Short answer: Do not step into the water until the electricity to the basement is off. Then find and stop the source, document the damage, remove the water and get the space drying within 24 to 48 hours, the EPA’s window for preventing mold. Treat sewage or outside floodwater as contaminated and call a professional.
Step 1: Make it safe
- If water is near outlets, cords, the furnace or the electrical panel, do not go in. Turn off power from a dry location, or call your utility or an electrician to do it.
- If you smell gas, leave the house and call the gas company or 911 from outside.
- Wear rubber boots and gloves. Floodwater and sewer backups can carry bacteria.
Step 2: Find the source
| Where the water came from | Clues | What it means |
|---|---|---|
| Burst or leaking pipe | Water spraying or dripping from a line; the water meter keeps moving | Shut off the main valve and call a plumber |
| Sewer or floor drain backup | Dark water and odor rising from a floor drain or toilet | Contaminated water; use a professional |
| Sump pump failure | Pit is full; pump not running or tripped | Check its power and float, then repair or replace it |
| Groundwater or surface runoff | Water seeping where the wall meets the floor during heavy rain | Outside drainage or grading problem; check flood coverage |
| Water heater or appliance | Water pooling around the tank or washer | Turn off its water supply and power |
Talk to a local pro
Water in your home, or mold you can see?
Call to be connected with an independent water damage and mold restoration company that serves your area. Calls are answered by the provider or their scheduling team.
For homeowners who need new service. Have ready: your address, where the water is coming from, which rooms are affected, and your insurance company.
Step 3: Document, then remove the water
- Photograph and film the water level and every damaged item before moving anything.
- Call your insurance company. Our guide explains what is usually covered.
- Pump or wet-vac standing water. For more than a few inches, a restoration company’s pumps are much faster.
- Move out wet rugs, cardboard boxes and furniture. Throw away soaked porous items that touched sewage.
Step 4: Dry it within 24 to 48 hours
The EPA advises drying water-damaged materials within 24 to 48 hours to prevent mold growth. Run dehumidifiers and fans, open windows if the outside air is drier, and pull back wet carpet. Wet drywall and insulation usually need to be cut out above the waterline so the wall cavity can dry.
What not to do
- Do not use a household vacuum on water.
- Do not run the furnace or air conditioning if it got wet or if you suspect mold inside it.
- Do not mix bleach with ammonia-based cleaners.
- Do not paint or caulk over damp or moldy surfaces.
- Do not pump out deep floodwater all at once while the ground outside is still saturated; ask a professional, because pressure outside the walls can damage the foundation.
Frequently asked questions
Who do I call for a flooded basement?
A plumber if a pipe or water heater caused it, and a water damage restoration company to remove the water and dry the structure. For sewage, the EPA recommends a professional experienced with contaminated water.
Why does my basement smell musty after a flood?
A musty smell after a few days usually means materials are still wet or mold has started to grow. Moisture readings will show where.