Barriers to Implementing Low Impact Development Approaches in Washington State Roadways and Highways

摘要

Low impact development (LID) is an approach to stormwater management that seeks to mimic the natural hydrologic functions of stormwater runoff prior to development. In general, LID techniques emphasize infiltration and evapotranspiration to remove pollutants and attenuate flows from urban runoff. As the largest land developer in Washington State, the Washington State Department of Transportation (WSDOT) is interested in better understanding the challenges of applying LID techniques to a highway setting and learning ways to address those challenges. This report identifies barriers to implementing LID approaches in a state roadway setting and provides recommendations on how WSDOT can overcome those barriers. This research question stems from a National Pollutant Discharge Elimination System municipal stormwater permit issued by the Washington State Department of Ecology (Ecology) to WSDOT in February 2009. Barriers were identified through a literature review, Ecology LID advisory committee meeting discussions, and interviews with people who are involved in stormwater management in a variety of capacities throughout Washington State.