Hell or High Water: A Case Study of Southern Historic Cities and the Threat of Climate Change

Introduction

When examining the practice of the preservation of historic buildings, it is undoubted that it’s principles fall in line with sustainability. Through saving buildings, preservationists often take something old, and repurpose it to fit newer needs. Even though some may view preservation methods as outdated and unfriendly to “green” energy, since older buildings can’t always incorporate new technology like new construction can, the reality is that much less total energy is expended by preserving an older building than constructing a new one [1]. Preservation also embodies the other sectors of sustainability beyond environmental impacts, allowing for economic opportunity through tax credits to owners as well as opportunity for craftsmen to work on repairs and maintenance, as well as the social aspects of preserving places of significance to our history and the tourism that can bring to historic areas [2].

Despite the inherent sustainability of preservation in its overall energy use, there are many aspects of sustainability that are not accounted for in preservation, particularly centering around environmental issues [3]. Though they ultimately conserve energy, many preservation practices have not caught up yet with modern day environmental concerns, such as climate change [4]. Along the coast of the Southeastern United States, the birthplace of the preservation movement in America, there is a particular threat in terms of water related to climate change. In the Fourth National Climate Assessment, conducted in 2018, scientists found that high tide coastal flooding, which is related to sea level rise, increased by 5–10x since the 1960s, and tropical storms are occurring more frequently while their storm surges are traveling further inland [5]. These threats are imminent, and preservationists in these areas will have to adapt to them if they want to ultimately save places beyond the next century.

In this case study, I will examine the effects that short and long-term moisture issues related to climate change are causing in terms of preservation efforts in historic southern coastal cities, and propose what more could be done to promote sustainability and longevity for these important cultural resources.

In the Short Term: Increased Small Flooding Events and Their Impact on Historic Coastal Southern Communities

To almost anyone inhabiting a southern coastal city, the nuisance of floodwater, even when it’s not raining, has become increasingly common. High tide flooding, often referred to as “sunny day flooding”, occurs when the sea level at high tide goes beyond the daily average, and causes water to spill into streets in low-lying areas. In a 2019 study done by the National Oceanic and Atmospheric Administration on high tide flooding trends from tide gauges set up in coastal cities throughout the United States, it was shown that high tide flooding is almost twice as likely to occur now than it was in 2000, and that overall, the relative sea level along the East and Gulf coasts, which border the American south, raised around 1.5 inches since 2018. Additionally, they examined Charleston, SC, where the first historic district was established, and saw that relative sea level rise was responsible for about 75% of the record-breaking high tide flooding occurrences in 2019 [6]. Another study of Charleston, conducted by the Coastal Conservation League, showed that in 2016, the city faced 50 days of high tide flooding — a drastic increase from the average 4 days a year the city would see in the 1970s, which would have usually been caused by a King Tide or another natural phenomenon not related to relative sea level [7].

Along with high tide flooding, another flooding issue involving sea level rise is flash flooding events that occur through even light rainfall. In low-lying coastal cities, outdated drainage systems coupled with sea level rise over the years has caused a large increase in the amount of flooding that occurs within the area during rainstorms. In Savannah, GA, as well as other coastal cities that share similar geography, an elevated sea level causes drains to be flooded, and therefore unable to drain rainwater as it was intended to [8]. These events, often coupled with high tide flooding, leave certain areas of these cities in up to feet of water, and can cause severe property and infrastructure damage as they continue to occur.

Not only does the geography of these cities allow for this threat to occur, but the unthoughtful development of these areas throughout history has also contributed to this. In southern port cities such as Charleston, Savannah, and New Orleans, the oceans and rivers that attracted settlers were filled in over time to create room for more development, leaving water nowhere to run off to [9]. One pertinent example of this is Septima Clark Parkway, known as the Crosstown in Charleston. It is one of the main high-traffic areas in the city, which was built on top of a filled in tidal creek that provided drainage for most of the area, and is now known as one of the most flood-prone areas of the peninsula. In 2009, the City of Charleston estimated that each flooding occurrence on the Crosstown cost the city around $12.4 million dollars [10]. New Orleans faces a similar struggle, however, the development of drainage systems in the first half of the city’s life actually lowered the level of the ground further than it already was, giving New Orleans the notorious title of the city that exists below sea level. As land was being dug up to create ditches and area for water to drain away in lower lying areas, soil was unable to be replenished through the rivers and water was not sitting where it used to, causing the soil to dry out and eventually compact together, leaving the ground lower than it originally was [11]. What seemed to be the easiest solution actually turned into one of the greatest problems structurally that the city sees today.

While these events are often short-lived and subside within a few days, they can have long-term, and often costly consequences, particularly for the historic buildings that reside in these areas. These buildings tend to be uniquely vulnerable as building materials weather over the years. Because these types of floods tend to infiltrate the lower levels of the home if they are affected, foundational damage can occur, which is not easy and very costly to correct. In this standing water as well are different chemical and biological elements, which can cause great damage to a building if it stagnantly persists around it for a long period of time. It creates the perfect storm for wood to rot and mold to develop, overall weakening the building and threatening its longevity. This not only increases the cost of maintaining a historic building, but can compromise its integrity and ultimately lead to the building no longer standing [12].

In the Long Term: Catastrophic Damage Done to Historic Coastal Southern Communities Through Tropical Storms

A longer lasting, more impactful climate change factor facing historic southern coastal cities is a rise in the intensity of tropical storms and hurricanes, and the surges that follow them. Due to an increase in global temperature, which in return causes an increase of surface level ocean temperatures, tropical storms and hurricanes are becoming more intense and carrying more water with them. This means more flooding, as well as more intense winds that can cause severe damage to structures [13]. Research has shown that in the Atlantic, a temperature increase could decrease the frequency at which these tropical phenomena occur, but could potentially double the number of category 4 and 5 hurricanes that take place[14]. This spells trouble, as a category 4 hurricane takes much longer to recover from than several smaller tropical storms. It is, however, the water rushing in from the storm surge where the greatest threat lives. Accompanying an increase in relative sea level, more intense storms that carry more water in with them have higher storm tides, meaning a greater influx of water entering coastal areas after a storm. It is, however, the water rushing in from the storm surge where the greatest threat lives. Accompanying an increase in relative sea level, more intense storms that carry more water in with them have higher storm tides, meaning a greater influx of water entering coastal areas after a storm [15].

The damages that these storms can cause to historic properties and districts is something that we are seeing first hand today. Hurricane Katrina, famous for devastating New Orleans, was one of the most catastrophic hurricanes many of this time have ever seen. What really caused the damage, however, was the high storm surge that infrastructure was not equipped for. Levees and floodgates failed, or were overtopped with water, flooding one of the nation’s most vibrant and unique historic districts [16]. Overall, the storm caused over $81 million dollars in property damage, much of which had historical context. Hurricane Irma, which swept along the coast of Florida and South Carolina, was one of the most intense hurricanes seen in the south since Katrina, and its intense winds and surges caused roughly $50 billion in damage. While most damage was done in Florida, South Carolina had enough destruction for the South Carolina Department of Archives and History to launch a disaster relief fund for any historic property damaged by the storm.

It is arguable that these flooding occurrences are more destructive to the idea of preservation than smaller tidal instances of tidal flooding. While tidal flooding can have long term issues if it persists, powerful hurricanes posses the threat to immediately damage a building beyond repair, making the ability to save a place and uphold its architectural integrity much more difficult.

Proposal for Changes to Be Made: How to Adapt Preservation Practices to Address Climate Related Issues

With these threats present in most of, if not all, southern historic cities and districts, it is obvious that changes need to be made in terms of how preservationists view their practice. The first thing that should be proposed to curb damages to historic properties in these areas from flooding events would be to focus on fixing failing infrastructure that does nothing to prevent these flooding occurrences. While we cannot fully prevent the repercussions from climate change that we face, we can build better to soften the blow for several decades until a more permanent solution can be reached. One instance in which we see this happening is in Charleston, where proposals to raise the seawall known as the Battery have been in the works for nearly a decade. The project, which is funded by tax dollars from tourism as well as food and beverage taxes, will cost nearly $65 million, and will be completed in phases over the course of what they are expecting to be a decade. The Army Corp of Engineers has also proposed a plan to build a 12 ft seawall spanning around the peninsula with pumps to carry water away [17]. The battery wall also spans along the section of Charleston that is the richest in history, and covers the vast majority of the National Historic District within the city, helping to save buildings that bring in tourism dollars and promote the sense of place that Charleston does. Focusing on fixing drainage systems and creating barriers between the ocean and the city could prevent millions of dollars of flood damage a year along the southern coastline.

Preservationists may also have to examine the methods in which we restore these properties, and tweak them to fit into the environmental crisis that many places where these properties lie are in. New innoventions and unconditional ideas will be needed to be able to adapt to these circumstances and meet the goal of saving places. At Cape Lookout National Seashore, a historic district in the Outer Banks of North Carolina, a study was conducted to create a model that would help guide in decisions on how to save buildings at threat to sea level rise, and in what manner they would save them. They collected data from the buildings by having a panel of qualified preservationists, park service members, scientists, and tourism experts judge the buildings on a series of attributes in regards to its importance, and then took that information along with a vulnerability assessment and used it to decide which buildings were most important to save [18].

One of the most important aspects of this study is its emphasis on budget spending. This is often one of the hardest things to accomodate when dealing with government owned historic buildings, as not much money is allocated to preservation efforts. The ability to preserve any building is only as far as the wallet can stretch, which means that budget has to be taken into serious account when weighing the options as to what to preserve and how [19]. It gives a realistic view on what saving buildings looks like, and shows that not everything can be saved, and that we need readily available plans to determine where to allocate funds, as the effects of climate change are rapidly worsening.

Despite the sad truth that not all historic buildings along the coastal south will survive climate change, there is hope in knowing that there are measures that can be taken to mitigate the damages. There are short term methods, such as flood proofing, but more long-term methods would include elevating the building, not using the lower stories of the building affected by water damage, or moving the building entirely to a new location [20]. While more short term methods are usually done, since they are cheaper and work in instances of smaller flooding, it could be argued that the investment of more long term solutions starting early could help save more historic buildings from the effects of climate change in the decades to come. This would also promote keeping the structure’s architectural and historical integrity by placing it somewhere with less harsh conditions.

While it may cost more up front, in the long run, the ultimate goal of preservation will be met much better if we begin working now to provide as much protection as we can to vulnerable buildings along coastal cities. This will require for either government budgets to expand, or for more money to come in from private donors who fund projects. With a combination of working to fix infrastructure to mitigate the effects of sea level rise and climate change, as well as investing in historic properties to lessen their exposure to such harsh elements, we can further continue to save the places we have set out to.

Sources

[1] Washington State Department of Archaeology and Historic Preservation. Sustainability and Historic Preservation Executive Summary. 2011, https://www.dahp.wa.gov/sites/default/files/209SustainabilityStudy_ExecutiveSummary.pdf

In this report put together by the Washington State Department of Archaeology and Historic Preservation, the inherent sustainability of practicing preservation is highlighted. They mostly discuss how preservation is incredibly effective for energy efficiency, and encourage readers to fix historic properties rather than build new construction. They provide several examples of historic buildings in the state that have been renovated to fit a more “green” way of living, while also offering suggestions for how to properly maintain historic properties.

[2] “Sustainability-Technical Preservation Services, National Park Service.” National Parks Service, U.S. Department of the Interior, www.nps.gov/tps/sustainability.htm.

This article by the National Parks Service examines sustainability, and how it falls in line with historic preservation practices. It especially highlights how it falls under the three pillars of sustainability, and gives examples of how it can be beneficial and long-lasting economically, socially, and environmentally.

[3] Erica Avrami (2016) Making Historic Preservation Sustainable, Journal of the American Planning Association, 82:2, 104–112, DOI: 10.1080/01944363.2015.1126196

In this article, the author weighs the challenge preservationists face in the renovations of historic properties. She argues that preservation has the power to really enhance the environment around the property, however, the codes that preservationists follow now do not align well with long-term sustainability in all three sectors- environmental, social, and economic.

[4] “Climate & Culture: National Trust for Historic Preservation.” Climate & Culture | National Trust for Historic Preservation, National Trust for Historic Preservation, 2021, savingplaces.org/climate-and-culture#.YIws7S2ZNQJ.

In this article from the National Trust for Historic Preservation, they highlight the upcoming changes to many historical landscapes in result to climate change, particularly sea level rise. I found their take very interesting in saying that climate change issues are complex within the preservation community because they challenge our sense of permanence that we try to achieve through the act of preserving a building. They argue that in order to truly “save places”, we must adapt our methods of preservation and be open to other possibilities.

[5] Usgcrp. “Fourth National Climate Assessment: Chapter 19: Southeast.” NCA4, 23 Nov. 2018, nca2018.globalchange.gov/chapter/19/.

The Fourth National Climate Assessment, conducted by the federal government between 2017–2018, examines climate trends and issues throughout the country. The report is set up in different regions, and I focused on chapter 19, which examines the southeast. The data shown for flooding shows an increase in tropical storms and the severity of their surges along with sever increases of high tide flooding. They specifically highlighted the work done in Charleston to combat these issues.

[6] United States, Congress, US Department of Commerce, et al. 2019 State of U.S. High Tide Flooding with a 2020 Outlook, National Oceanic and Atmospheric Administration, July 2020. tidesandcurrents.noaa.gov/publications/Techrpt_092_2019_State_of_US_High_Tide_Flooding_with_a_2020_Outlook_30June2020.pdf.

This study conducted by NOAA showed relations between relative sea level and high tide flooding. Using tidal gauges set up in coastal cities throughout the US, the agency tracked tidal levels and high tide flooding occurrences. They paid particularly close attention to the Atlantic and Gulf coasts, which assists in my research since it borders the American South. They found that most often, sunny day flooding occurs due to sea level rise, and that trends show that it will only continue to increase as time goes on.

[7] “Lowcountry Flood Mitigation.” Coastal Conservation League, 6 Aug. 2019, www.coastalconservationleague.org/projects/lowcountryflooding/.

This detailed description of the Lowcountry Flood Mitigation Project in Charleston, SC, written up by the Coastal Conservation League, examines the current situation regarding floods in the area. It not only discusses the cause of severe flooding in Charleston, but also looks at specific examples of what is being done to mitigate the issues, such as incorporating a new drainage system. I found it important that it mentioned the flooding problem as not only an environmental issue, but a public health one as well. This study incorporates all residents of Charleston into the plan, and highlights plans to move towards resiliency.

[8] “Sea Level Rise and Tidal Flooding in Savannah and Tybee Island, Georgia.” Union of Concerned Scientists, 30 Mar. 2016, www.ucsusa.org/resources/sea-level-rise-and-tidal-flooding-savannah-and-tybee-island-georgia.

This journal article examines the city of Savannah, GA and their tidal flooding events. They contribute these flooding occurrences to sea level rise coupled with infrastructure issues. They also discuss damage that has occurred due to these floods, and measures they city and surrounding areas are taking to mitigate the issue.

[9] Borick, Carl. “Downtown Flooding.” The Charleston Museum News and Events Downtown Flooding Comments, www.charlestonmuseum.org/news-events/downtown-flooding/.

In this posting from The Charleston Museum, LIDAR maps are used to show the topography of the Charleston peninsula. The author compares these maps to early maps of Charleston, and describes how the low-lying areas that are seen in the city today where flooding occur frequently were once tidal creeks that were filled in as the city developed.

[10] “U.S. Climate Resilience Toolkit.” Minimizing the Impacts of Coastal Flooding Helps City Prepare for Sea Level Rise | U.S. Climate Resilience Toolkit, 17 Jan. 2017, toolkit.climate.gov/case-studies/minimizing-impacts-coastal-flooding-helps-city-prepare-sea-level-rise.

This study, which focuses on flooding levels in Charleston, examines flood levels and looks at studies the city has done to project what flood levels and the frequency of their occurrence would look like in the coming year. They also emphasized how despite these projections, events often occur in which a higher tide coupled with rain can cause unexpected flooding. They also discussed what the city is currently doing to mitigate issues.

[11] Campanella, Richard. “How Humans Sank New Orleans.” The Atlantic, Atlantic Media Company, 7 Feb. 2018, www.theatlantic.com/technology/archive/2018/02/how-humans-sank-new-orleans/552323/.

This article discusses New Orleans struggle with topography, and why it occurred that way. It was very interesting to see how what some thought would be a solution, ended up causing trouble over time and sinking parts of the city below sea level. It really highlighted for me how important sustainable decisions are in planning of cities, because one decision could end up costing millions later.

[12] Drdácký, Miloš F. “Flood Damage to Historic Buildings and Structures.” Journal of Performance of Constructed Facilities, American Society of Civil Engineers, 10 July 2010, ascelibrary.org/doi/pdf/10.1061/%28ASCE%29CF.1943–5509.0000065.

This journal article discusses the threats that historic buildings can face due to flooding. It discusses physical aspects, such as damage to foundations and sinking of landfill underneath, as well as cultural aspects such as a loss of integrity of the building, or a loss of the building in general. He also discussed material goods, which I found interesting because historic homes often come with historic material culture. I found this really helpful in weighing the severity of the damage that small flooding events can do.

[13] “Global Warming and Hurricanes.” Geophysical Fluid Dynamics Laboratory, NOAA, 29 Mar. 2021, www.gfdl.noaa.gov/global-warming-and-hurricanes/.

In this article sponsored by NOAA by published under the Geophysical Fluid Dynamics Laboratory, the correlation between rising global temperatures and increased intensity of Atlantic tropical storms is explained. Warmer air causes the surface level of the water to be warmer, causing for increased evaporation and changes in pressure that make storms more intense than usual.

[14] Bender, Morris A., et al. “Modeled Impact of Anthropogenic Warming on the Frequency of Intense Atlantic Hurricanes.” Science, American Association for the Advancement of Science, 22 Jan. 2010, science.sciencemag.org/content/327/5964/454.abstract?casa_token=4F4qdmURc3gAAAAA%3Astxl7IdAmq48VxeYiMkY88swsr7bJfs_acbbMIAV96H7lUCUiCt_axsWVIwONnXpNa1dMhXYHvo596g.

This journal article examines the trend of rising intensity within hurricanes. I found it really interesting that the research the authors applied showed a decrease in the frequency of storms, which other research did not show me. Ultimately, they concluded that while the frequency may decrease, the intensity of the storms will increase, particularly in very intense storms.

[15] Rahmstorf, Stefan. “Rising Hazard of Storm-Surge Flooding.” PNAS, National Academy of Sciences, 7 Nov. 2017, www.pnas.org/content/114/45/11806.

In this journal article, the author looks at the 2017 hurricane season and the catastrophic damages that a summer of very intense storms left behind. He uses several storms as examples, though mostly focusing on NYC and Hurricane Sandy. While the subject of the article did not pertain to my research, the information within it about rising storm surges and the science behind them was particularly helpful.

[16] Fritz, Hermann M., et al. “Hurricane Katrina Storm Surge Distribution and Field Observations on the Mississippi Barrier Islands.” Estuarine, Coastal and Shelf Science, Academic Press, 15 May 2007, www.sciencedirect.com/science/article/pii/S0272771407000868?casa_token=vvazBUKCu7gAAAAA%3ADY8Ii6sr9aBXnJyRNioKdqUnLjpfvc2URDZmRfMPfwo4lBu6RS1M4NNCHBVMyCgYclRDOOhTl_M.

This journal article was a case study on Hurricane Katrina and the damage done within the Gulf area from it. It specifically examined the storm surge, which is what caused the mass destruction in Katrina. I found it very useful how the article explained how the infrastructure failed, and that ultimately caused the flooding of the whole city. It is a strong petition for fixing these city planning issues in order to curb the damage of storms like this, which we will see an increase of in the future.

[17] Gaul, Gilbert M, et al. “Fortress Charleston: Will Walling Off the City Hold Back the Waters?” Yale E360, 5 May 2020, e360.yale.edu/features/fortress-charleston-will-walling-off-the-city-hold-back-the-waters.

In this article, the author discusses a little bit of the history of Charleston as well as the historic battery wall. He highlights the severe flooding issue in the city and its surrounding areas, speaking with a local resident about her moving her family after her home flooded twice within two years. He discusses other cities as well, and their plans to also erect some sort of sea wall, and the challenges they have faced in terms of getting it funded.

[18] Xiao, Xiao, et al. “Optimizing Historic Preservation under Climate Change: Decision Support for Cultural Resource Adaptation Planning in National Parks.” Land Use Policy, Pergamon, 22 Feb. 2019, www.sciencedirect.com/science/article/abs/pii/S0264837718314807.

In this study of Cape Lookout in North Carolina, a model was created to determine the value of historic buildings along the shore, as well as how vulnerable they were to the effects of climate change, to determine what buildings to save and how to save them. They employed six different methods of damage prevention, while also accounting for the budget allocated to the historic district. I found this to be a really helpful example of how to go about preservation efforts in the face of climate change. Budget is very important and it was nice to see it taken into account.

[19] Wilson, Tarsha. When a Little Goes a Long Way: Tracking the Historic Preservation Fund & Its Impact on the Field of Historic Preservation. University of Pennsylvania, 2018, repository.upenn.edu/cgi/viewcontent.cgi?article=1644&context=hp_theses.

In this graduate thesis, the author discusses the Historic Preservation Fund allocated by the federal government, and look at the history of the funds and what they have been able to do. They argue that despite the fund being so small and rarely ever getting fully funded, the National Parks Service and other historic districts have been able to do quite well with the little money they have in terms of reaching the goals of preservation. They also highlight that federal and state governments have been fighting for a while to lower the amount of the HPF, so it is unlikely that the amount will change.

[20] Eggleston, Jenifer, et al. Guidelines on Flood Adaptation for Rehabilitating Historic Buildings. US Department of the Interior, Nov. 2019, www.nps.gov/tps/standards/rehabilitation/flood-adaptation-guidelines.pdf.

This article written by the US Department of the Interior and the National Parks Service is a guide to how to mitigate and prevent flood damages when rehabilitating a historic building. It offers several different methods, ranging from short term methods such as flood proofing and packing the basement, to long term methods such as raising the building or moving it all together. I like that this lays out all of the ways in which flood mitigation can happen in historic homes. It was very detailed in the restrictions of each method and in what situations it would be effective.