Savannah’s Rising Seas
This map shows the areas in and around Savannah, GA that would be inundated by a flood three feet higher than a large local high tide. It therefore serves as a crude indicator of lands vulnerable to a 3-foot sea level rise, without considering factors like shifting currents, sediment deposits, or salt marshes that may complicate the exact location of the future shoreline. The map also leaves out the full extent of vulnerable land because it does not include updated flood risk areas from storms on top of sea level rise. Most current research projects a global average sea level increase between two and five feet by 2100.
According to the U.S. National Oceanic and Atmospheric Administration's (NOAA's) Coastal Services Center, “uring coastal floods today when water reaches a level 1.5 feet below the level depicted on this map.
Water level on the map is 11.5 feet above “mean lower low water” (MLLW) at Fort Pulaski, GA. (MLLW is a standard reference measure for low tide.) The highest Fort Pulaski tide most months is between 8.5 and 8.7 feet above MLLW, and the NOAA warning just above corresponds to 10 feet above MLLW — still referenced to the Fort Pulaski tidal gauge. NOAA's Coastal Services Center developed the flood layer shown here based on a 6-inch vertical resolution elevation map of the Savannah area, produced by laser fly-over measurements conducted for the Chatham Emergency Management Agency. A NOAA Coastal Services Center website provides a Coastal Innundation Toolkit provides additional information on flood and storm surge scenarios (including for Chatham County, GA). The shallow coastal flooding scenarios factor in only sea level and land elevation — a method also commonly used to illustrate areas vulnerable to long-term sea level rise.1
Background imagery for this map comes via Google Earth. Inundation has not been modeled or represented in the very upper right and lower left hand corners. The water in these corners reflects tide at an unknown stage.