Description
There are a series of seven stormwater ponds that manage runoff generated by Kennedy Drive. The City is working with an engineer to design improvements to these ponds, so that they can treat additional runoff that currently bypasses the ponds untreated, as well as upgrading select ponds to subsurface gravel wetlands to enhance the phosphorous removal of the treatment system. Kennedy Drive Pond 7 has been selected for both expansion and retrofit to a subsurface gravel wetland.
Problem
Pond 7 currently manages a 3.5 acre portion of Kennedy Drive and Williston Road and was originally designed to meet the WQv and overbank protection design standards. However, the existing pond was only
designed to treat the additional impervious acreage associated with the Kennedy Drive road expansion, thereby not meeting the treatment standards for the entire contributing drainage area.
There is currently untreated stormwater runoff generated from an 18.35 acre drainage area that could feasibly be routed to Pond 7. This project proposes to capture this additional area, as well as expand and retrofit the pond into a subsurface gravel wetland to provide Water Quality and Channel Protection treatment for the existing and expanded drainage area.
This project was identified as part of the Potash Brook Flow Restoration Plan (FRP), prepared by the City of South Burlington, in an effort to reduce flows to the impaired Potash 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 70%, from 3.59 cubic feet per second (cfs) to 1.05 cfs.
Timeline
The City has received grant funding from the Vermont Agency of Transportation (VTrans) for final design and construction of the Kennedy Drive Pond 7 expansion and upgrade. The City is currently working with an engineering consultant to finalize the design drawings. Construction is anticipated for the 2025 season.
Plans
Draft Final Plan Set dated March 16,2022
This page was last updated on 8/09/2024