Dorset Street


Dorset Street crossing under I-89


Stream overflow
Stream flow during large rain event before project commencement

An undersized culvert was carrying Potash Brook beneath Dorset Street. In addition, adjacent stormwater runoff from the highway was flowing directly to Potash Brook without treatment. These issues were causing changes to the way that water flowed in the stream and resulted in deposition of sediment in Potash Brook.


Signs of erosion
Signs of erosion in problem area

The project included replacement of the undersized culvert with a new culvert that allows peak stream flows to move beneath Dorset Street without causing flooding or erosion problems. Streambanks were replanted using a natural design that will prevent erosion and provide enhanced streambank habitat. In addition, eroded channels that lead to Potash Brook were repaired reducing sediment inputs to the stream.


This multi-part project improved all aspects of water quality, hydrology and stream channel stability, at this critical point on the main stem of Potash Brook.

Best Management Practices

Wetland Basin
Wetland Channel
Biofilter (plant-based treatment)
Culvert replacement

Technical Advisors

Vermont Agency of Transportation; DuBois & King; Winooski Natural Resource Conservation District (NRCD)


USDA – Winooski Natural Resource Conservation District
Office of U.S. Senator Patrick Leahy
Vermont Agency of Transportation

Total Project Value



Phase 1 included culvert replacement and was completed in 2003.
Phase 2 included revegetation of the streambanks, repair of erosion and stormwater treatment and was completed 2005.

Funding Sources

South Burlington Public Works; Vermont Agency of Transportation Bridge & Culvert Grant (culvert); USDA Natural Resources Conservation Service funding secured by U.S. Senator Patrick Leahy
(re-vegetation, erosion repair & stormwater management)

Last Updated: 11/2009