Parking Lot Drainage Solutions
Parking lot drainage guide: catch basins, French drains, permeable pavement, bioswales, EPA/NPDES compliance, and cost analysis. Interactive stormwater calculator.
More Parking Construction Resources
Parking lot construction, paving, striping, lighting, and drainage — cost benchmarks, contractor selection, and specifications for building and resurfacing durable parking assets.
Parking Lot Drainage & StormwaterParking Lot Paving ConstructionParking Lot Lighting SafetyParking Lot Lighting StandardsParking Lot Striping & MarkingParking Lot Striping LayoutParking Lot Construction & BuildWhat causes drainage problems in parking lots?
Insufficient slope (under 1%), clogged/undersized catch basins, and pavement settling. Poor drainage is the #1 cause of premature failure, cutting lifespan from 20 to 12 years.
How much does a parking lot drainage system cost?
Catch basins + pipes: $2.50–$5.00/sq ft. French drains: $4.00–$8.00/sq ft. Permeable pavement: $8.00–$15.00/sq ft. Complete system for 50,000 sq ft: $40,000–$120,000.
What is the minimum slope for a parking lot?
1% minimum (1 foot per 100 feet). 1.5–2% recommended. ADA spaces: maximum 2% in all directions. Slopes over 5% require energy dissipation at discharge.
Does permeable pavement work for parking lots?
Yes — reduces runoff 85–95%. Costs $8.00–$15.00/sq ft but can eliminate $50,000–$200,000 in detention pond costs. Requires quarterly vacuum sweeping.