Weston Select Board Receives MWRA Briefing on $1.6 Billion Water Tunnel Plan

WESTON — January 10, 2023 — The MWRA presented a $1.5 to $1.6 billion water tunnel replacement program to the Weston Select Board at its January 10 meeting. Kathy Murtaugh, the authority's director of the Metropolitan Water Tunnel Program, described two new deep-rock pressure tunnels — one running north from Weston toward Waltham-Belmont and one running south to Mattapan — that would run 250 to 450 feet underground and create the redundancy needed to take the aging 1950s-through-1970s metropolitan tunnel system offline for repairs for the first time. Approximately 8,200 linear feet of tunnel would pass beneath Weston at roughly 350 feet deep, with construction concentrated near the I-90 and I-95 interchange on MassDOT and MWRA-controlled land; the authority expects to bid the first tunnel contract in 2027 and complete the program by 2040. Director of design and construction Paul Savard said the tunnel boring machine would be launched from the existing MassDOT tandem trailer lot, which would be temporarily reconfigured and then restored. The program is carried in the MWRA's capital improvement plan and was described by Murtaugh as a "mega project" timed to replace debt rolling off from earlier major projects including the Boston Harbor cleanup and the Carroll Water Treatment Plant, with the goal of avoiding rate shock to ratepayers.