MassDOT project seeks local wetlands sign-off for Pleasant Street bridge in Dighton

MassDOT’s planned replacement of the century‑old Pleasant Street bridge in Dighton, presented Feb. 19 to the Dayton Conservation Commission, will proceed under a local Notice of Intent while the project also seeks federal and state permits, the consultant said.

“My name is Tyler Drew with Beta Group. I’m here to present the Pleasant Street bridge replacement project,” said Tyler Drew, who described the crossing as showing “clear signs of deterioration.” Drew said the project “qualifies under the bridge exemption, from the Wetlands Protection Act,” but added the design proposes work in jurisdictional resource areas under the Dighton Wetlands Protection Bylaw and therefore will be submitted locally for authorization.

Drew described the design as a full replacement of the deck, abutments and wing walls, relocation of water and gas utilities that currently run through the bridge, installation of scour protection and a widened deck to accommodate a sidewalk and ADA ramping. The consultant said all staging will occur from the surface of Pleasant Street and the road will be closed during construction.

Commissioners and attendees pressed the team on construction sequencing and environmental constraints. A contractor on the call estimated the overall replacement could require “roughly around 5 to 8 years” of phased work given Division of Marine Fisheries (DMF) time‑of‑year restrictions and other agency windows; the consultant called that a general, conservative planning estimate. Beta Group also described a cofferdam approach to allow dewatering and dry work in the channel and said the contractor will submit a dewatering plan to MassDOT for review and a MassDEP dewatering location is expected to be reviewed as part of that submittal.

Laura Krauss of Beta Group reviewed the DMF guidance: a fall restriction (about Sept. 1–Nov. 15) that would permit work behind a cofferdam if the cofferdam is installed in advance, and a spring restriction (about Mar. 15–Jun. 30) during which DMF is currently discouraging in‑water work even behind cofferdams. Drew said the team is discussing mitigation measures with DMF and the Army Corps of Engineers and will adapt the schedule if mitigation or leniency is granted.

Drew also noted mapped coastal resources in the immediate area — including coastal bank, land under ocean and a mapped diadromous fish run and shellfish habitat — and said the plans include measures to avoid impacts to adjacent salt marsh and the downstream Totten River. As part of those protections, the consultant described a temporary chain‑link barrier between rock fill and salt marsh to reduce secondary impacts.

The town administrator told the commission MassDOT has not yet produced an official rating of the structure and the town will await that assessment and a detour plan. The commission continued the matter to its March 19 meeting to allow additional agency consultations and to review updated material.

What’s next: Beta Group will continue consultations with the Army Corps, DMF and MassDEP, submit the local Notice of Intent, and provide any requested firming of the construction schedule and dewatering details before the commission’s March 19 meeting.