With today's technology, we can accurately predict flood hazard areas. Flood models indicate which roads will overtop at various flood levels. Permanent signage and automated barricades alert drivers to potential danger or keep them from accessing a route.
But they won't keep the general public from underestimating the power of moving water.
Fast-moving flows only 6 inches deep can wash a man off his feet and carry him downstream. Likewise, it takes only 2 feet to push a car off the road.
Most people can't imagine a heavy SUV floating on water. You'd expect a half ton of metal to sink — and it will, eventually — but it'll float long enough to be swept from the road. The faster the water's flowing, the more likely it is that the vehicle will be pushed off the road into the stream.
Even still water can be dangerous to drive into.
The water may be covering a sinkhole or obstruction. Furthermore, the flat surface of the water is misleading. Water in the middle of the road is deeper than on the sides. This isn't obvious to drivers who can't see the road surface because of the murky water.
Since last year's fatal flooding, local governments throughout Douglas County have adopted a multijurisdictional mitigation plan that includes developing:A database of road crossings within flood hazard areas that indicates which will overtop during 5-, 10-, 100-, and 500-year storm events. About half of the county's more than 300 crossings are included. The rest will be added as flood studies are completed in the next three years.Procurement policies based on the county's DOT procedures that allow for the timely mobilization of consultants and contractors.
A hazard mitigation committee has been formed to update the Douglas County Hazard Mitigation Plan. Further efforts such as permanent signage and early warning systems will be discussed with a revised plan scheduled for implementation by the end of 2010.
“Have appropriate purchasing and solicitation policies in place so you can react quickly,” says DOT Assistant Director Keary Lord. “Having on-call construction contractors already in place and ready to mobilize, as well as an on-call consultant team to enhance and work as an extension of your staff, is a major part of being prepared for a disaster. Also, know FEMA's policies so you follow the rules to be eligible for reimbursement.”
The epic flash flood in September 2009 was devastating. I would never have thought such rainfall was possible had I not seen it myself. If it can happen once, it will happen again.