When a broken bypass valve on the 60-inch Weston Aqueduct Supply Main (WASM3) pipeline was discovered in August, it quickly became evident that the repair would require extraordinary coordination. The pipeline, running through Waltham, is a vital water supply line, and isolating it for repairs posed significant challenges, particularly for maintaining uninterrupted water supply to Waltham residents.
To tackle this complex issue, the Massachusetts Water Resources Authority (MWRA) and the communities of Waltham, Watertown, Newton, Lexington, and Weston came together to develop and execute a water supply plan that ensured stability during the repair process. This extraordinary collaboration not only highlights the strength of regional partnerships but also underscores the importance of emergency interconnections between neighboring communities—connections that can be critical for maintaining reliable water service during planned or unexpected events.
The Plan: Creative Solutions for Complex Challenges
The repair required isolating and dewatering a long section of the pipeline, a process that could significantly impact Waltham’s water supply. To mitigate these risks, MWRA engineers designed a plan to supplement Waltham’s supply through emergency interconnections with neighboring communities.
In preparation, MWRA hosted several meetings with the affected communities to review water supply and contingency plans. Interconnections with Watertown and Newton were tested and prepared to provide supplemental water. Additional interconnections with Lexington and Weston were identified as contingency options. Notably, the Weston interconnection required the use of a mobile pumping unit, which MWRA, Weston, and Waltham teams successfully set up and tested prior to the repair.
Execution: Precision and Coordination at Its Best
The repair began on Tuesday, December 10, with the careful isolation and dewatering of the pipeline. MWRA staff continuously monitored system pressures and flows, ensuring that all communities maintained stable water supplies. By Tuesday evening, the valve replacement was completed—well ahead of schedule—and the pipeline began refilling overnight. By midnight on Wednesday, December 11, the WASM3 pipeline was fully reactivated, and all emergency interconnections were closed.
This effort exemplifies how meticulous planning, technical expertise, and strong partnerships can achieve remarkable results. The repair was completed quicker than expected, with minimal disruption, and showcased the benefits of teamwork across municipal and agency boundaries.
The Critical Role of Emergency Interconnections
The success of this repair also highlights the critical role of emergency interconnections between communities. These interconnections, which allow neighboring systems to supplement one another during emergencies or planned work, are invaluable tools for maintaining water reliability. They provide a safety net during unexpected disruptions and reinforce the resilience of regional water systems.
A Model for Regional Collaboration
The successful repair of the WASM3 valve underscores the camaraderie and cooperation between MWRA and its member communities. This project stands as a testament to the value of partnerships and emergency preparedness in overcoming challenges and ensuring reliable water service for all residents.
We extend our deepest gratitude to the teams from Waltham, Watertown, Newton, Lexington, and Weston for their collaboration and dedication. By working together, we demonstrated what’s possible when communities unite for the common good.
