Science & Innovations - Porous Pavement

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Porous pavement is concrete, asphalt, or pavers that allow rainwater to pass through to soak back into the ground naturally. Typical roads and sidewalks are not porous, so rainwater can't penetrate the surface. Rainwater and runoff from storms is then carried into storm drains and becomes stormwater.

Stormwater carries pollutants from the surface to streams and erodes stream banks and bottoms. Porous pavements function to help protect streams, Puget Sound, and our groundwater supply.

Porous Pavement Projects:

The City began installing sections of porous pavement in 1999. Learn more about our porous pavement projects by downloading the printer-friendly project reports below:

North Street Reconstruction Project (1999). Installation of a section of regular porous concrete sidewalk on North Street.
Sidewalk Projects (2004). Various installations of smooth surfaced porous concrete.
RW Johnson Boulevard (2006). The City installed a porous concrete bicycle lane and sidewalks designed as the stormwater mitigation for the RW Johnson Boulevard /21st Avenue improvements. Download additional materials presented at a recent ASCE Low Impact Development Conference: - "Pervious Concrete Bicycle Lanes - Roadway Stormwater Mitigation within the Right of Way" - "Pervious Concrete Bicycle Lanes" Presentation
Decatur Street Stormwater Low Impact Development Project (2007). Upcoming reconstruction of a portion of Decatur Street features three new methods to clean and infiltrate stormwater runoff. The City was awarded a grant through the Washington State Department of Ecology. View a YouTube video about the Decatur Street Project or download materials presented at a recent ASCE Low Impact Development Conference and other project-specific information: - "Underpavement Infiltration Demonstration - Decatur Street Low Impact Development Roadway Project" Paper (PDF) - "Underpavement Infiltration Demonstration" PowerPoint Presentation (PDF) - Decatur Street Specifications, Plans, Bid Tabulations, and QAPP
Olympia Woodland Trail Eastside Street Trailhead. Learn more about the use of porous pavement in the Olympia Woodland Trail Park.

The Cost and Benefits of Using Porous Pavement:

Olympia has evaluated the costs and benefits of using porous concrete for sidewalks. Download the printer-friendly information about porous pavement below:

Analysis Summary Memorandum - "Traditional Versus Pervious Concrete Sidewalks - Construction and Maintenance Cost."
Paper and presentation to the Institute of Traffic Engineers, ITE District 6 Annual Meeting 2007. "Porous Concrete Sidewalks- How to Build Sidewalks and Not Stormwater Ponds" and accompanying PowerPoint presentation in PDF format, "Porous Concrete Sidewalks."

Maintaining Porous Pavements:

The City is committed to a maintenance program that ensures porous pavement continues to function for its serviceable life. Download our printer-friendly trial reports on pressure washing, sidewalk sweepers, hard surface cleaners, and leaf/litter vacuum cleaners.

Contacting Public Works:

Physical Address: 924 7th Ave. SE, Suite A
Mailing Address: PO Box 1967, Olympia, WA 98507
Download printer-friendly (PDF) directions to our office
Hours: M - F from 8 a.m. to 5 p.m. (except for City-recognized holidays)
Phone: 360.753.8588
TTY 360.753.270
Email: publicworks@ci.olympia.wa.us
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