Houston, TX · plumbing problem
Drains backing up in Houston
Updated · Editorial team; not yet technically reviewed
Short answer
Houston Public Works says 70% of the city's sewer overflows come from clogs of fats, oils, grease and flushed wipes, and crews answer twice as many grease-related overflows when temperatures drop. If one drain is slow, it's likely a local clog; if several back up together, the blockage is in your main line or beyond.
What's different in Houston
70% of Houston's sewer overflows are caused by clogs from fats, oils and grease poured down drains and wipes flushed down toilets. [1]
When temperatures drop each year, Houston Public Works responds to twice as many sewer overflows from grease blockages. [1]
The city asks residents to flush only pee, poo and toilet paper, and to put cooled grease in a jar, can or bag in the trash. [1]
Why winter makes it worse
Grease that flows as a liquid in a warm kitchen hardens faster in cold pipes and sewers, and holiday cooking adds more of it. That's why a line that drained fine in August can back up in December.
Safe checks first
- Count the affected fixtures: one is a branch clog, several is the main.
- Look at the outdoor cleanout: standing water means the blockage is downstream, toward the street.
- Skip chemical cleaners on grease clogs; they rarely clear them and make the line hazardous to open.
- Stop running water if toilets or the tub are rising.
What clears it
| Cause | Fix |
|---|---|
| Grease in the kitchen branch | Hydro jetting to scour the pipe walls |
| Wipes in the main | Cable through the cleanout, then stop flushing wipes |
| Roots or a sag in the sewer line | Camera inspection, then repair or lining |
You may also be dealing with
- SymptomSink not draining
- SymptomGurgling drains
- SymptomBasement flooding
- GuideWhy does my drain keep clogging?
Common questions
What causes most sewer overflows in Houston?
Clogs from fats, oils, grease and flushed wipes cause 70% of them, according to Houston Public Works.
Why do Houston drains clog more in winter?
Grease hardens faster in cold pipes; the city answers twice as many grease overflows when it turns cold.
What can I flush in Houston?
Only pee, poo and toilet paper, under the city's 3Ps guidance.
How should Houston residents dispose of cooking grease?
Cool it in a jar, can or heat-resistant bag and put it in the trash.
Are flushable wipes OK in Houston sewers?
No; the city counts wipes among the main causes of clogs.
What does water in my Houston cleanout mean?
The blockage is downstream of the cleanout, in the main line toward the street.
Does hydro jetting fix grease clogs?
It scours grease off pipe walls, which a cable often leaves behind.
When is a Houston drain backup an emergency?
When sewage rises in tubs or floor drains; stop using water and call for help.
Should I wipe pans before washing them?
Yes; the city suggests paper towels or scrapers to remove grease before washing.
Can roots cause Houston drain backups too?
Yes, in older sewer lines; a camera inspection shows roots or sags.
More plumbing help in Houston
- Water Heater Replacement in HoustonReplacing a water heater in Houston: the required plumbing permit, the registered master plumber rule, permit fees, inspection.
- Water bill suddenly high in HoustonHouston's leak adjustment: credits for leaks from freezes, corrosion or wear, 100% to 50% by repair speed, and the paperwork needed.
- Backflow Testing in HoustonHouston backflow testing: testing companies must register with the city, testers need TCEQ licenses, and gauges need annual calibration reports filed with Houston.
- Water Line Repair in HoustonHouston's service line inventory: no lead lines found so far, most lines still listed as unknown, the notices sent to customers, and how to check yours.
- Sewer Line Replacement in HoustonReplacing a sewer line in Houston: a registered master plumber must pull the permit, how the homestead permit differs, minimum fees and inspections.
- Frozen Pipe Repair in HoustonFrozen pipes in Houston: Houston Public Works' prep tips, why it has advised against dripping faucets (pumps, not towers), and shutting off and draining instead.
- Drain backing up: the full guideWhen water rises in a tub, shower or floor drain from another fixture, the main line is blocked. How to confirm it, what to stop doing and how it's cleared.
- Plumbing in HoustonLocal water, housing and climate conditions, and the calls Houston homes need most.
How other cities handle it
- Drains backing up in BoiseWhy drains back up in Boise homes: grease is the city's top cause of sewer clogs, older neighborhoods are most at risk, and what to check before calling.
- Drains backing up in OrlandoWhy Orlando drains back up: grease builds up in home lines and the city's 800-plus miles of sewer. Symptoms, safe checks, the city's oil recycling, and fixes.
- Drains backing up in Los AngelesWhy LA drains back up: grease in kitchen lines and the city's 6,600 miles of sewer, the FOG program that cut overflows 94%, and what to check before calling.
- Drains backing up in San AntonioWhy San Antonio drains back up: grease causes nearly 70% of local sewer blockages, the surprising sources of it, safe checks, and how to get rid of grease.
- Drains backing up in PhiladelphiaWhy Philadelphia drains back up: grease hardens in the lateral connecting homes to the sewer, sewage backs into houses, and how PWD says to dispose of it.
- Drains backing up in SeattleWhy Seattle drains back up: grease causes about a third of the city's sewer backups, the foods it comes from, safe checks, and when it's the side sewer instead.
Sources (1)
- Houston Public Works, Protect Our Pipes · checked 2026-10-03