Government issues direction on reservoir flood requirements

Defra has issued a ministerial direction on the requirements on reservoir undertakers to prepare a flood plan for each large reservoir in England – including any under construction.

Plans for reservoirs, whether high risk or not, must be prepared within the next 12 months according to the direction. For reservoirs under construction a flood plan must be prepared before the construction engineer issues a preliminary certificate for the reservoir.

The direction includes requirements on undertakers to include in their flood plans at least:

• a clear plan of actions that the undertaker will take in order to prevent an uncontrolled escape of water;

• a clear plan of actions that the undertaker will take in order to control or mitigate an uncontrolled escape of water;

• instructions on how to carry out an emergency drawdown of the reservoir;

• the areas that may be flooded in the event of an uncontrolled escape of water from the reservoir, including reservoir flood risk maps published by the Environment Agency where available;

• key risk factors or visual indicators that may indicate when the reservoir could fail and flooding occur;

• contact arrangements for key personnel who should be alerted in the event of an emergency; and

• size location and other data on the reservoir.

The undertaker must share the flood plan with:

• the Environment Agency when directed by the agency along with any information about its contents;

• the appointed engineer; and

• category 1 responder when requested by that responder or as directed by the environment secretary.

Defra has also issue guidance documents on owner and operator requirements and on-site plans.