September 2026 — with a powerful nor'easter dropping inches of rain across Brooklyn, Queens, Staten Island, and Manhattan, basement flooding calls are spiking across the city. If water is coming into your basement right now, this guide is for you.
1. Stay safe first — water and electricity are a deadly combination
Before you touch anything, kill the power to the basement at the breaker box — but only if you can reach it without walking through water. If the breaker panel is in the flooded area, or water is near any outlets or your electrical panel, stop and call an electrician or 911. Never wade into basement water that could be electrified.
If the water smells like sewage or is coming up through drains, treat it as contaminated. Wear waterproof boots and gloves, keep kids and pets out, and don't try to save porous belongings sitting in it — they can't be salvaged.
2. Stop more water from coming in
While the rain is still falling, do a fast lap around the house: clear clogged gutters and downspouts, make sure downspouts discharge at least 6 feet from the foundation, and check window wells — they fill up fast and pour straight into basements. If your sump pump isn't running, check that it has power and the float switch isn't stuck; a failed fifteen-dollar switch is behind a shocking number of flooded basements.
If water is pressing in around the foundation, sandbags or even rolled towels at door thresholds and basement entry points can slow it down. You won't stop a serious storm surge with towels — the goal is to buy time.
3. Get the standing water out — but pump it in stages
A submersible pump or a wet/dry shop vacuum is the fastest way to clear a few inches. Important: if the water is deep (a foot or more) and the ground outside is saturated, don't pump it all out at once. Basement walls and slabs are designed with water pressure in mind — removing interior water too fast while the soil outside is waterlogged can crack slabs and push walls inward. Pump it down a third, wait a few hours, then continue.
Once the bulk is out, mop up the remainder and pull up any wet carpet or rugs. Cut away soaked drywall at least 12 inches above the visible waterline — wet drywall is a lost cause and it hides mold.
4. Start drying immediately — mold doesn't wait
This is the step people skip, and it's the expensive one. Mold begins growing within 24 to 48 hours on damp drywall, wood, and insulation. Get air moving with fans, run a dehumidifier (or two — borrow one if you have to), and open windows if the outside air is drier than the basement. Pull furniture away from walls so air circulates behind it.
Anything porous that stayed wet — cardboard boxes, upholstered furniture, mattresses, carpet padding — should go. Hard surfaces can be scrubbed with soap and water, then disinfected. If you smell that musty odor a few days later, mold is already growing somewhere you can't see.
5. Document everything before you throw anything away
Photograph every room, every damaged item, and the waterline on the walls before cleanup begins. Make a written list with approximate values. Your homeowner's insurance may cover sudden water damage (though standard policies usually exclude flooding from rising groundwater or storm surge — check whether you carry separate flood insurance). Documentation is what gets claims paid; memories of what was down there are not.
6. What NOT to do
Don't use a regular household vacuum on water — it's dangerous and will destroy the machine. Don't wait until the weekend to deal with it; the difference between a one-day cleanup and a full mold remediation is often just 48 hours. Don't assume "it was only a little water" — a thin layer across a basement floor is still enough to wick up drywall and start mold inside wall cavities where you can't see it. And don't run your HVAC if the ducts or furnace got wet until they've been inspected.
7. When it's time to call a contractor
Call a professional if you see any of these: water coming up through cracks in the floor slab, bowing or new cracks in foundation walls, sewage backup, or flooding that happens every time it rains hard. Recurring flooding isn't bad luck — it's a drainage or waterproofing failure, and it will keep happening until the source is fixed.
That's where we come in. We diagnose where the water is actually entering — foundation walls, the cove joint, window wells, failed drainage — and install interior or exterior waterproofing systems built for NYC's housing stock, from brownstones in Brooklyn to raised ranch homes on Staten Island. The cheapest flood you'll ever have is the one that never happens.
Serving Brooklyn, Manhattan, Queens & Staten Island
If this storm left water in your basement — or if every heavy rain does — call us. We'll inspect, tell you honestly what's going on, and give you a straight price to fix it right.
Common questions
- Is water in my basement dangerous?
- Yes. Water and electricity are a deadly combination — never walk into standing water until the power to the basement is off. If you are unsure, call an electrician first.
- How fast does mold grow after a basement flood?
- Mold can start within 24 to 48 hours. That is why fast water extraction and drying matter more than almost anything else after a flood.
- Will my homeowner’s insurance cover a flooded basement?
- It depends on the cause. Sudden events like a burst pipe are usually covered; gradual seepage often is not, and storm flooding typically needs separate flood insurance. Document everything before you throw anything away.
- Should I pump the water out myself?
- You can, but pump in stages — removing all the water at once from a fully flooded basement lets outside water pressure crack the floor slab. A few inches at a time, with breaks in between.