Blackwall Hitch Permeable Parking Lot

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What is polluted runoff?

Parts of the Chesapeake Bay watershed contain a high percentage of impervious cover – paved or other hard surfaces such as roofs and roadways that prevent rain water from being absorbed into the ground.  Instead, water runs along these surfaces, collecting trash and substances such as motor oil, lawn fertilizers, and pesticides.  This polluted stormwater flows into streams and rivers, where it threatens aquatic ecosystems and public health.  

Effective stormwater management, on the other hand, creates safe paths for polluted runoff to be captured and filtered through the ground before it reaches waterways.  This helps keep the environment clean and our communities healthy!

before image
The permeable parking lot under construction. Credit: Spa Creek Conservancy.
Kids Planting Native Plants
Kids planting native flowers


Project location: Annapolis, MD

Problem: Parking lots typically contain significant amounts of impervious cover, and they can be a major source of pollutants to nearby streams. The parking lot of Blackwall Hitch, a seafood restaurant in downtown Annapolis, drains directly into Spa Creek, a major tributary of the Severn River.  Prior to this project, pollutant-laden rainwater flowed from the parking area and surrounding streets into the Creek.

Solution: Working with the private landowner, the nonprofit Spa Creek Conservancy installed permeable parking pads that allow rainwater to penetrate into the ground instead of washing the parking lot and sending polluted runoff into Spa Creek.  Additionally, bioretention cells consisting of rain gardens with “thirsty” landscaping plants were installed throughout the parking lot and at perimeters where runoff can be captured and absorbed.  Spa Creek Conservancy and Blackwall Hitch carefully selected native plants which create habitat, beautify the property, and absorb stormwater.

Maintenance needs: Periodic weeding

Funding sources: MD Department of the Environment; MD Department of Natural Resources’ Chesapeake and Atlantic Coastal Bays Trust Fund

More information:

Contact Information
Amy Clements | Spa Creek Conservancy | 410-271-5546
James King | Blackwall Hitch | 410-263-3454
Key project facts
Project Type
Story Focus
Environmental Benefits
Business Partnerships
Stormwater Funds
Problem Addressed
Flooding / Drainage
Runoff Pollution
Year Installed
Before 2013
State Legislative District
District 30A
Federal Legislative District
MD 3rd