St. Augustine, Florida

St. Augustine is a small city located along Florida's northeast coast. The city is the oldest continuously occupied European settlement in the United States, established in 1565 by the Spanish, but was also home to indigenous Native Americans in the pre-colonial era. As the capital of the then-Spanish colony of Florida, St. Augustine was often at the forefront of conflict with English settlements elsewhere in North America. Human conflicts and natural disasters repeatedly wrought destruction in the city, and few remnants of St. Augustine pre-1700 actually remain today.

St. Augustine recognizes the threat that flooding, coastal storms, and sea level rise poses to its historic resources. Hurricanes Matthew and Irma in 2016 and 2017 caused irreparable damage to a number of historic buildings and over 30 were ultimately demolished as a result.

The city has engaged with some recent planning around flood mitigation and sea level rise adaptation; however, it is unclear which sea level rise scenario the city intends to use as a baseline for future planning and resiliency efforts. Analysis does reveal that sea level rise will trigger "tipping points" after which historic resource vulnerability to flooding increases rapidly. For example, the percentage of historic buildings vulnerable to nuisance flooding increases substantially once mean sea level rises one foot. Likewise, vulnerability to daily tides will increase rapidly once mean sea level rises 2.5 feet. And under all future scenarios (and current conditions), the 1% annual chance storm would inundate over 80% of all historic buildings.

St. Augustine has engaged in a number of vulnerability assessments and solutions-oriented initiatives in the last five years. This has resulted in a number of actionable recommendations for flood and sea level rise mitigation but much of the work is still in its beginning stages. Many of the city's initiatives explicitly address historical resource protection in an acknowledgement of their economic importance and how they collectively inform St. Augustine's unique sense of place.

The city's 2016 Coastal Vulnerability Assessment mapped future sea level rise scenarios and identified highly exposed infrastructure and cultural resources (historic and archaeological). Priority issues included identifying "realistic options" for historical resource adaptation; understanding when "tipping points" of exposure will occur; and laying the groundwork for a coordinated financial response.

The city's 2017 Adaptation Plan, developed as part of the Florida Community Resiliency Initiative Pilot Project, is a complement to the previous year's vulnerability assessment. The adaptation plan recommends policymakers use the STAPLEE framework to evaluate a number of different factors that will help determine priorities:

• Social: "the action should be socially acceptable."
• Technical: "the action should be technically feasible, help to reduce losses in the long term, and have minimal cumulative and secondary impacts."
• Administrative: "the action should be implementable by the state or local government."
• Political: "the action should be politically acceptable."
• Legal: "the state or local government must have the legal authority to implement/enforce the action."
• Economic: "the action should be cost-effective and be likely to pass a benefit-cost analysis."
• Environmental: "the action should meet statutory considerations and public desire for sustainable and environmentally healthy communities."

The Adaption Plan also identifies a number of contextual factors that will influence (and in some cases potentially hinder) municipal responses to vulnerability. Importantly, the plan describes St. Augustine's historic districts as "vulnerable, immovable, and irreplaceable." Adaptation responses like elevation and relocation "would unravel significant aspects of the city's historic fabric and would be technically difficult to accomplish" and are unlikely to be popular options. In the short-term then, measures like accommodating in-place and protections that do not alter historic resources are likely to be favored even if they are not the most effective long-term options. Some of the hesitation to endorse more intrusive interventions may stem from the assertion that "many residents do not know what's coming." The plan points steadily rising property values and skepticism expressed by community members that the full scope of the effects of flooding and sea level rise are not fully appreciated and may hinder adaptation responses. Short planning time frames have also allowed municipalities to focus on immediate needs to the point of neglecting how environmental conditions will change in the long-term. St. Augustine used a 20-year planning timeline for its current comprehensive plan (covering 2011-2030)--the plan contains no reference to sea level rise and mentions flooding only twice. The city is in the process of updating its comprehensive plan and will again use a 20-year planning timeline.

The 2018 St. Augustine Historic Preservation Master Plan addresses four key questions-- what resources are important, how are resources threatened, how can preservation of resources be improved, and what strategies are needed to successfully preserve resources.

There are a number of key strategies that relate to flood and sea level rise mitigation in the master plan, generalized below:

• City-Wide Planning: incorporate historic preservation elements in all scales of planning initiatives, including hazard mitigation planning.
• Historic Resource Inventory: update inventories of historic resources to assess significance, vulnerability, and other factors to inform long-range planning goals
• Historic Preservation, Conservation, and Zoning: coordinate zoning ordinance with historic preservation and conservation goals; revise historic preservation guidelines to be more responsive to environmental hazards; create guidelines for acceptable property modifications to mitigate environmental hazards.
• Hazard Mitigation: participate in local hazard mitigation planning; inventory resources exposed to environmental hazards; create guidelines for acceptable flood mitigation measures; develop a disaster response plan to better prepare historic resources to withstand and recover from disasters.
• Education and Advocacy: advocate for resources and funding to encourage resiliency efforts in the city.

Work on implementing the strategies is underway. For example, comments from the city's Historic Architectural Review Board indicate that the historic preservation field is pushing for hazard mitigation issues to be thoroughly discussed in the ongoing comprehensive plan update. The City Commission also recently formed a citizen advisory committee to review potential flood mitigation-oriented updates to the building code; the issues regarding structural elevation of historic resources is expected to be a topic of discussion.

The 2020 Resilient Heritage in the Nation's Oldest City project puts some of the city's previous planning into practice. The project applied the STAPLEE framework and selected three properties to explore what short- and long-term flood mitigation could look like at the asset-scale. The project also created a number of in-depth directions, guidelines, and worksheets to aide local decision-makers in developing mitigation strategies, selecting sites for interventions, and discerning the social value of historic resources. To better understand the economic value of historic resources, the project also presents an in-depth analysis of the value of historic resources and how St. Augustine's heritage tourism industry may be affected by future flood and sea level rise scenarios.

Sea level rise and flooding is a clearly documented hazard in St. Augustine, yet the scope and timeline of future adaptation planning remains unclear. The city is uniquely dependent on historic resources, and heritage tourism drives much of the local economy. Properties in local and national register districts account for 41% of St. Augustine's total assessed value, and 75% are located within the 1% annual chance floodplain. The relationship between the city's historic resources and its economy is and will continue to be a motivation for adaptation planning. However, current city planning indicates that there is limited willingness to identify and apply more intrusive long-term solutions like relocation to protect historic resources from future sea level rise. There are also concerns that many historic resources are not ones that can be relocated even if there was an appetite for such an adaptation. While concerns about needing to maintain the historic integrity of a structure are valid, there is a need to consider all available sea level rise and flooding mitigation measures at a pace sooner than the city appears to be moving. Between the start of its major adaptation planning with the 2016 Coastal Vulnerability Assessment to today, St. Augustine has already lost over thirty structures to damages caused by storm-related flooding.