Projects

Project Abstract
Title	Watershed impact of stormwater bioretention and bioinfiltration BMPs
Coordinator	Dr. Robert G. Traver Ph.D., D.WRE
Contact	robert.traver@villanova.edu
Abstract	The proposed research focuses on making science-based recommendations for the design and performance of Low Impact Development (LID) Bioretention and Bioinfiltration best management practices (BMPs) to both understand and optimize their use as a stormwater control measure at the watershed scale. The research team integrates the diverse expertise and experience from three established stormwater research programs with differing climatic and soil conditions in the mid-Atlantic coastal zone (University of Maryland, North Carolina State, and Villanova University). Bioretention and Bioinfiltration BMPs attenuate stormwater runoff volume to reduce negative impacts from development and changing land use. These control measures directly address recharge, water quality, increased volume, peak delay and peak flow issues. These control measures are unique in that they are most effective strategically distributed over the landscape in an LID setting, contrasting to past practices of larger control technologies at the bottom of the watershed. Nonetheless, a wide range of design issues for these BMPs have slowed their implementation, and inhibits their use. Some of these issues stem from the fact that the bioretention/bioinfiltration concept is a new breed of BMP that integrates knowledge from a number of disciplines. Concerns over performance, groundwater contamination, longevity, and over infiltration have limited their size. Past practices and guidelines were directed at smaller runoff volumes and did not include peak rate reduction or large volumes as performance criteria. Specific objectives and tasks of this research include: • review current and past research on bioretention and bioinfiltration, to both better understand the science and to select preferred design criteria. • establish a standard monitoring protocol for the three universities to facilitate performance comparison (QA/QC). • perform field experiments to confirm performance hypotheses. o Maryland – Intensively monitor up to three bioretention facilities for hydrologic and water quality performance. o NC State – Select and monitor four existing bioretention BMPs for water quality, quantity, and peak flow performance. Measure post-construction in-situ soil infiltration rates. o Villanova – Build and intensively monitor four side by side bioretention and bioinfiltration BMPs for water quality, quantity, and peak flow performance. Measure post-construction in-situ soil infiltration rates • examine bioretention/ bioinfiltration performance from a LID perspective. Specifically, how close does a site properly fitted with these facilities approach that of an undeveloped site from a hydrologic and water quality perspective? • incorporate the results in a hydrologic model to determine the scale effects of their implementation over a watershed, and to assess effects of changes in rainfall caused by climate change. Note that this project leverages funds from many sources to include federal, state, and public sources. Though not required, matching funds are provided.