Number of raingardens: 6
Project partners: Ramsey County, City of White Bear Lake, and Vadnais Lake Area Water Management Organization (VLAWMO)
Estimated stormwater volume reduction: 1,096,717 gallons/year
Nearest waterbody: East Goose Lake
What is a curb-cut? A curb-cut raingarden is a basin (or bowl) with an engineered inlet that takes stormwater from the street. Stormwater enters through a break in the street curb, goes through the inlet, collects in the basin, and gets infiltrated into groundwater.
The 2003 County Road F reconstruction project was funded by Ramsey County, the City of White Bear Lake, and the County State Aid Highway Account.
The 2020 County Road F raingarden retrofit project was funded by Ramsey County, the City of White Bear Lake, and a 2020 VLAWMO Landscape Level 2 cost-share grant for $15,000.
The raingardens on County Road F between Highway 61 and McKnight Road were originally constructed as part of the 2003 County Road F reconstruction project. A total of six raingardens were installed to capture and treat runoff from County Road F and City streets.
In 2020 the County completed a maintenance and retrofit project to restore the full functionality of the County Road F raingardens.
A total of six raingardens were installed to capture and treat stormwater runoff from County Road F and City streets. Each raingarden is equipped with an overflow structure. Once the raingarden reaches its max ponding depth, water outlets like the overflow drain of a bathtub, directing it back into the existing storm sewer system.
The County and City entered into a cooperative agreement in 2003 to share the ongoing operation and maintenance costs associated with the raingardens. Regular maintenance includes clearing the inlets of debris, removing debris and trash from the raingarden basins, weeding, and replacing plants and mulch as needed. Specialists are contracted for maintenance and plant care.
In 2020, Ramsey County completed a maintenance and retrofit project to restore the functionality of the County Road F raingardens. The project included dredging accumulated sediment out of the raingardens, installing curb cuts to improve the flow of water into the raingardens, installing Rainguardian structures to capture sediment and other debris from the road (see photos below), and replanting.
A planting plan was created according to the soil, sun, and moisture conditions of the raingardens. Many species of native plants were incorporated into the design, including: Pennsylvania sedge, June grass, Canada Anemone, Wild Columbine, Beebalm, Cardinal flower, Giant Hyssop, Great Blue Lobelia, Swamp Milkweed, New England Aster, Bottle Gentian, Spiderwort, and Prairie Blazing Star.
Each raingarden varies between 400-1,100 square feet in area, with approximately 9-inch basin depths. The raingardens capture nutrients, sediments, and other pollutants found in stormwater runoff, and keeps these pollutants from entering East Goose Lake. The County Road F raingardens are a valuable component in a wide array of efforts that work together to improve East Goose Lake.
Estimated annual pollutant reductions:
Total Phosphorus (TP) reduction: 2.74 lbs/year
Total Suspended Solids (TSS) reduction: 498.9 lbs/year
Stormwater volume reduction: 1,096,717 gallons/year
The County Road F raingardens improve the stormwater runoff draining into East Goose Lake, and support the City of White Bear Lake’s MS4 permit for the future.