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.

• Find out if there is a reservoir in your area 

How you can prepare for reservoir flooding

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

Refer to our pages on preparing for flooding, and what to do during a flood to keep you and your family safe.

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.