us Home & property emergencies sink backing up • bathtub backing up • dirty water rising • sewage backup at home • wastewater coming up drain • drain overflow emergency • sink gurgling then overflow • shower drain backflow • black water in tub • grey water flooding bathroom • multiple drains backing up • toilet bubbling when sink runs • sewer line blockage • main drain clog • basement floor drain backup • standing contaminated water • sudden plumbing backflow • water coming up drain • home sewage spill • overflow from drainpipe

What to do if…
a sink or bathtub backs up and dirty water starts rising

Short answer

Stop using all water immediately, keep everyone away from the contaminated water, and make the area safe around electricity before you call a plumber or your local wastewater utility.

Do not do these things

Don’t run taps “to see if it clears,” flush toilets, or run the dishwasher/washer—this can make the backup worse.
Don’t step into standing water if it’s near outlets, power strips, appliances, or your electrical panel.
Don’t use chemical drain openers—contaminated water can splash and chemicals add burn risk.
Don’t try to snake from the fixture if multiple drains are backing up—you may need the main line/cleanout addressed.
Don’t let kids or pets near the water, and don’t shop-vac it unless you’re equipped to treat it as contaminated waste.

What to do now

Stop all water use now. No sinks, showers, toilets, garbage disposal, dishwasher, or laundry until the backup is controlled.
Keep people and pets out of the area. Close doors, block access, and ventilate the room if you can (open a window).
If water is near electrical hazards, shut off power from a dry location. If you can safely switch off the affected circuit (or main) without stepping in water, do so. If you would have to stand in water to reach the panel or switches, do not—call an electrician.
Shut off the home’s main water supply if someone might accidentally use water. This helps prevent more water being added to a blocked system.
Treat sewer cleanouts as “plumber territory” unless you already know it’s safe. If you have a sewer cleanout and you’re trained/experienced with it, it can help a plumber reach the blockage. Do not open it if water is actively rising, if it requires force/tools, or if you’re unsure—cleanouts can release sewage under pressure.
Call the right help based on what you’re seeing:
- Single fixture only (just one sink/tub): call a licensed plumber.
- Multiple drains backing up / toilet gurgling / water coming up from the lowest drain (often a basement floor drain): call a plumber and your local wastewater/sewer utility or city public works (some backups are in the municipal line).
- If you rent: contact your landlord/property manager immediately and follow the emergency maintenance process.
Quickly document, then contain spread. Take photos/video for your landlord/insurance, then use towels to limit water migrating into carpeted areas or under baseboards.
If the water reached porous items (carpet, padding, upholstered furniture), assume contamination. Keep the area closed off until professionals advise—sewage-contaminated porous materials often need specialist cleanup.

What can wait

You do not need to decide right now whether it’s your private lateral or the city main—just report it and get the flow stopped.
You do not need to disinfect immediately—first stop exposure, make it electrically safe, and get qualified help moving.
You do not need to make insurance decisions on the spot; just document and prevent further damage.

Important reassurance

Feeling alarmed is normal—backups are disgusting and stressful. The safest first win is simple: stop adding water, keep people out of contact with it, and bring in the right professionals.

Scope note

These are immediate stabilizing steps only. Full cleanup, drying, and restoration often require professional assessment—especially when sewage is involved.

Important note

This is general information, not medical, electrical, or legal advice. Sewage-contaminated water can carry germs, and electricity around standing water can be dangerous—prioritize safety and professional help.

Additional Resources

Support us

What to do if…a sink or bathtub backs up and dirty water starts rising