Flood Definitions & Information

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Not all flood events are created equal . . . general flood info for Findlay, OH


What is a FLOOD vs. a FLASH FLOOD?  

FLOOD: An overflow of water onto normally dry land. The inundation (another word for flooding) of a normally dry area caused by rising water in the Blanchard River, Lye Creek, Eagle Creek or a ditch.  Flooding is a longer-term event that usually develops more slowly.  A flood in Findlay can cause areas to be flooded for multiple days.
 
FLASH FLOOD: Unlike flooding, flash floods can develop in a few minutes. Flash floods can also occur in areas outside the flood plain. Flash floods are usually caused when more rainfall occurs than can be handled by the storm sewers in the area. Yards and streets can be quickly inundated when storm sewers are at capacity.  Flash floods generally recede fairly quickly, but damage can already be done. 


Every rain event is different:

  • Intensity - amount of rainfall
  • Duration of rainfall โ€“ how short or how long
  • Ground condition โ€“ saturated, crusted, or frozen
  • Travel time - rainfall location within the watershed.

These are just some of the factors that affect flooding. Because of the variables, it is difficult to predict exactly how Findlay will be affected each time we experience significant rain. One of the best data sources we have for flood level projections can be found on the Blanchard River Hydrograph (NOAA).


What happens in Findlay when it floods?

During flash floods and minor flood level stages, here are some things to expect:

  • Storm sewer systems can become overwhelmed causing flooded roads*
  • Certain thoroughfares and neighborhood streets will be closed due to high water
  • Basements may take on water
  • Downspouts overflow leaving water to saturate the ground around the home
  • Sump pumps fail to keep up with incoming water
  • Saturated utility storm and sanitary lateral trenches can carry water underground to basement walls
  • Backflow preventers on sump pumps can fail
  • Groundwater tables can rise and put pressure on basement walls forcing water in
  • Basement floor drains can surcharge
  • Basement toilets can surcharge in some areas
  • Many low-lying areas will have standing water
During more major flooding, in addition to the above, expect that:
  • The Blanchard River, Eagle Creek and/or Lye Creek will rise to flood level stages (can range from Minor to Major)
  • Many key north/south routes through Findlay may be closed, including Main St., Western Ave./Broad Ave. and Blanchard St.
  • Some people may be stranded at their homes

*Note:  Stormwater infrastructure is not constructed to handle the volume of water in flash flood โ€“ it would be cost prohibitive


BE SAFE!

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What is the difference between a Flood Watch and a Flood Warning issued by the National Weather Service?

Flash Flood Warning: Take Action! A Flash Flood Warning is issued when a flash flood is imminent or occurring. If you are in a flood prone area move immediately to high ground. A flash flood is a sudden violent flood that can take from minutes to hours to develop. It is even possible to experience a flash flood in areas not immediately receiving rain.

Flood Warning: Take Action! A Flood Warning is issued when the hazardous weather event is imminent or already happening. A Flood Warning is issued when flooding is imminent or occurring.

Flood Watch: Be Prepared:A Flood Watch is issued when conditions are favorable for a specific hazardous weather event to occur. A Flood Watch is issued when conditions are favorable for flooding. It does not mean flooding will occur, but it is possible.

Flood Advisory: Be Aware: An Flood Advisory is issued when a specific weather event that is forecast to occur may become a nuisance. A Flood Advisory is issued when flooding is not expected to be bad enough to issue a warning. However, it may cause significant inconvenience, and if caution is not exercised, it could lead to situations that may threaten life and/or property.