HomeMy WebLinkAboutDPW Review Memo - 04-2026 - Correspondence - 0 Prescott Street 4/1/2026
MEMOMRANDUM
To: M. Lis, Zoning Board of Appeals Chairperson
From: J. Borgesi, P.E., Asst. DPW Director/Town Engineer
Date: April 1, 2026
Re: 0 Prescott Street (Comprehensive Permit - 40B) – Proposed Drainage
Per your email request on March 7, 2026, I have reviewed the proposed 0 Prescott Street Chapter 40B
Residential Development specifically as it relates to the proposed drainage and connection into the Town
closed drainage system within High Street. I reviewed the following documents as they relate to the
proposed drainage system:
Initial Technical Peer Review Letter prepared by Horsley Witten Group, dated December 16, 2025;
0 Prescott Street – Peer Review – Response to Comments prepared by Civil Design Group, LLC
dated February 11, 2026; and
Second Technical Peer Review Letter prepared by Horsley Witten Group dated March 3, 2026.
Based on our review of the information provided and the impacts to this area of Town during the floods
in August 2023, the DPW has serious concerns about any additional flow being directed towards High
Street and the existing culvert.
Knowing these concerns, a virtual meeting was scheduled on March 25, 2026 with the applicant RCG East
Mill Housing, LLC, their design consultant Civil Design Group, LLC, and the DPW to review their proposed
drainage and connection to the Town’s closed drainage system. Earlier in the day on March 25, 2026, the
DPW received an email from Civil Design Group, LLC that included a narrative description of proposed
changes to the connection to the Town’s closed drainage system along with a preliminary revised grading
plan entitled “RCG East Mill Residential Development Grading Plan Set 3-24-2026”.
The Applicant and Civil Design Group, LLC proposed the following changes to the connection of the new
drainage system to the Town’s closed drainage system:
The project proposes an alternative drainage plan that includes a drainage connection
from the project to the existing 36” drain line traversing through the Avalon Bay West
Mill property. The connection is made via a proposed 18” drain line across the
Prescott/High Street intersection and would collect the new building rooftop and
internal courtyards. The Applicant/Design Engineer made note of the following:
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The 36” pipe was originally installed to convey offsite upstream runoff from the
Prescott Street neighborhood through the Avalon Bay West Mill property.
Based on discussions with DPW, portions of the Prescott neighborhood drainage
system have been routed over the years to discharge onto the RCG East Mill
property, therefore, it is difficult to delineate an accurate watershed.
The proposed DMH-6 will act like a diversion manhole whereby the proposed 18”
pipe connecting to the Avalon Bay West Mill property 36” pipe, would need to
reach maximum capacity before flow would be diverted to the proposed 12” pipe
that heads southwesterly towards High Street.
The project proposes a new catch basin at the Prescott/ High Street intersection
to capture surface runoff along the gutter line to redirect runoff away from High
Street and into the Avalon Bay West Mill 36” pipe.
The 36” pipe also has a 12” bypass on the Avalon Bay West Mill property
whereby the larger pipe would need to reach maximum capacity before the 12”
bypass is activated. (see DMH-3D on Avalon Bay West Mill development).
By proposing these changes to the connection to the Town’s closed drainage system,
these would provide multiple conveyance options for surface runoff to reach its
destination points west of the Mill campus, reducing the likelihood of a bottleneck at
the culvert at the High Street low point.
Upon review of the proposed changes, the flows from the new development will be redirected through
the closed drainage system that traverses through the Avalon Bay West Mill property, thereby limiting
any future impacts to the existing closed drainage system located on High Street. Given the Towns
experiences with the recent floods and impacts to this area, the DPW supports this proposed redirection
of flow through the West Mill campus and ultimate discharge to the same watershed endpoint.
If you have any further questions please do not hesitate to reach out.
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