Brookline is one of seven communities in the path of a 15-mile water tunnel project the MWRA plans to have running by 2040.
The Metropolitan Water Tunnel Program will bore two deep-rock tunnels to create a backup for the region's aging water supply system, according to an MWRA board staff summary from April 15. The system currently has no redundancy. It has operated without a backup since the Quabbin Reservoir was completed in 1939.
The South Tunnel will run about 10 miles from Weston to the Mattapan neighborhood of Boston. The North Tunnel will stretch about five miles from Weston to Waltham. Together, they will allow the MWRA to take the existing Metropolitan Tunnel System offline for repairs for the first time.
That existing system consists of the City Tunnel, the City Tunnel Extension and the Dorchester Tunnel. All three are decades old and have never been shut down for major maintenance because there was no alternative route for the water.
Why now
Two incidents forced the issue. Paul Savard, MWRA's acting director of the Tunnel Redundancy Program, pointed to a water main break in May 2010 that triggered a boil-water order and a more recent disruption in 2024. Savard spoke at an Aug. 11 presentation to Needham's Select Board, as reported by the Needham Observer.
"The main point here is that we want to make sure we provide uninterrupted delivery of our high-quality water to the communities that we serve, at any time of the year, without any service interruptions," Savard said at that meeting.
The MWRA board first approved the two-tunnel approach in February 2017. The project cleared its final environmental review in April 2024.
Timeline and cost
Design work is already underway. The 60% design for the South Tunnel was completed in March 2026, with 90% design planned for March 2027. Bid-ready documents are targeted for late 2027, and South Tunnel construction is set to begin in 2028. North Tunnel construction is targeted for 2029.
In April 2026, the MWRA board awarded a $153.8 million construction management contract to Hatch Associates Consultants for an 11-year term. The MWRA also holds a separate design engineering contract with WSP USA worth $93.6 million, running through November 2039.
What Brookline residents should know
Brookline receives all of its drinking water from the MWRA, which draws from the Quabbin and Wachusett Reservoirs, according to a town newsletter published in August 2026. The tunnel program serves more than 3 million people across eastern Massachusetts.
John VanScoyoc, who served on Brookline's Select Board from 2020 to 2026, flagged the project on X on Tuesday, Sept. 1, writing that the new tunnels would let the aged existing system be taken out of service for repairs.
As of early September, no MWRA presentation to Brookline's Select Board appears in public records. The authority has already met with Needham's board and expects to begin early enabling work there in spring 2027. Which of the two tunnels passes through Brookline, and what the local construction timeline looks like, has not been publicly detailed. Residents can contact Brookline's Department of Public Works at [email protected] or 617-730-2170 for updates.
