Spring flooding: how to protect your home, basement and yard
What to do before snowmelt and spring rains to protect your home: check your flood risk, clear gutters and drains, fit a backwater valve and sump pump, move valuables up and prepare sandbags.
In short
- Find out whether your home is in a flood-risk area: official flood maps and local history tell you a lot.
- In spring, most damage comes from water entering the basement through drains or walls, not from rivers overflowing.
- A backwater valve on your sewer line and a sump pump with battery backup prevent a lot of damage for little money.
- Move documents, appliances and valuables up, and check whether your insurance covers flooding: standard home policies often don't.
Spring is flood season in much of the world: snow melts, rain falls and the ground is already saturated. A lot of damage doesn’t come from rivers overflowing, but from water backing up through drains, seeping through basement walls or running off the yard toward the house. Almost all of it can be prevented with a day’s work and a modest budget.
What to do once water is already coming is in our flood guide. This one is about preparation.
1. Know your risk
- Official flood maps: FEMA’s Flood Map Service Center in the US, the Environment Agency’s flood risk checker in England, and national equivalents elsewhere.
- Ask long-time neighbors: were there floods 10, 20 or 50 years ago?
- Look at the land: are you in a valley, near a creek, below street level?
- Follow flood warnings from your national weather and hydrology services.
2. Yard and roof
- Clear gutters and downspouts of leaves in fall and spring.
- Downspouts should discharge away from the house, at least 5–6 ft (1.5–2 m) from the foundation.
- Clear storm drains and culverts in front of your home.
- The ground should slope away from the house, not toward it.
- Secure firewood, barrels and large objects: water can carry them off and block drains.
3. Basement
- Backwater valve on the sewer line: stops water backing up from the sewer when it’s full. Installed by a plumber.
- Sump pump with a float switch in a sump pit or the lowest point. Ideally with battery or power station backup.
- Seal cracks in walls and floor.
- Protect basement windows and doors with barriers or sandbags.
- Furnace, water heater and electrical panel: if they’re in the basement, ask a professional whether they can be raised.
4. Inside
- Important documents in waterproof bags, up high or with someone in a safe area. Make digital copies too.
- Appliances and valuable furniture from the basement or ground floor onto shelves or upstairs.
- Chemicals (paint, pesticides, fuel) up high and sealed: floodwater spreads them everywhere.
- Photograph your home and belongings now, for insurance.
5. Keep ready
- Sandbags or water-activated flood bags
- Heavy plastic sheeting and duct tape
- Rubber boots and gloves
- A flashlight and battery radio
- An extension cord and a small pump
- Your go bag, in case you need to leave: see the evacuation checklist
After a flood
- Don’t enter until the power is off and you’re sure the structure is sound.
- Photograph damage before cleaning up.
- Throw away food that touched floodwater, including dented or rusted cans.
- Disinfect everything floodwater touched: it’s contaminated.
- Dry the house thoroughly before refinishing, to prevent mold. See also indoor air quality.
Frequently asked questions
Does home insurance cover floods?
Often not. In the US, standard homeowners policies exclude flood; you need a separate policy (for example through the National Flood Insurance Program, which usually has a 30-day waiting period). In the UK and much of Europe flood is often included, but check exclusions for basements and sewer backup.
Are sandbags worth it?
Yes, for shallow surface water flowing toward doors or basement windows. They won't stop water rising through drains or the ground. Lighter alternatives exist: water-activated flood bags and removable door barriers.
What do I do if the basement has flooded?
Don't step into the water if the basement wiring may be live. Only switch off power at the panel if you can reach it without standing in water; otherwise call your utility or the fire department. Pump water out gradually, not all at once, so pressure on the walls doesn't become unbalanced.
Sources and further reading
Preper is for general education and does not replace instructions from your local authorities or advice from a doctor. In an emergency, call your local emergency number.