Monday…Flash Flooding

The Iowa Homeland Security and Emergency Management Division and the National Weather Service have declared the week of March 23 through March 27, 2015 Severe Weather Awareness Week. Severe Weather Awareness Week is an annual event to remind Iowans that severe weather is part of living in our state and that understanding the risks and how to respond to them can save lives. Each morning during severe weather awareness week, we’ll be focusing on a different severe weather topic. The topics this year include:

  • Monday – Flash Flooding
  • Tuesday – Warning Reception
  • Wednesday – Tornadoes
  • Thursday – Severe Thunderstorms
  • Friday – Family Preparedness

FlashFloodRisks2Each year, more deaths occur due to flooding than from any other thunderstorm related hazard, resulting in more than 140 fatalities each year. The majority of flash floods are caused by slow moving thunderstorms, thunderstorms that redevelop over the same area, or heavy rains from tropical storms and hurricanes. These floods can develop within minutes or hours depending on the intensity and duration of the rain, the topography, soil conditions, and ground cover.

What is a Flash Flood? DidYouKnow2

A flash flood is a rapid rise of water along a stream or low-lying urban area. Flash floods can roll boulders, tear out trees, destroy buildings and bridges, and scour out new channels. Rapidly rising water can reach heights of 30 feet or more. Flash flood-producing rains also can trigger catastrophic mud slides.

Flash Flood Myths versus Facts Matching Game



Almost half of all flash flood fatalities east year occur in vehicles. Many folks don’t realize that just 2 feet of water flowing over the road can sweep away a vehicle. Sometimes even less water if the water is flowing rapidly! Even SUVs and trucks can be swept away with a flash flood. Water can cause significant structural damage to roads and bridges, creating very unsafe driving conditions. Underpasses can fill up quickly with water and driving into one could put yourself into six feet of water very fast. Many flash flood, and thus flash flood related deaths, occur at night as the roads and water are difficult to see. This is especially true in Iowa as a high percentage of heavy rain events occur with the sunset.


What You Can Do to Protect Yourself from Flash Flooding


What is a Flash Flood Watch and Warning? And what actions should be done when NWS issues a Flash Flood Watch or Warning?