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Writer's pictureEmerson Goodrich

Planning for Coastal Adaptation and Resilience at the Neighborhood-Scale

Emerson Goodrich, Data and Planning Fellow for GPCOG and the Town of Scarborough, discusses the challenges vulnerable coastal communities are presented with when planning for coastal adaption and resilience at the neighborhood-scale. Scarborough’s Higgins Beach neighborhood recently grappled with the realities of flooding and sea level rise and what implications these impacts have on the future of their community at a neighborhood-specific meeting for the Town’s Vulnerability Assessment.


As a part of their ongoing Vulnerability Assessment project, the Town of Scarborough is hosting neighborhood-specific meetings to outline project processes and goals, as well as to collect community feedback on vulnerabilities and adaptation strategies. On September 5th, Town staff, consultants, and 60 residents gathered to discuss the Higgins Beach neighborhood’s specific constraints and considerations when planning for resilience in the face of flood hazards and sea level rise.

 

Maine as a state already necessitates specific adaption strategies, due to a tidal range that in some areas is over twice as large as the tidal ranges along the Eastern Seaboard.[1] This means successful examples of adaption and resilience building across the country cannot simply be recreated on Maine’s coast. Furthermore, the Town of Scarborough must also consider the Scarborough Marsh, the largest contiguous salt marsh in the state, during the adaptation process, including planning for increased tidal flow into the marsh and subsequent marsh migration. If there weren’t enough layers already, the Higgins Beach neighborhood is acutely vulnerable to flood hazards and sea level rise both oceanside and riverside, as seen during the January storms and expanded upon in my previous blog post. Simply put, this means that even without wave action caused by a storm event, the neighborhood will nonetheless be inundated by ponded water from the river during high tides as sea-level rise accelerates.

 



January 13th flooding on Bayview Ave. (Google Maps and the Maine Monitor)

 

The Higgins Beach neighborhood is situated almost entirely on an existing dune system which presents challenges in the present and looking into the future. Development directly abutting the beach, as well as other infrastructure and fortifications like the revetment on Bayview Avenue, has replaced dunes and dune vegetation that was previously present. When a dune system is no longer dynamic due to such constraints, its protective ability is severely diminished. Higgins is also largely mapped as being situated on a frontal dune which triggers stricter regulations, which massively impacts the viability of many common adaptation strategies.

 


Map showing frontal sand dune (D1), back sand dune (D2), and the erosion hazard area (Red Hash). (Maine Geological Survey)

 

According to frontal dune regulations, most of the Higgins neighborhood cannot construct new seawalls or expand current seawalls, expand current road footprints, or build new structures or additions to existing structures. The adaptation strategies that remain viable for the neighborhood, excluding no response, are accommodation, retreat, or ecosystem-based adaption. Any accommodation, retreat, and ecosystem-based strategies can also be classified based on scope and impact. Structural adaptation options include elevation, wet or dry floodproofing, wave attenuation devices, and retreat, which are relatively time and capital-intensive. Non-structural options capture strategies such as flood warning systems, flood emergency preparation plans, high water rescue vehicles, temporary barriers, and a municipal buy-out rent-back program. Lastly, “green” infrastructure offers options like dune restoration and artificial reef systems. Non-structural and “green” infrastructure options can almost always be implemented sooner than structural options.

 

Having been provided a basic adaptation framework and some tangible adaption strategies, Higgins residents were tasked with envisioning adaption and resilience in their neighborhood in near-term, medium-term, and long-term flooding and storm event scenarios. The near-term scenario captured conditions like those seen first-hand by many residents during the January storms. The medium-term scenarios, or 2050 scenarios, showed high-tide flooding factoring in 1.5 ft of sea level rise and then a storm event similar to January 13th with 1.5 ft of sea level rise, which is on par with the amount of sea level rise Towns should commit to managing by 2050. [2] The 2100, or long-term scenarios, presented high-tide flooding with 4 ft of sea level rise and a “worst case” scenario showing a 500-year storm event coupled with 7 ft of sea level rise.

 

Among the breakout group I facilitated, the conversation regarding the near-term timeline centered primarily around enhancing the dune system’s resilience and natural protective capacity through various potential restoration strategies. Emergency communication and access improvements were also identified as more immediate ways to improve near-term resilience. Adaptation suggestions were largely non-structural, or “green,” in this scenario, although acute structural concerns were mentioned.

 

The medium-term scenarios garnered more structural adaptation strategies. Relocation of the neighborhood’s utilities and pump station and elevation of the primary access road, currently situated in vulnerable locations, became a priority to ensure livability into 2050. Structural adaptation to homes, such as elevation and both “wet” and “dry” floodproofing, also arose as a necessity when looking at the level of inundation presented by the 2050 maps. The group emphasized that residential adaptation must be conducted strategically and as a community, to make sure individual structural investments do not harm other residents and properties. Individuals contributed lived experiences from flood and storm events in states such as Pennsylvania and Florida, as well as example adaptation strategies adopted by these communities. 

 

The 2100 scenarios were particularly jarring, and the conversation reflected that reality. Solutions, such as those offered plentifully in the near and mid-term scenarios, slowed to a halt as residents finally broached questions about the fundamental livability of the neighborhood in the long term. Participants inquired about retreat mechanisms, such as the logistics, environmental impacts, and viability of a municipal buyback program.

 


Higgins Beach neighborhood meeting on September 5th. (Town of Scarborough)

 

The Higgins Beach neighborhood is not alone in grappling with the realities facing coastal communities due to climate change and sea-level rise. Nearly 90 million people live in coastal communities along the US shoreline, many of which might become unlivable within the next two or three decades. [3] Many communities will soon be faced with critical decisions regarding adaption, to ensure a viable and resilient future or alternatively to commit to the managed retreat of the community. While these questions are undoubtedly overwhelming, notably for acutely vulnerable neighborhoods like Higgins Beach, the Town of Scarborough has a handful of additional resilience-based adaption projects in progress or coming down the pike residents can look to. The Route 1/Pine Point Road Resiliency Project is already underway, which aims to protect two major mobility and access corridors from future flooding and storm events. The Town of Scarborough also received a grant for a road removal and marsh restoration project on Sawyer Street, which will both eliminate vulnerable infrastructure and improve marsh health and tidal transparency. The Town’s Vulnerability Assessment is projected to be completed in July of 2025 and will deliver adaptation pilot projects and a roadmap for a more resilient Scarborough.


[2] “Resolve, To Analyze the Impact of Sea Level Rise,” LD 1572, State of Maine Legislature (2021). https://legislature.maine.gov/LawMakerWeb/summary.asp?ID=280080599 

[3] “Looming Deadlines for Coastal Resilience: Rising Seas, Disruptive Tides, and Risks to Coastal Infrastructure,” Union of Concerned Scientists (2024). https://www.ucsusa.org/sites/default/files/2024-06/Looming_Deadlines_for_Coastal_Resilience.pdf


About Emerson

Emerson is from San Francisco but split her time across Northern California while growing up. She recently graduated from Brown University where she received bachelor’s degrees in Public Health and International & Public Affairs and served as a captain on the varsity rugby team. Emerson cultivated an interest in planning through work on the Urban Transition Historical GIS Project, mapping patterns of neighborhood change, and with BAE Urban Economics, focusing on community economic development. As a Resilience Fellow, Emerson is eager to explore the intersection of community health, resilience planning, and placemaking while serving at both the municipal and regional level. Emerson looks forward to camping, snowboarding, trail running, walking on the beach, and generally enjoying time outdoors as she gets to know Maine.

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