Climate Ready Charlestown - Phase II
The 2022 "Coastal Resilience Solutions for East Boston and Charlestown (Phase II)" plan provides neighborhood strategies to address the impacts of coastal flooding and sea-level rise.
The plan seeks to preserve the essential functions and historic character of our waterfronts. It also works to undo the harm of historical planning that unjustly placed certain communities at risk of environmental hazards.
Phase II of the plan includes near- and long-term solutions for the Navy Yard, Little Mystic Channel, and the Boston Autoport.
This Climate Ready plan builds on the first phase of the study in 2017. It is part of a larger citywide effort to address climate change in Boston. With this report, the City has completed coastal resilience plans for Boston’s 47-mile coastline.
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Coastal Resilience Solutions
This report presents coastal resilience solutions in the Phase II of Charlestown’s coastline.
Stakeholder EngagementStakeholder Engagement
Community engagement was critical to the creation of this plan. The project team engaged with more than 550 community members through open houses, neighborhood presentations, and surveys. Climate Ready Boston incorporated community feedback into the design and implementation process.
Community Advisory Boards
Climate Ready Boston opened applications for Community Advisory Boards (CAB) for each neighborhood. The 10 members in the Charlestown CAB helped lead engagement and shared feedback. They participated in community events, shared information, flyers, and surveys to community members.
The Steering Committee consisted of representatives from City and State agencies. They defined goals and outcomes, discussed feedback, and guided the proposals and next steps. Through this partnership, they ensured practical solutions that align with City and State policy, planning, and investment.
COMMUNITY-SUPPORTED PRIORITIES THAT INFORMED THIS PLAN:
- Share a sense of urgency around the impacts of climate change and how it affects people, places, and services residents’ rely on
- Put in place effective solutions that provide more than one benefit
- Concern about new development and its impact on housing affordability and neighborhood character
- Improve access to the waterfront as a community resource
- Protect homes and essential infrastructure, such as public transportation and evacuation routes
- Restore natural habitats for plants and animals
- Address environmental and climate injustices, burdens, and hazards
Coastline Existing Conditions
Much of Charlestown’s coastline has been developed or hardened with infrastructure such as bulkheads, seawalls, and piers. These structures were created to support the growth of waterfront industries. They also stabilized the shoreline so that buildings could be built close to the water’s edge. Since the distance between properties and the water is narrow, coastal protection strategies are limited by available space.
Coastal Flood RiskCoastal Flood Risk
As the average tide rises, low areas along the shoreline that ere once dry will be flooded more often.
Storm surge is an increase in the water elevation above the normal everyday tide.
Coastal erosion is the process by which sea-level rise, wave action, and coastal flooding wear down or carry away rocks, soils, and sand along the coast.
Charlestown's different elevations impact how and how much the area floods. High tides and storm surge can lead to fringe flooding or flooding through flood pathways.
Impacts low-lying areas along the waterfront, including parks, industrial uses, homes, and businesses. Coastal flooding occurs as water levels rise above the ground elevation.
Impacts low-lying waterfront areas and inland areas. Water enters over a discrete low-lying location on the waterfront, like a bulkhead or roadway. Water then flows inland and creates widespread impacts to homes, businesses, and infrastructure.
Coastal flooding impacts depend on the size and severity of the storm that causes the flooding. The timing of when that storm arrives along the coast affects flooding impacts. Extreme storms will happen more often in the future. Without actions to reduce risks, the likelihood of coastal flooding from storms and high tides will increase over time due to sea-level rise.
The design flood elevation (DFE) is defined as the minimum elevation required to protect an area from a set level of coastal flooding. Areas that experience greater coastal flood risk require solutions that are designed to a higher DFE. The DFEs are measured relative to a fixed datum called North American Vertical Datum of 1988 (NAVD88).
The DFE is 15.5 feet NAVD88 for Charlestown. It is important to understand that the elevation of the DFE is not above the ground surface. In most areas along the Charlestown’s waterfront, the lowest-lying locations are currently at approximately 8 to 12 feet (NAVD88). Therefore, coastal resilience solutions need to be designed at 4 to 8 feet above the current ground elevation to reach the DFE of 16 feet (NAVD88) in Charlestown.
The coastal resilience approaches used in Charlestown draw on an existing toolkit of options developed for other areas of Boston that have been studied through past planning efforts. Design for Equity, Adaptability, and Ecological Restoration are core criteria used in this study to help guide the conceptual design process.
Neighborhood Resilience Strategies
The Charlestown study has 4 focus areas. Focus areas are key locations where flood pathways connect and lead to widespread flooding. Resilience solutions in the focus areas depend on each other to successfully reduce long-term coastal flood risk across Charlestown.
Focus Area 1: Constitution Wharf and Boston National Historic Park
This focus area is along the southwestern part of the Navy Yard waterfront. It extends from the Boston National Historical Park to Paul Revere Park and the new Charles River Dam.
The Boston National Historical Park property is particularly low-lying. Several flood pathways enter Charlestown at this location today and contribute to flooding elsewhere in the neighborhood.
Solutions include options for floodwalls combined with walkways and a raised Harborwalk. In collaboration with the National Parks Service, the City will further develop these solutions and implement them at the National Historical Park.
The long-term strategy will increase the Harborwalk's height by approximately 4 to 7.5 feet above the existing grade. This strategy includes the connection of the dam to Paul Revere Park and the elevated Harborwalk.
The Harborwalk's design will incorporate accessible sloped ramps, terraced seating, new park space, gates for waterside access, and other amenities. These will integrate the raised edge with the surrounding landscape.
Focus Area 2: Charlestown Navy Yard
This focus area extends along the waterfront from the Chelsea Street bridge at the northeastern edge of the Navy Yard to 5th Street at the southwestern edge of the Navy Yard.
Solutions include options for elevating the Harborwalk or raising 1st Avenue along with building-level adaptation. The strategy's goals are to reduce risk, address flood pathways from Boston Harbor, and enhance public access along the waterfront.
The preferred long-term strategy for the Navy Yard is to raise the Harborwalk by approximately 5 to 7 feet above the existing grade. To close near-term flood pathways, some sections of the Harborwalk would need to be raised by 2030. These sections include the Harborwalk fronting Charlestown Naval Shipyard Park, at the ends of 13th and 16th Streets, and next to the property at 114 16th Street. This will form a continuous line of coastal flood protection along the waterfront from the Chelsea Street Bridge to the Boston National Historical Park.
Focus Area 3: Little Mystic Channel
This focus area is along the Little Mystic Channel waterfront from Barry Field and the Chelsea Street bridge. It extends past the Charlestown Community Center and Little Mystic Boat Ramp, to high ground on the Lower Mystic Greenway.
The strategy includes options for a redesigned coastline and raised Harborwalk. It will improve public spaces to protect affordable housing developments and local amenities. It also plans for long-term ecological restoration. Over time, the strategy will integrate with solutions for the Navy Yard, preventing connected flooding from Little Mystic Channel and the Boston Harbor.
Through the 2030s, the Cooperatives of CharlesNewtown next to the south side of Little Mystic Channel may experience fringe flooding during severe storms. To reduce impacts to residents, a 2.5 to 4 feet floodwall can be constructed along the inner edge of the Harborwalk. This floodwall can include new seating, amenities, and general improvements to the Harborwalk and nearby public spaces.
The preferred long-term strategy re-envisions the appearance, function, and use of the Little Mystic Channel. This includes extending the southern and eastern edges of the Channel outward into the water as part of a new elevated park with integrated coastal flood protection. Flood protection should reach approximately 4.5 to 7.5 feet above existing grade.
This coastline extension would provide opportunities to introduce ecological restoration projects. Projects could include constructed wetlands that improve habitat, coastal resilience, and water quality. It also presents opportunities for new community amenities along the Little Mystic.
Focus Area 4: Terminal Street and the Boston Autoport
This focus area includes the waterfront along Terminal Street and the Autoport. Solutions here focus on building- and site-level adaptations for water-dependent industrial uses. Options for perimeter protection at the Autoport are also suggested but will need further coordination between the City, Massport, and Autoport businesses.
To minimize the disruption of industries in this study area, site- and building-scale adaptation measures are appropriate in the near-term. These solutions give business owners flexibility as they integrate resilience into their sites and preserve business continuity.
In the long-term, some water-dependent uses at the Autoport may need to move elsewhere as sea-level rises. The City recommends Massport to evaluate options that provide perimeter protection of the Autoport.
Implementation of Climate Ready Charlestown
The City of Boston will continue to collaborate with all stakeholders on project progress and design. The City will ensure that outcomes are consistent with community goals and values. Strategic partnerships between public, private, and non-profit stakeholders will play a key role in the implementation of the solutions in Charlestown so that we can move Boston one step closer toward creating a resilient, equitable, and accessible waterfront for all.