Which post-construction BMP involves vegetation to slow and treat runoff?

Which post-construction BMP involves vegetation to slow and treat runoff?

• A. Vegetated swales/bioretention areas.
• B. Silt fence.
• C. Riprap channel.
• D. Pervious pavement.

Answer: (A)

Using vegetation to slow and treat runoff is the purpose of vegetated swales and bioretention areas. These post-construction practices combine plant life with shallow, engineered soil media to reduce water velocity, promote infiltration, and remove pollutants through filtration, adsorption, plant uptake, and microbial action. The result is better water quality and lower peak flows as stormwater moves through the landscape. Silt fences are temporary erosion controls used during construction to trap sediment before runoff leaves the site, not post-construction vegetation-based treatment. Riprap channels rely on rocks to dissipate energy and reduce erosion, not vegetation. Pervious pavement lets water infiltrate through a permeable surface, focusing on infiltration through the surface rather than vegetation-driven treatment.

Using vegetation to slow and treat runoff is the purpose of vegetated swales and bioretention areas. These post-construction practices combine plant life with shallow, engineered soil media to reduce water velocity, promote infiltration, and remove pollutants through filtration, adsorption, plant uptake, and microbial action. The result is better water quality and lower peak flows as stormwater moves through the landscape.

Silt fences are temporary erosion controls used during construction to trap sediment before runoff leaves the site, not post-construction vegetation-based treatment. Riprap channels rely on rocks to dissipate energy and reduce erosion, not vegetation. Pervious pavement lets water infiltrate through a permeable surface, focusing on infiltration through the surface rather than vegetation-driven treatment.