Research Webinar: How Effective Are Subsurface Gravel Wetlands at Treating Stormwater Runoff in Vermont

Watershed Consulting Associates collaborated with the University of Vermont to conduct a two-year monitoring study on subsurface gravel wetland systems in Chittenden County, Vermont. As many Vermont municipalities are required to obtain the State’s Operational Stormwater Permit (3-9050) for new development or redevelopment of impervious surfaces, the implementation of subsurface gravel wetlands has proliferated around Vermont to treat stormwater runoff under the 3-9050 permit requirements.

The presentation reviewed the 2020-2021 performance data on the flow attenuation and phosphorus capture of two gravel wetlands which were selected for this study and introduce design recommendations to improve the performance of future permitted gravel wetlands. Findings from this study will also be provided to the Vermont DEC’s Stormwater Program to optimize the subsurface gravel wetland design requirements.

This webinar is part of the Lake Champlain Sea Grant Research Seminar Series; it took place on September 28, 2022.

Andres Torizzo is a registered Certified Professional in Erosion and Sediment Control (CPESC), Certified Professional in Stormwater Quality (CPSWQ), Certified Erosion, Sediment, and Stormwater Inspector (CESSWI), and Certified Inspector of Sediment and Erosion Control (CISEC). Andres earned his Undergraduate Degree in Geological Sciences from Tufts University and his Master’s Degree in Geography from the University of Colorado, Boulder. Andres has particular interest and expertise with green stormwater infrastructure, watershed planning, and stormwater retrofit design. He has been actively working on improving water quality with a variety of clients and partners throughout the United States for over twenty years.

Nisha Nadkarni is a Water Resources Scientist at Watershed Consulting. Nisha focuses on stormwater master planning, water quality monitoring, best banagement practices assessments, and engineering feasibility analyses. She is a graduate of the Environmental Sciences Program in UVM’s Rubenstein School of Environment and Natural Resources with a concentration in ecological design and geospatial technologies.