How to protect your home from flooding: a UK homeowner’s guide

You cannot stop a river rising or a storm drain backing up. What you can decide is how much of that water reaches your rooms, and how much it costs you when it does. Knowing how to protect your home from flooding comes down to a handful of practical moves: understand your risk, sign up for warnings, keep water out with the right physical measures, limit the damage inside, hold insurance that actually pays, and have a plan ready for the day it happens.

This guide works through each of those for UK homes, with the figures, the funding and the free tools behind them. Some of it you can do this weekend for the price of a few coffees. Some of it is a longer project worth thousands of pounds. All of it is cheaper than a flooded ground floor. And if you are buying in a flood area, remortgaging, or already flagged as high-risk, an independent flood risk assessment for your property gives you the site-specific evidence the national maps cannot.

Around 6.3 million properties in England now sit in an area at risk of flooding, and the Environment Agency expects that to reach roughly one in four homes by the middle of the century.

Know your flood risk before you spend a penny

Start by finding out how your home could flood, and how badly, because every other decision follows from it. Check the Government's free long-term flood risk service for your postcode, look at every source rather than just the nearest river, and find out whether the property has flooded before. A home can be dry for decades and still sit in a flood zone, because a zone describes probability over time, not history.

The four sources behave very differently, and the measures that stop one do little against another:

• Rivers and the sea are the best mapped and usually give the most warning, though they cause the deepest, most destructive floods.
• Surface water, the flooding that happens when rain overwhelms drains and runs off hard ground, is faster, harder to predict and now the most widespread source of all.
• Groundwater rises slowly in wet winters, can sit for weeks, and is often missed because nothing overflows: the water simply comes up through the floor.
• Sewers and drains back up when the system is overwhelmed, pushing contaminated water into the lowest rooms first.

It is worth checking the different sources of flood risk and, if your postcode surprises you, reading why a house can be in a flood zone even if it has never flooded. For a quick read on your own address, Unda's free flood risk map pulls the rivers, sea, surface water and reservoir layers together in one place, and the official GOV.UK long-term flood risk checker gives the Environment Agency's own view. If you are buying, or an insurer has priced off that map, a property-level flood risk survey goes well beyond the postcode band to your actual floor levels and history.

Surface water is now the single biggest source of flood risk in England, threatening about 4.6 million properties, more than rivers and the sea combined.

How do you flood-proof your home?

Protecting the building works on two fronts, and a genuinely flood-ready home uses both. Resistance measures keep water out for as long as possible: flood barriers and door guards, self-closing air bricks, non-return valves on drains and sealed external walls. Resilience measures accept that water may still get in during a serious flood, and limit what it ruins: electrics raised up the wall, solid tiled floors, resilient plaster and appliances lifted clear of the ground.

Resistance buys you time and stops the smaller, more frequent events entirely. But no barrier is watertight for ever, and standing water pushes hard against walls and floors. Above roughly 600mm outside, the sensible assumption is that some water will find its way in, so keeping it out and limiting the damage are partners, not alternatives. This is the thinking behind the Government's FloodReady plan, which wants property flood resilience to become as routine for homeowners as loft insulation or a smoke alarm.

Not all of it involves builders. Keeping gutters, gullies and soakaways clear does real work against surface water, and how you treat the garden matters too. For the detail on measures and how they are specified, see our guide to property flood resilience, and the practical steps for maintaining your drains to prevent surface water flooding. If you are tempted to pave the front garden, read first why paving over gardens raises flood risk.

The safest planning assumption is that above about 600mm of standing water outside, some will get in, so resilience matters every bit as much as resistance.

What grants and funding can help you protect your home?

You may not have to pay for all of it. After a flood, the Flood Re Build Back Better scheme lets eligible households claim up to £10,000 through their insurer to install resilience measures on top of like-for-like repairs, so the home comes back better able to survive the next one. Many councils also run property flood resilience grants, commonly around £5,000 per property, after a recognised flood event. Build Back Better is claimed through your policy, so the time to check you have it is before you need it, not after.

• Flood doors and barriers. Purpose-made doors and removable or automatic barriers across vulnerable openings.
• Self-closing air bricks. Vents that float shut when water rises, closing off a common entry route under the floor.
• Non-return valves. Fitted to drains and soil pipes to stop sewage backing up into the house.
• Raised electrics. Sockets, wiring and consumer units moved up the wall so a shallow flood does not condemn them.
• Resilient floors and walls. Concrete or tiled floors and lime-based or resilient plaster that dry out and clean up.
• Pumps and sumps. A sump and pump to remove water that does get in, quickly.

The full detail on eligibility and how to claim is on the Flood Re Build Back Better pages, and our explainer on what Flood Re is sets out how the wider scheme works.

Fifteen insurers now offer Build Back Better, worth up to £10,000 towards resilient repairs after a flood. That money only reaches you if you ask for it.

Will your insurance actually pay out?

Check two things on your buildings and contents policy: that flooding is covered at all, and what the excess is. Both matter, because a policy that technically covers flood but carries a five-figure excess is little use in a real event. Since 2016 the Flood Re scheme has helped keep cover affordable for homes in higher-risk areas by capping the flood portion of many policies.

There are two important limits. Flood Re does not apply to homes built since 1 January 2009, and it is designed to taper out by 2039, after which premiums are expected to reflect a property's real, evidenced flood risk. That is exactly why the resilience measures above are becoming a financial decision as well as a practical one, and why flood risk increasingly affects mortgage lending as well as insurance. Emerging Flood Performance Certificates are intended to let a home prove its resilience and, in time, earn a fairer premium. Where an insurer has loaded, restricted or refused cover on a crude map, an independent flood risk assessment for insurance gives you property-level evidence to challenge the decision.

Flood Re is not permanent: it is designed to end in 2039, and it never covered homes built since 2009, so evidence of your home's real risk is becoming the thing that sets your premium.

Sign up for flood warnings and know what they mean

Free flood warnings buy you the hours you need to act. The Environment Agency runs a three-tier system, and you can register online or through Floodline on 0345 988 1188, a 24-hour service. Sign up for the property, and for anywhere else that matters: an elderly relative's home, a business, the route you drive to work.

Once a warning is live, the live river levels map lets you watch the nearest gauge rise in near real time, and you can register for alerts on GOV.UK.

In a single recent winter the Environment Agency issued more than 3,000 flood alerts and 1,600 flood warnings, with around 600 staff on call around the clock.

Make a flood plan and a flood kit

A flood plan is the short, ordered list of what you will do when a warning comes. A flood kit is the bag of essentials you keep ready to grab. Neither takes long to prepare, and both are worth far more than the effort when the water is rising and there is no time to think. Start with the plan:

1. Agree who does what. Decide in advance who moves the car, who takes the children and pets, and who deals with the utilities.
2. Learn your stopcocks. Find, and label, where to turn off gas, electricity and water, and make sure more than one person knows.
3. List what moves upstairs. Note the irreplaceable items, key documents and electronics to lift clear, in priority order.
4. Sort somewhere to go. Arrange in advance where the household, and any pets, will stay if you have to leave.
5. Write it down and share it. Keep the plan with your kit and make sure everyone in the house knows it exists.

Free flood plan templates are available on GOV.UK. Keep the kit somewhere you can reach it in a hurry, ideally upstairs:

• Documents. Insurance policy and account details, ID and useful phone numbers, in a waterproof wallet.
• Power and light. A torch, spare batteries and a charged power bank for phones.
• Warmth and health. Blankets, warm and waterproof clothing, any regular medication and a first aid kit.
• Water and food. Bottled water and food that needs no cooking, plus supplies for babies and pets.
• Practical extras. Rubber gloves and boots, a mobile phone, and spare keys for home and car.

What should you do during a flood?

When flooding is actually happening, your safety comes first and your belongings a distant second. Move people, pets and the most important items upstairs, turn off the gas, electricity and water at the mains if you can reach them safely, and put your barriers and door guards in place. Then leave the water alone.

• Never enter flood water. It hides open drains and debris, is usually contaminated, and moves faster than it looks.
• Do not drive through it. Even shallow water can stall or sweep a car; see our guide on driving through flood water.
• Avoid contact with electrics. Do not touch sockets or switches if water is near them.
• Keep listening. Follow the Environment Agency, local radio and any instructions from the emergency services.

Just 30cm of flowing water is enough to float a car, and 15cm can knock an adult off their feet — which is why most flood deaths involve people entering the water.

What to do after a flood

Once the water drops, the priorities are safety, evidence and drying out. Do not switch the electricity back on until it has been inspected, and do not assume the tap water is safe until you are told so. Before you clear anything away, photograph and list the damage for your insurer, then start the slow business of drying the building out, which can take months rather than weeks.

Recovery is a job in its own right, and rushing it causes lasting damage. Our step-by-step guide to cleaning up after a flood covers the order to do things in, from documenting the damage to getting the silt out and drying the structure properly.

When should you get a professional flood risk assessment?

If you are buying in a flood-risk area, struggling to get affordable insurance, or planning work that could change how your property drains, an independent flood risk assessment gives you property-specific answers the national maps cannot. The maps tell you a postcode's broad risk; a site-specific assessment tells you your home's, including floor levels, historic events on the actual plot, and which mitigation would genuinely work.

It is also the document that can unlock cover or a fairer premium when an insurer has priced off a crude, outdated map. Unda has completed more than 5,000 flood risk assessments across the UK, and can produce an independent report for a property purchase or specifically for insurance purposes, or simply talk it through with you.

A national map tells you a postcode's risk; a site-specific flood risk assessment tells you your home's — and it is often what unlocks cover an outdated map has priced out of reach.

Frequently asked questions