Bioswale
Type of Development
New Development, Restoration
Topography
Hills, Valley
Longevity
Long Term
Environment
Natural Habitat, Urban
Maintenance
Medium
Cost
Vary greatly depending on size.
Overview
Bioswales are long biorientation areas that allow stormwater to slow down and filter through the ground. They are usually large, long, curving areas of depressed land filled with thick rooted native plants and rocks placed near flood zones, and are best used in place of underground pipes and in areas untouched by concrete. Bioswales can be used on a small scale in residential neighborhoods or can cover hundreds of feet along floodplains or highways.
Function
Capture, store, and filter water efficiently into the ground while sequestering pollutants.
Benefit
Bioswales direct rain and storm water to controlled locations in order to be captured, reducing flooding of impervious surfaces. They are attractive and require little to no maintenance. Bioswales are implementable on many different scales including the individual level. Bioswales can be built to divide pedestrians and cyclists from vehicular traffic, increasing everyone's safety. Their natural beauty increases community health and prosperity.
Dependency
Sunlight, areas with high percolation rates, access to water runoff
Development Considerations
Percolation rates should be greater than 1 in/hour. A parabolic or trapezoidal shape is best with side slopes no deeper than 3:1. Graded side slopes, generally less than 2ft in depth a minimum bottom width of either 12 or 18 in. Maybe need a physical barrier ( grate, fence, high vegetation) to reduce injury risk among pedestrians and cyclists. Underground utilities may prevent space capacity.
Environmental Considerations
Native and ecologically suitable plants are extremely important. Water table needs to be considerably below the level of the bioswale. Rock or a grated pathways over biorientation area allow better accessibility to roads.
Maintenance Consideration
Maintenance is minimal due to native plants ability to self regulate. However, invasive plants need to be removed regularly and underdrains become clogged frequently. First years of implementation requires regular maintenance to ensure effectiveness.
Cost Considerations
Vary greatly depending on size.
