This month’s Research in Action features the assessment of low impact development (LID) strategies used for the Lorton Road Widening Project in Fairfax County, Virginia. The project addresses growing concerns regarding highway stormwater runoff quality. As more roads are built and widened, and vehicle travel increases, the impervious surface areas of watersheds increase and additional pollutants are added to runoff from highway surfaces. To reduce the effects of highway runoff on receiving waters, decentralized, LID stormwater management systems are being implemented as an alternative to centralized best management practices (BMP) for runoff.
LID systems are an innovative approach to stormwater management. Mimicking natural conditions, they employ landscape features, such as grassy swales, and design techniques that infiltrate, filter, store, evaporate and detain runoff, moving stormwater away from a structure or site and leveraging natural features to protect water quality.
While LID practices for stormwater management are becoming more common, knowledge gaps still exist concerning their long-term performance and maintenance, particularly along highways. Dr. James Smith, Ph.D., the Henry L. Kinnier Professor of Environmental Engineering at the University of Virginia (UVA), and his research team are working with VDOT, VTRC and Fairfax County to implement an innovative, strategic approach to determine the long-term effectiveness of LID strategies.
Phased in over several years, the Lorton Road Widening Project offers a unique opportunity to evaluate a variety of LID systems that receive essentially identical rainfall, climate, daily traffic, and maintenance. The research team is implementing a comprehensive plan to determine the effectiveness of multiple LID systems and the maintenance requirements, procedures and operating costs associated with the LID systems in a highway setting.
“This is a huge study, eventually encompassing 47 LID systems within a two mile area. In essence, the construction site is a microcosm in which we can study a variety of stormwater issues and solutions over an extended period,” explained Michael Fitch, Ph.D., Associate Principal Research Scientist at VTRC. “Ultimately, we hope to answer questions about the cost effectiveness of using LID systems and share this information with other DOTs that are under pressure to reduce costs and improve stormwater quality.”
Phase 1 of the project is underway with 6 LID systems in place. Dr. Smith and his team will be monitoring the water passing through the LIDs to determine how rainfall amount, rainfall intensity, and LID influent quality impact the performance of the systems.
For more information, contact Michael Fitch at Michael.Fitch@VDOT.Virginia.gov.
The Virginia Transportation Research Council (VTRC) is one of the country’s leading transportation research centers. Specializing in applied research to support VDOT, its scientists and engineers also provide technical consulting and training to promote innovations in structures, pavements, materials, safety, operations, traffic engineering, planning, environmental, and economic issues.
The goal of VTRC is to conduct research that enables VDOT to deliver transportation initiatives that save lives, save time and save money, while protecting Virginia’s environment.