Fluid Dynamics Water weighs about 62.4 pounds per cubic foot and typically flows downstream at 6 to 12 miles an hour. When a vehicle stalls in the water, the water's momentum is transferred to the car. For each foot the water rises up the side of the car, the car displaces 1,500 pounds of water. The Human Element Most vehicles will become buoyant in two feet of water or less. Few people, including Public Safety and Rescue personnel, appreciate the power of flowing water.
Fewer people realize how fast water can rise in a small stream to flood a low-water crossing area.
More than half of all low-water crossing vehicular related deaths occur at night. Under conditions of low-visibility the vulnerability of the driver and passengers to the hidden danger is greatly magnified. High volumes of moving water play havoc on bridges, road beds, and other structures. What may appear as a normal road, may in fact, be a death trap. Therefore, all posting warnings and barriers adhered to.