Pervious Strip
ELM-PVS-21 Situational / Discouraged Element
Pervious Strip
A linear strip of permeable surface (gravel, permeable pavers, or open-graded aggregate), allowing stormwater to infiltrate directly into the ground rather than running off to a drain, typically installed within a parking lane, shoulder, or buffer zone.
Why this pattern exists
A conventional impervious strip in this same location contributes runoff volume with no infiltration benefit; converting it to a pervious surface reduces runoff at a relatively low cost compared to a full bioswale or planter, without requiring a change in the strip’s basic use. This pattern exists to document that lower-intervention infiltration option.1
Key considerations
- Underlying soil infiltration rate needs to be verified before installation; a pervious surface over poorly-draining soil underperforms significantly
- Surface material should be selected for the loads it will bear; a parking-lane application needs a different specification than a pedestrian-only buffer strip2
- Periodic maintenance (removing sediment buildup) is required to keep the surface functioning as intended over time
Related patterns
Pervious Pavement (ELM-PVP-22) (a related but distinct full-surface treatment); Bioswale (ELM-BIO-19), Flow-Through Planter (ELM-FTP-20) (higher-intervention alternatives)
References
- Legal / regulatory U.S. Environmental Protection Agency, National Menu of Best Management Practices, "Permeable Pavements" fact sheet.
- Precedent-based National Association of City Transportation Officials, Urban Street Stormwater Guide.
"Legal / regulatory" here refers to the EPA guidance that municipal NPDES stormwater permits are legally built around, not a single mandatory design spec like MUTCD or PROWAG.