We spent the first years of this decade worrying about persistent droughts. And then, 2018 happened. Last year was one of the wettest in the history of North Georgia. On average, Gainesville receives 54 inches annually. In 2018, we got almost 70. That’s a big reversal from the situation in 2007, one of the worst drought years in our city. Fall season at Clarks Bridge Landing had Lake Lanier shrinking to almost half its width. After 18 drought days, governor Perdue led a public prayer for rain on November 13. Apparently it helped, as 0.6 inches fell on Gainesville 48 hours later. But the total for 2007 only came to a meager 31 inches.
Ten years ago, when climatic change was still a policy topic in the U.S. government, it looked like water shortages would dominate North Georgia’s climate for decades to come. Now, flash flood warnings and trees getting uprooted from the soggy ground are a more urgent problem. Predicting “forever drought” for our region was obviously incorrect. So is the expectation of constant wet conditions. The climatic adjustments in progress will continue to bring more variability to our weather patterns. We’ll see cold, warm, wet and dry spells as we always have, but with more unusual timing and in a more capricious fashion.
According to factfinder.census.gov, Hall County’s population has grown by 11% between 2010 and 2017. This is accompanied by growth of housing, streets, shopping centers and offices to support the increasing number of residents. Inevitably, more landscape gets paved over or covered with buildings. That, in turn, increases flash flood hazards.
If 2019 follows last year’s rain patterns, we need to be aware of the rising flood probability. According to the National Weather Service, nearly half of all flood deaths involve vehicles, and more than half the victims are male. The 2019 flash floods can destroy mobile homes. But the people at greatest risk are drivers trying to make it across flooded streets. A common misjudgement is underestimating the speed at which water rises, and the pushing power that it exerts. The second one is assuming that there’s still a road beneath the water surface, when in fact there could be a new, 10-foot deep underwater ravine. Keeping in mind that more covered surfaces lead to more water runoff is the first step toward flash flood preparedness.
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.