Use this if you are an undertaker dealing with a reservoir incident or emerging defect

An incident is any event that threatens the safety of the reservoir or people downstream. A defect is any change in condition that could lead to uncontrolled release of water. If life is at immediate risk, call 999 first.

1. Make people safe

If there is risk to life, call 999. Move people away from the dam, spillway, and any downstream flood path. Stop any work on the structure that could worsen the defect.
2. Activate your on-site flood plan

Follow the actions in your on-site emergency flood plan. Notify the local resilience contacts and any off-site plan holders identified in it.
3. Notify the enforcement authority immediately

England: Environment Agency reservoir incident line. Wales: Natural Resources Wales. Scotland: SEPA. Northern Ireland: DfI Reservoir Safety team. Notify by phone first, then in writing.
4. Engage your supervising or inspecting engineer

Contact your supervising engineer without delay. The enforcement authority can require an inspecting engineer if the defect is serious.
5. Record everything

Log times, observations, photographs, water levels, and every notification made. Retain this with the reservoir record book.

Reservoir incident and safety defect reporting duty

Statutory duty on undertakers to notify the enforcement authority of any incident, defect or safety concern that could affect reservoir safety.

Undertakers must notify the enforcement authority immediately of any incident, defect or safety concern that could affect the safety of a reservoir. This duty applies in all four UK nations and is a cornerstone of the reservoir safety regime — late notification is itself an offence.

Who to notify (England): Environment Agency reservoir safety team (24-hour incident line)
Who to notify (Wales): Natural Resources Wales
Who to notify (Scotland): SEPA (under Part 7 of the Reservoirs (Scotland) Act 2011)
Who to notify (Northern Ireland): Department for Infrastructure (DfI) Reservoir Safety team
Notification timing: Immediately on discovery; do not wait for the supervising engineer's next visit

What counts as a reportable incident

Overtopping or imminent risk of overtopping
Spillway, valve or outlet failure
Significant seepage, piping or internal erosion
Visible cracking, settlement or movement of the dam
Loss of control over reservoir water level
Any event the supervising engineer considers prejudices safety

Scotland — Part 7 incident regime

Under the Reservoirs (Scotland) Act 2011 the undertaker must notify SEPA in writing as soon as reasonably practicable, and SEPA can issue a direction requiring further information, monitoring or remedial works. SEPA can use civil sanctions (Fixed and Variable Monetary Penalties) for breach of the reporting duty.

Record-keeping: Keep a written log of the incident, time of notification, recipient, and engineer's advice
Engineer involvement: Engage the supervising engineer (or inspecting engineer for high-risk reservoirs) without delay
On-site flood plan link: Activating the on-site flood plan does not replace the statutory notification — both are required

Your on-site flood plan

The on-site flood plan tells you who to call, what to do, and in what order. If you do not have a current plan, you are not compliant and must rectify this after the incident is contained.

Confirm your duties as undertaker

Reservoir undertaker duties and responsibilities

Legal duties of reservoir undertakers (owners and operators) under the Reservoirs Act 1975 and devolved legislation.

The undertaker is the person or organisation responsible for a reservoir. This is usually the owner, but can be a lessee, operator, or manager with control over the reservoir.

Primary duty: Ensure reservoir safety and comply with all statutory requirements
Record keeping: Maintain complete records of construction, modifications, inspections, and safety measures
Engineer appointments: Appoint and maintain supervising and inspecting engineers for high-risk reservoirs
Safety measures: Implement all measures required by inspecting engineer within specified deadlines

Ongoing undertaker responsibilities

Register new reservoirs within 28 days of final certificate
Notify enforcement authority of any change in ownership or undertaker
Give notice before making alterations to the reservoir
Maintain reservoir in safe condition at all times
Provide access and facilities to appointed engineers
Keep all certificates, reports, and records for the life of the reservoir
Notify authority immediately of any incident or defect that could affect safety

Change of undertaker notice: Must notify enforcement authority within 28 days
Alteration notice: Required before any construction, alteration, or abandonment work
Records retention: For the lifetime of the reservoir (indefinitely)

Failing to notify is a criminal offence

Penalty:

Failure to report an incident or comply with engineer directions is a criminal offence under section 22 of the Reservoirs Act 1975 (England and Wales), Part 9 of the Reservoirs (Scotland) Act 2011, and the Reservoirs Act (Northern Ireland) 2015. Penalties include unlimited fines on indictment and, in Scotland, SEPA civil sanctions for late reporting. The on-site flood plan direction has applied in England since 22 April 2021.

After the incident

Once the immediate risk is controlled, your inspecting engineer must assess the structure and specify any safety measures. Implement those measures within the deadlines given. Submit a written incident report to the enforcement authority and update your on-site flood plan with any lessons learned.

Incident reporting hotlines

Environment Agency incident hotline
24-hour incident line for reservoir, flood, and pollution incidents in England (0800 80 70 60).
SEPA pollution and incident hotline
SEPA 24-hour reporting line for reservoir incidents in Scotland.
DfI Rivers - reservoir safety contact
Department for Infrastructure reservoir safety contact for Northern Ireland.

UNDER CONSTRUCTION

Guvnor

Report a reservoir incident or safety defect

Use this if you are an undertaker dealing with a reservoir incident or emerging defect

1. Make people safe

2. Activate your on-site flood plan

3. Notify the enforcement authority immediately

4. Engage your supervising or inspecting engineer

5. Record everything

Your on-site flood plan

Confirm your duties as undertaker

Failing to notify is a criminal offence

After the incident

Compliance Assistant

🚧 UNDER CONSTRUCTION

Use this if you are an undertaker dealing with a reservoir incident or emerging defect

1. Make people safe

2. Activate your on-site flood plan

3. Notify the enforcement authority immediately

4. Engage your supervising or inspecting engineer

5. Record everything

Your on-site flood plan

Confirm your duties as undertaker

Failing to notify is a criminal offence

After the incident

Related guides in Health & Safety

UNDER CONSTRUCTION