A failing sewer line usually announces itself: repeated clogs, multiple slow drains, gurgling fixtures, sewage odors, soggy or extra-green patches of lawn, foundation-level dampness, and pest activity. Any two of these together justify a camera inspection — the only way to confirm what's actually happening underground.
Sewer lines almost never fail without warning. The backup that floods a basement on a Saturday night usually spent months sending signals first. Here are the seven we see most, roughly in the order they tend to appear.
1. The same drain keeps clogging
One stubborn clog is life. The same clog coming back every few weeks is a symptom — something in the line (roots, scale, a sag) is catching debris in the same place every time. Clearing it repeatedly treats the symptom while the cause keeps growing.
2. Multiple drains slow down at once
Your sink, tub, and toilet all share one main line out of the house. When several fixtures slow down together — especially on the lowest floor — the problem is downstream in that shared line, not in any one fixture.
3. Gurgling toilets and drains
Gurgling is air being pulled through water where it shouldn't be. It usually means a partial blockage is forcing air back up through your fixtures as water fights past it. This is the early-warning stage — the cheapest possible time to act.
4. Sewage smell indoors or outside
A working sewer line is sealed. If you're smelling sewage in the basement, near floor drains, or in the yard, gas is escaping somewhere it shouldn't — a dried-out trap at best, a cracked or separated pipe at worst.
5. A soggy or suspiciously green patch of lawn
A leaking lateral fertilizes and waters the grass above it. If one strip of your yard is greener, spongier, or smellier than the rest — and it traces roughly between your house and the street — your line may be leaking under it.
6. Dampness or backups at the foundation level
Water appearing around basement floor drains after laundry or showers means the main line can't keep up. Waste water takes the lowest exit available — and in a house, that's the basement.
7. Pests you didn't used to have
Rats and insects follow broken sewer lines. A sudden pest problem with no other explanation is an underrated clue that a pipe has opened up underground.
Which signs mean "call today"?
Signs 1–3 justify scheduling a camera inspection soon — you have time, and acting early usually means jetting instead of repair. Signs 4–7 mean the line is likely compromised: call now, because leaks under a yard or foundation get more expensive the longer they run. And an active backup — sewage coming up a drain — means stop running water and call immediately.
The good news in all of it: none of these signs tells you what the fix costs. Only the camera does that, and more often than people expect, the answer is a cleaning, not a construction project. That's why every job we quote starts with an inspection — and why you watch the footage with us. Worried about the price tag? See what sewer repairs actually cost in Denver.