The Environmental Services Department for the City of Portland, Oregon wanted to investigate different forms of permeable street surfacing to see which system would best handle storm runoff and help reduce the need for stormwater treatment. They installed pervious concrete, porous asphalt, and permeable pavers in 1,000 square foot sections on residential streets in Portland’s Westmoreland neighborhood.
The reason for this project was to find a way to improve water quality and reduce stress on Portland’s sewer system. Heavy rains cause combined sewer overflows (CSOs) bringing pollution and heavy metals into the nearby Willamette River. Intense storms also caused overloaded sewer systems and backups into basements across the city.
Mutual Materials® Uni-EcoLoc® pavers were used on the street’s parking strips to provide an attractive and functional way to identify parking areas. Besides all of the stormwater mitigation benefits that come with permeable pavers, EcoLoc is laid mechanically which makes installation fast. This makes them an outstanding choice for industrial areas, like ports, manufacturing plants, storage depots, military installations, loading docks, and maintenance areas.
Then came the test: the City flushed 2,000 gallons of water in a ten-minute period over each surface to see how they would perform. The results were dramatic. The concrete and porous asphalt absorbed the water at a rate of 47 inches per hour, while the permeable pavers handled it 27% faster, at a whopping rate of 60 inches per hour. By comparison, soil alone can only absorb 1-3 inches.
Not only do the pavers perform well, but the local residents love the Old World look. –
– Brett Kesterson, Project Engineer, City of Portland, Oregon
If you are interested in learning how Mutual Materials’ interlocking concrete permeable pavers can meet your needs for controlling stormwater runoff, call us today at 1-888-688-8250 to speak with a hardscape sales representative.
- City of Portland, Oregon
- Mutual Materials
- Mutual Materials – Uni-EcoLoc Permeable Pavers
- Introduction To Permeable Concrete Paving