Reducing Stormwater Impacts in Lake Michigan Watershed Improves Water Quality

 

Project Summary: Fixing road-stream crossings, restoring river banks, and installing rain gardens in the Little Traverse Bay reduced sedimentation and nutrient loading.

 

Project name: Little Traverse Bay Stormwater Management Initiative

Location: Little Traverse Bay, Michigan 

Stormwater can carry excessive levels of sediment, nutrients, and other pollutants into Little Traverse Bay. Photo courtesy of Tip of the Mitt Watershed Council.

Stormwater can carry excessive levels of sediment, nutrients, and other pollutants into Little Traverse Bay. Photo courtesy of Tip of the Mitt Watershed Council.

Description: Little Traverse Bay, located in northwestern Michigan, is home to many species of wildlife, as well as many people who rely on it for their drinking water. While the water quality in the bay and its surrounding watershed is relatively high, it is subject to many of the same impairments affecting other watersheds in the area. In particular, sediment and nutrients picked up by stormwater and washed into the bay and its tributaries can pose significant environmental and health risks for people and wildlife. Sedimentation can inundate aquatic wildlife habitats and reduce the ecosystem’s productivity by blocking out sunlight, while excessive nutrient levels promote bacterial growth and can result in harmful algal blooms that can close beaches and threaten drinking water.

A coalition of local stakeholders interested in identifying solutions to these threats released a “Little Traverse Bay Watershed Protection Plan.” This included a series of recommendations aimed at reducing the harmful impacts of stormwater runoff and its associated erosion, sedimentation, and nutrient loading. Thanks to a Great Lakes Restoration Initiative grant, a local organization called the Tip of the Mitt Watershed Council is enacting several recommendations to reduce stormwater runoff. The first component restored heavily eroded road-stream crossings. Due to erosion, these crossings contribute significant amounts of sediment into the watershed during storms. The Watershed Council worked with a team of engineers to re-design these crossings to prevent future erosion while still allowing traffic to cross the streams. The second component involved restoring eroded stream banks along tributaries to the bay, using rocks and native vegetation to stabilize the banks and reduce future sedimentation. For the third component the Watershed Council developed rain gardens for the Bay View Association, a community of cottages along the bay shore. Following a series of presentations to the community, the Council worked with any interested cottagers to plant gardens with native vegetation that absorb rainwater runoff, reducing the amount of

Rain gardens were installed at the homes of several Bay View residents. Photo courtesy of Tip of the Mitt Watershed Council.

Rain gardens were installed at the homes of several Bay View residents. Photo courtesy of Tip of the Mitt Watershed Council.

stormwater flowing into the bay. Finally, a pond on the campus of North Central Michigan College was converted into a stormwater retention wetland that allows sediment and nutrients to settle out of the stormwater. The converted wetland also served the dual purpose of increasing wildlife habitat, thanks to the construction of several habitat features such as nesting islands for waterfowl and perching snags for birds of prey.

Approximate cost of project: $887,723 provided by the Great Lakes Restoration Initiative.

Resource challenges addressed: Stormwater runoff; sedimentation; stream bank erosion; and nutrient loading. 

Key partners (public and private): Top of Michigan Trails Council; Northwest Design Group; Team Elmer’s; Michigan Department of Environmental Quality; Michigan Department of Natural Resources; US Fish & Wildlife Service; North Central Michigan College; Emmet County Road Commission; Charlevoix County Road Commission; and the Bay View Association.

Types of jobs created: Road Commission crew members; excavators; engineers; landscapers; designers; and general labor.

Results and accomplishments: This project will significantly improve the water quality for both the people and wildlife of the Little Traverse Bay watershed. The project will reduce the amount of sediment carried into Little Traverse Bay by 900 tons annually, and will decrease nutrient levels in the bay and its tributaries. The project will also increase the amount of habitat for native wildlife by building habitat features into a stormwater wetland. The high visibility of this project has increased local awareness of stormwater issues, fostering a stewardship mentality within the community.

Originally published on July 9, 2015

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