Reducing Stormwater Impacts in 

Lake Michigan Watershed Improves Water Quality

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

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, sedi­ment and nutrient runoff during storms 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. 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 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.

Resource Challenges Addressed

  • Stormwater runoff
  • Sediment build up
  • Stream bank erosion
  • Nutrient pollution

LITTLE TRAVERSE BAY STORMWATER MANAGEMENT INITIATIVE 

Map of rain gardens installed in Bay View, Michigan

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

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.