Again, filter strips are often used as pretreatment for downstream BMPs. Provides physical, chemical, and biological water quality treatment of stormwater runoff where a continuous baseflow can be ensured. Wetlands support a variety of aquatic flora and fauna, and is characterised by a non-soil substrate which is saturated with water or covered by shallow water at some time during the growing season. Usually implemented in conjuction with other BMPs for large catchment areas. The captured runoff is stored in this reservoir until it either infiltrates into the underlying soil, or is routed through a perforated underdrain system to a conventional stormwater conveyance.
Porous pavements operate in a similar fashion to infiltration trenches.