Mystic & Charles River Regional Coastal Interventions Analysis

The Greater Boston area faces a growing threat of coastal flooding due to the combined effects of sea level rise and intensified storm surges.

While the Amelia Earhart Dam (AED) and Charles River Dam (CRD) currently provide significant protection against coastal flooding for upstream communities, the Massachusetts Coast Flood Risk Model (MC-FRM) shows that AED is at risk of being flanked or overtopped by 2030, and the CRD by 2050. Additionally, the MC-FRM identified eight other coastal flood pathways that threaten nine Greater Boston communities: Arlington, Belmont, Boston, Cambridge, Chelsea, Everett, Malden, Medford, and Watertown.

In response, the City of Cambridge, in collaboration with the Resilient Mystic Collaborative and with technical support from Weston & Sampson, Abt Associates, Woods Hole Group, and Dewberry is conducting the Mystic Charles Regional Coastal Flood Interventions project. The project scope involves a comprehensive approach to addressing regional coastal flooding and climate resilience. It includes analyzing regional economic impacts by estimating flood damage to building structures and contents under a no-action scenario, as well as implications of interrupted economic activity in the region that factors business income losses (capital losses), wage losses, and economic output.

The project evaluates existing conditions, including completed coastal resiliency projects within the project area, proposed interventions currently in design or construction, and assesses their efficacy and any potential residual flood risk gaps contributing to regional flood risks. Extensive data collection has documented existing resiliency measures, and detailed site investigations have been conducted as part of the gap analysis. Based on the identified gaps and the need for regional flood resiliency interventions, the project involves developing high-level concepts to address these gaps and advancing schematic designs for selected sites, informed by stakeholder input and permitting feasibility.