|
MWRA's Metropolitan Water Tunnel ProgramMassachusetts Water Resources Authority Home | About the Program | Program Updates The History of Redundancy Planning for the Metropolitan Boston Area1937 Plan
1937 Northern Tunnel Loop Plan While much of the 1937 plan for pressure aqueducts and tunnels was implemented from 1937 to present day, the proposed tunnel loop was never completed. Redundancy Planning 1990 through 2016 1990 Northern Loop Tunnel Plan In 2011, the MWRA completed a new evaluation of alternatives for redundancy within the Metropolitan Boston area. This evaluation included surface pipe alternatives in addition to tunnel alternatives with an objective of incorporating redundancy planning into the existing pipeline asset management program (ie. allocating funds already budgeted for rehabilitation of existing pipelines toward replacing the existing pipelines with larger pipelines). The result of that evaluation was a plan of constructing primarily large diameter surface pipes to provide redundancy. However, as the planning for this program progressed, it became apparent that the construction of large diameter pipelines through dense urban areas would cause unacceptable community disruption and had serious implementation challenges. 2011 Surface Pipe Plan Finally, in 2016 MWRA revisited the all-tunnel approach (PDF) to providing redundancy to the Metropolitan area. Over 30 alternatives were screened based on level of redundancy, constructibility, cost and operation and maintenance. Based on this evaluation, an all-tunnel alternative was recommended for redundancy. |