In the late 1960s, the concept of porous pavement was proposed to “promote percolation, reduce storm sewer loads, reduce floods, raise water tables, and replenish aquifers." Throughout the 1970s, the concept was discussed and refined to a point where the Environmental Protection Agency (EPA) contracted to “determine the capabilities of several types of porous pavements for urban runoff control, in terms of cost and efficiency."
Some of the initial installations of porous asphalt pavement were in Delaware, Pennsylvania, and Texas. The Woodlands site in Texas, which was constructed under an EPA grant, was the only site where substantial scientific monitoring instrumentation was installed in these early days. Today many sites around the country are being monitored by academic institutions.
In 1977, Edmund Thelen and L. Fielding Howe co-authored a design guide for porous pavement for the Franklin Institute in Philadelphia. This document has been widely referenced in subsequent years and provides a solid foundation for porous pavement designers. Click here to download a copy.
Many additional porous pavement sites have been constructed since the late 1970s. While there have been both successes and failures, the overwhelming majority have succeeded. Where porous pavements have failed, the reason cited most often was that silts and other fine material were allowed to enter the site uncontrolled, essentially clogging the pavement. Cahill Associates has been involved in the design and construction of more than 200 porous asphalt pavements since the 1980s and have reported no failures of pavements for which proper design and construction practices were followed.
Some of the benefits conferred by the successful installations include runoff control, aquifer recharge, reduction of drainage structures needed to comply with stormwater regulations, and increased skid resistance.
One of the earliest examples of a porous asphalt pavement is the parking lot for the visitor center at Walden Pond State Reservation in Massachusetts, which was constructed in 1977. This photo was taken in 2008.