The U.S. Army Corps of Engineers, Rock Island District (District), requests public review of the Draft Feasibility Report with Integrated Environmental Assessment titled, Pool 18 Forestry Habitat Rehabilitation and Enhancement Project. The Rock Island District is interested in public review and comments regarding the plan formulation and project analysis and outcomes. The Draft Feasibility Report with Integrated Environmental Assessment along with the associated appendices can be found at the following link: Draft Feasibility Report with Integrated Environmental Assessment.
The public is invited to submit comments for this project until June 30, 2026. The District is required to seek public comment on the Environmental Assessment as part of the National Environmental Policy Act. All comments will be compiled and addressed in a final decision document or in additional findings.
Comments can be submitted through email at: CEMVR_Planning@usace.army.mil, or by writing to the address below.
To request a paper copy, contact the District’s Environmental Planning Branch at 309-794-5540, email CEMVR_Planning@usace.army.mil, or write to:
Department of the Army
US Army Corps of Engineers, Rock Island District
Attn: RPEDN, Pool 18
Clock Tower Building
P. O. Box 2004
Rock Island, IL 61204-2004
PROJECT INFORMATION
The Project’s website is found at the following link: https://www.mvr.usace.army.mil/Missions/Environmental-Stewardship/Upper-Mississippi-River-Restoration/Habitat-Restoration/Rock-Island-District/Pool-18-Forestry/
This Integrated Feasibility Report and Environmental Assessment summarizes the Study process utilized for the Pool 18 Habitat Rehabilitation and Enhancement Project, part of the Upper Mississippi River Restoration Program. During this Study, the Project Delivery Team evaluated the feasibility of alternatives to address problems and opportunities within the Study area. The Study area consists of floodplain forests and wetlands within the Iowa River delta and two islands located in Pool 18, Mississippi River miles 434.8 – 420.2, Louisa and Des Moines Counties, Iowa.
Historically, the Study area contained a robust and diverse forest community. Over time, natural and anthropogenic (human caused) drivers have caused reductions in natural forest regeneration and tree species richness. Young forests transitioned to large open areas of non-native invasive herbaceous species and a declining mature forest. Emerald ash borer infestations in green ash trees are also suspected to have caused significant loss to species diversity and structural development.
Impoundment of Pool 18 by the lock and dam system resulted in higher water elevations, which negatively affected the health of the forested wetland habitat at Blackhawk and Johnson Islands. Reductions in forest composition and regeneration led to mature even-aged timber stands that are dominated by silver maple and cottonwood. Increased flood frequency, duration, and silt deposition have accelerated forest structural diversity loss. Mature forests within the Study area are overstocked, restricting the growth of younger trees.
At the Iowa River Delta, flooding and sediment deposition has degraded the remaining highly fragmented stand of native Kentucky coffeetree. Ground cover in canopy gaps is dominated by non-native species such as reed canary grass and Japanese hops. Those herbaceous species inhibit the natural succession of forested wetland communities.
Without action, forest health and resilience in the Study area will continue to decline and the ability to sustain forested wetland communities vital to wildlife habitat will continue to decline. Acting now will preserve what is left of the forest canopy structure and function without additional significant wildlife habitat loss. Implementation of the Project will restore the understory to a more desirable condition through natural regeneration and planting efforts instead of reliance on significant planting efforts after all canopy trees have been lost.
The goals of the Project are to maintain, enhance, and restore quality habitat for native, desirable plant and animal species and function for a resilient and sustainable ecosystem. The objectives identified to meet these goals for the 50-year period of analysis are:
- Restore forest diversity based on species richness and age class.
- Increase area and vegetation diversity of seasonal wetlands and their transitional zones.
- Improve understory based on amount and diversity of vegetation.
Cost and habitat benefits were estimated for each alternative. Habitat benefits were estimated using Habitat Evaluation Procedures. Cost Effectiveness and Incremental Cost Analysis was conducted to identify cost effective plans and changes in cost for increasing levels of environmental outputs.
The Tentatively Selected Plan (TSP) includes timber stand improvement, ridge and swale creation, pothole scraping, and non-forestry plantings, which will maintain, enhance, and restore quality habitat for native and desirable plant and animal species and functions for a resilient and sustainable ecosystem, which will maintain, enhance, and restore quality habitat for native and desirable plant and animal species and functions for a resilient and sustainable ecosystem. This plan includes timber stand improvement, ridge and swale creation, pothole scraping, and non-forestry plantings.
Section 906(c) of the 1986 Water Resource Development Act states that first cost funding enhancement measures will be 100% Federal cost because all Project measures will be on federally owned lands. The Iowa Department of Natural Resources will be responsible for the operation, maintenance, and repair of the lands.
The Rock Island District’s District Engineer reviewed the Project outputs and fully funded costs estimated to be $ 23,232,000 with outputs of 362 net Average Habitat Units (AAHU) and $2,558 in average annual costs per AAHU and determined that the implementation of the TSP is in the Federal interest.