Rising Seas in the Holy City: Preserving Historic Charleston in the Face of Global Climate Change

Will Grossenbacher

Will Grossenbacher is a 3L at the University of Virginia School of Law and is the former Editor-in-Chief of the Virginia Environmental Law Journal. This post is part of the Environmental Law Review Syndicate.

From October 2–5, 2015, the State of South Carolina, and the City of Charleston in particular, experienced historic rains: sites in the Charleston area reported up to twenty-six inches of rain.[1] The downpour combined with high tides to create flooding that closed dozens of streets throughout the City. Then, at the end of October, Charleston experienced the fourth-highest tide ever recorded in the City.[2] Persistent winds combined with the bi-monthly spring tide to create a high tide that reached 8.7 feet above mean lower low water level in Charleston Harbor.[3] The two unrelated events in the same month show just how vulnerable the City is to flooding. When rising sea levels and other climate-change-induced flooding are added to the mix, the flood risk will only increase, especially for the Charleston’s numerous historic properties.

Charleston is a city rich in historic resources. In fact, the City’s Historic District contains more than 1400 “historically significant buildings.”[4] Additionally, of the seventy-seven National Historic Landmarks (“NHLs”) in the State of South Carolina, thirty-three are located in Charleston.[5] While the City of Charleston has begun working to address flooding issues,[6] it has yet to address specific climate-change-related threats to its historic resources.[7] Charleston should therefore look to the example provided by other coastal cities and begin implementing law and policy changes designed at protecting historic resources from the impacts of global climate change.

I. The Impact of Sea Level Rise

Although the exact amount of sea level rise is difficult to predict, Charleston is one of the five cities in the Southeastern U.S. “most at risk” from higher sea levels.[8] By 2100, relative sea levels for Charleston are predicted to rise at least a foot, if current rates of sea level rise remain the same.[9] However, if rates of sea level rise increase, Charleston could see anywhere from 2.5 to six feet of relative sea level rise.[10] At these levels of relative rise, higher seas would likely inundate between 250 and 1100 square miles of land throughout South Carolina.[11]

Even modest sea level rise could be detrimental to Charleston’s historic district. With sea level rise of 1.6 feet and a seven-foot high tide, several NHLs would likely be inundated, along with numerous other historic structures.[12] If there are higher rates of sea level rise, the threat only increases. With ten feet of sea level rise, most of the Charleston peninsula would be under water at high tide.[13] Since Charleston’s storm water drainage system empties into coastal waters,[14] increased sea levels will also make drainage during storms more difficult, further increasing the flood risk.

II. Adapting to the Threat

Because the City of Charleston has significant control over historic properties through the power of the Board of Architectural Review (“BAR”),[15] the City must begin developing a climate change adaptation plan with specifically designed with historic structures and the historic preservation district in mind. While the Charleston City Code contains provisions regarding construction in flood zones,[16] the historic preservation ordinances make no mention of flooding.[17] The City should rectify this by amending the Zoning Ordinance to recognize the threat of flooding for historic properties. Aside from amending the Zoning Ordinance, the City should provide guidance to historic property owners regarding modifications of historic properties. Such guidance could be included in city plans or issued by the BAR. At least two other East Coast cities are well ahead of Charleston in implementing climate-change readiness plans with historic resources in mind. These cities provide examples of the kind of changes the City of Charleston should consider adopting.

In the wake of Superstorm Sandy, the City of Somers Point, New Jersey, which is located on a small coastal peninsula, implemented a comprehensive recovery plan.[18] The plan recognizes the growing threat that rising sea levels will pose to much of the city through increased flooding, including to it’s historic properties. While city zoning ordinances exempt historic properties from requirements to elevate or storm proof, the plan nonetheless includes recommendations for protecting historic properties from flood damage.[19] These include locating mechanical equipment above flood levels and elevating or flood proofing any additions.[20] Additionally, the plan recognizes that homes in the City’s historic district may nonetheless have to be elevated five or more feet.[21] Charleston’s BAR should take similar steps in recognizing the inevitable fact that sea level rise may necessitate raising historic properties in order to preserve them.

Annapolis, Maryland, is another historic East Coast city that is facing the threat of flooding caused by sea level rise. In recent years Annapolis has experienced “regular flooding resulting from rising sea levels and increasing storm surges.”[22] Additionally, the entire Chesapeake Bay region is sinking due to a the slow depression of a “glacial forebulge” created during the last ice age, which will increase relative sea level rise in the region.[23] In response to the almost certain threat of sea level rise to its City Dock and Historic District, the Annapolis has collaborated with a variety of stakeholders to develop a climate change resiliency plan.[24] In order to protect Annapolis’s historic core, which contains “one of the largest collections of 18th-century buildings in the country,” the City is working to provide property owners with resources to protect those structures.[25] Annapolis also plans to add back flow preventers where draining pipes empty into the bay in order to keep high tides from flowing back up the pipes.[26] Additionally, the City has begun a comprehensive survey of properties in the 100-year floodplain, which can be used to identify those historic properties that are most at risk.[27]

Charleston should follow examples of Somers Point and Annapolis and begin to tackle sea level rise head on. In addition to modifying historic preservation laws and providing guidance to historic property owners, an important first step would be to begin surveying properties in the city that are most vulnerable to flooding. Additionally, the City should begin to develop a comprehensive plan to protect its infrastructure and historic properties from sea level rise. Charleston has built a multi-million dollar tourism industry based on its image as a center for historic architecture. Any additional delay may put that industry, and many sites that are integral parts of our history, at risk of destruction.