If your basement if flooded, don’t rush to pump it out.
Water in the ground outside your house will still be pushing hard against the outside of your basement walls, and the water inside your basement is pushing right back. If you drain your basement faster than the water outside drains out of the ground, the outside pressure will be greater than the inside pressure, causing walls and floors to crack and possibly collapse.
How to Safely Pump Water Out of Your Basement
1) Never go into a flooded basement unless you are sure the electricity is off.
2) Start pumping the water out of the basement when floodwaters no longer cover the ground.
3) Don’t use gasoline-powered pumps or generators indoors. Gasoline engines create deadly carbon monoxide exhaust fumes.
4) Pump the water level down 2 or 3 feet. Mark the level, and wait overnight.
5) Check the water level the next day. If the water level went back up over your mark, it is still too early to drain your basement. Wait 24 hours, then pump the water down 2 or 3 feet again. Mark the level and check it the next day.
6) When the water stops rising, pump down another 2 or 3 feet and wait overnight. Repeat steps 4 and 5 until all water is pumped out of the basement.
What to Do After Draining Your Basement
· Disinfect the floors and walls to remove bacteria left from the floodwaters.
· Before turning the power back on, check any electrical service that may have been damaged. Replace any wiring, switches, outlets that were wet during the flood.
· Remove heating and air conditioning vents or registers as soon as possible and hose out the ductwork. Those ducts that were flooded will have mud and bacteria in them.
· Check your water system for leaks in pipes that may have been moved.
· Check your water supply to be certain it is not contaminated.
· Check all other utilities and drains for damage from the floodwaters.
Source: Protecting Your Home from Flood Damage, revised 1996, 2nd Edition, Federal Emergency Management Agency