Farrell Street Stormwater Treatment System


Farrell Street


The City of South Burlington worked with private landowners and the State of Vermont to construct this large stormwater treatment project in the Potash Brook watershed. This project included 5 different components (stormwater detention pond, bioretention area, culvert replacement, porous asphalt and a hydrodynamic swirl separator) and provides treatment for large impervious areas near Farrell Street.

Porous asphalt
Porous asphalt installed in foreground
Detention basin
New detention basin installed during construction



This multi-part project will improve all aspects of water quality, hydrology, and stream channel quality in the main stem of Potash Brook. The stormwater treatment practices will remove sediment and other pollutants from stormwater runoff prior to discharging to Potash Brook. The new culvert improves stream conditions and was designed with a bottom that emulates a natural stream bed.

New culvert
New culvert under Farrell Street

Best Management Practices

Detention Basin, Bio-infiltration basin, Hydrodynamic Swirl Separator, Porous Asphalt, New Culvert



Construction Cost


Technical Advisors

Hoyle, Tanner, and Associates, VHB-Pioneer Environmental

Funding Sources

Stormwater Utility Funds, STAG Grant, SIWR Grant, Town Highway Structures Grant

Last Updated: 3/2012