River Hills Conservancy – Constructed Wetlands

River Hills, WI

The River Hills Conservancy project restored former agricultural land to a prairie with constructed wetlands capable of storing nearly 2.5 million gallons of stormwater. The project balances land stewardship and stormwater management with the need and intention for future nearby development.

Project Details

The two constructed wetlands in the River Hills Conservancy, with storage capacity of nearly 2.5 million gallons, meet the stormwater detention needs of future development while adding ecological value with surrounding restoration. The wetlands would remove 60% of the total suspended solids from projected new (greenfield) development. The upland restored prairie both reduces runoff and improves the habitat for wildlife.

The wetland size exceeds the minimum guidelines, allowing for more controlled changes in water level and increasing potential for pollutant removal. Risers in the wetlands act as weirs and control discharge from the basins for small rain events, while outlet control structures control discharge for moderate or large rain events.

Restoration Opportunity

The River Hills Conservancy project included restoration of upland prairie with native plant communities. Native plants were also used in the wetlands and were selected based on the depth profile. The deeper pools in the center of each wetland were designed to accommodate fish depth tolerances and to support diverse aquatic communities.

The 28.4-acre nature conservancy serves a nearly 35-area drainage area and incorporates 18 acres of restored prairie in addition to the two constructed wetlands. The conservancy provides habitat for native species and passive recreation for community members.


Milwaukee Metropolitan Sewerage District
The Village of River Hills




gallons captured

Prairie Restored