If sewage backs up into your Brooklyn basement, stay out of the water, report it to 311 and take photos. On 75% of Brooklyn backup calls in the past year, DEP found no city sewer problem (counts calls, not pipe condition).
If a sewage backup comes up the floor drain in your Brooklyn basement, stay out of the raw sewage, stop using water in the house, and report it to 311.
Then get the main line cleared and on camera to find the cause.
What to do first
- Stop using water. No flushing, showers, dishwasher or laundry.
- Stay out of the water. DEP warns floodwater "may contain sewage water and germs."
- Call 311. DEP says to "report it immediately to 311" and will "inspect the location within six hours" (NYC DEP).
- Keep your numbers: the 311 tracking number and DEP's Customer Service Request number (CSR#).
- Take photos before cleanup, and keep receipts for your insurer.
- Clean and disinfect everything the water touched, or hire a remediation company.
Is it the city's sewer or yours?
DEP inspects the city sewer system within six hours of the 311 complaint, though heavy rain or snowmelt can delay it. If it confirms a problem in the city sewer, DEP starts the repair.
If the cause is your private sewer service line, you get a Notice to Repair, because you own that line all the way to the city main in the street.
Our count of 311 calls: across Brooklyn, from October 2025 to September 2026, DEP found no backup in the city sewer at the time of its visit on 1,049 calls and suspected internal plumbing on 659 more: 1,708 of 2,271 sewer backup calls (75%).
The figures count calls, not pipe condition. Grease in the city sewer was confirmed on 220 calls, and heavy rain on 200.
No city problem found, by Brooklyn community board:
- Borough Park (CB 12): 88 of 112 calls
- Bensonhurst and Bath Beach (CB 11): 80 of 109
- Williamsburg and Greenpoint (CB 1): 79 of 143
- Flatbush and Midwood (CB 14): 75 of 109
- Park Slope (CB 6): 50 of 77
- Bay Ridge (CB 10): 39 of 55
Common causes of basement sewer backups
- Grease, wipes and other items put down toilets and sinks: DEP calls this the most common cause.
- Heavy rain that fills the city sewer (confirmed on 200 Brooklyn calls in our count).
- Problems in the private sewer service line (suspected on 659).
Will a backwater valve help?
A backwater valve lets sewage flow out but not back in. FloodHelpNY says it reduces the risk of sewage backing up through your sewer pipe (FloodHelpNY).
- Ask a plumber first. FloodHelpNY: on certain properties a valve "can actually make things worse."
- Cost: "as little as $600 or more than $5,000."
- Upkeep: open the valve access point "a couple of times per year" to check for clogs.
- It does not fix your own clogged sewer line. If it backs up in dry weather, check your own line first.
Does homeowners insurance cover a sewer backup?
It depends on your policy. The Insurance Information Institute says some policies cover sewer and drain backups but many do not, and that a sewer backup rider can be added (Triple-I).
Ask your insurer about water damage and property damage from a backup:
- Do I have a water or sewer backup endorsement, and what is its limit?
- What is the deductible for it?
- Does it count cleanup and drying?
- What photos and receipts do you need, and how fast must I report?
If the city caused the damage
DEP says to contact the New York City Comptroller's Office within 90 days to file a claim. If it happened during heavy rain, you do not need a CSR# to file.
Clear the line and find the cause
Power Rooter offers same-day service in Brooklyn. It snakes the line first, jets only when the camera shows it is needed, and films every jetting job before and after.
Book hydro jetting in Borough Park, hydro jetting in Park Slope or hydro jetting in Bay Ridge, or call (718) 686-8686.
Common questions
Who do I call for a sewer backup in NYC?
Call 311 so DEP checks the city sewer, and call a sewer company to clear your line if the problem is on your side.
What are the common causes of sewer backups in New York City?
DEP says the most common cause is blocked pipes from grease, wipes and other items put down toilets and sinks. In our count of Brooklyn 311 calls, heavy rain was confirmed on some calls too.
Can a renter report a sewer backup?
Yes. Anyone can report a backup to 311. Tell the landlord too.
KEEP READING
More from Power Rooter
Who Is Responsible for the Sewer Line From the House to the Street? Westfield, Cranford and NYC
In New York City, the property owner owns the whole sewer line to the city main in the street. Westfield's Public Works repairs broken sewer mains, and Cranford checks each backup to decide whose it is. Here is what each place says.
Orangeburg Pipe, Clay or Cast Iron: What Sewer Pipe Is Under an Older House in Westfield, Cranford or Brooklyn
Orangeburg pipe is a fiber sewer pipe of compressed wood fibers and coal tar pitch, used in many towns in the mid-1900s. As it ages it flattens and loses its round shape. A camera inspection gives clues to whether you have Orangeburg, clay or cast iron.
Belly in a Sewer Line: How Serious Is It, and Does It Need Fixing?
A belly is a sag in a sewer line where water and waste collect. Home inspectors report over 1 inch of standing water as a flag to look closer. A minor sag may not affect the line; one that keeps clogging needs a repair quote.
Dealing with this right now? We run same-day trucks across NYC and northern NJ.
Call (718) 686-8686