HomeMy WebLinkAboutSP-22-060 - Supplemental - 0224 0268 Market Street (13)STORMWATER MANAGEMENT SUMMARY
City Center
November 7, 2022
PERMIT STATUS:
An individual stormwater discharge permit (7736-INDS.A) was obtained for the
lands owned by South Burlington City Center, LLC. The Permit approved a
comprehensive approach to the stormwater management system for the future site
development along Market Street, as well as the future construction of Garden
Street and the associated site development. The stormwater collection system along
Market Street is subject to a separate permit associated with the City’s
reconstruction of the street and utilities. The proposed permitted stormwater
treatment practices for City Center consist of a wet pond, five constructed wetlands,
two bioretention areas, an infiltration trench/chamber system, and simple
disconnection. Note that the simple disconnection applies to the path leading to
Dumont Park.
The Permit approved a total impervious surface of 18.5 acres. The stormwater
management system provides water quality treatment for 9.65 acres of offsite
impervious surface (included in the 18.5 acre total).
CONSTRUCTION STATUS:
Site Development
146 Market Street (Allard Square)CONSTRUCTED
180 Market Street (City Hall)CONSTRUCTED
310 Market Street (Garden Apartments) CONSTRUCTED
303 Market Street (Union Place)UNDER CONSTRUCTION
112 Garden Street (Prospect Place)UNDER CONSTRUCTION
324 Garden Street (Dover Place)CONSTRUCTED
Market Street Commons (Black Bay)CONSTRUCTED
Garden Street – north & south segments PARTIALLY CONSTRUCTED
Stormwater Practices
Gravel wetland #1 (GW#1)CONSTRUCTED
Gravel wetland #2 (GW#2)CONSTRUCTED
Gravel wetland #3 (GW#3)CONSTRUCTED
Gravel wetland #4 (GW#4)not constructed
Gravel wetland #5 (GW#5)CONSTRUCTED
Storm pond #1 (pond #1)CONSTRUCTED
Infiltration system UNDER CONSTRUCTION
Bio-retention area #1 (BR#1)PROPOSED
Bio-retention area #2 (BR#2)not constructed
Note that not all of the site development areas listed contribute fully to the listed
stormwater practices.
Gravel Wetland 1 Drainage Data
Subwatershed description Drainage
area
Impervious
surface
303 Market Street (Union Place) 0.96 acres 0.70 acre
Future development 1.22 acres 1.26 acres*
Approved TOTAL 2.18 acres 1.96 acres
* Note that the impervious surface exceeds the drainage area
Gravel Wetland 2 Drainage Data
Subwatershed description Drainage
area
Impervious
surface
310 Market Street (Garden Apts) 1.07 acres 0.87 acre
324 Garden Street (Dover Place) 0.63 acre 0.53 acre
Garden Street (north of Market St) 0.66 acres 0.55 acre
Partial Lot B **1.99 acres 1.67 acres
Future development 0.23 acres 0.84 acres*
Approved TOTAL 4.58 acres 4.46 acres
* Note that the impervious surface exceeds the drainage area
** Lot B includes bioretention area #1
Gravel Wetland 3 Drainage Data
Subwatershed description Drainage
area
Impervious
surface
Market St. Commons (Black Bay) 0.62 acres 0.60 acres
Approved TOTAL 0.62 acres 0.60 acres
Gravel Wetland 4 Drainage Data
Subwatershed description Drainage
area
Impervious
surface
Future development 0.43 acres 0.41 acres
Approved TOTAL 0.43 acres 0.41 acres
Gravel Wetland 5 Drainage Data
Subwatershed description Drainage
area
Impervious
surface
112 Garden St (Prospect Place)2.08 acres 1.98 acres
303 Market St (Union Place)0.37 acre 0.37 acre
Garden Street ROW (south of
Market St)1.35 acres 1.11 acres
Future development 1.42 acres 1.64 acres*
Approved TOTAL 5.22 acres 5.10 acres
* Note that the impervious surface exceeds the drainage area
Storm Pond #1 Drainage Data
Subwatershed description Drainage
area
Impervious
surface
Offsite 13.95 acres 9.65 acres
146 Market St. (Allard Sq. rooftop) 0.21 acres 0.21 acres
City Hall/School driveway 0.43 acres 0.27 acres
Lot B 1.02 acres 0.90 acre
Future development 4.69 acres 3.51 acres
Approved TOTAL 20.30 acres 14.54 acres
Notes:
-Allard Sq. rooftop area taken from Permit 7736-INDS application
-City Hall/School driveway taken from Operational Stormwater Permit
Application prepared by Engineering Ventures, PC
Rooftop Infiltration System Drainage Data
Subwatershed description Drainage
area
Impervious
surface
112 Garden St (portion rooftop)0.32 acres 0.32 acres
Future development 0.86 acres 0.86 acres
Approved TOTAL 1.18 acres 1.18 acres
Bioretention Area #1 Drainage Data
Subwatershed description Drainage
area
Impervious
surface
Partial Lot B 0.60 acres 0.45 acres
Future development 0.38 acres 0.50 acres
Approved TOTAL 0.98 acres 0.95 acres
Bioretention Area #2 Drainage Data
Subwatershed description Drainage
area
Impervious
surface
Future development 0.92 acres 0.88 acres
Approved TOTAL 0.92 acres 0.88 acres
Note that some stormwater practices are in series. For larger storm events, the
rooftop infiltration system discharges to GW#1, bioretention area #1 discharges to
GW#2, and bioretention area #2 discharges to storm pond #1.
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K EXISTING CONCRETE SIDEWALKEXISTING CONCRETE SIDEWALKEXISTING PAVED PATHEXISTING PAVED PATHSOUTH BURLINGTON CITY CENTERCATAMOUNT RUNMARKET ST. & GARDEN ST. SOUTH BURLINGTONDateSheet numberScaleCheckedDrawnSurvey DateRevisionByThese plans shall only be used for the purpose shown below:Sketch/ConceptFinal Local ReviewConstructionRecord Drawing11-07-22KBABRB>HE SNYDER GROUP, INC.4076 SHELBURNE ROAD, SUITE 6SHELBURNE, VERMONT 05482802-985-5722WWW.SNYDERHOMESVT.COMAS SHOWNSTLOT BSTORMWATER EXHIBIT1-888-DIG-SAFE PRIOR TO ANY EXCAVATION.THE CONTRACTOR SHALL NOTIFY "DIGSAFE" AT GRAPHIC SCALE3003060120(IN FEET)1" = 30 ft.#324 GARDEN STREETDOVER PLACE#310 MARKET STREETGARDEN APARTMENTS#180 GARDEN STREETCITY HALL & LIBRARYFUTURE MIXED-USEBUILDINGFUTURE MIXED-USEBUILDING#200 GARDEN STREETCENTRAL SCHOOLBIO-RETENTION AREAOVERFLOWS TO GW#2LOT B DRAINAGEAREA TO GW#2LOT B DRAINAGE AREATO STORM PONDTO STORM PONDTO GW#2