Reservoir Advice

Local Authorities are responsible for emergency planning for large raised reservoirs that can hold 25,000 cubic metres of water above natural ground level.

There are over 2,000 of these in England and Wales.

There has been no loss of life from reservoir failure in the UK since the 1920s and there is robust legislation in place setting safety standards.

Flood maps publicly available online have been prepared for emergency planning purposes and for this reason they reflect a worst case scenario rather than the flooding that would most likely occur in the event of a reservoir failure.

If a reservoir did fail it would most likely be far less severe than the worst case scenario shown on the Environment Agency website. However, these maps are useful to emergency planners so they know the areas that might need to be evacuated and where it is safe for residents to go.

There is a very small risk to communities near reservoirs, these communities are already fully aware of this, and that has always been the case. The maps do not give any information about the depth or speed of the flood waters or the length of time it would take for the flood waters to reach any location.

Even in a worst case scenario many areas highlighted blue would be expected to receive no more than one or two centimetres of flood water. Provided reservoirs are properly maintained then the likelihood of reservoir flooding is much lower than other forms of flooding.

Current reservoir regulation, which the Flood and Water Management Act further enhances, aims to ensure that all reservoirs that pose a risk are properly maintained and monitored in order to detect and repair any problems as early as possible.

Reservoir flood planning is being undertaken at a Greater Manchester level to ensure that where the flood waters affect more than one local authority area, the response can be consistent.

Reservoir flood maps are available on the Environment Agency website .

Environment Agency - What’s in my backyard?

Use the interactive maps on the Environment Agency website  to find out more about the environment where you live.