Picard Circle

Description

The City of South Burlington Stormwater Utility received a grant from the Vermont Agency of Transportation to improve the existing stormwater system on Airport Parkway and install an underground Stormwater treatment practice in Picard Circle. The project includes the design and construction of a stormwater infiltration basin within the Picard Circle right-of-way (ROW) and drainage infrastructure which would allow for the treatment of up to a 51 acre drainage area that consists primarily of City owned roadways.

Problem

Currently untreated stormwater runoff generated from a 51 acre drainage area, including 15 acres of impervious surface, discharges directly to the impaired Centennial Brook near the intersection of Airport Parkway and Picard Circle. This project was identified as part of the Centennial Brook Flow Restoration Plan (FRP), prepared by the City of South Burlington, in an effort to reduce flows to the impaired Centennial Brook and improve water quality in the Lake Champlain drainage area.

Benefit

Based on HydroCAD modeling conducted by the consultant, the project could reduce the peak flow of the 1-year, 24-hour storm event by 86.7%, from 9.09 cubic feet per second (cfs) to 0.38 cfs. Overall watershed modeling conducted by the State indicates a 4.3% flow reduction at the watershed outlet. According to an analysis of the drainage area using the Simple Method, the proposed improvements are anticipated to remove 7,900 lbs/year of sediment load, a substantial water quality benefit for Centennial Brook.

Timeline

Construction is currently scheduled for 2019.

Funding Sources

This project has received $229,600 in funding support from the Transportation Alternatives Grant Program administered by VTrans. The remaining project costs will be paid using stormwater utility capital project funding.

Photos

Page last updated: 10/26/2017