This project came to us as an Action Grant from the Mississippi Watershed Management Association, with the aim of providing an ecological solution to reduce stormwater runoff on this commercial site. The site is in the industrial zone of North Minneapolis and owned by Fourth Street Woodworking Guild, housing Rogue Arc Contractors as a tenant. They had worked with a civil engineering firm, Burns & McDonnell, to calculate the stormwater runoff and installed two large rain cisterns to hold water coming off the roof.
For our part of the collaboration, we installed a rain garden in front of the building intended to complemented the building’s modern and industrial aesthetics. The rain garden works in harmony with the civil engineering work by making use of the water collected in the cisterns. We designed the rain garden with swales for the topography, which are shallow channels with sloping sides that slow and retain water. We selected appropriate plants that thrive in moist and wet soils like Cardinal flower to filter and use that water, cleaning it before it enters the watershed.
In addition to the rain garden, we created two pervious parking spots in the lot using a concrete grid with pea gravel and a growing medium beneath, so that rain can permeate and plants can grow. With all these methods combined, we were able to reduce the site’s overall runoff by 55%!
