My water suddenly stopped — how do I know if it's a main break?

Check how far it reaches. A main break is a city-side failure that usually affects more than one building and often shows visible signs: water bubbling up through the street or sidewalk, a pressure drop across the block, sometimes discolored water or buckled pavement. If only your building or only your apartment is dry with nothing happening in the street, it's more likely a building or branch problem, not the city main.

Who's responsible — NYC DEP or my building?

Roughly, the public water main under the street is DEP's, and the service line from the main plus everything inside the building is the owner's. So a true main break is a DEP repair (report it via 311), while a dry building caused by the service line, internal piping, a pump, or a rooftop tank is the building owner's responsibility. The reach of the outage usually tells you which side of that line you're on.

Where's the water shutoff if I need it?

In a house or brownstone, the main shutoff is usually in the cellar near where the service enters — street-facing wall, by the meter. In an apartment, there's typically no single master valve you control; fixtures have shutoff stops, but risers and the building main are run from the basement by the super. Know your shutoff before you need it, because pressure returning after an outage is a common moment for a weak pipe to start leaking.

Should I call a plumber for no water?

Only when the problem is plumbing you're responsible for — your house's service line or piping, your own equipment, a failed valve or pump you own. A city water main break is DEP's repair, reported through 311, not a plumber call. And in a rental, a building-wide outage is the owner's to fix; report it in writing and escalate via 311 if it drags on, rather than hiring a plumber to work on building systems you don't control.

No water or a suspected water main break in NYC

When the taps go dry with no warning, the first question isn't who to call — it's how far the problem reaches. Here's how to tell a single dry apartment from a building outage from a city water main break, and who's responsible for fixing each.

First: is it just you, your building, or the block?

Start by mapping how far the outage reaches, because that single fact tells you whose problem it is. Check every tap in your apartment — hot and cold. If only the hot side is dead, that's a water-heater or hot-supply issue, not a water outage, and our no-hot-water guide is the right one. If both sides are dry at every fixture, the supply to your apartment has stopped, and the next question is how far out the problem goes.

Find out whether neighbors have water. Ask the apartments on your line, check the building chat, look for posted notices about water shutoffs or repairs. If the whole building is dry, the problem is at the building level or upstream at the city connection — the owner's and possibly the city's domain. If it's just your apartment while neighbors have water, the issue is closer to home: a closed valve on your line, or work happening on your specific branch.

Then look past the building. Is there a notice about planned water work? Are crews or barricades in the street? Is water bubbling up from the roadway or the sidewalk? A dry building plus signs of work or water in the street points to the city main — a DEP matter — rather than your building's plumbing. The reach of the outage, from one tap to a whole block, is the most useful diagnostic you have, so establish it before you call anyone.

How NYC water gets to your tap

City water travels through DEP's water mains under the streets, then branches off into a service line that runs from the main into each building. From that service line, the building's internal plumbing — and in taller buildings, often a pump and a rooftop tank — distributes water up to the apartments. The dividing line that matters for responsibility sits roughly where the building's service line meets the city main: the public main is DEP's, and the service line and everything inside the building are generally the owner's.

That structure explains the failure modes. A problem in the city main under the street is a DEP issue and usually affects more than one building. A problem in the building's service line, internal piping, pump, or tank is the owner's, and affects that one building. A closed or broken valve on your branch, or work on your line, affects just your apartment. Knowing this map turns 'no water' from a mystery into a short list of possibilities you can narrow by how far the outage spreads.

Taller buildings add a wrinkle: many rely on a pump and a rooftop tank to get water to upper floors, so a pump failure or tank issue can dry out the high floors while the lower ones are fine. If the outage tracks with height in the building rather than with a specific line, that points at the building's pumping system — squarely the owner's equipment — rather than the city main or your own plumbing.

Water main break: what it looks like and who handles it

A water main break is a failure of the city's main under the street, and it tends to announce itself: water bubbling or flooding up through the roadway or sidewalk, a sudden drop or loss of water pressure across multiple buildings, sometimes discolored water, occasionally a sinkhole or buckled pavement. If your building's gone dry and there's water surfacing in the street nearby, a main break is the likely culprit — and it's not a plumbing call you make for your apartment, it's a city repair.

Report a suspected main break to 311, which routes to NYC DEP — the agency responsible for the public water mains. DEP investigates and repairs the city's side. A 311 report also creates an official record, which matters if the break causes flooding or damage. What DEP does not do is fix anything inside your building or restore water to your specific apartment beyond getting the main back in service; the building's own plumbing is private and stays the owner's responsibility.

If the break is flooding the street near your building, treat any resulting water intrusion like any flood: keep it away from electrical, document the damage, and notify the right parties. But the repair of the main itself is DEP's, on the city's timeline. Your job is to report it, document anything affecting your building, and stay out of the roadway — a broken main can undermine pavement and is genuinely dangerous to approach.

Shutoff basics

Knowing where the water can be shut is useful both for diagnosing an outage and for stopping a flood if a no-water problem flips into a leak when service returns. In a house or brownstone, the main shutoff is typically in the cellar near where the water service enters — street-facing wall, by the meter. Closing it isolates the whole building from the service line; that's the valve you reach for in a true emergency, and the one that confirms whether a problem is upstream or inside.

In an apartment, there usually isn't a single master valve you control. Individual fixtures have shutoff stops on their supply lines, but the risers and the building main are operated from the basement or a locked utility room — the super's territory. That's a recurring theme in NYC plumbing: inside the apartment you control fixtures, but anything building-wide runs through building staff. For a no-water situation that's confined to your apartment, a stuck or closed fixture stop or branch valve is worth checking before you assume a larger failure.

One caution for the moment water comes back: when service is restored after a main break or a building shutoff, pressure returns suddenly and air can hammer through the lines. If a pipe was already weak — or got disturbed during the work — that surge is when a leak shows up. Open a tap slowly when water returns, let the air clear, and if anything starts leaking, our burst-pipe guide covers the next ten minutes. Knowing your shutoff before that happens is what keeps a surprise leak from becoming a flood.

When to dispatch a plumber

Dispatch a licensed plumber when the dry taps trace to plumbing that's yours to fix: your house's service line or internal piping, your own branch in a condo or co-op where the bylaws put it on you, a failed valve or pump on equipment you're responsible for. A plumber can find where the supply stopped — a failed pressure-reducing valve, a stuck main valve, a service-line problem, a dead pump — and repair it. A true city-main break, by contrast, isn't a plumber call; that's DEP through 311.

In a rental, a building-wide outage is the owner's to resolve, not yours to hire out. The building's service line, internal piping, pump, and tank are the owner's equipment and access — report the outage to the super and management in writing immediately, and if it's prolonged with no progress, a loss of water service is exactly the kind of essential-services failure 311 and HPD exist for. Don't pay a plumber to work on building systems you don't control.

When the dispatch is genuinely yours, Reset shows which licensed plumbers can move now, with price bands and published trip fees shown before you book, every profile verified against the DOB roster, and Reset's own crew labeled In-House when it takes a job. A sudden total loss of water is an emergency, so the Reset Guarantee applies: emergency requests are confirmed within 30 minutes, or Reset's in-house crew is dispatched automatically. Coverage is live across the Bronx, Manhattan, Brooklyn, and Queens, with Staten Island opening later in 2026.