Green Infrastructure Assessments for Coastal Resilience

Southeast Michigan has an extensive coast, spanning 400 miles of Great Lakes shoreline from Lake Huron to Lake Erie connected by the St. Clair River, Lake St. Clair and the Detroit River. It is shared by four coastal counties (St Clair, Macomb, Wayne, and Monroe) and 37 coastal communities.

These coastal areas must be resilient to fluctuating water levels in the Great Lakes, changing rainfall patterns, stormwater runoff, and other shoreline challenges. Developing resilient solutions, especially within coastal communities, is a local and regional priority to ensure that communities can withstand and recover from extreme weather events. The implementation of nature-based solutions like green infrastructure (GI) is key to enhancing coastal resilience.

The  Southeast Michigan Council of Governments  (SEMCOG) and  Center for Watershed Protection  (CWP) were awarded a Michigan Coastal Management Grant to assess locations to build coastal resilience in Southeast Michigan. Through this grant, the project team coordinated with communities to identify high-priority, publicly-owned properties and assess feasibility for GI. The  Final Report  for this project includes details on the assessments as well as descriptions of the various retrofits and their benefits.

As the designated water quality management agency for Southeast Michigan, SEMCOG has been actively involved with water resource planning since the 1970s. SEMCOG convenes local governments, watershed organizations, and technical experts across Southeast Michigan to develop integrated water resource management and resilience capacity building. SEMCOG promotes informed decision making to improve Southeast Michigan and its local governments by providing insightful data analysis and direct assistance to member governments.

CWP is a nonprofit organization working to advance clean water resources and healthy ecosystems through responsible land and water management. CWP is a national leader in stormwater management and watershed planning. CWP served as a pivotal partner in this work, bringing their expertise to Southeast Michigan.

The need for GI implementation in Southeast Michigan is significant, and identifying areas for implementation, partnerships, and funding sources is a critical next step.

Implementation of nature-based solutions enhances coastal resilience through a suite of ecosystem services: mitigating stormwater runoff; reducing pollutant loading into local waterways; providing habitat for coastal fish and wildlife; contributing to strengthening coastal habitat through reconnection; improving access to natural resources; and reducing erosion.

The primary solutions for the sites identified in this project include shoreline softening, bioretention, permeable pavement, and rain gardens. Below are examples of various nature-based solutions:

SEMCOG and CWP coordinated with 50+ local agencies and partners to identify potential project sites. Individual discussions, virtual meetings, and an online ArcGIS Survey123 facilitated collection of potential project site locations. These activities strengthened relationships with stakeholders and provided opportunities to communicate with the project team throughout the duration of the project. This process ensured that projects were aligned with community needs.

In developing the list of sites for field assessments, CWP and SEMCOG:

• Created a list of up to 80 sites for field assessment
• Ensured sites are distributed through each of the coastal counties
• Focused on publicly owned property within the Coastal Zone Boundary
• Identified a balance of shoreline and upland potential projects

After field assessments of nearly 80 sites, this project identified 48 feasible green infrastructure projects within Southeast Michigan’s coastal communities. These plans represent over $20M in projects covering a drainage area of approximately 60 acres and 2 miles of shoreline restoration.

Collectively, these projects could have a significant impact on regional stormwater management, in addition to providing a variety of ecosystem services. The cumulative impact of these projects will make a difference at the regional scale. Investments are needed from the local, state, and federal level, to make these projects a reality.  

The maps below display the GI project implementation(s) at each site location. Hover over a site location to view the site details, which include current site features and information on proposed retrofits. Click on the site name to download its Concept Plan.

The following were key elements of the field assessment process:

All community stakeholders were invited to join the project team for the field assessments. About 20 different communities and organizations participated. By meeting with representatives from the community, the project team was able to learn more about the sites and community priorities.

The project team used a Site Analysis Approach from the CWP Urban Stormwater Retrofit Practices Manual to determine if a site met the criteria for green infrastructure implementation. Additional site data and drainage area details were collected using tablets equipped with ArcGIS Field Maps.

At each site location, a sketch was developed detailing the current site features and conditions, as well as the proposed green infrastructure that would be implemented there. Each sketch included any constraints identified at the site, such as trees or utilities. Sketches also detailed the measurements of the proposed green infrastructure implementation.

A site ranking criterial analysis was developed to determine the highest priority sites. Two priority lists were developed, one for shoreline projects and the other for upland (inland) projects. Each list was ranked based upon five factors:

• Volume of stormwater treated or length of shoreline restored
• Cost per acre treated or length of shoreline restored
• Presence of implementation challenges
• Equity and Environmental Justice
• Geographic Distribution

CWP created concept designs for each proposed retrofit. Each concept design includes a basic CAD (Computer-Aided Design) layout with an aerial photo-based plan view of the proposed work, cross sections and other details as necessary, and a full narrative describing the proposed project, including hydrologic calculations, projected benefits, potential constraints, and a preliminary cost estimate. These plans were shared with communities to be used in planning documents, grant applications, or other future work.

The locations identified for retrofits in this study are not the only locations for upland or shoreline retrofits. Several member communities have already identified excellent retrofit opportunities and begun the planning and design process.

• Marysville Veterans Park, Marysville (St. Clair)
• Cherry Street Mall, Mt. Clemens (Macomb)
• Ford Cove, Grosse Pointe Shores (Macomb)
• Trenton Rotary Park, Trenton (Wayne)

All sites identified through this project are viable green infrastructure locations and should be considered for future implementation and funding. Building community resilience and preparing for climate challenges are ongoing priorities across the region and many local governments in Southeast Michigan have limited staff capacity and resources. Repeating or expanding this project is a consideration for the future planning to support local resiliency priorities.

SEMCOG will continue to work with many of these local communities on identifying project funding opportunities for design and construction. Below are grant opportunities for future coastal resiliency for Southeast Michigan.

The  Michigan Coastal Management Program  (MCMP) is a resource and project funder for local communities who are working to mitigate the impacts of coastal hazards using nature-based solutions. This grant opportunity is ideal for communities who are looking to better understand coastal hazards and implement nature-based solutions.

The  Southeast Michigan Resilience Fund  is a public-private partnership that increases the resilience of communities and natural resources in Southeast Michigan by reducing the impact of stormwater, improving water quality, enhancing habitat, and increasing the accessibility and usability of public green space and natural areas.

The  Transportation Alternatives Program  (TAP) is a grant program that uses federal transportation funds designated by Congress for specific activities that enhance the intermodal transportation system and provide safe alternative transportation options. Green infrastructure projects supported by TAP include projects that infiltrate and treat stormwater runoff, stormwater best management practices that reduce runoff volume and improve local water quality, and vegetative management within the right-of-way to improve road safety.

 SEMCOG Planning Assistance Grants  provide direct funding for local planning projects that move regional plans and priorities forward, including stormwater management planning. This annual grant funding opportunity is available to SEMCOG community members.

Please email Katie Grantham (grantham@semcog.org), Planner, SEMCOG with any questions or concerns.

Financial assistance for this project was provided, in part, by the Coastal Management Program, Water Resources Division, Michigan Department of Environment, Great Lakes, and Energy, under the National Coastal Zone Management Program, through a grant from the National Atmospheric Administration, U.S. Department of Commerce.