Posted March 4, 2010
... And here we're not talking about the kind that comes from plumbing, but flood waters that result when too much rain falls in too short a time to be absorbed and channeled away safely by soil and by the drainage system that includes creeks, streams, rivers, and in urban areas, gutters, curb drains, piping and culverts. Flooding can be initiated on a slow time scale and over wide areas by sustained rain over a series of days or by very heavy rain over a large area, something our region has had unfortunate experience with in a number of tropical storms and hurricanes, with Fran and Floyd in particular jumping right to mind. In addition, intense thunderstorms during the spring and summer sometimes move along at a very slow pace, or may "train" across a localized area one after another. In these cases, waters can rise very rapidly and sometimes in unexpected locations, leading to "flash flooding."
While it doesn't always get the attention some other atmospheric phenomena do, the Centers for Disease Control tell us that flooding is the number one weather-related killer in the country, and that more than half of the drownings that occur in flooding happen because of people driving into flooded areas, with many more losing their lives when they walk into flood waters. The basic problem seems to be that many of us simply underestimate how much force is really involved when you combine the density and velocity of moving water with the temporary buoyancy of a vehicle or the relative "lightweight" status of a human being.
The common examples stressed by safety experts are that just a few inches of fast-flowing water can take a person off their feet, and that around two feet of water and sometimes less can sweep a vehicle off a breached roadway and very quickly into much deeper, and often violently turbulent, water, from which they may not return alive. Worse, it can be very difficult to judge visually how deep some water you consider crossing might really be, or to gauge how fast it may be moving. Many people rescued from ruined cars have reported that the water they drove into just didn't look that deep or swift until it was too late.
While I've been lucky enough to avoid any major problems along the way, I have been sensitized to these issues by a couple of incidents that made a big impression. As a teenager delivering newspapers in Rocky Mount way back when, I covered an area just south of City Lake and east of the Tar River. There was a house near the river where I routinely pulled into a sloping driveway, tossed a paper into the garage, then backed out to go the opposite direction from which I had arrived. One dark early morning I turned in to see the driveway covered in what appeared be a large sheet of shallow, still water from recent rains. As I was pulling the last couple of feet into the drive and slipping a paper into a plastic bag, I felt the front of the car suddenly lurch a few inches down, then float upward and begin to yaw to the left. Part of the drive had washed out, and the seemingly calm water was in fact moving along. The front tires and steering offered no bite or control at all, but when I threw it into reverse and pressed the gas, the rear tires slipped a bit at first but then managed enough traction to skitter backwards and get back into the street, where I caught my breath a bit, and continued on with my route.
Since that brush with how quickly control of the car could be lost in seemingly innocuous water, I don't mind finding an alternate way around when I encounter a flooded road, which happened with some regularity when I was a student at Florida State in Tallahassee (an apartment I lived in there flooded in a big rainstorm as well, but that's another story!). This is behavior that I would recommend for anyone, and so does the National Weather Service, in the form of its "Turn Around, Don't Drown" campaign. I've included links to more info on the campaign, and other flood safety and insurance information, most of which you can reach through the NWS Flood Safety Awareness page.