Historic Preservation and Sea Level Rise
July 9, 2021
Kellie King is a 2021 graduate of the Weitzman School of Design, where she earned a Master of City Planning with a focus in land use and environmental planning. She is passionate about climate change adaptation planning in coastal communities. Kellie is an AmeriCorps alumna and also holds a M.A. in teaching from the Relay Graduate School of Education and a B.A. in international relations and environmental studies from Tufts University.
Sea level rise is an inherent threat to the physical integrity and long-term existence of coastal historic places. The need for action is widely accepted, but the question of how to appropriately balance sea level rise adaptation and historic preservation goals varies across communities. Interventions like elevating structures, replacing materials with flood-resistant ones, or even relocating buildings can run counter with imperatives to preserve historical integrity.
Historic assets at risk
The National Register of Historic Places (NRHP) is a federal list of districts, sites, buildings, structures, and objects deemed to have local, state, or national historical significance. The National Park Service (NPS) is the administrative agency in charge of maintaining the NRHP. As a preservation tool, historic designation is important to ensure that we understand, celebrate, and learn from places important to our shared history.
As of 2018, the NRHP contains over 75,000 properties in the United States and its territories. Approximately 8,300 listed properties (11 percent of all listings) are within five miles of the coast and may be vulnerable to sea level rise.
National Park Service response to sea level rise exposure
The 2009 Secretarial Order 3289 established an “approach for applying scientific tools to increase understanding of climate change” for all Department of the Interior offices and agencies, including the NPS. Since then, climate change education and risk assessment have been increasingly incorporated into federal-level planning for cultural resource protection.
The NPS has pursued efforts to improve its spatial understanding of risk across its assets; for example, the agency has generated maps for its coastal parks to evaluate the effects of sea level rise and storm surge. The NPS developed replicable scenario planning models for local managers to use when planning for short- and long-term adaptations. These models can assess how a variety of hazards, from sea level rise to ocean acidification, will affect assets and test the effectiveness of different management strategies. Social, political, and economic data can be integrated into the models for NPS managers to fine-tune their decision-making. Large storms have also increased activity around cultural resource planning. Following Hurricane Sandy, for example, the NPS created a Rapid Review Team to “identify sustainability and natural and cultural resource priorities for recovery and reconstruction projects”.
Despite ongoing initiatives, climate change presents a particularly unique challenge to cultural resources. Disrupting the surrounding context of a place-based cultural resource or relocating it in the name of adaptation risks degrading the historical integrity of the resource. For extremely vulnerable place-based assets, conversations around climate change adaptation consider a continuum of responses, with the acknowledgement that not all resources can be protected in situ and without alteration. A 2014 NPS forum, Preserving Coastal Heritage, proposed seven adaptation responses for cultural resources managers to consider. Note that opting to do nothing in the short-term does not preclude managers from undertaking more intrusive interventions in the long-term.
Table 1: Range of Adaptation Options
|Do nothing||No active intervention warranted or possible.||Add water-level sensors to coastal building foundations to monitor change.|
|Offsite action||Remove or deflect environmental stresses from the resource.||Install a living shoreline or build an offsite retaining wall to reduce erosion near the resource.|
|Improve resiliency||Alter or modify the resource itself to better withstand stressor or impacts.||Elevate resource above projected flood levels.|
|Relocate or allow movement||Actively relocate some or all of the resource to a less vulnerable location.||Relocate resource inland of coastal hazards.|
|Data recovery, then let go||Comprehensively record as complete a resource as possible, then allow resource to undergo full effects of stressors.||Complete a full excavation of archeological resource and then allow site to weather hazards without further interventions.|
|Record, then let go||Document or otherwise preserve a record of the resource, then allow resource or portion of resource to undergo full effects of stressors.||Complete a partial excavation of archeological resource to create a record of site and then allow site to weather hazards without further interventions.|
|Interpret the change||Interpret the effects of climate change on the resource, and actively engage visitors in that change.||Add high water markers to resource to show depth of inundation from coastal flood hazards.|
Source: National Park Service, “Preserving Coastal Heritage Summary Report”, 2014
Local responses to sea level rise exposure
Many of the cultural resources listed on the NRHP—like your town’s historic house listed because of its vernacular architecture or importance to local history—are outside federal management, meaning local municipalities will be tasked with deciding how to best manage the vulnerable historic assets in their jurisdictions.
Local responses to sea level rise exposure in three case study cities, Newport, Rhode Island; Charleston, South Carolina; and St. Augustine, Florida are assessed with a special emphasis on district- and building-scale strategies, as these resources are often managed by local authorities.
Newport, Charleston, and St. Augustine have long been leaders in the historic preservation field. Each city is experiencing worsening flooding and is projected to see several feet of sea level rise by 2100; important historic districts in each city are increasingly exposed. The planning response to flooding and sea level rise vulnerability in each city is highly specific to the historic context, with appropriateness of different adaptations evaluated at the asset- and district-scale. The local environmental context dictates the feasibility of different options: historic preservation in Charleston, for instance, is tied deeply to protecting an entire portion of the city from rising waters. The cultural and economic value of historic resources is firmly emphasized when discussing the need to fund what can be massively expensive mitigation measures—the historic resources in each city are integral to local heritage tourism industries. And perhaps most importantly, the ways in which historic resource managers view adaptation interventions have changed over time. In both Newport and Charleston, for example, frequent flooding has made local officials reevaluate their positions on elevating historic buildings.
Given the degree of exposure in Newport, Charleston, and St. Augustine, successful historic preservation will likely depend on redefining what it means to maintain an asset’s historic integrity (if the asset is moved, for instance, does that change its historic value or only add to its long history?) to open up a broader range of adaptation options. Ultimately, historic resource managers will have to grapple with questions of loss as sea level rise progresses:
“We will ensure that our management options recognize the potential for loss. Responsible stewardship requires making choices that promote resilience and taking sustainable management actions. Funding temporary repairs for resources that cannot, because of their location or fragility, be saved for the long term, demands careful thought.” – Jonathon B. Jarvis, former National Park Service Director
Source: (L) National Register of Historic Places Registration Form for the Browning’s Beach Historic Districtt and (R) State of Rhode Island Historical Preservation & Heritage Commission
A beach cottage in the Browning’s Beach Historic District in South Kingston, RI. Despite surviving earlier storms like the Hurricane of 1938 and Hurricanes Carol and Edna in 1954, this Queen Anne style cottage was battered beyond repair by Hurricane Sandy in 2012. State permitting authorities approved the demolition of the structure after the property owners determined it was cost-prohibitive to continue protective measures.