What is a Bioswale?
Bioswales are storm water runoff conveyance systems that provide an alternative to storm sewers. They can absorb low flows or carry runoff from heavy rains to storm sewer inlets or directly to surface waters. Bioswales improve water quality by infiltrating the first flush of storm water runoff and filtering the large storm flows they convey.
The Vintage Cooperative of Ankeny has two Bioswales, one to the north and one to the south of the complex. There are two primary purposes for the bioswales. One is to receive water from the garage’s sump pump system. The second purpose is to receive the rain and melting snow from the building’s gutters and parking lot. They often are referred to as retention ponds. It is a misnomer to call them ponds because they are not meant to trap and hold water.
The bioswale that is north of the building was seeded with wild flowers and grasses in the spring of 2018 and 2021 begins the fourth year of its development. It is a slow and difficult process getting an area as large as the north bioswale to become an eye catcher. The major issues are: 1. Keeping weeds from overtaking the area, 2. Reseeding after the initial seeding is washed away from heavy storms, and 3. Getting a mix of flowers to bloom through three seasons.
The seeding mix applied to the north bioswale includes the following flowers and grasses:
| Blue Wild Indigo Butterfly Milkweed Pale Cone Flower Partridge Pea Cardinal Flower Old Field Golden Rod Golden Alexanders Purple Prairie Clover Blue Grama Sideoats Grama | Nodding Onion Great Blue Lobelia Purple Cone Flower Wild Bergamot Dense Blazing Star Ohio Spiderwort Foxglove Beards Tongue Blackeyed Susans Little Bluestem Prairie Dropseed |
The most prominent flowers in the bioswale are the following: Black Eyed Susan, Butterfly Milkweed, Purple Prairie Clover, Wild Bergamot, and Partridge Pea. More recently these plants have begun to become more numerous: Pale Cone Flower, Purple Cone Flower, Golden Alexander, and Foxglove Beards Tongue. Only one cardinal flower and Ohio Spiderwort has been seen. An effort is being made to increase the number of Dense Blazing Stars to get more red color in the bioswale. Getting more spring flowers and fall color remains a goal.