What is a bioswale in the context of green infrastructure?

• A. A landscape feature that channels and treats stormwater runoff using vegetation and soil.
• B. A landscape feature that channels and filters air.
• C. A type of private irrigation control.
• D. A plumbing device for rainwater.

Answer: (A)

At the heart of green infrastructure is shaping landscapes to slow, filter, and infiltrate rainwater where it falls. A bioswale is a shallow, vegetated channel designed to capture runoff from nearby surfaces and pass it through soil and plant roots. The combination of plants, soil media, and the swale’s shape removes pollutants, traps sediments, and promotes infiltration and evapotranspiration. This slows the flow, reduces peak discharge, and helps recharge groundwater, all while blending into the landscape.

Other descriptions miss the stormwater focus or the vegetated treatment aspect—for example, filtering air, acting as a private irrigation control, or serving as a plumbing device for rainwater—so they don’t describe what a bioswale does in green infrastructure.