Pumping Your Flooded Basement -- Use Caution

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Release date: 
July 28, 1999
Release Number: 
1282-09

CEDAR RAPIDS, Iowa -- Emergency management officials are urging Iowa residents with basements flooded by the recent storms to use caution when pumping out. Removing all of the water at once may cause serious structural damage to the house.

Draining the water too fast could cause the collapse of the cellar walls, floors, and foundation of the house. The water must be drained slowly to equalize pressure on both sides of the wall.

Although the flood has receded, water still in the ground outside your house may be pushing hard against the outside of your basement walls. The water in your basement is pushing back. If you drain your basement faster than the water in the ground is draining, the outside pressure may be greater than the inside pressure and may cause the foundation or the floor to crack or collapse.

The Federal Emergency Management Agency (FEMA) and the Iowa Emergency Management Division (IEMD) recommend the following procedures be followed when pumping a basement to avoid serious damage, collapse, or injury:

  • Begin pumping when floodwaters are no longer covering the ground outside.
  • Pump the water out one foot at a time. Mark the water level and wait overnight.
  • Check the water level the next day. If the level went back up (covered your mark) it is still too early to drain your basement.
  • Wait 24 hours, then pump the water down one foot again. Check the level the next day.
  • When the water in the basement stops returning to your mark, pump out two to three feet and wait overnight.
  • Repeat daily until all the water is out of the basement.

"We understand people are anxious to return home and begin the clean-up," said Curt Musgrave, FEMA federal coordinating officer, "but we urge caution because the expense of rebuilding collapsed walls could be more than the cost of clean-up from the flood."

Safety precautions should also be taken to avoid injury.

  • Never enter a flooded basement unless you are absolutely sure the electricity has been turned off.
  • Do not use gasoline-powered pumps or generators indoors or in a confined space. Gasoline engines emit deadly carbon monoxide exhaust fumes.
  • Tetanus shots are strongly recommended when working around contaminated floodwaters.

"Safety is always a major concern in a disaster clean-up," said Steve Zimmerman, IEMD coordinating officer. "Under these stressful conditions it is critical that people be concerned for their health and safety."

Last Updated: 
July 16, 2012 - 18:46
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