Dr. Bridget Wadzuk ’00 and Dr. Robert Traver, PE, MCE ’82 of the Department of Civil and Environmental Engineering received a $251,762 grant from the Pennsylvania Department of Environmental Protection to evaluate, assess, and monitor the benefits of evapotranspiration in several stormwater best management practices (BMPs) at Villanova University. The results of their studies will lead to improvements in the design and regulation of green infrastructure and will promote sustainable development through education and outreach by the Villanova Urban Stormwater Partnership.
Evapotranspiration is the process by which water is returned to the atmosphere, either by evaporation, as from surface water, or by transpiration, as from plants, which release water vapor from their leaves. In urbanized areas, where paved surfaces have replaced vegetation, less rainfall is returning to the atmosphere through evapotranspiration. As a result, the volume of stormwater runoff has increased.
Some stormwater BMPs involve standing water or heavily vegetated systems; however, the evapotranspiration benefits that they provide are not fully understood. The goal of this project is to quantify the daily and seasonal evapotranspiration from mesocosms of the constructed stormwater wetland, biorentention, bioinfiltration, and green roof facilities on campus. With this data, the researchers will be able to determine whether evapotranspiration is significant for different green infrastructures and whether evapotranspiration loss can be predicted over time, since atmospheric conditions, geographic location, and site characteristics affect results.
“If we can show that certain stormwater BMPs have significant evapotranspiration and can quantify that, then those BMPs can receive more volume-reducing credit, which is important for builders who need to meet stormwater regulations,” Dr. Wadzuk said.
More and more government officials are turning to green technologies to address the problem of urban stormwater runoff. In March, Dr. Traver testified on this topic before the U.S. House of Representatives’ Subcommittee on Water Resources and Environment.