Floods and Flash Floods
the awesome power



  • Even though Wisconsin doesn't have steep mountainous terrain, it has had its fair share of flash floods and floods which have injured or killed many people, and caused millions of dollars in damage to all kinds of property. Wisconsin has many old, earthen dams which are getting weaker each year for a variety of reasons, one of them being tree roots expanding down through the compacted soil. These old earthen dams are very susceptible to flash flooding! Find out if there is an earthen dam in your local area!!!
  • Flash flooding or flooding due to ice jams are a threat every year somewhere in Wisconsin since most of its river's ice over in the long, cold winters. Flash floods due to ice jams are highly unpredictable, and can happen very quickly.
  • Between 1990 and 2008, flash floods and other floods killed 8 Wisconsin residents.
  • The parts of Wisconsin that are most susceptible to flash floods and other floods are the urbanized southeast locations, and the hilly southwest and west central counties.
  • The Milwaukee Metro area to Fond du Lac and Sheboygan experienced major flash flooding on June 21, 1997 after numerous thunderstorms dumped 5 to almost 10 inches of rain. Luckily, there were no deaths or injuries, but property and agricultural damage totaled about 92.1 million dollars.
  • A killer flash flood occurred on the Baraboo River and Skillet Creek near Baraboo in Sauk County overnight on July 17, 1993. Heavy rains of 12 to 13 inches triggered the flash flood which resulted about 7.8 million dollars in property damage. Sadly, a 12-year old boy drowned in a car he was riding in after it was swept away by the flood waters.
  • A flash flood damaged 50 to 75 miles of highways in Florence and Forest Counties on July 15, 1999, after 5 to 8 inches of rain fell in only a few hours. Damage to 49 homes, 2 businesses and the roads totaled about 2 million dollars.
  • On July 25, 1999, heavy rains of 3 to 6 inches on top of wet soils resulted in flash flooding across Douglas, Bayfield, and Sawyer Counties. Many roads were washed away. Flood damage in Douglas County alone totaled 2 million dollars.
  • Widespread heavy rains totaling 6 to over 12 inches across southern and central wisconsin during the period of August 18th through 23rd, 2007, resulted in widespread flash flooding and a few all-time river crests across southern Wisconsin.  The worst of the rains and flooding
    affected the area near the Mississippi River between La Crosse and Prairie du Chien.
  • Widespread heavy rains totaling 7 to over 15 inches across southern and central wisconsin during the period of June 5th through 13th, 2008 resulted in widespread flash flooding and all-time river crests.  Several roads and bridges were washed out, majro highways and
    Interstates were closed, and numerous homes, farms, and businesses suffered moderate to severe damage.  Total damage amounts were at least $764 million and may be as high as $1 Billion. There was only 1 directly-related flood death.


  • Warm season flash floods are the result from intense rainfalls in a short period of time due to slow moving thunderstorms. Topography, soil conditions, and ground cover also play an important role.
  • Flash Floods occur within a few minutes or hours of excessive rainfall, a dam or levee failure, or a sudden release of water held back by an ice jam. You may have only SECONDS to save your life by the time you realize what is happening!
  • It takes only 6 inches of fast flowing water to sweep you off your feet!
  • Water only 2 feet deep can float away most automobiles!!!
  • Nearly half of all flash flood fatalities in the USA are auto related!!! Once a car is floated away, it can easily be flipped over, thus trapping its occupants, and leading to possible drowning.
  • Many flash floods occur at nighttime... when it is difficult to see. 75% of flood deaths occur at night.
  • Flash Floods can affect built-up urban areas because run-off is increased 2 to 6 times thanks to the paved roads, parking lots, sidewalks, and buildings. 60 % of flood deaths occur in urban areas.


  • Know which county you live in. The National Weather Service issues Flash Flood or Flood Watches on a county basis when there is a possibility of flash flooding or flooding in or close to the designated watch area. Be on the alert!
  • Flash Flood or Flood Warnings are issued when flash flooding or flooding has been observed or is highly imminent.
  • Urban and Small Stream Advisories are issued for inconvenience flooding of small streams, streets, and low-lying areas such as railroad underpasses and urban storm drains.
  • Know your area's flood risk, flood history, and elevation above flood stage. Determine whether you live in a flood plain. Identify where high ground is located should a flood occur.
  • Check your homeowner's or renter's insurance coverage concerning flood damage. You may have to pay an extra premium for flood coverage.
  • Have a family emergency plan. Have a pre-determined spot away from your home where you & your family can go to if told to evacuate. Chose an out-of-state friend as your family check-in contact, should you get separated from your family.
  • NEVER drive across a flooded road!!! You don't know how deep the water is, or if the road has been washed away underneath the water level. DO NOT attempt to wade across a flooded street!!!
  • Do not camp or park your vehicle along streams and washes, particularly during threatening conditions.

...Produced by Warning Coordination Meteorologists from the NWS Offices servicing the state of Wisconsin

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