Four sources of basement water
| Source | Clue | Water type |
|---|---|---|
| Groundwater | Enters at the floor-wall joint or sump pit, after thaw or rain | Gray |
| Surface water | Comes through window wells or a walkout door | Gray to contaminated |
| Plumbing | Appears suddenly, any weather | Clean |
| Sewer or septic | Comes up the floor drain, has an odor | Contaminated |
Cleanup in brief
Make it safe, pump and extract, remove what will not dry, open wet walls where needed, dry the structure and clean. The full process is on our flooded basement cleanup page.
Prevention, outside the house
- Extend downspouts at least six feet from the foundation.
- Keep gutters clear so they do not overflow next to the wall.
- Slope soil away from the house.
- Add covers to window wells and keep their drains clear.
- Move snow piles away from the foundation before the thaw.
Prevention, inside the house
- Test the sump pump every spring and add a battery backup. See the sump pump guide.
- Store belongings on shelves or in plastic bins, not cardboard on the floor.
- Replace washing machine hoses and old water heaters before they fail.
- Place a water alarm near the sump, water heater and laundry.