US Army Corps of Engineers
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District Projects

UMRR Program – Green Island HREP – Pool 13

Published March 25, 2020

Location

Pool 13, Upper Mississippi River Miles 548.5 and 546.0, Jackson County, Iowa.

Description

The Green Island Project (Project) is located near Green Island, Iowa. The Project lies within the Green Island Wildlife Management Area (WMA) which is managed by Iowa Department of Natural Resources. The Green Island WMA is located in Pool 13 of the Upper Mississippi River (UMR) below the confluence of the Maquoketa River.

The Project are is a 4,000-acre wetland complex that includes shallow lakes, emergent vegetation and managed moist soil areas, and braided channels surrounded by degrading riparian timber.

The goals are to maintain, enhance and restore quality habitat for all native and desirable plant, animal and fish species and maintain, enhance, restore and emulate a natural river process, structures and function for sustainable ecosystem. The objectives identified to these goals are (1) maintain and restore existing aquatic habitat complexes for fish and wildlife; (2) enhance and restore over-wintering habitat areas by increasing the number of acreage of centrarchid habitat; (3) enhance and restore the bottomland forest by increasing the acreage, age class, diversity, and species diversity; (4) restore and increase the coverage of aquatic vegetation for waterfowl habitat; (5) manage pooled water elevation to emulate more natural seasonal water elevation; and (6) reduce average wind fetch in open water areas.

Potential Project Features include:

  • A pump station for water level management
  • Excavate channels to pump station
  • Excavate channels for overwintering
  • Water level control structures
  • Island creation
  • Implement Timber Stand Improvement techniques

Background

The existing forest is degrading at an alarming rate with numerous stressed and dying trees. The ox-bow lakes have lost much of their depth due to sedimentation and provide little fish refuge in the summer and winter.  The pump system is old, inefficient and expensive to operate. The old drainage ditches are sediment filled to the point that a drawdown cannot be completed to regenerate high quality moist soil or emergent and aquatic vegetation.  Elevated water tables on the Mississippi River proper are also adversely affecting floodplain forest composition and regeneration.

Status

Feasibility report started in November 2019 and is scheduled for completion in 2022.

Additional Information

Authority

CG - Construction General

Summarized Project Costs

Estimated Federal Cost $ 25,288,000
Estimated Non-Federal Cost $ 0
Estimated Total Project Cost $ 25,288,000
Allocations prior to FY 2019 $ 264,186
FY 2020 Allocations $ 426,000
FY 2020 Total Capability $ 33,170,000

 

Major Work Item Current Year

FY 2020: Funds are being used to continue the feasibility report and pre-project monitoring.