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 on a residential street in Portland’s Westmoreland neighborhood. Mutual Materials® Ecoloc® pavers were used on the street’s parking strips to provide an attractive and functional way to identify parking 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. Brett Kesterson, the City’s project engineer, has been very impressed. “Not only do the pavers perform well, but the local residents love the Old World look.”