Barry, Chantal, Dorian and Erin will be names appearing in the news as hurricane season 2019 has officially started. If NOAA predictions are correct, we won’t make it all the way down the list to Sebastien, Tanya, Van and Wendy. The National Oceanic and Atmospheric Administration predicts a near-normal hurricane season with 9 to 15 named storms coming from the Atlantic Ocean and the Gulf of Mexico.
For North Georgia, this has a different meaning than it does in coastal cities. Hall and neighboring counties are far enough from the ocean to experience hurricanes only in their dissolving stage. Gale-force winds are a lesser concern here than flash flood hazards. In our hilly landscape, buildings at the bottom of valleys are vulnerable. If Georgia follows the example of Texas, where rain intensity has increased significantly in the past few years, we can expect rainstorms to be stronger than they used to be. It doesn’t mean more storms, just heavier ones. Harder rain produces faster runoff, which can quickly overpower storm sewers and stream beds.
The town of Helen is a first point of concern, built largely on an old floodplain of the Chattahoochee. That peaceful little river flowing past the cafes on North Main Street can swell to terrific proportions if its headwaters catch severe short-term rain. Much of Helen’s downtown area is less than a dozen feet above normal river level. Lake Lanier protects Gainesville, providing a large reservoir that can absorb flood waters and release excess flow at Buford Dam when necessary. Cleveland isn’t on a floodplain as narrow as the one in Helen. But Mossy Creek, Cox Creek and a few others come together in that area. A number of structures along US 129 are located on flat sediment terraces that were built by ancient flooding.
When a hurricane or tropical storm is headed for our area, I don’t board up all the windows, as I used to do while living on the North Carolina coast (elevation 37 feet). The operative term up here, at 1,200 to 1,600 feet, is drainage. It’s important to be aware of how high the property stands above a river or creek. If it’s only a few feet, flash flood warnings become crucial. Even when power, phone lines and internet are disabled, an old-fashioned battery-operated NOAA Weatheradio still provides a lifeline of information.
Rudi Kiefer, Ph.D., is a professor at Brenau University, teaching physical and health sciences on Brenau’s Georgia campuses and in China. His column appears Sundays and at gainesvilletimes.com.