Agenda Text
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DPW Commissioner responding to #197238 re: Shore Drive drainage.
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Official Text
TO: The Honorable Board
FROM: Melissa A. Miguel, P.E.
Acting Director of Engineering
Re: Agenda Item 197238
Shore Drive Drainage
During the fall of 2012 and spring of 2013, as part of the I/I (Inflow/Infiltration) removal requirement under the City of Somerville Stormwater Management Policy (February 3, 2011), Federal Reality and Trust (developer for Assembly Row) performed sewer and drain improvements in the Tens Hills section of Somerville. Those improvements included:
• Sewer and drain separation in Shore Drive; and
• Drain pipes in Shore Drive were increased from 15” VC to 18” PVC, increasing capacity, along with an increase in pipe slope increasing flow rate.
As a result, the stormwater system in Ten Hills discharges directly to the Mystic River above the Amelia Earhart Dam and the stormwater system for the Assembly Row development discharges to the Mystic River below the Amelia Earhart Dam through a new 72” outfall pipe. The two systems are separate; therefore, the development at Assembly Row should have no impact on the stormwater outfall along Shore Drive in Ten Hills.
On Wednesday June 18, 2014, this office conducted a site visit along with Richard Mathews, VHB. No evidence of buckling in the roadway was observed along Shore Drive between Puritan Road and Ten Hills Road. The observation of water coming up through the manhole cover at the corner of Shore Drive and Putnam Road could have been the result of a blockage in the stormwater outlet pipe to the Mystic River. The sewer department cleaned the line on June 19, 2014 in an effort to mitigate future backups.