It only takes one storm to change your life and community. The theme of this year’s Hurricane Preparedness Week, along with the reminder #ItOnlyTakesOne, underscores the devastating power of tropical cyclones. Scheduled for May 15-21, Hurricane Preparedness Week will focus on encouraging states, communities, and the general public in storm-prone areas to understand regional wind and water threats and prepare accordingly.
In states in the Southeast and along the Gulf Coast, part of that vital preparation includes development of a comprehensive hurricane evacuation plan. We prepared the Georgia Hurricane Evacuation Study (HES) for the Savannah District of the U.S. Army Corps of Engineers (USACE), and it is now serving as a model for other states and communities focused on this critical aspect of hurricane planning. In particular, the Federal Emergency Management Agency’s (FEMA) National Hurricane Program (NHP), which funded the USACE project, has adopted the interactive study format developed through this project as the national standard for future hurricane evacuation study efforts.
Providing the Latest Tools and Technical Data
According to the National Hurricane Center, Georgia has the potential for the highest storm surge inundation levels of any East Coast state, with the possibility of inundation levels reaching heights of more than 30 feet along the shoreline. As the primary study manager, we were tasked with conducting and assimilating the various components of the hurricane evacuation study for coastal Georgia. These components included the behavioral analysis, the shelter analysis, the vulnerability analysis, and the transportation analysis. The USACE’s goal was to provide state and local emergency managers with the latest tools and technical data to develop plans and procedures to protect the population at risk from tropical storms and hurricanes.
As a first step, our team performed more than 2,000 phone surveys with coastal residents to determine behavioral patterns of the at-risk population, followed by development of a report to document the findings. Next, we conducted a vulnerability analysis of the population, infrastructure, and buildings and compared these to the surge inundation areas from the National Hurricane Center’s Sea, Lake and Overland Surges from Hurricanes (SLOSH) model. We conducted meetings with coastal county emergency managers and other representatives to assist with the development of evacuation areas for six potential categories of storms (as Georgia has such a huge surge potential, tropical storm scenarios were also calculated), and then created a vulnerability report examining populations and structures at risk through six SLOSH surge zones and the newly created evacuation zones. These products educate emergency managers on the vulnerability of communities and help communicate risk. They also provide the data necessary to develop the next phase: the evacuation plan.
The final phase involved determining clearance times for evacuating at-risk populations. All of the data developed and compiled in these analyses was presented in an interactive technical data report (ITDR) that allows users and emergency management personnel to query the document to assist in timely planning and evacuation decision-making. The data is used by state and local agencies to run exercises, plan preparedness activities, develop mitigation actions, and explore potential support for recovery and post-disaster plans.
A GeoPDF was developed for each of the six coastal counties, encapsulating the results of the spatial analysis performed in GIS. The GeoPDF packages this information into an easy-to-use format available to all emergency personnel. A “Re-Entry” template was also developed for the coastal areas to enable counties to develop an organized and orderly return of the evacuated population.
Preparing for a Successful Evacuation
According to Will Lanxton, state meteorologist and hurricane program manager for the Georgia Emergency Management Agency, “The Georgia Hurricane Evacuation Study allows us to examine vulnerable coastal areas and know where critical facilities are in relation to flood, surge, and evacuation zones. It provides comprehensive analyses on the societal, behavioral, and transportation issues that go into a successful evacuation. The next time a hurricane hits Georgia and a news camera is in our State Operations Center, you will see the Georgia Hurricane Evacuation Study on a big screen being utilized by our hundreds of partners.”