TRACKING THE EFFECTS OF Chatham SEA LEVEL RISE IN GEORGIA’S COASTAL COMMUNITIES: Chatham, Liberty, and McIntosh Counties Liberty Fall 2012 McIntosh A project of the Georgia Conservancy Chatham TRACKING THE EFFECTS OF SEA LEVEL RISE IN GEORGIA’S COASTAL COMMUNITIES: Chatham, Liberty and McIntosh Counties Georgia Conservancy Blueprints Partners American Council of Engineering Companies of Georgia American Institute of Architects - Atlanta Chapter American Society of Landscape Architects - Georgia Chapter Association County Commissioners of Georgia Atlanta Neighborhood Development Partnership Atlanta Regional Commission Georgia Institute of Technology - College of Architecture Georgia Municipal Association Georgia Planning Association Institute of Transportation Engineers Southface Energy Institute Urban Land Institute - Atlanta District Council U.S. Green Building Council - Georgia Chapter We are Grateful to the Generous Donors who Supported the Sea Level Rise Blueprints: The Home Depot Foundation THIS REPORT WAS CREATED IN PARTNERSHIP WITH The School of City and Regional Planning College of Architecture Georgia Institute of Technology 245 4th St. NW Atlanta, GA 30332 Our mission is to protect Georgia’s natural resources for present and future generations by advocating sound environmental policies, advancing sustainable growth practices and facilitating common-ground solutions to environmental challenges. TABLE OF CONTENTS TABLE OF CONTENTS 1.0 INTRODUCTION 1 5.0 ADAPTATION 67 Blueprints Initiative 1 Full Retreat 68 Executive Summary 2 Full Protection 69 Partnerships 3 Accommodation 70 How Will Sea Level Rise Affect the Triple Bottom Line: Vulnerability Physical Landscape? 3 Justification 70 How Will the Population on the Coast be Mixed Methodologies 74 Impacted? 5 Alternatives for Shore Protection 84 Infrastructure Adaptation 94 2.0 BACKGROUND 7 Adaptation Strategies for Wetlands 101 Three County Study Area 7 Education, Outreach and Community Sea Level Rise Data 8 Input, and Social Vulnerable Resources 110 Study Approach 9 The Gullah-Geechee Community 113 Under the Umbrella of Community 3.0 PHYSICAL IMPACTS 13 Development 115 Land Cover and Existing Habitats 13 Land Use 19 6.0 FURTHER ACTION 119 Building Number and Replacement Value Data 21 7.0 REFERENCES 125 Suggestions for Further Land Use Analysis 29 PARTICIPANTS 129 Savannah, Chatham County 29 Tybee Island, Chatham County 33 Darien, McIntosh County 35 Physical Variables 37 4.0 SOCIAL IMPACTS 45 Population Density and Households 47 Age 49 Race and Ethnicity 50 Gender and Family Status 51 Education 51 Occupation and Employment 52 Income and Poverty 57 Housing and the Built Environment 58 Mode of Transportation 60 Disability 60 Gullah-Geechee 60 Conclusion 65 1.0 INTRODUCTION Blueprints for Successful Communities (Blueprints) is 1.1 BLUEPRINTS INITIATIVE an 18-year-old sustainable community design program of the Georgia Conservancy. The Blueprints process Through a research driven process, the Blueprints uses a community-based approach to sustainable team (composed of Blueprints staff, instructors Larry planning and design. It is unique in that it involves key Keating and Dana Habeeb, and the Georgia Institute stakeholders – including citizens, businesses, agency of Technology graduate City and Regional Planning and institutional representatives, and elected and studio) worked to determine not only the impacts of appointed officials – throughout the entire planning sea level rise (SLR) on three coastal counties, but also process of redeveloping a community to better the impacts of rising seas on current populations. The incorporate and focus on natural resource protection, team conducted data collection within the communities green space accessibility, sustainable land use, and to produce maps and outputs; some stakeholder live-work connectivity. The Blueprints process is one of interviews and site visits; and a set of conclusions the most highly respected planning processes in our and draft recommendations for stakeholders’ state because of its inclusiveness, transparency and consideration. These recommendations form the basis technical quality. of this report and will be utilized in upcoming years to educate stakeholders and advance this knowledge. 1 BLUEPRINTS PRINCIPLES Consider the effect of the Maintain and enhance Employ regional strategies built environment on the quality of life for residents for transportation, land use, Employ efficient land uses natural environment as well of the community and economic growth as history and culture In this report we focus on the sea level rise impacts today’s levels. While this prognosis is significant and and adaptation opportunities for three counties along potentially devastating, the change will be incremental. the Georgia coast: Chatham, Liberty, and McIntosh. We are fortunate to have the opportunity to take We investigate the effects that SLR will have on the advantage of the early warnings and to investigate population, the natural and built environments, and the effects that a SLR of this extent would have on our the economy of this three county area. Our goal is to population, our natural and built environments, and provide residents, decision-makers, and researchers our economy. with information that can help them proactively plan for future SLR so that the Georgia coast is better equipped In an effort to confront the challenge of planning for for the coming changes. This report is the result of a sea level rise, ten graduate students from the Georgia semester-long graduate planning studio led by Dr. Larry Institute of Technology’s School of City and Regional Keating and Dana Habeeb. Planning, under the direction of Dr. Larry Keating, Ph.D., FAICP, and Dana Habeeb, and in partnership with The Blueprints for Successful Communities program the Georgia Conservancy, have investigated potential adheres to values that protect communities and the impacts and adaptation opportunities for three environment, and it respects the link between the counties along the Georgia coast: Chatham, Liberty, health of our environment, our economic stability and and McIntosh. This study region, spanning 1,378 the way we use land. The Blueprints for Successful square miles and containing a population of 334,099, Communities principles are shown at the top of the is an important piece of the state of Georgia. Our hope page. is that residents, decision-makers, and researchers will take advantage of the more detailed warnings that By following these principles, we raise public awareness we have compiled to prepare for a future in which the in Georgia about alternative land use and transportation coast is better equipped for the coming changes. strategies that are good for the environment and good for the economy. Several times in this report supplemental information from an “Appendix” is mentioned. This online Appendix 1.2 EXECUTIVE SUMMARY can be found on the Georgia Conservancy website at http://www.georgiaconservancy.org/blueprints/sea- Based on measurements indicating a significant rise in level-rise.html Earth’s sea levels since 1935, scientists have projected that by the year 2110, the surface of the oceans on the Georgia coast will be approximately one meter above INTRODUCTION 2 1.3 PARTNERSHIPS include: supplying additional sediment to promote wetland accretion rate; installing “soft” shoreline Partner organizations and decision-makers are protection alternatives to allow wetland migration; and instrumental in the dissemination of the research and building and enhancing barrier islands to create an recommendations found in this Blueprints report in offshore protection system. their respective communities. Though SLR seems to be on the long-term horizon, action must be pursued These four strategies are supplementary to one now to better position Georgia’s coastal communities another and should be considered inclusively in any to a changed landscape. The Georgia Conservancy is adaptation plan for wetlands. Hardscaping shorelines working with coastal agencies to convey report findings has been a popular method for mitigating damage and work through some impending issues related to caused by changing water levels; however, this method SLR. While the research and recommendations in this causes significant disruption in wetland migration. We report are specifically based off three counties, the recommend that municipalities consider removing counties are of varied sizes with differing advantages some of the hardscaping currently in place to create and disadvantages. Therefore, these studies can be more area for wetland movement. modified to address other coastal communities and the approach to discovering vulnerable populations can be In the end, it is important to remember that though applied across the coast. The Georgia Conservancy will SLR is a slow process, local governments must take continue to share this information with thought-leaders early action to reduce the costs and difficulties of on the coast and work to make the policy and planning implementing plans to protect the natural environment. changes to better our community adaptability. THE BUILT ENVIRONMENT 1.4 HOW WILL SEA LEVEL RISE AFFECT THE PHYSICAL LANDSCAPE? McIntosh County has the largest percentage of residential land threatened by flooding due to SLR at nearly 20%. Most of this land is concentrated in The most obvious effects of sea level rise will be Darien (where 30% of residential areas are projected physical. Simplified projection models indicate that by to experience