Coastal Resilience Planning

Coastal flooding impacts depend on the size and severity of the storm that causes the flooding, as well as the timing of when that storm arrives along the coast. 

• A storm with a higher probability of occurring is likely to happen more frequently but result in less flooding. For example, a winter nor'easter may have a 5-10% chance of occurring in a given year.
• A storm with a lower probability is likely to happen less frequently but result in more severe flooding. For example, a severe winter nor'easter or a hurricane may have a 0.1-1% chance of occurring in a given year.

Coastal flooding from storms and high tides will increase over time due to sea level rise. All of Boston's coastal resilience plans developed strategies that are designed for a 1% annual chance storm with sea level rise projections for 2070. 

The City of Boston refers to the Massachusetts Coast Flood Risk Model (MC-RFM) for the best available data for sea level rise projections over time, flood extents, and depths of flooding. For additional information about this model, please see the MC-FRM Modeling Overview and Frequently Asked Questions document.

Resilience is generally defined as the ability of a system (such as a city) to prepare for, withstand, and recover quickly from a disaster. Coastal Resilience is the ability of a community to adapt and respond to the chronic stresses and acute shocks resulting from climate change, specifically sea level rise and coastal storms.

Before we can take action to address coastal flooding, we need to understand where we are vulnerable, who and what is at risk, and what our adaptation options could be. Coastal resilience planning is important because it lays the groundwork for the actions Boston must take to protect its communities from current and future flood risk.

To protect Boston from coastal flooding and build a resilient coastline, we need to raise the elevation of waterfront land to prevent floodwaters from overtopping the land and impacting communities, infrastructure, open spaces, and more. The type of coastal resilience strategy that could be built depends on the existing conditions of the waterfront in a given location. Some examples of strategies included in Boston's coastal resilience plans are:

Each coastal resilience plan involved multiple steps to assess a neighborhood's coastal flood risk and determine how to adapt the waterfront to protect the community from current and future flooding. 

1. Identify the location and timing of coastal flood risk: The plans studied where flooding is likely to take place in a given area, how flood risk may evolve over time between present-day through 2070, and what is at risk, such as residences, businesses, critical infrastructure (i.e. trains, rail yards, roads, tunnels, etc.), critical facilities (i.e. hospitals, fire stations, police stations, etc.), community assets (i.e. schools, community centers, libraries, etc.), parks and open spaces, natural areas, and more.
2. Engage community members and stakeholders: Each plan involved engaging with community members, non-profits/community-based organizations, business owners, private landowners, and City, State, and Federal agencies to learn about their priorities and concerns and to identify opportunities and constraints to inform coastal resilience strategies.
3. Develop coastal resilience strategies for vulnerable areas of the waterfront: For each vulnerable area, the City worked with technical experts to evaluate and determine the preferred coastal resilience strategies that could effectively prevent or reduce coastal flooding while also providing multiple benefits for the community. Co-benefits could include tree canopy, green infrastructure, multi-modal transportation improvements, ecological restoration opportunities, new waterfront access, and more. 
4. Create an implementation roadmap: Each plan included an implementation roadmap that outlines when each coastal resilience strategy needed to be constructed to reduce coastal flooding and next steps for advancing each project, such as presenting cost estimates, funding opportunities, design/engineering considerations, permitting pathways. Together, the implementation roadmaps enable the City to prioritize the implementation of projects over time.