The City of Burnsville and the Metropolitan Council worked with Barr to develop a prototype rainwater garden system in a residential area to catch stormwater runoff from streets and driveways. The project was funded as part of an implementation plan to protect nearby Crystal Lake from excess phosphorus and large volumes of stormwater, based on recommendations from a total maximum daily load (TMDL) report developed by Barr for the Black Dog Water Management Organization.
The retrofit of the 1980s neighborhood involved property-owner conferences to develop 17 individual designs for each participant’s property and provide educational seminars about ongoing maintenance. The shallow depressions feature gradual side slopes, limestone retaining walls, and colorful plantings. Deep-rooted vegetation was planted to facilitate infiltration, filter pollutants, and create bird and butterfly pollinator habitat. The rainwater gardens were designed to meet the property owners’ low maintenance needs. In addition to civil engineering, landscape architecture and planting design, Barr provided construction oversight.
To assess the system’s effectiveness, Barr helped city staff compare the neighborhood and its new rainwater gardens to a similar residential area without such gardens, which served as a control site. Stormwater monitoring data collected for two seasons before and two after the gardens were installed determined that the rainwater gardens reduce runoff volumes by approximately 90 percent, helping to protect Crystal Lake from excess phosphorus and stormwater runoff.
Landscape Architect and Ecologist
Vice President Senior Civil Engineer