GSI Project Types and Examples

Disconnected Downspouts (Households)

Photo of a disconnected downspout rain gutter — Photo of a disconnected downspout cited in the City of Detroit's Drainage Program Guide.

Traditional downspouts often direct rainwater into Detroit’s sewer system, increasing stormwater runoff during heavy rain events. Disconnecting downspouts allows water to drain into lawns, gardens, or other permeable areas where it can soak into the ground instead.

This is one of the most accessible household-scale GSI strategies. The City of Detroit has a disconnected downspout guide available here.

Rain Gardens (Households)

Photo of a rain garden captured by the Huron Watershed Council — Photo example of a rain garden. Photo credit: Huron Watershed Council.

Rain gardens are shallow planted areas designed to collect and absorb stormwater runoff from roofs, driveways, and other hard surfaces.

They help reduce localized flooding, improve infiltration, and create habitat for native plants and pollinators. Rain gardens are especially effective in residential spaces and can often be implemented at the household level.

Impervious Surface Removal (Households or Neighborhoods)

Hard-packed gravel lot, replacing impervious asphalt. Photo credit: City of Detroit Water & Sewerage Department.

Impervious surface removal replaces hard surfaces like concrete or asphalt with natural ground or permeable materials that allow water to soak into the soil. Projects can range from removing small paved areas to larger neighborhood-scale efforts that improve stormwater management and reduce localized flooding.

Things to Consider:

Some projects may require city review or permits
Utilities should be marked through MISS DIG (811) before excavation
Larger projects may require soil erosion permits
Some projects may qualify for drainage charge reductions. Read more about drainage charge reductions here

Constructed Wetlands (Organizations)

Photo of a constructed wetland at the William Milliken state park — Constructed wetland located at William Milliken State Park.

Constructed wetlands are engineered landscapes designed to capture, slow, and filter stormwater runoff using natural vegetation and soils. These systems improve water quality while creating habitat for birds, pollinators, and other wildlife.

In Detroit, examples of constructed wetlands include the restored wetland at William G. Milliken State Park along the riverfront and the Great Lakes Restoration Initiative project at Recovery Park in Poletown East.

Bioswales (Organizations)

Bioswale at Stein Park. — Bioswale located in Franklin Park. Photo credit: Detroit Stormwater Hub, Greening of Detroit.

Bioswales are planted drainage channels that absorb and filter stormwater before it enters sewer systems. They help reduce runoff, improve water quality, and manage smaller storm events through natural infiltration.

An example can be found at Franklin park, where a bioswale was installed and is maintained by The Greening of Detroit.

Green Alleys (Organizations)

Photo of a green alley in Midtown, Detroit — Green alleyway in Midtown, Detroit. Source: Peggy Brenan.

Green alleys replace traditional pavement with permeable surfaces and vegetation that allow stormwater to soak into the ground. Because they often require city permitting and higher installation costs, green alleys are typically implemented at the organizational level.

Green Roofs (Organizations)

Photo of a green roof at the beltline center — Green roof project by the Inhabitect at the Belt Line Center.

Green roofs are vegetated rooftop systems that absorb and slow rainfall runoff before it enters Detroit’s sewer system. They can help reduce stormwater runoff while improving insulation and urban green space.

Detroit examples include the green roofs at the Coleman A. Young Municipal Center and the Belt Line Center.