Electricity first. Always.
Standing water in a basement is a shock hazard until proven otherwise. If your breaker panel is upstairs and dry, cut the basement circuits before going down. If the panel is in the flooded basement, or you’d have to stand in water to reach it — stop and call your utility or 911. People die doing this every year, and no possession down there is worth it.
Where the water is coming in tells you which trade
Once the power is safely off, stand at the edge of the water on dry ground and find the entry point. That decides who you call. What kind of water it is decides your cleanup and your insurance, which is the next section.
Through the walls, or seeping up along the joint where the wall meets the floor → groundwater under hydrostatic pressure. This is not a plumbing failure, and a plumber cannot fix it. You need a restoration company to extract and dry now, then a basement waterproofing or foundation contractor for the permanent fix. Fixr puts waterproofing at $3,000 to $10,000 (national average $5,000, or $3 to $10 per square foot), an interior perimeter drain at $40 to $120 per linear foot, and epoxy crack injection at $250 to $1,000 per crack.
Through a visible crack in the foundation wall or floor slab → same route, but have a foundation contractor say whether the crack is structural before anyone seals it. Sealing a moving crack just moves the leak.
In over the top of a window well, through a basement door, or down the outside of the wall → the water is arriving above grade, from outside. The fix is drainage: downspout extensions, regrading away from the house, window well covers, an exterior french drain at $10 to $100 per linear foot per Fixr. That is a drainage or landscaping contractor, not a plumber.
From a pipe, the water heater, a washing machine hose, or the ceiling → shut the main valve, then plumber. This is the one version of a flooded basement a standard homeowners policy normally covers.
Up through the floor drain, a basement toilet, or the lowest shower — with no fixture obviously clogged → this is a sewer problem that happens to be in your basement. Call your city or county sewer department first; if the blockage is in the public main it is theirs to clear, at their cost. Only once they confirm the main is clear do you call a plumber for your lateral.
Out of the sump pit, or the pit is full and the pump is silent → sump pump failure. A plumber or sump pump specialist; an electrician only if the circuit itself is dead. Fixr puts a sump pump installation at $600 to $2,500.
Timing narrows it further:
- Only during and after heavy rain → groundwater, grading, or a surcharging sewer main. Effectively never a supply pipe.
- Any time, rain or not, and getting worse → supply-side plumbing. Check the water meter with every fixture off; if it’s moving, you have a live leak.
- Mid-storm, right after the power blinked → your sump pump stopped. This is the most common flooded basement there is.
- Every spring as the snow melts, then it dries out → a seasonal water table. That’s a waterproofing project, not an emergency repair.
If two apply, follow the timing: rain-linked means outside water, use-linked means plumbing.
Then identify the water — it decides the cleanup and the coverage
Clean water (supply line, water heater, rain through a window well): lowest risk, standard drying. Fixr puts Category 1 cleanup at $3.50 to $4.25 per square foot, typically $1,000 to $5,000.
Groundwater / storm water: comes in through walls, floor cracks, or the window wells. Treated as contaminated — Category 2, “grey water” — which Fixr prices at $4.10 to $5 per square foot, typically $4,000 to $8,000. Also the type your standard homeowners policy most likely does not cover.
Sewage backup (toilets bubbling, foul smell, dark water): biohazard. Do not attempt cleanup yourself — this needs a restoration crew with the right protective equipment and disinfectants. And call the city first: if the blockage is in the municipal main, the repair and sometimes the cleanup are theirs, but only if you report it promptly and document it. Fixr puts Category 3 black water cleanup at $6.25 to $7.25 per square foot, and a Category 3 basement flood commonly at $10,000 to $15,000 — the reason it matters that you name it correctly on the phone.
Overall, Fixr puts flooded basement cleanup at $2,000 to $7,000 with a national average of $4,000.
Who to call first, in order
- Power to the basement off — at the panel if you can reach it from dry ground, otherwise the utility or 911. Nothing else happens until this does.
- Stop the source if it’s yours — main water valve for a pipe, stop using every drain if it’s a backup.
- The city sewer line, if there is any chance this is a backup. Free, fast, and it may be their bill.
- Restoration company for extraction and drying. Standing water is a clock, not a mess — 24 to 48 hours to mold.
- Your insurer, before demolition and before you throw anything away.
- The permanent fix — plumber, waterproofer, or drainage contractor — once it is dry.
Getting the order wrong has specific costs:
- Walking down before the power is off is the only step on this list that can kill you.
- Calling a plumber for groundwater buys you a call-out fee and a shrug. He is not wrong to shrug; it isn’t plumbing.
- Calling a waterproofer while the basement is still full wastes the visit — they cannot see the entry point through six inches of water, and most will decline to quote.
- Skipping the city and calling a plumber for a backup means paying to diagnose a problem the utility would have diagnosed free, and possibly paying to clear their main.
- Demolishing or discarding before the insurer sees it removes the evidence your claim is built on. Photograph first, always, including the water line on the wall.
- Pumping a groundwater flood out too fast can crack a foundation, because the pressure outside no longer has anything pushing back. Drain gradually.
Who will tell you it’s not their job
A flooded basement sits between four trades, none of which does the whole thing. Knowing who declines what saves you a day of phone calls.
- Plumbers decline groundwater. “That isn’t a plumbing problem, call a waterproofer” is the most common sentence people hear on this, and it is accurate. Plumbers own the pipes. Water coming through a wall belongs to drainage.
- Restoration companies decline the repair. They extract, dry, disinfect, and remove what can’t be saved. They will not waterproof your foundation or fix the pipe, and a good one will ask who is doing that before they set equipment.
- Restoration companies without Category 3 certification decline sewage outright. If you say “sewage” on the phone and they hesitate, call someone else — you want the crew that says yes immediately and arrives in proper protective equipment.
- Waterproofing and foundation contractors decline the cleanup, and most decline to quote while the basement is wet. Their visit is worth booking for the week after, not the day of.
- The city declines anything past the property line or past the main. They will check their side and stop there.
- Carpet cleaners and general handymen decline anything past clean water, and should. Category 2 and 3 water is not a shampoo job.
- Electricians won’t pump your basement, but they are the right call for a dead sump circuit, a soaked panel, or outlets that were underwater — none of which a plumber will certify.
The insurance question, before you spend anything
Which policy pays is decided by where the water came from, and there are three separate products involved:
- A failure inside the house — burst pipe, water heater, appliance hose — is the sudden, accidental event a standard homeowners policy is built for.
- Groundwater or surface water entering from outside is flood, and standard homeowners policies exclude it. That needs a separate flood policy you either bought or didn’t.
- Sewer or drain backup is normally excluded too, and covered only by a specific endorsement.
Sequence matters more than argument here. Photograph everything before extraction, including the height the water reached. Call the claims line before demolition, not after. Keep every receipt — pump rental, fans, the restoration invoice, a hotel if the house was unlivable. And do not throw out damaged contents until they have been photographed, ideally with a rough list; contents claims fail on missing evidence far more often than on disputed coverage.
The other common denial is time-based. A basement that “has always taken a bit of water in spring” is a maintenance condition rather than a sudden loss, and a claim filed weeks after the event invites exactly that reading. Report it the day it happens, describe what you found and when you found it, and let the adjuster classify it — that is their job, not yours to pre-argue.
Why the sump pump usually fails at the worst moment
The storm that floods your basement is the same storm that knocks out your power, and a sump pump without electricity is a plastic ornament. If you’ve had one failure, install a battery-backup pump before the next season — it costs a fraction of one cleanup.
Test the one you have: pour a bucket of water into the pit and confirm it kicks on and drains. Do it twice a year. A stuck float is the second most common failure and it’s free to catch.