Protect your business premises from flooding

How to assess flood risk to your business premises and implement practical protection measures. Covers checking your flood zone, resistance and resilience measures, creating a flood plan, securing commercial flood insurance, and available grant funding for property flood resilience.

UK-wide
Guide summary

Check your business premises' flood risk using the Environment Agency's service. Take steps to protect your property, such as installing flood barriers and raising electrical sockets. Create a flood plan and sign up for warnings to stay prepared.

  • Check flood risk using your postcode on the Environment Agency website
  • Photograph your premises and note vulnerable areas for insurance
  • Install flood barriers and seal walls to keep water out
  • Raise sockets and use water-resistant materials inside
  • Make a flood plan with emergency contacts and evacuation routes
  • Sign up for free flood warnings by phone, text or email
  • Ensure your business insurance covers flood damage
  • Flood Zone 3 has a 1 in 100 chance of flooding yearly
  • Surface water causes one-third of all flood damage
  • Rehearse your flood plan annually before winter
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UK-wide

Related guides in Environment & Sustainability

When this guide applies

This guide is for any business that occupies premises in England, Wales, or Scotland, whether you own or lease the property. It applies to all types of business premises including offices, shops, warehouses, workshops, and hospitality venues.

Flooding is the most significant natural hazard facing UK businesses. Around one in six commercial properties in England is at risk of flooding from rivers, the sea, or surface water. Surface water flooding from overwhelmed drains can strike almost anywhere and accounts for roughly a third of all flood damage. Climate change is increasing both the frequency and severity of these events.

This guide helps you assess your flood risk, implement practical protection measures, prepare a flood response plan, and arrange appropriate insurance.

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    1. Check your flood risk

    Use the Environment Agency's long-term flood risk service to check your postcode. This shows your Flood Zone (1, 2, or 3) and surface water risk separately. In Scotland, use SEPA's flood maps. In Wales, use Natural Resources Wales flood risk maps. Check both river/sea and surface water risk.

  2. 2

    2. Assess your premises vulnerability

    Walk through your premises and note what would be damaged at different flood depths. Record where electrical sockets, consumer units, boilers, IT servers, stock, and important documents are positioned. Photograph everything for insurance purposes. For premises in Flood Zone 2 or 3, consider hiring a property flood resilience surveyor.

  3. 3

    3. Implement resistance measures (keeping water out)

    Install flood barriers or gates at doorways. Fit airbrick covers or self-closing airbricks. Apply waterproof sealant to external walls below the likely flood level. Install non-return valves on drains to prevent backflow. Fit covers for ventilation openings and pipe gaps. Resistance measures protect against flooding up to about 600mm depth. Beyond that, water pressure risks structural damage.

  4. 4

    4. Implement resilience measures (reducing damage)

    Raise electrical sockets, consumer units, and meters to at least 1.5 metres above floor level. Replace ground-floor flooring with water-resistant materials such as ceramic tiles or treated stone. Use lime plaster instead of gypsum, which crumbles when wet. Fit stainless steel or plastic kitchens rather than MDF units. Move valuable equipment and IT infrastructure above likely flood levels.

  5. 5

    5. Create a business flood plan

    Write a plan covering who activates it, how to monitor warnings, actions at each warning level, safe shut-down procedures (gas, electricity), emergency contacts for insurer, landlord, council, and key suppliers, staff evacuation routes, and data backup arrangements. Keep copies on site and off site. Rehearse annually before winter.

  6. 6

    6. Sign up for flood warnings

    Register for the Environment Agency's free flood warning service by phone, text, or email. In Scotland, register with SEPA Floodline. A flood alert means prepare. A flood warning means act on your plan. A severe flood warning means danger to life.

  7. 7

    7. Arrange commercial flood insurance

    Confirm your business insurance includes adequate flood cover with business interruption protection. Check the flood excess, which may be higher than for other perils. Flood Re does not cover commercial properties. If cover is hard to obtain, use a specialist commercial insurance broker with flood risk experience.

Understanding your flood zones

The Environment Agency classifies land into Flood Zones based on the annual probability of flooding from rivers and the sea. Your zone determines how urgently you need to act.

Property flood resilience measures

Property flood resilience (PFR) measures fall into two categories. Most businesses benefit from combining both.

Resistance measures (keeping water out)

  • Flood barriers and gates - removable or permanent barriers for doorways (£300 to £2,000 per opening)
  • Airbrick covers - snap-on or automatic self-closing versions (£30 to £60 per unit)
  • Non-return valves - prevent contaminated water backing up through drains (£100 to £300 per valve plus installation)
  • Waterproof wall coatings - exterior sealants applied below the expected flood level

Resilience measures (reducing damage when water enters)

  • Raised electrics - sockets, consumer units, and meters at 1.5m or above (the single most impactful measure)
  • Water-resistant flooring - ceramic tiles, concrete, or treated stone replacing carpet or laminate
  • Lime plaster - dries out and recovers, unlike gypsum plaster which must be stripped after flooding
  • Raised plant - boilers, servers, and fixed equipment on plinths or wall-mounted
  • Water-resistant fixtures - stainless steel or plastic kitchen units replacing MDF

A basic resistance package for a small shop typically costs £2,000 to £5,000. Comprehensive resilience works for a medium premises may cost £10,000 to £30,000, but are usually recovered after a single avoided flood event.

Business continuity planning

Before a flood

  • Keep an emergency kit on site: torches, waterproof clothing, sandbags, and your flood plan
  • Maintain off-site backup of critical business data
  • Identify an alternative trading location
  • Review your flood plan annually

During a flood

  • Prioritise staff safety above everything else
  • Deploy barriers and move stock to upper floors if safe
  • Turn off gas and electricity before water enters
  • Do not enter floodwater - it may be contaminated

After a flood

  • Do not re-enter until authorities confirm it is safe
  • Photograph all damage before cleaning, for insurance
  • Contact your insurer immediately
  • Have a qualified electrician inspect before reconnecting the supply
  • Allow the building to dry thoroughly before repairing

Insurance for commercial premises

The insurance market for commercial flood risk works differently from residential cover.

Getting commercial flood cover

Because Flood Re excludes commercial properties, you must secure cover on the open market. This can be challenging in Flood Zone 2 or 3.

  • Use a specialist broker - access specialist underwriters who understand flood risk
  • Demonstrate resilience measures - insurers increasingly reduce premiums for premises with PFR measures installed
  • Review business interruption cover - loss of trading income during recovery often exceeds physical repair costs; ensure an adequate indemnity period (12 to 24 months)
  • Document your assets - maintain an inventory with photographs and valuations kept off site

Grants for property flood resilience

  • Flood and Coastal Erosion Risk Management Grant in Aid - Environment Agency capital funding for schemes that can include property-level protection. Contact your Lead Local Flood Authority to check coverage.
  • Local authority grants - some councils operate flood resilience schemes, particularly after significant flood events.
  • Repair and renew grant - following major floods, the government may activate a grant of up to £5,000 per property for resilience measures during repairs. This is not permanently available.

Check with your Lead Local Flood Authority, the National Flood Forum, and the Environment Agency for current programmes.

What to do next

Start by checking your flood risk using the service linked below. If you are in Flood Zone 2 or 3, or have surface water flood risk, prioritise these actions:

  1. Sign up for free flood warnings
  2. Write or update your business flood plan
  3. Review your insurance for flood and business interruption cover
  4. Get a property flood resilience survey
  5. Implement resistance measures as a first line of defence
  6. Plan resilience improvements for your next refurbishment cycle

Official flood risk guidance

Check your long-term flood risk (opens in a new tab)