Flood advice

Flood alerts, warnings, and zones

In England, the Environment Agency provides three types of flood warning:

  • Flood alert. This means that flooding is possible.
  • Flood warning. This means that flooding is expected.
  • Severe flood warning. This means that flooding could be a risk to life. This warning type can be issued before, during, or after flooding.

You should act quickly and take flood warnings seriously. The action you need to take is different for each type.

Flood AlertFlood alert 1

  • Flooding is possible.
  • Use reliable news sources for local updates.
  • Start preparing for a potential flood.

Flood warningFlood warning

  • Flooding is likely.
  • Use reliable news sources for local updates.
  • Prepare for a flood: Ensure your household is safe and aware.
  • Turn off all gas, electric and water supplies.
  • Move valuable items to a safe place.

Severe flood warningSevere flood warning

  • Severe flooding is likely.
  • Flooding carries a danger to human and animal life.
  • Prepare for a flood: Ensure your household is safe and aware.
  • Turn off all gas, electric and water supplies and be ready to evacuate your home.
  • Cooperate with the emergency services.
  • Call 999 if you are in immediate danger.

Flood zones

Harrow sits within three river catchment areas and we are at risk of flash floods. High rainfall can exceed the drainage capacity. Our rivers and streams can flood above ground after this.

We record and investigate all floods from sources including:

  • rivers,
  • surface water and
  • ground water.

Homeowners and businesses should work with risk management authorities to check for flood risk. You can do this on our flood asset register page.

If your property or business is in a flood zone, it is your duty to protect it. Do this with resilience and emergency planning. You should also make preparations for a flood and know what to do in the event of a flood.

Depending on the level of flood risk, you may want to consider more robust property resistance measures. We cannot recommend specific products.

But, successful trials have been done on BSI Kite mark PAS 1188 accredited flood protection products. Major insurers recognise these and can reduce premiums or excess.

It may also be possible for homeowners at risk of flooding to get grant funding.