My sewer is backing up right now — what do I do first?

The first ten minutes

1. Stop all water use. Tell everyone in the house. No flushing, no showers, no laundry, no dishwasher. If the washer is mid-cycle, pause it. The backup rises with every gallon.
2. Keep people and pets out. Close the door on the wet room. Turn off power to outlets in the flooded area at the breaker if water is near them.
3. Find the cleanout. It is a capped pipe, usually at the foundation, in the yard, or near the property line. Remove the cap carefully with a rag over it. If it is full of water, your side sewer is blocked. If it is empty or low while the basement is flooding, the blockage is inside the house's own drain lines.
4. Look outside. In heavy rain, is water at the curb, a manhole lifting, or a neighbor with the same problem? That points to the public main.
5. Take photos. The water, the level, the time, the weather. Whether this ends up an insurance claim or a city claim, the photos are what you will be asked for.

Whose problem is it?

What to have ready when you call

• Where the water is coming up and whether it is still rising.
• Whether the cleanout is full and where it is.
• The age of the house, if you know it, and whether the line has been cleared before.
• Whether it is raining and whether neighbors are affected.

Those four answers let a dispatcher send the right equipment. A crew arrives with a cable machine and a jetter, clears from the cleanout toward the main, and gets the house draining. In an older Seattle house that is usually the easy part.

What happens after it drains

The clearing is a treatment, not a diagnosis. The reason for the backup is still in the pipe — roots, a belly, a collapsing section, scale — and it will do this again. Ask for a camera pass while the crew is there. It adds under an hour and turns "we cleared it" into "here is the root mass at the third joint and here is what your options are." That is the difference between an emergency you handle every winter and one you handle once.

Cleanup

Once the line is open: wet-vac standing water, remove anything porous that soaked it up, wash hard surfaces with detergent and then disinfect, and run fans and a dehumidifier until the slab is dry. Keep the photos and the receipts. If a city surcharge was involved, file with SPU promptly; if your own line was the cause, check whether you carry water-backup coverage — the insurance article explains what those policies usually do and do not pay for.

Prevention, briefly

Most backups announce themselves weeks in advance as gurgling, slow drains and a faint smell. If any of those return after tonight, do not wait for the next flood; a camera on a normal weekday is a very different experience from a crew at 2 a.m.