Beaver Island plan moves forward

Submitted photoAerial view of Beaver Island shows its diverse wetland complex of backwater lakes and floodplain forest.

The Beaver Island Habitat Rehabilitation and Enhancement Project is progressing through the planning stage. Project construction is still a few years away due to funding constraints but details of this multi-million dollar project are being identified.

The two primary objectives are restoration of deep water habitat within the interior lakes and diversification of the forest community.

The habitat rehabilitation project covers the lower three-fourths of Beaver Island. This area is owned by the U.S. Army Corps of Engineers and managed as part of Upper Mississippi River National Wildlife and Fish Refuge. The project is part of the Upper Mississippi River Restoration Program, a Corps funded program that focuses on restoration of Upper Mississippi River habitat.

Beaver Island is one of the largest islands on the Upper Mississippi River and is the largest backwater complex in Pool 14. Its 1,800 acres extends 4 1/2 miles long and 1 mile wide. The island lies in the Mississippi River floodplain with the annual flood pulse controlling the composition of floral and faunal communities.

The construction of the lock and dam system for the nine foot navigation channel in the 1930s resulted in higher water levels that drastically changed habitat conditions on Beaver Island. Annual high water events, flooding and sedimentation have filled in the once deep backwater lakes and degraded habitat for fish and wildlife.

The loss of deep water habitat in the island’s backwater lakes is being addressed. Six to eight feet of material need to be removed from these lakes because they are important habitat for over-wintering fish that require low flows and oxygen-rich water. The project must also ensure there is future protection of these interior lakes from sedimentation.

The island’s forest community is dominated by an even-aged stand of silver maple trees dating back to the 1930s. This species is more flood tolerant than many hardwood species. Forest system management recommendations identify a 100-year rotation. A project feature is to increase tree species diversity, especially the planting of mast producing hardwoods. In addition, a comprehensive forest improvement project is included.

The dominance of a tree species in any forest community is a concern. Lessons learned from Dutch elm disease, pine beetles and emerald ash borer show that forest devastation can occur on a landscape scale in a relatively short period of time.

The protection of adjacent Albany Island is also a project feature. Albany Island was constructed during Corps dredging operations in the 1940s to keep the river channel open for commercial navigation. Erosion is severe along the northern and eastern shorelines due to wave action causing the loss of soil and trees.

Progress reports and milestones on the Beaver Island habitat restoration project are available on at the Corps of Engineers website at www.mvr.usace.army.mil.

Ed Britton is a Wildlife Refuge Manager on Upper Mississippi River National Wildlife and Fish Refuge and volunteer at Bickelhaupt Arboretum.

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