A sewer backup is one of the worst kinds of water damage a Calgary homeowner can deal with. During intense summer thunderstorms, or when a private sewer line is blocked by roots, grease or “flushable” wipes, sewage can come up through basement floor drains, toilets and showers. That’s Category 3 black water, and it needs professional cleanup.
Sewage in your basement? Emergency cleanup 24/7.
Emergency water extraction, drying & repairs in every Calgary quadrant. Free phone assessment.
Is It Your Line or the City’s?
- Only your home affected; slow drains and gurgling beforehand: likely a blockage in your private service line. Call a licensed plumber or drain company to clear and camera-inspect it.
- Several homes affected during heavy rain: possibly a system issue. Report it to the City of Calgary through 311.
Immediate Steps
- Stop using water: no flushing, showers, laundry or dishwasher.
- Keep everyone out of the contaminated area.
- Shut off power to the basement from a dry location if water is near electrical.
- Turn off the furnace if it or the return air is in the affected area.
- Photograph everything and call your insurer.
- Call a professional for sewage cleanup and water damage restoration in Calgary.
Professional Sewer Backup Cleanup
| Step | What happens |
|---|---|
| Containment | Plastic barriers and HEPA air scrubbers keep contamination out of the rest of the home |
| Extraction | Sewage and solids are removed and disposed of properly |
| Removal | Contaminated drywall (flood cut), insulation, carpet, underlay and porous items |
| Disinfection | Concrete, framing and hard surfaces cleaned and treated |
| Drying | Structural drying verified with moisture meters |
| Rebuild | Insulation, drywall, flooring and finishes replaced |
Typical cost in a developed basement: $12,000–$35,000+ with rebuild. See the cost guide.
Insurance
Sewer backup is usually not part of a basic Alberta home policy. It’s an optional add-on with its own limit and sometimes its own deductible. If your basement is developed or has a suite, make sure your limit is high enough. See our Calgary insurance guide.
Preventing Sewer Backups
- Backwater valve: a licensed plumber can install one on your main line (a permit is typically required). It’s the most effective protection. Maintain it annually.
- Camera-inspect your line if you have mature trees, an older home or recurring slow drains.
- Never pour fats, oils or grease down drains.
- Flush only toilet paper.
- Make sure sump pumps and downspouts aren’t connected to the sanitary sewer.
- Store valuables in plastic bins, off the basement floor.
Basement Suites Need Extra Protection
A sewer backup in a basement suite affects tenants’ homes and health. Landlords should prioritize a backwater valve and adequate sewer backup coverage. See basement suite water damage.
Related: river and overland flooding · mould
Safe sewer backup cleanup anywhere in Calgary
Emergency water extraction, drying & repairs in every Calgary quadrant. Free phone assessment.