Development of a Stormwater Best Management Practice Placement Strategy for the Virginia Department of Transportation

About the report:

Since the implementation of the federal and state stormwater management regulations, the Virginia Department of Transportation (VDOT) has constructed hundreds of best management practices (BMPs) for controlling stormwater runoff from highways and its other facilities, such as maintenance headquarters, storage areas, etc. In recent years, the U.S. Environmental Protection Agency (USEPA) has promoted the watershed approach in controlling pollution from various sources in a watershed. One of the key elements of the watershed approach is to include the participation of all stakeholders in the planning and implementation of control measures. The USEPA expects stakeholders, such as regulators, pollutant dischargers, citizens, etc., to work together to develop the best strategy for pollution control with the entire watershed as a planning unit. VDOT is such a stakeholder in many watersheds in Virginia. In the present study, a holistic methodology for determining the cost-effective placement and configuration of stormwater BMPs for VDOT was developed. The methodology involves the coupling of a comprehensive watershed simulation model with an optimization technique. Specifically, the methodology consists of three interacting functional components: a watershed simulation model, a BMP simulation module (the impoundment routine), and an optimization model. A highway application case study was conducted using the VDOT Rt. 288 Project in Chesterfield County, Virginia. The results showed that the current VDOT BMP placement approach, (which consists of on-site treatment of stormwater runoff from highways), might not be cost-effective in terms of protecting the water quality at the watershed level. The results of the case study indicate that if VDOT were to work with other stakeholders in developing a BMP placement strategy for the entire watershed, greater cost-effectiveness would be achieved as a result of fewer BMPs being required for VDOT to construct than would otherwise be the case. The methodology developed in the present study can be modified and expanded into a decision support system, which can include more types of BMPs and which would allow more BMP placement scenarios.

Authors