The First 24 Hours After a Flood: A Step-by-Step Checklist

The first 24 hours after a flood set the course for everything that follows — your safety, what you can save, and whether your insurance claim goes smoothly. This checklist gives you the order of operations the official guidance recommends: secure people, stop the water, kill the power, document, then dry out. It is the hands-on companion to our master guide on what to do when your house floods.

Hour 0–1: Make people safe

Nothing on this list matters more than the people in the house.

1. Account for everyone, including pets. If anyone is missing, trapped, or injured, call 911 before doing anything else.
2. Get out if the water is rising fast or contaminated. You cannot tell how deep moving water is, and as little as six inches of moving water can knock an adult off their feet.
3. Avoid the electrocution zone. Do not wade through standing water that may be in contact with outlets, cords, or submerged appliances.
4. Watch for structural failure. A sagging, bulging ceiling means water is pooling above it — stay out of that room.

Hour 1–3: Stop the water and the power

Once people are safe, your job is to stop the situation from getting worse.

Shut off the water source

If the flooding is from inside — a burst pipe, a failed water heater, an overflowing appliance — close the main water shut-off valve. It’s typically where the supply line enters the home: a basement, crawlspace, garage, or a curb box near the street. Turn it clockwise. If the flooding is from outside (storm, rising water), you can’t stop the source; focus on people and higher ground.

Cut the electricity — safely

If your breaker panel is dry and reachable without stepping into water, switch off the main breaker to flooded areas. If reaching it means walking through water, leave it and call an electrician. The complete procedure is in how to shut off water, gas and electricity in an emergency.

Shut off gas only if you suspect a leak

If you smell rotten eggs or hear hissing, leave immediately, then shut the gas off at the meter if you can do so on your way out — and let the utility restore it.

Hour 3–6: Document everything

Before you move a single piece of furniture or pull up any carpet, document the damage. This protects your insurance claim.

• Wide shots first: every affected room from the doorway, capturing the water line on the walls.
• Then close-ups: damaged furniture, electronics, flooring, and the standing water itself.
• Capture identifying details: model and serial numbers on appliances and electronics.
• Video walkthrough: narrate what happened and when as you walk through.
• Save receipts for anything you buy to stop further damage (pumps, tarps, fans).

You have a duty to take reasonable steps to prevent further damage — but document before you mitigate. The full method, including how to build a room-by-room inventory, is in how to document flood damage for insurance.

Hour 6–12: Call your insurer and assess water type

Start the claim

Call your insurance company (and, if this is rising floodwater, your flood/NFIP insurer) to open a claim as soon as you reasonably can. Ask what they need and whether they’ll send an adjuster. Keep a log of who you spoke to and when. The differences between policies are explained in does homeowners insurance cover water damage.

Identify the water category

What you do next depends heavily on what kind of water flooded your home:

• Category 1 (clean): from a supply line or rain — lowest risk.
• Category 2 (gray): from appliances, washing machines, or seepage — some contamination.
• Category 3 (black): sewage backups and storm floodwater — contaminated and a genuine health hazard.

If you’re dealing with Category 3 water, wear protective gear and consider professional remediation. The full breakdown is categories of water damage explained.

Hour 12–24: Begin removing water and drying out

Now the mold clock is the priority. Mold can begin growing within 24 to 48 hours — so this work cannot wait.

1. Remove standing water with a submersible pump (for deep water) or a wet/dry vacuum. Step-by-step in how to remove standing water from your home.
2. Get porous items out — area rugs, cushions, and carpet padding hold water and slow drying.
3. Maximize airflow. Open windows if the outdoor air is drier, and run fans pointed across wet surfaces.
4. Run dehumidifiers continuously to pull moisture from the air and materials.

The complete drying strategy — how many fans, where to point them, and how long it takes — is in how to dry out a flooded house. For the science of why speed matters, see how long does it take mold to grow.

Food, water, and what to throw away

• Tap water: assume it’s unsafe until authorities say otherwise. Watch for boil-water notices.
• Food: discard anything — including canned goods with dented seals — that contacted floodwater.
• Medicine and cosmetics: throw out anything that got wet.
• Big items: mattresses and upholstered furniture soaked by contaminated water usually can’t be safely salvaged.

Photograph before discarding. The full keep-or-toss list is in what to salvage and what to throw away after a flood.

Protecting what matters most while you work

In the rush to deal with the structure, two categories of items deserve a moment of deliberate attention before the cleanup churn loses them.

Irreplaceable documents and keepsakes. Gather passports, birth certificates, insurance policies, deeds, photographs, and any cash or valuables out of the wet zone and into a dry, secure spot. Wet paper documents and photos can often be saved if you act fast: separate them gently, lay them flat to air-dry, or — if you can’t get to them immediately — seal them in a bag and freeze them to stop deterioration until you have time. The freezer trick buys you weeks.

Medications and medical equipment. Discard any medication that was submerged in floodwater, and don’t use powered medical devices that got wet until they’ve been checked. If a prescription is essential, contact your pharmacy about a replacement — many will expedite refills after a disaster.

Understanding your “duty to mitigate”

Insurance policies obligate you to take reasonable steps to prevent further damage once a loss occurs — this is called the duty to mitigate, and meeting it actually strengthens your claim rather than complicating it. In practice it means:

• Stopping the water and removing standing water promptly counts as mitigation.
• Putting tarps over a damaged roof, moving undamaged furniture out of a wet room, and starting fans all count.
• Keeping every receipt for emergency supplies and temporary repairs — insurers typically reimburse reasonable mitigation costs.

What it does not mean is gutting the home before the adjuster has seen it. Mitigate the spread, document thoroughly, but leave the assessment of the damage itself for the claim. Our insurance hub explains where this fits in the broader claims process.

When 24 hours isn’t enough — and you need to leave

Sometimes the honest answer after assessing a flooded home is that it isn’t safe to stay or work in yet. Step back and call for help when any of these are true:

• The electrical system was submerged and hasn’t been cleared by an electrician.
• You smell gas, or the gas meter was underwater.
• Floodwater is contaminated (sewage or storm water) and covers a large area.
• Ceilings sag, floors feel spongy, or the foundation shows new cracks — signs of structural compromise.
• The water has been standing for days, not hours.

There is no prize for pushing through a hazardous home alone. Restoration and remediation professionals exist precisely for situations beyond a safe do-it-yourself scope; our guide on DIY vs. professional water cleanup helps you draw the line. For the question of occupancy specifically, see is it safe to stay in your house after a flood.

Your first-24-hours checklist at a glance

1. Confirm everyone — including pets — is safe; call 911 if needed.
2. Stop the water source (main valve) if it’s a plumbing failure.
3. Cut power to wet areas at the breaker — only if safe to reach.
4. Shut off gas only if you suspect a leak.
5. Photograph and video everything before touching it.
6. Call your insurer and open the claim.
7. Identify the water category (clean, gray, or black).
8. Remove standing water; pull out soaked porous items.
9. Run fans and dehumidifiers to start drying within the 24–48 hour window.
10. Avoid contaminated tap water and discard food that touched floodwater.

Work the list in order, stay out of any water that touches electricity, and remember the governing rule of the whole 24 hours: safety first, then speed. The faster you dry the home, the more of it you save.