Power, pumping speed, contamination and drying for a flooded basement, plus how sump and sewer backup coverage works. From FEMA, CDC, EPA and the Red Cross.
By the WaterDamageRated team · Facts checked against the sources listed below on November 1, 2026. General information, not professional advice.
A flooded basement can be electrified. The First District Health Unit's guidance on pumping a flooded basement says never to go into one unless you know the electricity is off. CDC adds that you should never turn power on or off, or use an electric tool, while standing in water: switch off the main breaker from a dry spot if you can, and call an electrician if you would have to wade to reach it. If you smell gas, CDC says to shut the main gas valve, open the windows and leave.
Don't run a gasoline pump or generator indoors. The First District Health Unit warns that they produce deadly carbon monoxide, and CDC says never to run one inside a home, basement or garage, or less than 20 feet from any door, window or vent.
The source decides how careful you need to be, and often who pays:
Water in the soil outside presses on basement walls. Pump the inside out too fast and that outside pressure can win. FEMA's guidance:
FEMA says draining too fast could collapse the basement walls, floors and foundation, and that rebuilding them could cost more than cleaning up after the flood. The Red Cross gives a similar rule of thumb: pump out about one-third of the water per day.
Basements are full of materials that soak up water. EPA's flood cleanup fact sheet says to throw away materials that absorb a lot of water, such as drywall, carpets and ceiling tiles, and generally anything that cannot be cleaned and dried within 24 to 48 hours. EPA's water damage table says wet cellulose and fiberglass insulation should be discarded and replaced. The Red Cross says to remove all drywall and insulation that has been in contact with floodwater.
The Red Cross says to throw out all food, drinks and medicine exposed to floodwater and mud (when in doubt, throw it out), and items that have absorbed water and cannot be cleaned or disinfected. Before anything goes to the curb, photograph it. The Minnesota Department of Commerce says not to throw out damaged items until the insurance adjuster has inspected them.
If the water came from outside or from a sewer, it may be contaminated, and the order changes. EPA's table covers clean water only; for water contaminated with sewage or chemical or biological pollutants, EPA says OSHA requires protective equipment and containment, and an experienced professional should be consulted if you lack expertise in that work. The full sequence is in our guide to the restoration process.
Basement water claims often fall between policies. The Minnesota Department of Commerce says neither flood insurance nor a typical homeowner's policy covers damage from sewer backups or from sump pumps that can't handle the runoff from a major downpour, and that you need a separate product or endorsement. It adds that some companies exclude sewer backup that happens at the same time as a flood, and that a sewer or sump endorsement does not give you flood coverage.
The Texas Department of Insurance's worksheet for comparing homeowner policies lists backup of sewers and drains as its own coverage item, and notes that homeowner policies typically don't cover floods and that the National Flood Insurance Program provides flood insurance in many areas. If you do file a claim, Minnesota's regulator suggests calling the insurer as soon as you can, photographing the damage, providing a home inventory, asking about loss-of-use coverage if you need to stay elsewhere, and getting written estimates. Our guide to water damage insurance covers the 30-day wait on flood policies.
Slowly. FEMA says to start only when floodwater no longer covers the ground outside, pump about a foot a day at first, and move to 2 to 3 feet a day once the water stops coming back. The Red Cross suggests about one-third of the water per day.
It can be. The IICRC lists rising water from rivers or streams, and sewage, as examples of Category 3 water, which is grossly contaminated. Make sure the electricity is off before you go in.
Usually not without an add-on. The Minnesota Department of Commerce says a typical homeowner's policy doesn't cover damage from sewer backups or from sump pumps that can't handle runoff from a major downpour, and that you need a separate product or endorsement.
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