2021 Allocation
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$ 100,000
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FY 2022 Allocation
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TBD
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FY 2022 President’s Budget
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$ 160,000
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FY 2022 Total Capability
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$ 160,000
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Major Work Item Prior Fiscal Year
FY 2021: Continued additional Stage III plantings, plant production and monitoring progress. Post-project monitoring was applied using active management principals to help design future HREPs.
Major Work Item Current Year
FY 2022: Stage III will continue additional plantings, plant production and monitoring progress. Post-project monitoring will be applied using active management principal to help design future HREPs.