Petoskey Green Stormwater Infrastructure

In 2021, Tip of the Mitt Watershed Council was awarded funding from the Petoskey-Harbor Springs Area Community Foundation to work on a green stormwater infrastructure visioning process. This project assessed opportunities for integrating green stormwater infrastructure (GSI) with existing gray stormwater infrastructure within the Little Traverse Bay Watershed. It brought together GSI experts, Drummond Carpenter, and city staff to determine how these practices can protect Little Traverse Bay and beautify Petoskey. Through the storymap and survey this project gives the community an opportunity to learn and share their input.

This project is intended only for soliciting feedback on potential GSI locations and community preferences on designs. Depending on future grant opportunities and the city's priorities, we hope to implement the key GSI concepts that garner the most support.

We appreciate your participation and the support of the Petoskey-Harbor Springs Area Community Foundation.

Little Traverse Bay (Bay) is a high-quality water resource beloved by many, but suffers from the ongoing threats of nonpoint source pollution. This is pollution that enters the water through indirect sources. Tip of the Mitt Watershed Council has identified and created a framework to address these threats through the creation of the Little Traverse Bay Watershed Protection Plan. 

The Watershed Council has identified critical areas in the plan to help prioritize and target management efforts within the Little Traverse Bay Watershed. Critical areas refer to locations where actions are needed to address known and potential pollutant sources. Petoskey, being the largest development within the Watershed, contains the largest amount of impervious surface area and discharges the largest amount of stormwater runoff to the Bay and the Bear River.

Stormwater runoff is generated when rain or snowmelt flows over land or impervious surfaces (paved streets, parking lots, and building rooftops) and is directed into our surface waters instead of soaking into the ground. Stormwater accumulates debris, chemicals, sediment, nutrients, bacteria, and other nonpoint source pollutants that adversely affect water quality of nearby lakes, streams, wetlands, and could impact human health.

Over 50 stormwater outfalls (discharge point of stormwater into body of water) within the Watershed contribute pollutants to the Bay. High topographic relief, or elevations, throughout Petoskey encourages quick drainage, but poses challenges when planning the implementation of best management practices (BMPs), especially when combined with the dense development occurring along the waterfront. The downtown corridor has relatively few infiltration BMPs installed. 

Newer developments on the southern periphery of the city have incorporated detention ponds to retain and treat stormwater; however, these are not considered GSI, but gray infrastructure. This approach moves the stormwater offsite, usually through a series of pipes, to have it treated elsewhere unlike GSI, which aims to treat the water where it lands. 

Green Stormwater Infrastructure (GSI) is an approach to land management that works with nature to manage stormwater. GSI uses native vegetation and natural processes to capture pollutants, minimize nutrient runoff, and reduce stormwater.

GSI offers a number of advantages over traditional, engineered stormwater drainage approaches, including:

• Addresses stormwater at its source - GSI practices seek to manage rainfall where it falls, reducing or eliminating the need for detention ponds and flood controls.

• Promotes groundwater recharge - Many GSI techniques allow stormwater to infiltrate the earth, recharging groundwater aquifers.

• Allows for more flexible site layouts - Designs can incorporate stormwater management in a variety of open spaces and smaller landscaped areas.

• Preserves streams and watersheds - GSI practices reduce both pollutant loads and streambank erosion associated with peak flows because of greater infiltration.

• Enhances aesthetics and public access/use - Well-designed vegetated practices, such as rain gardens, should be visually appealing as well as functional.

• Reduces costs - GSI reduces the need for pipes, asphalt, detention basins, or other infrastructure traditionally needed to handle runoff. It can also reduce energy costs and increase potential developable land area.

Watch the video below to learn about different types of GSI practices from Drummond Carpenter, or continue to scroll to read about different options.

Watch the video below to learn about the Petoskey GSI renderings created by Drummond Carpenter.

Thank you for your interest. Our survey is now closed.

More resources on GSI practices can be found here:

Tip of the Mitt Watershed Council is dedicated to protecting our lakes, streams, wetlands, and groundwater through respected advocacy, innovative education, technically sound water quality monitoring, thorough research, and restoration actions. We achieve our mission by empowering others and we believe in the capacity to make a positive difference. We work locally, regionally, and throughout the Great Lakes Basin to achieve our goals.

Funding for this project was generously provided by the Petoskey-Harbor Springs Area Community Foundation and we greatly appreciate their support.