Today, it’s hard to point fingers at large specific sources of water pollution, as most of it is no longer due to direct dumping of waste.
Instead, another culprit —rainwater — gives pollutants a ride to waterways as it makes its way through parking lots, street gutters and lawns. Contaminants are picked up from puddles of leaked oil, animal waste and anything else the water runs into on its way to the storm drains that discharge directly into rivers and lakes.
The Southeast Como Improvement Association is looking to change this by helping its residents and businesses use rain gardens to catch and absorb water as it comes off downspouts and driveways, so that it leaves the property through the ground rather than across its surface.
Stormwater management is part of SECIA’s larger Green Village project which includes wind and solar power promotion as well as green transportation options, environmental coordinator Justin Eibenholzl said.
With the help of a McKnight Foundation grant, SECIA is picking up the tab for residents to attend a workshop and get rain garden design consultations through gardening nonprofit Metro Blooms , neighborhood coordinator James De Sota said.
He added that SECIA is also offering $1,000 to offset the cost of rain garden design assistance for up to six neighborhood businesses.
Metro Blooms employs third and fourth year students in the University’s landscape architecture program to help residents determine the size, shape and types of plants that should go in their rain gardens, Becky Rice , the organization’s executive director, said.
Native plants, with their deep root systems, are encouraged in rain gardens because they’re better able to survive droughts and use water than the shallow rooted Kentucky bluegrass that occupies most yards, Stephanie Hankerson , SECIA’s community garden organizer, said.
Tedd Johnson , owner of the property leased to Budget Tire on 21st and Como avenues and SECIA board member, worked with a master gardener to fill his 400 square foot rain garden with perennial native plants.
Johnson said he likes the garden because it reduces the storm water runoff that ends up in streams — but he’s also looking forward to the monetary benefits of being green, which come in the form of a reduction to the city-assessed stormwater fee.
He said he hopes to receive a 40 percent reduction in the fee — charged to all Minneapolis businesses — once he files the required paperwork.
When he applied for a permit to build an addition on his property, he offered to put in a rain garden — which prompted the city to make it a mandatory part of his permit, he said.
Andy Erickson , a researcher at the University’s St. Anthony Falls Laboratory , said new regulations usually require developers to include a stormwater management system in any new development or redevelopment. Existing developments are being grandfathered in, he added.
The system that works best for a particular site varies depending on its size and the type of soil it contains — rain gardens don’t work when clay or bedrock underlies the property, he said.
Systems like detention ponds and underground vaults that treat stormwater before discharging it are two of a variety of other ways to deal with stormwater, he added.
Rain gardens can work very well, he said, but there are still a lot of unknowns about how well they pull out pollutants and how long they last.
He said people should get design assistance before starting a rain garden to make sure that it will work for their site.
He added that maintenance is important — replanting is commonly required, and sometimes clogged soil must be replaced.
However, Johnson said his garden hasn’t taken a lot of work to maintain, and added that he hopes other area businesses will start using rain gardens.
“It was fun,” he said.