Look Ahead
The Metropolitan Water Tunnel Program consists of two new water supply tunnels that will provide redundancy for MWRA's existing Metropolitan Tunnel System. The Tunnel Program is currently in the design phase. The next few years will include Program wide activities including detailed design, continued field investigations, construction management, and preparation of construction contract document, land acquisition, TBM power supply, and stakeholder outreach.
City of Newton City Engineer and MWRA Board of Directors
Member Louis M. Taverna visits MWTP test boring/rock
coring site in Newton, Massachusetts, July, 2021
A snap shot of upcoming Tunnel Program activities includes:
- A Final Design Engineering consultant will be contracted in late 2024 to begin detailed design of both the North and South Tunnel systems. Field investigations at future shaft sites and along the tunnel alignment will continue during final design. The Final Designer will serve as the engineer-of-record for the Tunnel Program and will be involved throughout construction. The Final Designer will work closely with MWRA’s Tunnel Redundancy Department through all phases of final design which is expected to take about 3.5 to 4.5 years.
- Procurement for a Construction Management consultant will begin in 2025 with selection occurring in 2026. The Construction Manager will be responsible for construction management and resident inspection services for all construction and construction support activities during the pre-construction, construction and start-up phases of all Construction Contracts for the Tunnel Program. The Construction Manager will work closely with MWRA’s Tunnel Redundancy Department, have expertise in deep hard rock tunnel construction, and managing complex megaprojects (i.e., projects over $1B).
- Procurement for construction of the South Tunnel is targeted to begin in 2027 with actual construction starting in 2028. Procurement for construction of the North Tunnel is targeted to begin in 2028 with actual construction starting in 2029. Tunnel construction, including surface work and commissioning, is estimated to take 8 to 12 years to complete. Construction of the new tunnels is planned to be completed and the tunnels in operation by 2040.
- It is expected that two or three smaller construction contracts will be procured and completed prior to the start of tunnel construction to remove early enabling works from the tunnel contracts’ critical paths. These enabling contracts are related to demolition of existing buildings, site reconfiguration to allow continuity of current use, and dewatering drain line work at or near future launching shaft sites.
- Prior to construction the MWRA will acquire land at shaft sites and easements along the tunnel and in roadways or on public land for new water and drain pipelines.
- Subterranean easements will be acquired for each property below which the new tunnels will be constructed. The subterranean easements will be 200 to 450 feet below ground and will not allow for surface access, and thus will not affect property usage above the tunnel. Currently, it is estimated that approximately 600 subterranean easements will be required.
- The MWRA is working with Eversource to ensure that sufficient power supply is available at the launching shaft sites prior to the start of tunnel construction. When the Tunnel Program is complete, the added power supply will remain and provide further resilience to the power grid.
- Community and stakeholder outreach has been ongoing since the early stages of the Tunnel Program. Over 140 meetings with various community representatives, state agencies, stakeholders, and property owners have occurred. Starting in late 2024, broader public information sessions will be held with a variety of topics including a Tunnel Program overview, an overview of tunneling methods (i.e. “Tunneling 101”) and associated construction period impacts such as traffic, noise and vibration, and other topics of interest to stakeholders. Outreach to stakeholders will be in alignment with MWRA’s overall environmental justice strategy and will continue through final design and construction.
For more information on ongoing and future activities for the Metropolitan Water Tunnel Program, see the MWRA Board of Directors March 13, 2024 meeting materials.
For more information, or if you have any questions or concerns about the Metropolitan Water Tunnel Program, contact Us at tunnels.info@mwra.com
