Environmental Benefits of Permeable Shoulders

Focus Area

Water Quality/Wetlands


Natural Resources







Research Idea Scope

This project would look at the use of permeable pavements along shoulders. It would primarily look at the suitability of such pavements from a design, constructability, maintenance, and longevity standpoint. However, it would also look at the flow spreading, energy dissipation, and treatment benefits with respect to managing highway stormwater runoff. Representative spot samples of the water quality benefits from pervious pavement will be taken. That in combination with results from the primary flow control study of this research will be used to direct future research. 


The proposed U.S. EPA rulemaking will most likely require volume reduction from highways. Permeable pavements in shoulder areas would be one way for DOTs to reduce the volume of runoff from highways. The research should be started now to coincide with the release of the final EPA rule in 2012. 

Urgency and Payoff

The benefits resulting from this research include:

  • Revealing the challenges of constructing permeable pavements in a highway setting;
  • Identifying the maintenance necessary to keep the material functioning properly;
  • Determining life expectancy of pervious pavement in typical highway shoulder
  • applications;
  • Developing design criteria for pervious pavement shoulder applications; and
  • Identifying in-situ flow spreading, energy dissipation, and treatment performance in
  • Washington State.

Suggested By

Center for Environmental Excellence, Stormwater Community of Practice