Reservoir flooding

Reservoirs are artificially created lakes that are usually formed by building a dam, across a river. If one of these dams failed then water could escape from the reservoir, resulting in land or properties being flooded. In order to ensure that reservoirs are properly maintained and to minimise the possibility of reservoir failure, large reservoirs are regulated under the Reservoirs Act 1975. This legislation, which is enforced by the Environment Agency, requires reservoirs to be routinely inspected and maintained to an appropriate standard.

Provided a reservoir is properly maintained the likelihood of it failing and causing flooding is extremely low. However, in the very unlikely event of a dam collapse, a large volume of water could be released, quickly flooding a large area and possibly causing significant property damage or even loss of life. Such a scenario is extremely unlikely to occur and reservoirs in the UK have an excellent safety record.

How you can prepare for reservoir flooding

While trained officials work hard to prepare for emergencies, it’s important that you are prepared too.

It’s important that you are aware of what to do in an emergency to keep you and your family safe.

There are some quick steps you can take to prepare for an emergency:

  • put together a grab bag of things you might need in an emergency e.g. medication and personal documents
  • know who you would need to contact and how
  • be vigilant and be prepared to act quickly to get yourself to safety


In some cases seeking refuge from floodwaters upstairs would be unsafe and you may need to evacuate the area.

If you do need to evacuate the area you will be informed in one of the following ways:

  • by officials knocking on your door
  • by local radio or television stations

What to do in an emergency

  • Be prepared to act quickly to get yourself/your family to safety.
  • Co-operate with the emergency services if they tell you to evacuate and go to the designated assembly point/evacuation centre.
  • If you choose to go to a friends or relatives house please inform the police by calling 101.
  • Put small animals/pets in pet carriers or a secure box.
  • Ensure neighbours are aware of the emergency and check if they need help.
  • Pack spare clothing, essential medicine and any special dietary foods required.
  • Don’t forget baby care items if you have an infant.
  • Take personal documents and valuables with you if you have time to gather them.
  • Turn off gas, electricity and water supplies and lock your property when you leave.
  • Keep listening to local radio for updates.
  • Move away from the reservoir, keeping to higher ground.

Important advice

  • Call 999 if you are in danger.
  • Avoid walking or driving through flood water. 6 inches (15 centimetres) of moving water can knock you off your feet or disable a car.
  • Keep children and vulnerable people away from flood water.
  • Remain calm and act quickly.

Evacuation centres and routes

The emergency services may tell you to go to a temporary evacuation point where you will be picked up to be taken on to a designated evacuation centre.

The emergency services will tell you the best route to the evacuation centre or temporary evacuation point depending on the circumstances of the emergency, so please follow their directions.

There are a number of designated evacuation centres in Cheshire East. People running evacuation centres are trained to give you support and advice. They will help you through the stress of an emergency and prepare you for what to do afterwards.

Road closures

In the event of an emergency, it’s likely that a number of roads may need to be closed to assist evacuations and the work of the emergency services. Please don’t ignore road closure signs; they are there for a reason and your safety.

Emergency services

Partners have worked together to prepare emergency response plans to deal with incidents at reservoirs in Cheshire East.

In the event of an emergency, the following organisations will coordinate the response, this is not an exhaustive list:

  • Cheshire Police
  • Cheshire Fire and Rescue Service
  • North West Ambulance Service
  • Cheshire East Council

Keep updated

You can keep up to date with flood warnings and advice during a flood by tuning into your local BBC Radio and visiting your local BBC News website.

Follow us on social media for regular updates:

Large raised reservoirs in Cheshire East

A large reservoir contains over 25,000 cubic meters of water.

Map of large reservoirs in Cheshire East (PDF, 3MB)

Further reservoir information

For general information on reservoirs including frequently asked questions visit the Environment Agency website where you'll find reservoir flood maps. These show:

  • the maximum area that could be flooded in the event of a 'worst case' reservoir failure
  • the consequences of reservoir flooding but not the likelihood of the risk of flooding.

Or contact the Environment Agency on: 03708 506 506

Reservoir emergency contacts

In the event of an emergency you can contact:

  • Cheshire Police (if you are in immediate danger): 999
  • Environment Agency Incident Hotline: 0800 80 70 60

If you think you spot any warning signs of a problem with a reservoir you should ring the Environment Agency Incident Helpline.

Page last reviewed: 30 April 2024