25A-139 Bates Street no wetland impacts-2010
June 21, 2010
Northampton Conservation Commission
c/o
Gloria McPhearson
Kohl Construction
31 Campus Plaza Road, Suite 3,
Hadley, MA 01035
Re: Munska property
Bates Street, Northampton
Dear Conservation Commission Members:
The Berkshire Design Group, Inc. prepared the plans for the “Trailside
Condominiums at Munska Park” in 2006, consisting of an access drive, retaining
walls, parking lot, stormwater management system and an eight unit condominium
building. The project received an Order of Conditions from the Commission.
Essentially the only portion of the project that was actually constructed were the
retaining walls for the drive access and a cross culvert. Kohl Construction has
submitted a plan titled “Request for Determination of Applicability, Bates Street,
Northampton”, dated May 11, 2010.
On June 19, 2010, the undersigned conducted a field observation in order to
determine if the project as constructed will have a negative impact on nearby
bordering vegetated wetlands and also to evaluate if the proposed addition of fill as
designated on the May 11, 2010 plan would have a negative impact on the BVW.
The limit of my observations and comments within the context of this letter are only
for areas within the limits of work within the 100 foot buffer zone, and do NOT
include any observations/comments or certifications regarding the completeness or
adequacy of the remainder of the parcel.
This office did NOT prepare final As-Built plans or measure the exact
elevations/inverts or the horizontal/vertical location of all work as depicted on the
approved plans, and my observations did not include any detailed horizontal or
vertical measurements.
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June 21, 2010
Munska Property, Bates Street Page 2 of 2
The northerly retaining wall as constructed is not in the approved location or
configuration. The topography of the site and the walls as constructed are directing
some surface runoff from both the easterly and westerly portion of the parcel towards
the northerly retaining wall and the joints in the wall allows the water to pass through
the retaining walls. The size of the retaining wall blocks and location and nature of
the joints allow the water to pass through without compromising the integrity or
stability of the blocks. In my opinion, the walls as constructed appear to be stable
and are not creating any detrimental impacts to the wetlands located on the northerly
side of the Manhan Rail Trail.
The “Request for Determination of Applicability, Bates Street, Northampton” plan
dated May 11, 2010 shows proposed fill between a portion of the southerly and
northerly retaining walls. If this fill consist of clean fill material and is properly
installed and stabilized with loam and seed, it should not generate any detrimental
change in the stormwater volume, quality or rate of runoff generated on the site. In
order to retain the current drainage characteristics of the site and wall, as well as
conformance to standard retaining wall construction methodology, it would be
prudent to install a band of crushed stone approximately 12 inches wide adjacent to
the retaining walls prior to installation of the fill.
In summary, based upon my visual observation conducted on June 19, 2010, and a
review of the plans dated May 11, 2010, it is my professional opinion that the project
as currently constructed, and if the area to be filled is installed with the
aforementioned crushed stone and then stabilized, then this project will NOT have
any detrimental effects on the wetland located on the north side of the bike trail.
Sincerely,
The Berkshire Design Group, Inc.
Mark B. Darnold, P.E.
Principal