March 25-29 is Severe Weather Awareness Week for Nebraska and Iowa. Each day, a different aspect of severe weather will be highlighted, explaining the science behind them, and how you can stay safe when severe weather threatens. This article will focus on flooding and flooding safety.
THE POWER OF WATER
Fast-moving water is quite powerful. It takes 6 inches of water to sweep you off your feet. It only takes 12 inches to move a car, and 18-24 inches to move a larger vehicle such as a truck.
These distinctions might not mean much if you can not tell the depth of the water, as most flooding situations have brown murky water where you can't see the depth. This is why avoiding floodwaters at all costs is the preferred safety method.
RIVER FLOODING VS FLASH FLOODING
Flooding can come in all forms but there are three main types of flooding seen in Nebraska and Iowa: river flooding, ice jam flooding, and flash flooding. We can see a combination of all three, like we did in March 2019.
RIVER FLOODING - River flooding is often more gradual, lasts longer, and impacts those near its banks. Sometimes river flooding can last from several days to whole seasons depending on the severity of it.
FLASH FLOODING - Flash flooding typically occurs during a period of heavy rain in a thunderstorm, if the rain is heavy enough it can overwhelm waterways or water drainage systems, leading to flooding in the area. As was seen in the Old Market in 2021, flash flooding can occur any place with little to no warning.
ICE JAM FLOODING - A form of flash flooding that combines it with river flooding is ice jam flooding. In the late winter as the river ice breaks up, it can become jammed in river bends, bridges, or shallow areas of the river. This acts as a dam to back the water up, leading to flooding in the surrounding area.
FLOODING SAFETY
The number 1 thing to remember about flooding safety is: turn around, don't drown! You do NOT know the depth of the water, and if the road is even there. As shown above, water 1 to 2 feet can float most vehicles.
If you are in your home during a flash flood, evacuate if it is safe to do so and find higher ground.
