Restoring Connectivity in the Two Hearted River Watershed

Project Summary: Repairing culverts, regrading roads and stabilizing river banks at 23 road crossings and man-made erosion sites along Michigan’s Two Hearted River has naturalized river flow, reduced sediment by more than 625 tons, and connected 35 miles of river. This has improved habitat for fish and wildlife and increased recreational opportunities.


Location:
Luce County, Michigan

A stream crossing in the Two Hearted River system prior to restoration efforts. The old culvert restricted stream flow. © The Nature Conservancy.

A stream crossing in the Two Hearted River system prior to restoration efforts. The old culvert restricted stream flow. © The Nature Conservancy.

Description: The Two Hearted River watershed, flowing into Lake Superior, remains relatively pristine. The area is largely forested and supports a variety of fish and wildlife species, including several fish designated as conservation priorities such as brassy minnow, brook trout, and Coho salmon. Intersections between the river and roads or public access points can significantly impact this ecosystem. These crossings typically employ culverts, or tunnels that pass under roads, that allow the river to continue flowing through to the other side. To be effective, culverts should be wide enough to allow for the natural flow of the river to be unobstructed. Unfortunately, many culverts have broken down over time; others weren’t large enough even at the time they were installed. By constricting the river’s flow, these crossings serve as partial impoundments, altering the hydrology of the river system and fragmenting the habitat of many fish and aquatic wildlife species.

The stream crossing following restoration efforts. A new culvert was installed to naturalize stream flow. © The Nature Conservancy.

The stream crossing following restoration efforts. A new culvert was installed to naturalize stream flow. © The Nature Conservancy.

These crossings can also result in significant sedimentation of the river, further degrading fish and wildlife habitat by inundating streambeds and reducing water clarity. Many roads are poorly maintained, exacerbating sedimentation by allowing sand and gravel to wash into the river during rainstorms. At many crossings roads above culverts are relatively low; as the water upstream becomes impounded, it may actually spill over these roads. In addition to making these crossings extremely hazardous for people, the water will pick up sediment and gravel before it continues to flow downstream into the river. A few crossings don’t have any culverts; instead there are fords where vehicles can drive through shallow sections of the river, depositing gravel along the streambed and further restricting stream flow. Traffic from kayakers, anglers, and illegal off road vehicle use has also eroded many of these areas, sometimes resulting in extremely steep embankments that contribute to sedimentation.

Eroded stream banks were regraded to be less steep, reducing sedimentation. Stairs were also constructed to provide recreational access with limited erosion. © The Nature Conservancy.

Eroded stream banks were regraded to be less steep, reducing sedimentation. Stairs were also constructed to provide recreational access with limited erosion. © The Nature Conservancy.

Thanks to grants from the Great Lakes Restoration Initiative, the Environmental Protection Agency, U.S. Fish and Wildlife Service, and the National Fish and Wildlife Foundation, the Nature Conservancy is addressing these issues. The Conservancy, along with project partners, conducted an inventory of road crossings and access points within the watershed and identified 27 priority sites to restore. Old culverts that were restricting river flow were removed and replaced with new, wider culverts, or bridges. Severely eroded banks were regraded to be less steep, using stakes, and native plantings to stabilize the new slopes. Roads crossing over the culverts were also regraded so that water flowing onto these roads now flows into retention basins that filter out sediment before rejoining the river. At two of the fords gravel was removed to naturalize the streambeds, and the banks were stabilized. So far, work at 19 of the sites has been completed; the remaining 8 sites will be finished by the end of this year. This work is expected to reduce annual sedimentation of the Two Hearted River by more than 625 tons, that’s about 23 dump trucks worth of soil per year. The project will also reconnect 35 miles of previously fragmented aquatic habitat for fish and wildlife. Road erosion and flooding will also be reduced, making the roads safer and increasing opportunities for activities such as fishing, canoeing, kayaking, and snowmobiling.

Approximate cost of project: $1,399,255. Of this, $883,013 was provided by the Great Lakes Restoration Initiative.

Resource challenges addressed: Sedimentation, erosion, altered hydrologic function of the river, restriction of fish migration, and loss of fish and wildlife habitat.

Key partners (public and private): Superior Watershed Partnership, Luce County Road Commission, East Branch Sportsmens Club, Michigan Department of Natural Resources, Tahquamenon Area Snowmobile Association, Educating to Control Off Road Damage, Compass Land Consultants Inc., Kevin Brow & Son Excavating, U.P. Pipe and Concrete, Wilson Creek Woodsmithing, Van Straten Brothers Inc., AECOM, J.E. Kloote Contracting Inc., Newberry Redi Mix, and D & D Home Center (Newberry).

Types of jobs created: Contractors, hydrologists, engineers, equipment operators, and general labor.

Results and accomplishments: The project has restored natural stream flow or stabilized banks at 19 sites along the river. Another 8 sites will be restored between June and December of 2014. This work is expected to reduce annual sedimentation of the Two Hearted River by more than 625 tons per year. Sediment reductions are exceeding expectations at 12 crossings that have been measured so far. Sedimentation degrades aquatic habitats by inundating streambeds, reducing water clarity, and increasing nutrients in the river, so this reduction in erosion will help restore fish and wildlife habitat. The project will also reconnect 35 miles of previously fragmented aquatic habitat. Road erosion and flooding will also be reduced, making the roads safer and increasing opportunities for activities such as fishing, canoeing, kayaking, and snowmobiling.

Website: http://bit.ly/1oCVJkd

Originally published on May 28, 2014.

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