Plants managing stormwater
Green infrastructure uses soil and vegetation to capture, infiltrate, and filter rainfall rather than piping all runoff to combined sewer systems. Bioswales are vegetated channels designed for temporary ponding.
Design elements
- Ponding depth and duration — typically 15–30 cm for 24–48 hours max.
- Soil media — high sand content for infiltration; organic matter for filtration.
- Underdrain — when native soil infiltration is insufficient.
- Pretreatment — catch sediment before it clogs swale surface.
Plant palette
Select species tolerant of both inundation and drought between storms. Native grasses and forbs often outperform ornamental species in harsh swale conditions.
Maintenance
Remove sediment berms, replace mulch, and replant after extreme events. Without maintenance, bioswales become weed patches or dry detention basins.