Emergency management officials in Nebraska are urging residents with basements flooded by the recent storms to use caution when pumping them out. Removing all 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. The water must be drained slowly to equalize pressure on both sides of the wall, federal and state disaster response coordinators from the Nebraska Emergency Management Agency and the Federal Emergency Management Agency indicated.
Although the flood waters have receded, water still in the ground outside your house may be pushing hard against the outside of your basement walls. The water in the basement is pushing back. If basements are drained faster than the water on the outside is draining, the outside pressure will be greater than the inside pressure and may cause the foundation, basement walls or floor to crack or rupture.
We recommend the following procedures be followed when pumping basements to avoid serious damage, collapse or injury to occupants:
- Begin pumping when floodwaters are no longer covering the ground outside.
- Pump out 1 foot of water. 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, and then pump the water down 1 foot again. Check the level the next day.
- When the water in the basement stops returning to your mark, pump out two to 3 feet and wait overnight.
- Repeat daily until all the water is out of the basement.
It is understandable that people are anxious to return home and begin the cleanup but we urge caution, as the expense of rebuilding collapsed walls could be more than the cost of cleanup from the flood.