Modernizing Performance Metrics for Stormwater Infrastructure



Elizabeth Fassman-Beck, Stevens Institute of Technology

Monday, October 14, 2019 - 10:00am to 12:00pm


Underlying the stormwater industry is a fundamental assumption that regulatory policy and engineering design guidelines create urban infrastructure that protects downstream receiving environments. Despite decades of research and increasing data availability, many jurisdictions retain minimal hydrologic and broad pollutant mitigation objectives derived from the knowledge base of the 1960s-1990s, while design approaches imply that different stormwater technologies perform every mitigation function equally, and/or all functions can be achieved by a single form of technology. To the contrary, the wealth of information now available provides opportunities to introduce evidence-based design and policy, to consider site-specific design in a meaningful manner, and to address the dynamic loadings of urban stormwater runoff.

As examples in this talk, data from green roof studies are used to explore nutrient management objectives, and how the composition of an individual technology can influence its performance. Permeable pavement and green roof monitoring studies, among others, are used to consider the potential of more sophisticated, yet somewhat traditional hydrologic metrics uncommonly applied to stormwater design, such as flow duration and frequency analysis, to evaluate hydrologic mitigation potential over a spectrum of rainfall events. The role of bioretention planters in combined sewer overflow mitigation by delaying runoff discharge is discussed in the context of this technology’s unique urban retrofit potential. Overall, the intention is to demonstrate credible metrics available now to advance the design and implementation of stormwater infrastructure to contribute to meaningful water resource protection.

Elizabeth Fassman-Beck photo

Speaker Bio

Dr. Elizabeth Fassman-Beck is an Associate Professor of Civil Engineering at Stevens Institute of Technology in New Jersey. Her research in urban stormwater management using green infrastructure quantifies the hydrologic and water quality performance of living (green) roofs, rain gardens, permeable pavements, and floating treatment wetlands. Research outcomes have led to numerous publications in highly respected journal, a co-authored technical book Living Roofs in Integrated Urban Water Systems, and GI design specifications for regulatory agencies.

Named 2018 ASCE-NJ Educator of the Year, Dr. Fassman has recently constructed a “Living Laboratory” on the Stevens’ campus, including 47 experimental GI systems. She was the primary advisor to a Capstone Senior Design team which won 2nd place in the 2015 USEPA Campus RainWorks Challenge, a national competition to develop a green infrastructure campus master plan.

Elizabeth earned her B.S.E. in Civil and Environmental Engineering from Duke University (1996). Her M.S. (1998) and Ph.D. (2002) in Civil Engineering from the University of Virginia were followed by two years of engineering consulting in Colorado before beginning her academic career at the University of Auckland (New Zealand) in 2004. She returned to the USA in 2014, taking up her position at Stevens Institute of Technology. In Autumn 2019, she’ll be heading west, taking up a position as Principal Engineer at the Southern California Coastal Water Research Project to implement their stormwater research theme.