My basement is flooding. Here's what to do right now.

A flooding basement is one of the few plumbing situations where the first ten minutes actually matter. Not because you can stop it yourself (usually you can't), but because what you do first decides whether this stays a wet floor and a service call, or turns into a shock hazard and a much bigger bill. Here's the order we'd want our own family to work through, and the honest part about which of these problems even need a plumber.

The first four things, in order

Do these before you start moving boxes or hunting for a shop vac. It takes about five minutes and it's the part people skip.

• Look for electricity before you look at anything else Basements are where the outlets sit low, the furnace sits on the floor, and the freezer is plugged in behind everything. If water is touching any of that, stay on the stairs. If your panel is upstairs or you can reach it without walking through water, shut off the basement circuits. If the panel itself is down there in the water, don't go for it. That's an LG&E and electrician call, not a homeowner call.
• Shut the water off at your main If the water is clean and you suspect a burst supply line, a failed water heater, or a fixture upstairs, close the main shutoff. In most Louisville homes it's on the wall where the water line enters the basement, often near the meter. Turn it clockwise until it stops. If you've never found yours, find it today anyway. Knowing where it is beats learning during the emergency.
• Figure out where the water is entering This is the whole diagnosis. Water rising in and around the sump pit means the pump isn't keeping up or isn't running. Water bubbling up out of a floor drain or a basement toilet, usually dirty and with a smell, means the sewer is backing up. Water tracking down a wall, in at a window well, or at the floor-to-wall seam is rainwater from outside. Three different problems, three different people to call.
• Lift what you can, then take pictures Get anything off the floor that you can safely carry: boxes, tools, anything with a cord. Then photograph the water, the depth against a wall, and the damaged items before you clean up. If insurance ends up involved, those photos are worth more than anything you'll remember later. Don't put yourself in the water to save stuff. It isn't worth it.

What's actually causing it

Four things put water on a Louisville basement floor. The one you're looking at determines whether this is a same-day plumbing call, a cleanup call, or a gutters-and-grading project.

• The sump pump quit, or lost power The classic. The storm that floods a basement is usually the same storm that knocks the power out, and a pump with no electricity is no pump at all. A tripped GFCI outlet is the single most common reason a sump pump goes quiet, and it costs nothing to rule out. Check the plug and press the reset button only if that outlet is dry, sitting well above the water line, and you can reach it without stepping into the water. If it's wet, close to the water, or you'd have to wade over to get to it, leave it alone and call an electrician or your utility instead, same as the panel. If the pump is running nonstop and losing ground, it may be undersized, or the check valve may be letting the water fall right back into the pit.
• The sewer is backing up into the house If the water is coming up out of the lowest floor drain and it's dirty, this is a main line problem, not a sump problem. It can be a clog in your own line, and roots in an old clay lateral are the usual cause in Louisville's older neighborhoods, or it can be the city sewer itself being overwhelmed in a downpour. Stop running water upstairs. Every flush and every load of laundry is going straight to the floor.
• A pipe or the water heater let go Clean water, no rain, no storm. A supply line burst, a water heater rusted through, or a washer hose failed. This is the one where shutting off the main actually stops the flooding, so do that first and then call. A tank that's finally rusted through can put its whole capacity on the floor and keep going, because it refills as fast as it empties.
• Storm water coming in from outside Water down the wall, in through a window well, or seeping at the seam where the wall meets the floor is groundwater and roof runoff, not plumbing. The fixes are gutters, downspout extensions, regrading so water runs away from the house, and sometimes waterproofing. We'll tell you when that's what we're looking at, because paying a plumber for it won't fix it.

How we'd approach it

When we get there, the first job is confirming the source, because everything else follows from it. A standard diagnostic visit runs $89. If it's the sewer, we clear the main line. Through an existing cleanout that's $300–$400, and when there's no usable access and we have to make one and evaluate with a camera it's $500–$600. A standalone camera inspection to see what's actually down there runs $300–$400, and after a backup in an older home it's usually money well spent, because it tells you whether you have a one-time clog or roots you'll be fighting every spring. If it's the pump, sometimes it's a free float adjustment and sometimes the pump has aged out; a standard sump-pump replacement with a fresh check valve runs $800–$900, and a failed check valve on its own is $100–$200. If losing power is what put you here, that's when we bring up a battery backup, which runs $2,000–$2,200. Not as an upsell, but because the storms that flood basements are the same ones that take the power down. Want a ballpark before anyone comes out? Ask Goldie can walk you through it.

Common questions we get