Vegetative Filtering Systems Wet Swales
Broad vegetative filtering
Grass cover crop or wetland vegetation acts as filter bed
Swale soils are fully saturated or have standing water
May intercept water table
24-hour storage of water quality volume
Notes:
The wet swale also consists of a broad open channel capable of temporarily storing the WQv (also a volume based sizing criteria), but does not have an underlying filtering bed. The wet swale is constructed directly within existing soils and may or may not intercept the water table. Like the dry swale, the WQv within the wet swale should be stored for approximately 24 hours. The wet swale has water quality treatment mechanisms similar to stormwater wetlands which rely primarily on settling of suspended solids, adsorption, and uptake of pollutants by vegetative root systems.