Incorporating low impact development (LID) practices into the Lorton Road widening project in Fairfax County is a significant effort that promises to regulate the quality and quantity of stormwater runoff to approach pre-development conditions. However, the specific performance of such technologies – with respect to decreasing peak flows, removing suspended sediments and reducing dissolved nitrogen, phosphorus, heavy metals and organic contaminants – is difficult to predict. Long-term maintenance costs and potential changes in performance also are unknown.

The purpose of this project is to develop a plan to assess the short- and long-term performance and maintenance requirements of the multiple LID practices that will be implemented in the Lorton Road widening project. The Virginia Department of Transportation (VDOT) will review and modify this plan as needed before full implementation. VDOT also will finalize the plan concurrently with the completed construction of the LID designs.