What to Do After a Flood: A Home, Well Water, and Food Safety Checklist

Knowing what to do after a flood matters more than anything you did to prepare for it. Isaias came ashore on the Florida Panhandle overnight Friday and has weakened to a post-tropical cyclone over Alabama, but the rain isn’t done. The National Hurricane Center expects 4 to 8 inches through the weekend across southern Alabama, the Florida Panhandle and Big Bend, and southwest Georgia, locally up to 15, with flash, urban, and river flooding possible across the Southeast as the storm moves into the Tennessee Valley. If that’s your area, the hardest decisions usually aren’t during the storm. They’re in the days after the water starts to go down, when you’re deciding whether it’s safe to walk back into your own house, whether your well is still good, and what in your kitchen you have to throw away.

This guide is built for that exact window, and it works the same way whether the flooding came from this storm or from a flash flood, a river overflow, or a dam release years from now, so it’s worth bookmarking rather than reading once and forgetting. If a hurricane is still headed your way, start with my hurricane preparedness checklist. If you’ve already been through evacuation, my flood and dam-failure evacuation checklist and flash flood safety tips cover the watch-to-warning-to-evacuation phase. This guide picks up right where those leave off: the water is receding, and now what.

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Is It Safe to Go Home?

Water receding from the street doesn’t mean your house is clear. Floodwater undermines foundations, soaks structural wood, and can leave live electrical hazards behind long after the visible water is gone. Before you go further than the driveway, confirm a few things.

Don’t go back on your own timeline if your area is still under a mandatory evacuation or re-entry restriction, even if your specific street looks dry. Once re-entry is allowed, walk the exterior first and look for shifted foundations, sagging rooflines, cracked or leaning walls, standing water still against the foundation, and any downed power line near the property or touching standing water. Treat a downed line as live until a utility crew confirms otherwise. If you smell gas or hear hissing near a gas line or appliance, leave immediately without flipping a switch or lighting anything, and call your gas utility or emergency services from outside. Ready.gov’s flood safety page covers the broader return-home timeline alongside what’s below.

If your home took on more than a few inches of water, or the water sat for more than a day, plan on a professional structural inspection before you treat the house as fully safe. That’s a reasonable expense to protect, not an overreaction.

Your Re-Entry Checklist

Once the outside checks out, work through this in order rather than diving straight into cleanup. The order matters: gas and electrical hazards can hurt you in the first five minutes, and photos have to happen before anything gets moved or thrown out.

1. Check for gas first. If you smell it or hear hissing, leave immediately and call your gas utility or emergency services from outside.
2. Cut power at the main breaker if the panel, outlets, or wiring got wet, and don’t touch a wet panel yourself. Have a licensed electrician inspect anything that was submerged before it gets switched back on.
3. Shut off the main water supply if you’re on a private well or suspect contamination, until you know what you’re dealing with (more in the next section).
4. Photograph everything before you move or toss a single item: water lines on the walls, damaged flooring, ruined furniture, and the outside of the house, from multiple angles. Keep a written list as you go for your insurance claim.
5. Open windows and doors to start ventilating as soon as it’s safe. You’re racing the clock on mold, covered below.
6. Remove standing water and soaked porous materials that were in contact with floodwater, carpet, carpet pad, drywall, insulation, upholstered furniture, rather than trying to dry them in place.
7. Don’t run appliances that were submerged, furnace, water heater, dishwasher, washer or dryer, until they’ve been inspected. Floodwater in a motor or control board is a fire and shock risk even once everything looks dry.

Wear rubber boots and heavy work gloves while you work. Floodwater routinely carries sewage, chemicals, and bacteria regardless of how clean it looks, and small cuts picked up during cleanup are a common source of infection in the days after a flood.

Well Water Safety After a Flood

If your home is on a private well, this is the section I’d read most carefully. It’s the piece that doesn’t get covered anywhere else on this site, and it’s the one people get wrong most often.

Why clear water isn’t safe water

When floodwater reaches a wellhead, casing, or the ground around a well, it can carry sewage, agricultural runoff, fuel, and bacteria down into the water your well draws from, especially on older wells, shallow dug or bored wells, or any well whose cap was submerged. The contamination that matters most, coliform bacteria and E. coli, has no taste, smell, or color you’d notice on your own. The EPA’s guidance on private wells after a flood is direct about this: treat any well that was submerged as contaminated until it’s tested, regardless of how the water looks or tastes coming out of the tap.

The first 24 hours: assume it’s unsafe

• Stop drinking, cooking with, or brushing your teeth with well water the moment you know the wellhead was underwater or the pump lost power during flooding.
• Check the wellhead and pump for visible damage or debris before restoring power to the pump. If the pump itself was submerged, have an electrician inspect it first. Running a flooded pump before it’s dry can damage the motor or create a shock hazard.
• Switch to bottled water, water you stored before the storm, or water you treat yourself in the meantime.

The first week: shock chlorination and testing

The standard fix for a flooded well is shock chlorination followed by lab testing, not a product you buy off a shelf but a disinfection process. The CDC’s guidance on disinfecting wells after an emergency and the EPA page above walk through the specific chlorine concentration and contact time for your well type: you introduce a chlorine solution into the well and plumbing, let it sit for several hours, then flush the system thoroughly until the chlorine smell clears from every tap. A licensed well or pump contractor can do this for you, and your county health department or extension office can usually walk you through it over the phone if you’d rather do it yourself.

Get the water professionally tested afterward, specifically for total coliform and E. coli, before you treat it as safe again. Many county health departments offer free or low-cost post-flood well testing during disaster response. Don’t rely on a home test strip alone for this decision; those are fine for general monitoring, not for clearing a well that sat under floodwater. If a test comes back positive, fix the actual contamination source, a cracked casing or a low wellhead seal, before you shock chlorinate again. Re-treating water without fixing the entry point buys time, but it is not a real solution.

While you’re waiting on results, which can take anywhere from a day to over a week depending on your local lab, you still need water for drinking and cooking. A manual pump filter like the Survivor Filter Pro is built to handle turbid, flood-stirred water, a genuinely different job than the ultralight backpacking filters a lot of people already own but that clog fast on sediment-heavy water, and it needs no batteries or power source. If you’d rather keep it simple, Aquatabs chlorine tablets are inexpensive, shelf-stable, and effective against the bacteria and viruses you’re most worried about here, though they won’t clear sediment or chemical contamination the way filtration does. I’ve got a more detailed breakdown of which approach fits which situation in my tablets versus filters comparison, and a deeper look at building a full home water system in my emergency water filter guide. My water calculator is useful here too, for figuring out exactly how much treated water your household needs per day while you wait.

One more thing worth knowing: a boil-water notice from your municipal utility is a different situation than a private well, but the logic is the same. Boiling kills bacteria and viruses; it doesn’t remove chemical contamination or sediment. If water looks cloudy or smells off even after boiling, that’s a filtration or alternate-source problem, not something to boil harder.

Food Safety After a Flood

Food safety after a flood splits into two separate problems, and treating them the same way is how people either throw out food that was fine, or worse, keep food that wasn’t.

Problem one: food that lost power but never touched floodwater. This is a temperature problem. A full freezer that’s stayed closed generally holds a safe temperature for about 48 hours; a half-full freezer, closer to 24. A refrigerator without power is only good for about 4 hours before food starts moving into the danger zone. Use an appliance thermometer if you have one: anything that’s been above 40°F for more than two hours should be treated as a loss for perishables like meat, dairy, and leftovers. Never taste food to decide if it’s safe; harmful bacteria don’t reliably change taste, smell, or appearance. When in doubt, throw it out. That’s the actual standard the CDC uses for food safety after a disaster.

Problem two: food that had any contact with floodwater. This is a contamination problem, and it’s a hard line, not a judgment call. Floodwater carries sewage, chemicals, and bacteria, and anything porous absorbs it in a way you can’t wash off. This category has to go, no exceptions:

• Any food in cardboard, paper, or other porous packaging that touched floodwater, even briefly.
• Canned goods that were submerged, unless you’re prepared to properly decontaminate: remove the label, wash the can in hot soapy water, then sanitize it in a bleach solution before use. If the can is dented along a seam, bulging, rusted, or leaking, it goes in the trash regardless.
• Plastic containers, bottles, and jars with screw-on, snap, or pull-off caps that touched floodwater, since those seals aren’t designed to keep contaminated water out.
• Fresh produce, bagged or boxed dry goods, spices, and anything already opened that had any floodwater contact.
• Baby formula, baby food, and bottled water that touched floodwater, even if the container looks sealed. Infants have far less tolerance for contamination than adults, so this isn’t a category to stretch the rules on.
• Wooden cutting boards, bottle nipples, pacifiers, and other porous kitchenware that touched floodwater, since these can’t be reliably sanitized the way glass, metal, or ceramic can.

The two problems can overlap, a freezer that both lost power and sat in two feet of water is a total loss either way, but keeping the categories straight helps you make faster, more confident calls instead of agonizing over every item. The cost of replacing food is always lower than the cost of a foodborne illness on top of everything else you’re dealing with that week.

Generators, Carbon Monoxide, and Mold in the First 48 Hours

I’m keeping this part short on purpose, because I’ve already covered generator and carbon monoxide safety in depth elsewhere, and I’d rather point you to the full version than give you a thin summary here. If you’re running a generator during cleanup, carbon monoxide is the fastest way this week turns into a tragedy rather than just a hard stretch: keep it outdoors, well away from windows, doors, and vents, every time, including in the rain, and get a battery-backed carbon monoxide alarm running as soon as you have any power restored. I cover placement, sizing, and the full safety rundown in my power outage emergency kit guide and my backup power options comparison.

Mold is the quieter risk, and the first 48 hours matter more than people expect. Growth can start on wet drywall, carpet, and furniture within 24 to 48 hours, which is why this competes directly with water and food safety for your attention early on, not something to get to later. The CDC’s guide to mold cleanup after a flood recommends getting air moving and humidity down as fast as possible: open windows when weather allows, run fans, and use a dehumidifier if you have power and one available. Remove wet carpet, carpet padding, and insulation that’s been soaked for more than 24 to 48 hours rather than trying to dry them in place, since these hold moisture deep inside even once the surface feels dry. Wipe down hard, non-porous surfaces with a detergent solution, and never mix bleach with ammonia-based cleaners; the combination produces toxic fumes.

Wear gloves, eye protection, and an N95 or better respirator while cleaning anything already visibly moldy, and keep kids and anyone with asthma, allergies, or a compromised immune system out of the area until it’s cleaned. If the water damage is extensive, walls, insulation, or large sections of flooring, bringing in a restoration professional is the cost-effective call, not a luxury. The difference between drying a structure correctly in the first week and dealing with hidden mold six months later is significant.

Your Tiered Recovery Checklist

Here’s the whole plan in one table, organized by timeframe first, then by category, so you can scan it fast when you’re standing in your kitchen trying to decide what to do next.

FAQ

How long after a flood is it safe to go back home?

There’s no fixed number of hours. It depends on when local officials confirm roads and your area are safe, when standing water has receded from your property, and whether your home’s structure and utilities check out once you’re there. Confirm the all-clear with local officials before you drive back, then do the exterior safety check in this guide before going inside.

Does clear-looking well water mean it’s safe to drink?

No. The bacteria that make flooded well water dangerous, mainly coliform bacteria and E. coli, don’t reliably change how water looks, tastes, or smells. Any well that was submerged or lost power during flooding should be treated as contaminated and tested before you drink from it again, according to EPA guidance on private wells after flooding, regardless of appearance.

What food should always be thrown out after a flood?

Anything that had direct contact with floodwater and is in porous packaging, cardboard, paper, or bags, plus any container with a screw-on, snap, or pull-off lid that touched floodwater, since those seals aren’t flood-proof. Separately, any refrigerated or frozen food that’s been above a safe temperature for more than about 2 hours in the fridge, or 24 to 48 hours in the freezer, should also go. When you’re not sure, throw it out rather than risk it.

How long should I run my well before testing the water?

Running the tap doesn’t make a flooded well safe and isn’t a substitute for testing. The correct sequence is to shock chlorinate the well and household plumbing, flush it thoroughly until the chlorine smell clears from every faucet, then collect a sample for professional lab testing. Follow your state or county health department’s specific flushing and sampling instructions, since timing can vary by well type and the lab you’re using.

Is tap water safe for mixing baby formula under a boil-water notice?

Boiling tap water for a full minute kills the bacteria and viruses a boil-water notice is typically protecting against, and boiled-then-cooled water can be used for formula under most notices. Boiling doesn’t remove chemical contamination or heavy sediment, though, so if the notice mentions a chemical spill or your water looks visibly off even after boiling, use bottled water for formula instead. Avoid using water from a private well for formula at all until it’s tested and confirmed safe after a flood.

How soon should I worry about mold after a flood?

Sooner than most people expect. Wet drywall, carpet, and insulation can start growing mold within about 24 to 48 hours, so get air moving, remove soaked materials you can’t dry quickly, and run a dehumidifier as soon as it’s structurally and electrically safe to do so.