Rain Gardens and Bioswales

Deep-rooted native plants work to absorb excess surface water.

You can create a bioswale or large rain garden with fluctuating water depths of up to 18 inches.

Rain garden require a flat-bottomed, excavated planting basin and will benefit from location in natural drainages. True rain gardens are typically shallow--from 6-12" deep--and seldom hold water as opposed to detention basins which are deeper and usually hold some water.

A bioswale is a large channel planted with a rich variety of functional native shrubs and grasses that works year-round to
slow, filter and infiltrate stormwater, trap pollutants, cleanse the water and, if necessary, funnels excess water into a wetland pond.

Bioswale design consists of a swaled drainage course with gently sloped sides (less than 6%), planted with vegetation, then filled with compost and/or rock. The water's flow path and wide and shallow shape are designed to maximize the time water spends in the swale and thereby increase the trapping of pollutants and silt. Bioswales may be meandering or almost straight Site selections and optimum sizes for rain gardens and bioswales are based on the project area and its projected watershed. For more information about how to calculate the best size and select appropriate plants, see 10,000 Rain Gardens website. By using deep-rooted native grasses and forbs, you can improve the stormwater absorption quality of any site, increase wildlife diversity and improve your landscape's aesthetic values.