Dam Break Modeling and Inundation Mapping for Sudbury Reservoir and the Framingham Reservoir System

The Commonwealth of Massachusetts, Metropolitan District Commission (MDC) operates and maintains six reservoirs associated with the water supply system which services over 2.5 million people in 46 towns and cities within the metro-Boston area. The MDC has demonstrated its commitment to dam safety by commissioning the preparation of FERC-style Emergency Action Plans for each of these high hazard dams. Their proactive posture toward dam safety has produced a comprehensive, integrated, and uniform approach to the development and implementation of EAPs for some of the largest dams in the northeast. This paper is presented as a case study highlighting some of the key components of the plan for Sudbury Reservoir and the three Framingham Reservoirs, which is the latest in a series of EAPs that have been developed. EAPs for the MDC'S Quabbin and Wachusett Reservoir Dams have already been implemented within the last two years. The physical layout of the reservoirs, topography of the downstream river valley, design history of the structures, and their location within densely developed urban areas in eastern Massachusetts, created interesting considerations and issues while developing the EAP. What follows are highlights of various components of the dam break input methodology and results. GIS applications in developing the Inundation Maps are also discussed.