What to Do After a Flood: A Step-by-Step Guide
The water is still on the floor, the power may be flickering, and your phone is full of half-formed questions. In the first hour after a flood, what you do matters far more than what you feel, and the good news is that the right moves are simple, calm, and in your control.
This is a plain step-by-step guide to what to do after a flood, written for the messy reality of the first 24 to 48 hours: how to stay safe, stop the water, document everything for your insurance, start drying before mold gets a foothold, and recognize the moment to call a professional. It is built for Las Vegas, where a dry climate and flash-flood plumbing create a very specific kind of water emergency. If water is actively spreading in your home right now, skip ahead and call our 24/7 emergency line first, then come back and read.
Las Vegas homeowner standing in a flooded entryway during the first hour after a floodThe first hour
Step 1: Make the space safe before you touch anything
Before you wade in to save the rug or rescue boxes, stop and read the room for danger. Water and electricity are the real hazard in a flood, not the water itself. If floodwater has reached outlets, appliances, or the bottom of walls where wiring runs, do not step into it. Standing water can be energized, and you will not see it.
If you can reach your breaker panel safely, without standing in water to do it, shut off power to the affected area. If the panel itself is wet or you have to cross standing water to reach it, leave it alone and call an electrician or the utility. A dry rug is not worth your life.
Watch for two other things. First, structural sag: a ceiling that is bulging or dripping from above means water is pooling on top of drywall, and it can come down all at once. Stay out from under it. Second, contamination. Clean water from a supply line is one thing, but water that backed up from a drain, a sewer, or came in across the ground from a storm is a different category entirely, carrying bacteria you do not want on your skin. When in doubt, treat the water as dirty, wear gloves and boots, and keep children and pets clear. The same care applies to a serious indoor failure like a burst pipe, where a wall cavity full of water can hide both an electrical and a structural risk.
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Stop the source
Step 2: Shut off the water and stop the flood at its source
Once the space is safe, your next job is to stop more water from arriving. A flood that you can cut off in five minutes is a far smaller problem than one that runs for an hour while you look for towels. Where you go depends on where the water is coming from.
Knowing where your main shutoff is before an emergency is one of the highest-value things a homeowner can learn, so if you had to hunt for it this time, tag it now for next time. Once the source is stopped, the clock that really matters starts: the race to get the structure dry before mold begins.
Protect your claim
Step 3: Document everything for your insurance before you clean up
This is the step people skip in the rush to clean, and the one they regret most. Before you move, mop, or throw anything away, document the damage thoroughly. Your photos and video taken in the first hour are the evidence your claim will rest on, and you only get one chance to capture the scene as the water left it.
Walk the affected area with your phone and record video, narrating what happened and when. Then take still photos: wide shots of each room, close-ups of the water line on the walls, soaked flooring, damaged furniture, and the source of the water if you found it. Photograph serial numbers and model plates on any damaged appliances. If you remove a sopping rug or pull baseboards to start drying, photograph them first and set damaged items aside rather than discarding them, because an adjuster may want to see them.
Call your insurance carrier early to open the claim and ask two specific questions: what emergency mitigation they expect you to perform, and whether they need an adjuster to inspect before you begin drying. Most policies actually require you to take reasonable steps to prevent further damage, which means starting to dry quickly, so you generally do not have to wait helplessly for an adjuster to begin protecting your home. Keep receipts for anything you buy or rent. If the cause was sudden and accidental, a documented timeline is what separates a smooth water damage insurance claim from a disputed one, and it is also the foundation of any larger water damage restoration job that follows. A professional restoration crew will produce this documentation as a matter of course, with moisture readings and a written scope, which is exactly the record carriers want to see.
Air movers and a dehumidifier set up to begin drying a flooded roomStep 4: Start drying fast, because the mold clock is already running
Here is the hard fact that drives every decision after a flood: mold can begin to colonize wet drywall, wood, and flooring within roughly 24 to 48 hours. After about 72 hours, the conversation shifts from drying and saving materials to removing and replacing them. So the moment the water is stopped and documented, drying becomes urgent.
- Remove standing water. Pull out as much water as you can with a wet vacuum, mops, and towels. Lifting water out is far faster than waiting for it to evaporate.
- Get air moving. Set up fans to push air across wet surfaces and open interior doors so air circulates. In dry Las Vegas weather, opening windows can help, but during a humid monsoon it can make things worse, so judge the outside air.
- Pull up what traps water. Lift soaked rugs and pad, and move wet furniture off carpet onto blocks. Wet carpet and its pad hold water against the subfloor and slow everything down.
- Run a dehumidifier. A home dehumidifier helps pull moisture out of the air so wet materials can keep releasing water. This is the engine of real drying.
- Watch the hidden cavities. Remember that the surface dries first. Wall cavities, subfloors, and the inside of cabinets stay wet long after the floor feels dry, which is exactly where mold starts.
Your home equipment can handle a small, quickly-caught spill. What it usually cannot do is dry a wall cavity or a saturated concrete slab fast enough to beat the mold clock, because that takes commercial dehumidification, properly placed air movers, and moisture readings to confirm the structure is actually dry and not just dry on the surface. That measured process is called structural drying, and it is the difference between hoping a wall is dry and having data that proves it.
Know your limits
Step 5: When to stop and call a professional
Plenty of small floods are genuinely DIY, and an honest restorer will tell you so rather than rushing a truck to a spill you could have toweled up. The point of this section is the opposite of a sales pitch: it is to help you recognize the floods that are past the point of a wet vacuum and a box fan, because calling early is what saves a floor from becoming a tear-out.
Call a professional when the flooded area is large, when water has soaked into walls or traveled across more than one room, or when it has been sitting for more than a day. Call right away if the water is contaminated, from a sewer backup, a toilet overflow, or storm water across the ground, because that water carries health hazards and the porous materials it touched usually have to be removed, not just dried. A serious storm event almost always crosses this line, which is why flood restoration treats the water, the contamination, and the drying as one continuous job.
The reason a credential matters here is that drying to a verified standard is a measured discipline, not guesswork with a few fans. Our owner Craig Herrmann co-authored the ANSI/IICRC S520 standard that the industry dries by, and every technician on our crew is a certified W-2 employee, never a subcontractor, so one accountable team owns the water, the drying, and the mold risk from the first reading to the last. You can read more about Craig’s credentials and the standard he helped write. If you are unsure whether your flood crossed the DIY line, that uncertainty itself is the signal to get a second opinion before the 72-hour window closes.
Desert specifics
What makes a Las Vegas flood different
Flood advice written for a rainy climate misses what actually happens here. Las Vegas floods in two very different ways, and both have a desert twist worth understanding while the water is still on your floor.
The first is the flash flood. The valley’s hard desert soil and concrete washes do not absorb a sudden monsoon, so a brief, intense storm sends water racing through low streets and into garages and ground-floor units in minutes. That water is dirty by the time it reaches your door, picking up whatever it crossed, so it should be treated as contaminated from the start. The second is the indoor failure that the desert quietly sets up: slab-on-grade construction is everywhere here, and a hidden slab leak or a failed line can flood a home from the inside with no warning.
The dry air fools people the most. Because the surface evaporates so quickly in our climate, a floor can feel dry within a day while the subfloor and wall cavities stay soaked underneath, and our extreme summer heat can drive that trapped moisture deeper into cool wall cavities through condensation. A concrete slab that feels dry on top can hold water for weeks. This is precisely why surface feel is the wrong test and measured drying is the right one, a problem we go deeper on in our guide to what to do after water damage and in the science of how fast mold grows after water damage. The desert does not make floods rarer. It makes them easier to underestimate.
What to do after a flood: common questions
- What is the very first thing to do after a flood?
- Make sure the space is safe before anything else. Watch for the combination of water and electricity, and shut off power to the affected area only if you can reach the breaker panel without standing in water. Once it is safe, stop the source of the water, then document the damage before you clean. Safety, source, documentation, then drying, in that order.
- How long do I have before mold becomes a problem?
- Roughly 24 to 48 hours from when materials get wet, with about 72 hours as the point where the job shifts from drying and saving to removing and replacing. That short window is the whole reason drying is treated as an emergency rather than a scheduled appointment. The faster a controlled drying environment is set up, the more of your home you save.
- Should I start cleaning up before the insurance adjuster arrives?
- Document first, then mitigate. Take thorough photos and video before you move or remove anything, and call your carrier early to ask whether they need to inspect before you dry. Most policies actually require you to take reasonable steps to prevent further damage, so you generally should start removing water and drying quickly, just keep damaged items and your receipts. A clean record protects your insurance claim.
- Can I dry out a flood myself, or do I need a professional?
- A small, quickly-caught spill on a hard surface is often a DIY job with a wet vacuum, fans, and a dehumidifier. Call a professional when the area is large, when water soaked into walls or crossed rooms, when it sat more than a day, or when the water was contaminated. The risk with DIY is that the surface dries while wall cavities and subfloors stay wet, which is exactly where mold starts. Measured structural drying proves the structure is actually dry.
- The water came in from the storm. Is that different from a pipe leak?
- Yes, and it matters. Storm water and any water that backed up from a drain or sewer is contaminated, carrying bacteria and debris, so the porous materials it touched usually have to be removed rather than just dried. A clean supply-line leak is far simpler. When the water is dirty, the job becomes flood restoration with containment and removal built in, and an independent third-party lab can verify the result.
- How do I know when my home is truly dry and mold-free?
- You measure it. The surface drying first is the trap, so feel is not a reliable test. Moisture meters and thermal imaging give each material a real number and confirm when it has hit a dry target. If a past flood was never properly verified, the calm way to find out where you stand is a free inspection for property owners, and if lab analysis is warranted, samples go to an independent third-party lab, billed at cost.
Flooded right now? Get it dried right before mold gets its chance.
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