Water coming up the floor drain almost always means the line past it is blocked: your main drain, your sewer service line, or occasionally the city main. Stop using water, keep people out of it, and don't pour chemicals in. If water rises when nothing is running, call the city first. In Cottage Grove that's Public Works at 651-458-2808, 24 hours a day.
Why the floor drain is where it shows up
Every drain in your house, from the kitchen sink to the upstairs shower, empties into one building drain that leaves the house under the basement floor. The floor drain sits on that same line and is the lowest opening in the house. When something blocks the line between that point and the street, the water has nowhere to go, so it rises and comes out at the lowest opening first.
That's why plunging the floor drain rarely works. The clog isn't in the drain grate you can see. It's somewhere downstream, often several feet out under the floor or the yard.
What to do in the first hour
- Stop all water use. Tell everyone in the house: no flushing, showers, laundry or dishwasher. Every gallon you send down comes back up on the basement floor.
- Watch what the water does when nothing is running. If it keeps rising with every tap off, or neighbors on the street are dealing with the same thing, the city main may be blocked. Call the city before anyone else (numbers below).
- Keep kids and pets away from it. Water that came up from a sewer line carries bacteria. Wear boots and gloves if you have to walk through it.
- Move what you can, and photograph everything. Take pictures of the water, the drain and anything damaged before you start cleaning. Insurers ask for them.
- Skip the chemical drain cleaner. It won't reach a main line clog, it sits in the standing water, and it's a hazard for whoever opens the line.
Water still coming up? A drain tech can clear the main from the cleanout and tell you what caused it.
Call nowIs it my line or the city's?
In Cottage Grove, the city maintains the main sewer line under the street. Problems inside the house, and in the sewer line between your house and the main, are the property owner's responsibility (City of Cottage Grove, Sewer). The city's own advice is that water coming up when no water is being used, or neighbors reporting problems, could mean a mainline issue, and you should call Public Works right away.
- Cottage Grove Public Works: 651-458-2808, answered 24 hours a day including weekends and holidays.
- South St. Paul: the city asks residents to call its Utilities Division before hiring a drain cleaning company. Weekdays 7:00 to 3:30, call 651-554-3225. After hours, weekends and holidays, call 911 to report a sewer emergency (South St. Paul, Sanitary Sewer Maintenance).
- Hastings: utility line 651-480-6185, after-hours emergency 651-248-3271 (City of Hastings, Utility Systems).
If the city checks its main and finds it flowing, the blockage is in your line, and that's when you call a drain tech.
Read the pattern: what else is happening?
It backs up when the washer drains
A washing machine dumps a lot of water fast. If the floor drain overflows only during the drain cycle, the line is partly blocked: enough gets through for a sink, but not a 20-gallon surge. This is an early warning. Get the line cleaned before it blocks completely.
It backs up after heavy rain
That can point to groundwater or storm water getting into the sanitary system, through cracks in an old line or a sump pump discharging into the sanitary drain. A camera inspection shows whether water is entering through a broken section.
It backs up when the kitchen sink drains
The kitchen line usually joins the main near the floor drain. If kitchen water shows up in the basement, grease has likely built up in the main just downstream.
Sewage, not just grey water
If what's coming up contains toilet waste, the blockage is past the point where the toilet lines join, deep in the main or out in the service line. Stop flushing completely.
What the fix usually looks like
A tech opens the main cleanout (often a capped pipe near where the line leaves the house) and runs a cable or jetter toward the street until the water drops. Once the water is draining, a camera inspection is worth asking for: it shows whether the cause was a one-off clog, a root intrusion, a sag in the line, or a broken pipe. Without it, you're guessing whether this will happen again.
If your cleanout is buried, covered by a finished wall, or you don't know where it is, say so on the call. It changes how the line is reached and how long the job takes.
Preventing the next one
- Don't flush wipes, even "flushable" ones. South St. Paul's sewer guidance lists wet wipes, diapers, sanitary products and rags as things never to flush.
- Keep grease and cooking oil out of the kitchen sink. Let it cool, wipe the pan, and throw it in the trash.
- If you've had roots before, schedule cleaning before it backs up, not after.
- Pour a bucket of water down a rarely used floor drain every few months so the trap doesn't dry out and let sewer gas in.