Blueprints: Sea Level Rise on Georgia's Coast
A multi-year project of the Georgia Conservancy and Georgia Tech’s College of Architecture is tackling the realities of sea level rise on Georgia’s coast. Our primary goal with the multi-year Blueprints for Successful Communities studios is to aid Georgia’s coastal communities in planning for a projected one meter rise in sea levels by 2110. Comprehensive and informed planning and design will enable communities to adapt, respond and invest in future development and redevelopment in a sustainable and fiscally responsible manner.
The Georgia Conservancy has been a regional leader in advancing sustainable growth since launching our Blueprints for Successful Communities program in 1995. The Blueprints technical assistance program, along with our Good Urbanism and School Siting programs, help Georgia communities make informed development decisions through more robust and comprehensive planning. Combining the expertise of our staff planning professionals with that of academic leaders from the state’s premier colleges and universities, including the University of Georgia, Georgia Tech and the Savannah College of Art and Design, drives more thoughtful planning that enables communities to thrive economically with fewer resources, lower costs and more efficient land use.
In 2011, the Georgia Conservancy launched a mapping and outreach project to tackle the issue of Sea Level Rise (SLR). Working with the University of Georgia’s River Basin Center and the state’s Department of Natural Resources, we produced interactive mapping tools demonstrating land mass changes projected to occur on the Georgia coast as a result of rising sea levels.
Coastal cities are vulnerable to many natural hazards - hurricanes, flooding, beach erosion, subsidence and sea level rise. There are many negative social and economic effects that may result from natural hazards on the coast such as loss of historic structures and communities, devastation of infrastructure, contamination of ground water by saltwater intrusion, and loss of important coastal wetlands and habitats. With over half of the world’s population living less than 100 miles from the ocean, and with coastal cities having a population density that is three times higher than the global city average, these hazards pose a major threat to human civilization. Climate change will only exacerbate this.
Sea level rise is one of the biggest challenges facing coastal communities. Though sea level rise is a slow process, communities must plan well in advance in order to develop adequate adaptation strategies that will help mitigate future social, economic and environmental losses.
“Changing sea levels will impact Georgia’s entire coast in the coming years,” said Katherine Moore, Georgia Conservancy Senior Director of Sustainable Growth. “Because of this approaching challenge, local leaders need to understand now the variety of scenarios that sea level rise will likely create for planning, preparation and response. It is critical that we not overlook the specific impacts that will occur, and that we consider both our human populations and our natural environments in response to such change.”
A more recent SLR study on Georgia’s coast utilized tidal gauge data measured since 1935 at Ft. Pulaski (now operated by the National Oceanic and Atmospheric Administration) and analysis indicates that by 2110, the water level along Georgia’s coast will be one meter above today’s levels. The percentage of undeveloped dry land on the coast is projected to be reduced by eight percent, while open water could increase by 10 percent. Much of what we now see along the coast and in coastal marsh may be permanently inundated. With even modest sea level rise, the impacts on the state’s coastal population, industries, transportation infrastructure and historic communities will be significant.
Simplified models indicate this rise will meaningfully impact up to 30 percent of the Conservancy’s initial three-county study area (Chatham, Liberty and McIntosh counties). While our data analysis tells us where the greatest impacts will likely occur, the data itself is not sufficient to direct communities (individuals, companies, government officials and others) as to how they should best manage for the expected changes.
Our efforts through the following Blueprints studios is the next step.
Tracking the Effects of Sea Level Rise in Georgia’s Coastal Communities – Chatham, Liberty and McIntosh Counties
Our initial work focused on understanding the projected SLR levels and the physical impacts to vulnerable communities and their infrastructure. The Georgia Conservancy worked with students and experts at Georgia Tech to project SLR levels in Chatham, Liberty and McIntosh counties. Findings include:
- McIntosh County is likely to experience the highest percentage of impacted residential land - 20%
- Chatham County is projected to have the greatest loss of buildings – 8,900
- Tybee Island is projected to suffer significant impacts: loss of 50% of residential land, 48% of transportation-utilized land, and 30% of commercially-occupied land
- Impacts to environmentally sensitive facilities include four hazardous material sites, one landfill and three wastewater treatment plants
- Thirteen miles of I-95 and US 80 are projected to be impacted; 11 miles of CSX Norfolk Southern rail also impacted
Overall, nearly one-third (54.91 square miles) of all globally imperiled habitats in Georgia (G1-G3) will be impacted by the projected rise in sea level, and 70 percent of this inundation is of G3-ranked habitats, which are expected to lose nearly half of their existing areas.
Working Waterfronts (Port of Savannah and Darien): Economic Impacts of Sea Level Rise on Georgia’s Coast
This Blueprints studio describes and quantifies sea level rise’s impact on coastal Georgia’s economy and the potential repercussions. Sea level rise has the potential to affect communities equally but differently, so theBlueprints team focused on two very different sites to capture the diverse impacts. One is the Garden City Terminal at the Port of Savannah, which is one of the country’s largest container terminals and the second busiest container exporter by tons (Georgia Ports Authority 2013). The terminal is expected to continue rapid growth facilitated by a multi-million dollar port deepening project.
While the Port of Savannah is a major economic engine for the entire state, the city of Darien — which is the second study site — is a quintessential small, coastal town. Darien has nearly 2,000 residents and a heritage extending back to 1736. Darien’s economy is heavily dependent on a few industries, namely fishing, tourism and small business, and residential real estate, which makes it more vulnerable to sea level rise than larger cities. Both the Port of Savannah and the city of Darien have diverse constituents that will be impacted based on what is of value to them. The impacts on one site should not be understood to be greater than the other, but rather attests to fundamental differences in character.
The Blueprints team analyzed economic impacts on each site, taking different approaches depending on economic characteristics. Whereas the research team analyzed the Port of Savannah using a traditional economic impact study to measure the effects of a port shutdown, it approached the city of Darien entirely differently, conducting in-depth industry studies to draw connections between sea level rise and local 4 livelihoods. Each methodology was chosen based on site-specific characteristics, such as industry makeup, economic scale, and available data.
The studio’s analysis is intended to inform elected officials, residents, industry, community planners, and others as they prepare for sea level rise on the Georgia coast. Moreover, the analysis reveals that sea level rise is not just a coastal issue, but rather is important at regional, state and even national levels because of the accompanying economic impacts.
Community Adaptation and Design Solutions for Sea Level Rise
In this Blueprints studio we focus on the sea level rise impacts and adaptation opportunities for five communities along the Georgia coast: City of Savannah, Tybee Island, City of Darien, City of Brunswick, and City of St. Marys. Georgia’s coastal population, economic activity and culture will continue to be drawn to, and benefit from, a relationship with the water -- but what shape will the built environment of communities take in the future? Communities across the country are considering the implications of sea level rise and the options of defending the shoreline, retreating from the shoreline or adapting. We believe there is a way for Georgia’s communities, natural and man-made, to continue to thrive through adaptation.
Through a research and design- based process the Blueprints team (composed of Georgia staff, Professor Richard Dagenhart and the Georgia Tech graduate studio - composed of architecture, urban design and city and regionally planning students) made presentations, collected information and maps, conducted data collection within the community, and performed resident and business interviews to develop a set of draft recommendations for stakeholders’ consideration. These recommendations were supported by the community and form the basis of the final report.
The final output of the process is a Blueprints report that includes responses and mitigation strategies for the future of Georgia’s coast. Implementation of plan recommendations will be the responsibility of governments and authorities which have jurisdiction in the identified locations. The Blueprints process seeks to involve existing government leadership so that the final plan can be communicated to a wide array of stakeholders.
The report is the third report from the Georgia Conservancy looking into sea level rise impacts on Georgia’s coast.
For more information about our Sea Level Rise Blueprints studios read Sea Level Rise and the Future of Georgia's Coast by Ken Edelstein from our Winter 2015 issue of Panorama Magazine.
The Georgia Conservancy’s sea level rise work would not be possible without the generous support of Gulfstream, The Home Depot Foundation and The Ray C. Anderson Foundation, as well as the indispensable data supplied by Dr. Clark Alexander at the Skidaway Institute of Oceanography in Savannah.