Vegetated Swale

Vegetated swales, commonly referred to as eco-swales and bio-swales, are an increasingly popular way of integrating a functional native community into the landscape.

Rather than utilizing curb and gutter to channel runoff into storm sewers, where there is no chance to mitigate its quality or quantity, runoff is funneled through swales planted to appropriate native vegetation.

Vegetated swales serve to remove sediment, nutrients and other contaminants, increase infiltration, and beautify the development. These low maintenance plant communities may be established wherever runoff must be transported from hardscapes to retention areas. Plant communities established in these swales normally utilize species of wet-mesic prairie and sedge meadow.

Benefits of Vegetated Swale include:

• Removal of contaminant including nutrients and suspended solids
• Increased filtration
• Provides an economical and environmentally friendly alternative to curbs and gutters
• Erosion control fabric holds soil during establishment
• Densely rooted native grasses and sedges provide permanent stabilization

Grasses and sedges are the workhorses of these installations. Their dense fibrous root systems not only hold the soil, they form numerous root channels that result in increased infiltration, helping to reduce the volume of runoff reaching retention ponds or other bodies of water. It is vital to chose rhizomotous species that tolerate flowing water.

The rhizomes knit the community together, binding the soil and preventing erosion.

Specifications for vegetated swales will vary greatly according to a variety of environmental factors. Most swale installations will require some type of  erosion blanket or bioengineering fabric for erosion control. The soil type and resulting infiltration rate is another important engineering variable. The grade and water volume are also important variables in the design specifications for vegetated swales.

For these reasons, we do not provide AIA-USA construction document formatted specifications.

Many vegetated swales and roadside ditches can also be exposed to seasonal road salt applications.

Refer to our list of Salt Tolerant Plant Species when designing projects where salt exposure is a concern.