Short answer
Shut off the main water valve first. In basement homes it's usually on the wall where the main enters, near the meter. In slab homes it's often on the main line near the front hose bib or in the garage by the water heater. Then turn off power to any wet area, move valuables, start removing water, photograph everything for insurance, and call a plumber.
1. Stop the water
Find the main shutoff. Depending on how your home is built, look:
- In the basement or crawl space on the front wall, where the main enters next to the water meter
- In a utility closet or near the water heater, in homes without basements
- On the main line where it rises out of the ground near the front hose bib, common on slab homes
- At the curb box or meter pit by the street (it may need a meter key)
2. Make it safe
If water is near outlets, a panel or appliances, turn off those breakers, and don't stand in water to do it. If the water heater is involved, shut its gas or power.
3. Limit the damage
- Move furniture and electronics
- Mop and wet-vac standing water
- Run fans; open cabinets to dry them out
- Photograph and video everything before cleanup
4. Call for help
Call a plumber to repair the pipe. For wet drywall, carpet or cabinets, a water damage restoration company can dry the structure properly so mold doesn't follow.
When to call a plumber
- Water is still running after you've closed what you can.
- You can't find or turn the main shutoff.
- There's sewage involved.
What the plumber does: see slab leak repair & reroutes.
Common questions
Should I turn off the water heater after closing the main?
Yes, turn off gas or power to a tank that may drain. Heating an empty tank damages it.
Editorial note: this guide is general information for homeowners, not a diagnosis. Conditions vary by home, so a licensed plumber should confirm the cause before any repair.