Guidance

Reservoir supervising engineers: written statements and site visit reports

How to write a reservoir written statement and a site visit report and what information to include.

• From: Environment Agency
• Published: 27 June 2022
• Last updated: 23 February 2024 — See all updates

Applies to England

This guidance is for supervising engineers. You should follow this guidance when writing a written statement or a site visit report.

Owners and operators of high-risk reservoirs must appoint a competent engineer to supervise it at all times. They must appoint a supervising engineer if a construction engineer is not supervising it. This is a requirement of the Reservoirs Act 1975 (the act).

Part of your role as a supervising engineer is to provide advice to the owner or operator to help them keep their reservoir safe and compliant with the act.

You should use written statements and site visit reports to tell owners and operators and the Environment Agency:

• about anything which might affect the safety of the reservoir
• whether statutory records including the Prescribed Form of Record (PFR) are up to date
• if there has been a breach of the act

Further guidance on the role and duties of supervising engineers can be found in Institution of Civil Engineers (2014) A Guide to the Reservoirs Act 1975, Second edition. ICE Publishing.

Written statements

Written statements should clearly communicate:

• apparent or possible changes to the physical condition or operation of safety-critical reservoir structures, informed by visual observations, surveys and monitoring data
• apparent or likely changes in the threats to reservoir safety and any actual or impending changes in consequential risks associated with the reservoir breach
• any breach of the act
• progress on delivering measures in the interest of safety (MIOS) and statutory maintenance
• clear actions on what the owner or operator must do to remain compliant with the act
• the priority, timescales and reasons for taking actions

When to do a written statement

You must provide the owner or operator with written statements:

• at least once in any calendar year about ‘matters that need to be watched’ – these are listed in the annex of the final certificate or section 10(4) of the latest inspecting engineer’s report
• at least once every 12 months with details of any steps taken to maintain the reservoir as recommended in section 10(3)(b) of the latest inspecting engineer’s report

These are 2 separate legal requirements under section 12(2), and 12(2A) of the act. You can combine both written statements into a single document or do each one separately. State which of these sections of the act apply at the front of each statement.

In practice, most supervising engineers opt to provide the owner or operator with a combined written statement at least every 12 months.

You must send written statements to the owner or operator of the reservoir and the enforcement authority. For reservoirs located in England the enforcement authority is the Environment Agency.

What to include in your written statement

A combined written statement should include:

• a reservoir compliance summary
• a completed written statement template
• a summary action list
• any site visit reports since the date of the last written statement - attach as appendices

Complete the reservoir compliance summary

It is good practice to put a reservoir compliance summary at the front of your written statement. The summary should highlight the areas that do not comply with the act to help the owner or operator and the Environment Agency.

Include the questions in the reservoir compliance summary questions template, as a table or text. If any of your answers are ‘no’ refer to the section of the written statement that gives more details. Use text or colour coding to make the status clear to the owner or operator and the Environment Agency.

Some reservoir owners and operators will have their own preferred reservoir compliance summary format for supervising engineers to follow.

Record any actions needed to make sure the reservoir remains compliant with the act in a summary action list.

Reservoir compliance summary questions template

Is the supervising engineer satisfied with the reservoir’s safety and does not need to recommend an early inspection? Section 12(3) of the act refers. See section 2.5.4 of the written statement.

Is the supervising engineer satisfied with the reservoir’s safety and does not need to direct (legally compel) the owner or operator to carry out visual inspections? Section 12(6) of the act refers. See section 2.6 of the written statement.

Is the supervising engineer satisfied with the progress of carrying out measures in the interest of safety (MIOS)? Section 10(3)(c) of the act refers.  See section 2.5.2 of the written statement.

Is the supervising engineer satisfied that all matters to be watched (legally required to check) are in compliance with the construction or inspecting engineer’s instructions? Section 12(2) of the act refers. See section 2.3 of the written statement.

Is the owner or operator compliant with their duties for monitoring, surveillance and record keeping? Sections 6, 9 and 11 of the act refer. See section 2.4 of the written statement.

Has the owner or operator satisfactorily completed any statutory maintenance recommendations? Section 12(2A) of the act refers.  See section 2.2 of the written statement.

Does the owner or operator have a certified, up to date and satisfactory on-site emergency flood plan? Section 12AA of the act refers. See section 2.7 of the written statement.

Complete a written statement template

This section provides a template of section headings for your written statement. It also gives some advice on completing it and things you need to consider.

Although considered good practice, it is not a legal requirement to follow this format. Some reservoir owners and operators will have their own preferred template for supervising engineers to use.

1. General information

1.1 Reservoir name

This should exactly match the registered name given in the Prescribed Form of Record (PFR). Note also any local names used for the reservoir.

1.2 Reservoir location

Include the postcode and National Grid reference.

1.3 Name and address of undertakers (owners and operators)

Include the following contact details:

• name and address of the undertaker as registered with the Environment Agency
• name of the person responsible for reservoir safety
• name of the person to issue the written statement to (if different)
• other people to distribute the written statement to

The undertaker (owner or operator) should tell you who to report to and who to escalate outstanding matters to. This should be the individual responsible for reservoir safety.

In larger organisations, this should be the person responsible for corporate safety at director level (or equivalent). In the case of single owners, clubs or small companies, this should be the owner (or equivalent).

1.4 Name and address of supervising engineer

1.5 Alternative supervising engineer contact details

Include the details of the stand-in supervising engineer. The owner or operator may contact them with concerns when the supervising engineer is unavailable for short-term periods.

1.6 Name of last inspecting engineer or construction engineer

2. Status and findings

2.1 Construction engineer’s requirements in relation to section 6(2) to 6(4) or 9(2)

This relates to new reservoirs or re-use of abandoned reservoirs.

Note any specific requirements from the construction engineer’s final certificate that the owner or operator must adhere to. Use sub-headings in this section, if required.

Include any matters to be watched by the supervising engineer from the final certificate. Highlight any special requirements or matters that need to be watched that are complete or outstanding. Use text or colour coding to make this clear to the owner or operator and the Environment Agency.

2.2 Statement under section 12(2A) on the directions given for maintenance of the reservoir under section 10(3)(b) (statutory maintenance)

You must include details of any steps that the owner or operator has taken to complete statutory maintenance.

 For each statutory maintenance item you should:

• state whether the owner or operator has followed the inspecting engineer’s instructions - use text or colour coding to make this clear to the owner or operator and the Environment Agency
• include the status of the direction – is it complete or ongoing?
• comment, if necessary, on the actions taken or not by the owner or operator
• consider its current condition – is it stable, deteriorated or improved since it was last examined 

Discuss the reasons for any non-compliance with the owner or operator and include these in your statement.

For outstanding maintenance directions consider directing the owner or operator to carry out visual inspections until the maintenance is complete. See section 2.6.

If you have concerns or think that the reservoir is unsafe because of an outstanding maintenance direction you should consider:

• discussing your concerns with the inspecting engineer
• recommending an early inspection, see section 2.5.4

2.3 Matters to be watched by the supervising engineer under section 7(5) or 10(4)

List all the matters that you are watching.  Make a note against each one about their status. Comment on any actions taken and whether there are any issues or concerns relating to these matters. State if there are no issues. Use text or colour coding to make the status clear to the owner or operator and the Environment Agency. 

2.4 Records, monitoring and supervision by the undertaker under section 11

You should regularly review the information in the Prescribed Form of Record (PFR) and advise the owner or operator if anything is missing.

Your written statement should:

• state whether you consider the PFR to be up to date and complete
• specify any updates required to make sure it complies with the act
• note the location of the document
• note the means of accessing it

Summarise and comment on the monitoring data provided since the last written statement.

If you have concerns about the owner or operator’s monitoring results, consider directing them to do extra monitoring. See section 2.6.

2.5 Inspection under section 10(2)

2.5.1 Date of last section 10 report and section 10(5) certificate

State the date of the last section 10 inspection report and the section 10(5) certificate.

Following the section 10 inspection a formal meeting should take place between the inspecting engineer, the owner or operator and supervising engineer to discuss the inspecting engineer’s findings. If your written statement is the first to follow a section 10 inspection you should record the date of this meeting. State whether you or a different supervising engineer attended.

2.5.2 Description and status of any measures to be taken in the interests of safety under section 10(6)

Include the measures in the interests of safety (MIOS) details, the deadline to complete them and the qualified civil engineer (QCE) appointed to oversee them. Highlight if a QCE is not appointed.  

Report on the progress of completing the MIOS and current condition of the asset. Include whether the work is complete or not. If not complete state if the owner or operator has been directed to keep the water level in the reservoir low until the work is complete. State if this is being achieved.

Note any temporary measures put in place (physical or operational) to mitigate the safety risk until the MIOS is complete. 

Include any concerns you have about the timely completion of MIOS requirements and share the written statement with the appointed QCE if appropriate.

Discuss the reasons for any delay with the owner or operator and include reference to these communications in your statement.

2.5.3 Date of next scheduled inspection under section 10(2) of the act

Include the date of the next scheduled inspection.

2.5.4 Recommendation under section 12(3) for an inspection under section 10(2)

If you recommend a section 10 inspection, state the reasons. You should remind your undertaker that they should appoint different people to carry out the roles of inspecting, construction and supervising engineer.

Discuss any safety concerns with the owner or operator and the named individual responsible for reservoir safety. Do this immediately after the site visit.

Include the recommendation in the summary action list and give it a priority assessment of ‘high’. Refer to the ‘Assess priority for maintenance and actions’ section for more details.

You must tell the owner or operator if you recommend a section 10 inspection. You should do so in writing, separate to the written statement.  You must also send a copy to the Environment Agency within 28 days.

2.6 Directions by the supervising engineer as to the visual inspection by the undertaker under section 12(6)

If the owner or operator has been directed to carry out visual inspections, provide details. Include how the owner or operator should carry out the visual inspection. Specify what needs closer monitoring, inspection and recording. State how often they must do the visual inspections and how long they should continue to do them.  Record whether the visual inspections are complete or outstanding.

2.7 Directions and certification of directions for flood plans under section 12AA

You should make the owner or operator aware that the reservoir must have an on-site emergency flood plan (flood plan). Record that you have done this.

Record the date the flood plan was last reviewed, who reviewed it and include a summary of the changes made to it.

2.7.1 Certification under section 12AA(3) of acceptance of flood plan requirements of sections 12A(2)(a) and (b)

Record who certified the flood plan and the date.

2.7.2 Direction as to testing of the flood plan under section 12AA(4)

Record any directions the owner or operator has been given to test the flood plan.

State whether the owner or operator is compliant with the directions. Include details of any testing carried out and the findings.

Review the owner or operator’s proposals to review, test and exercise the flood plan. Consider if the planned actions at each stage of testing and exercising and their frequency meets the requirements.

2.7.3 Direction as to revision of the flood plan under section 12AA(7)

Detail any necessary revisions to the flood plan.

You should routinely review the flood plan when you visit. Check all the details of the plan are still relevant. Record any changes needed. Changes could include updating:

• the access arrangements
• how to operate any equipment used for drawdown
• the triggers to activate the plan
• the emergency contacts

3. Summary of visit reports

Include the dates of visits. List any site visit reports attached as appendices and include a summary of any matters of concern.

4. Signature of supervising engineer and date of expiry of current panel appointment

5. Date of written statement

Record the date you issued the written statement.

Supervising engineer directions

The directions of supervising engineers to owners and operators must:

• be given separately to the written statement
• use the form of words prescribed in the act
• be sent to the Environment Agency within 28 days

Site visit reports

The site visit report should clearly communicate:

• the current condition of the dam and associated structures
• clear actions on what the owner or operator must do to keep the reservoir in a safe condition
• clear actions on what the owner or operator must do to remain compliant with the act
• the priority, timescales and reasons for taking actions

How often should you do a site visit

You should visit the reservoir often enough to carry out your duties. In practice (and unless under very exceptional circumstances) this should be at least once a year. In many cases it may be more appropriate to visit at least twice a year.

Refer to the recommendations of the construction engineer or last inspecting engineer as guidance. Visit at different times of the year to allow you to observe the reservoir operating under different conditions.

You should visit the reservoir as soon as possible after any significant change in the condition or operation of the dam. This could be after:

• a change in reservoir ownership
• a significant flood
• extreme weather
• seismic activity
• any other event that could affect reservoir safety

When to do a site visit report

You should write a site visit report each time you visit the reservoir.

Write a full and detailed site visit report annually. For interim site visits during the year you can write a shorter report if appropriate.

Submit your site visit reports to the reservoir owner or operator after each visit and include them as appendices to the next written statement.

What to include in the site visit report

Your site visit report should include:

• completed site visit report template
• photographs
• instrument readings and graphs
• clear comments on the condition of all elements of the reservoir and associated structures
• a summary action list with priority and timescale for each action
• comments on the significance of any issues and actions so the owner or operator knows why they need to take action
• any specific changes in the reservoir condition since the last site visit
• any changes since the last section 10 inspection and the last site visit

When writing the report the supervising engineer should take into account the owner or operator’s technical knowledge, the resources they have and the type of reservoir. Write in clear English using terminology that is appropriate for the type of owner or operator and their experience.

Complete a site visit report template

This section provides a template of section headings for your site visit report. It also gives some advice on completing it and things you need to consider.

Although considered good practice, it is not a legal requirement to follow this format. Some reservoir owners and operators will have their own preferred format for supervising engineers to follow.

Visit date

Include the date and time of the visit and who was present.

Water level, site conditions and scope of supervising engineer’s site visit

Record the weather on the day of the visit and in the weeks before your visit. As a minimum you should get local knowledge of the weather from the owner or operator. Other sources of information which give rainfall measurements from local monitoring stations include:

• Environment Agency’s rainfall API demonstrator
• UK Water Resources Portal

Provide details of the:

• water level, ideally in metres relative to the top water level (the overflow level) and how you measured it, for example using a gauge board or dip stick
• extent of the examination of the day, the equipment tested and areas of the dam and associated structures examined
• parts of the reservoir site that could not be examined during this visit and why

Significant events since previous inspection

Include any significant events such as floods or seismic activity since the last inspection. Also, include those not included in previous written statements or section 10 inspection reports. You should:

• review the monitoring data and use online resources, such as BGS earthquake database, the UK High Flows database and the National River Flow Archive to search for events
• gather local knowledge of events
• comment on significantly high overflow levels during these events

Include any incidents that could have affected the safety of the reservoir. Record the date and details of the incident and if it was reported to the Environment Agency. Incidents involving unplanned and urgent physical safety works, serious operational incidents or incidents leading to an unplanned reservoir drawdown should be reported.

Include details of any unplanned drawdown of the reservoir, why it was drawn down, and any observations made during the drawdown. It is good practice for the owner or operator to tell the supervising engineer of a drawdown in advance, and it may be appropriate for you attend.

Recommend the owner or operator includes details of significant events, incidents and any unplanned reservoir drawdown in section 11 of the PFR.

Include details of any improvements or remedial works carried out. Recommend the owner or operator includes these in section 2 of the PFR.

Include any significant changes since the last section 10 inspection report or since the last site visit. The following list may be useful but is not exhaustive:

• a change in reservoir ownership
• changes in condition, for example deterioration
• new observations of movement or leakage
• any failures to operate safety critical valves or gates efficiently
• any changes in operation, resources, procedures or use of the reservoir
• changing conditions downstream which may change flood risk category
• things not included in the PFR

Include any changes to legislation or guidance in relation to management of the reservoir that may be of relevance to the owner or operator.

Access and security

Provide details of any access restrictions and details of any changes or deterioration of the access arrangements to:

• the reservoir site
• the dam
• ancillary structures such as valve tower bridges

Include any concerns you have regarding security of the reservoir site.

Upstream conditions, catchment and inlets

Provide details of any changes to catchments or inlets that could affect reservoir safety.  This could include comments on:

• any upstream reservoirs that could pose a risk to the dam if breached
• direct or indirect catchment areas that could have a bearing on reservoir drawdown
• whether the flows from the catchments can be controlled

Significant changes in upstream conditions which could affect reservoir performance may be cause for calling an early section 10 inspection.

Include details of any inlet valves or penstocks you saw operating or any records of their operation. Comment on how they perform and their condition.

Dam structure

Sub-divide this section to include all the important and major parts of the dam. For each part of the dam note any changes in condition and any causes for concern. Use photos and reference them in your report.

Overflow or spillway

Include the condition of all overflows and spillways. Comment on their ability to pass flow efficiently and without impediment. Comment on the type and function of each spillway or overflow, for example if it is gated or a service or auxiliary overflow. For each one note:

• if the spillway was in operation during the visit and if the there was anything significant about the flow regime
• if it was free from obstruction both upstream and downstream of the weir
• the condition of the forebay (the area upstream of the spillway), channel walls, invert (the base of the spillway) and joints, including details of any vegetation, settlement or movement or missing blocks in masonry spillways
• any associated element which impacts on the performance of the spillway or overflow, for example, under drainage, ground anchoring, out of channel protection or fixed access equipment
• the performance and condition of the gates for gated overflows

Read the spillway examination guide for more details on how to inspect the spillway.

Draw-off works

Include details of any fixed or temporary facilities to draw off water from the reservoir.

Include an overview of the condition of each outlet and its ability to lower the reservoir water level. Comment on:

• the accessibility of the valves or other equipment
• how the facility operates
• the condition of access to the draw-off facilities
• any unique hydraulic features, for example debris screens, which may affect performance
• if the draw-off information is in the flood plan and is correct

For each of the fixed and any temporary draw-off facilities state:

• how to test it, if it has been done and the results of the test (you could put it in a table)
• if the owner or operator meets the requirements for testing, and if not, why not

Bottom outlet

Include an overview of the condition of the bottom outlet and its ability to lower the reservoir water level. Comment on:

• the accessibility of the valves
• if the valves are manual or actuated, and how they operate
• how easy it is to operate the valves and the number of people needed to operate them
• the condition of access to the bottom outlet
• any unique hydraulic features which may impede performance
• if the bottom outlet information is in the flood plan and is correct

Comment on the condition of any other ways to discharge water from the pipework, such as washout valves. State if they were tested during the site visit or not.

For each outlet state:

• how to test it, if it has been done and the results of the test (put it in a table)
• if the owner or operator meets the requirements for testing, and if not, why not

Seepage or drainage flows

Include an overview of the facilities to measure seepage and drainage flows.

Comment on:

• the measurement of flows, if any, and identify any trends within the data - take readings on the day of your visit to validate the data if safe to do so and practicable
• if the flow is turbid or discoloured
• if any changes in flow, turbidity and colour is significant and a cause for concern
• any evidence for the cause of the changes to readings or performance
• any difficulty you had assessing seepage or drainage flows, for example, if the drains were blocked or concealed

Settlement and movement

Include:

• how settlement and movement is monitored
• any apparent structural movements of the dam
• how you identified the movement, for example through instruments monitoring the dam or visual inspection
• what the movement is in relation to (if known)
• if the movement or settlement is in the dam or its associated structures
• any notable events, changes, leakages, incidents or unusual occurrences since the last site visit

Comment on:

• if the movement is new since the previous report, or historic
• the likely cause for any new or historic movements (if known)
• if the reservoir freeboard is affected
• if the movement may be linked to any potential failure modes
• if the movement could be seasonal, weather or reservoir level fluctuations related

Surveys and instruments

Summarise any surveys or investigations carried out since the last site visit, including the scale, scope and findings. Provide an analysis of any instrument data unless already included in previous sections of the report.

Comment on:

• condition of the access to the instrumentation
• general condition of the instrumentation
• the historical and current instrument readings and trends
• the confidence in accuracy of the data and instrument performance
• whether the instruments need calibrating or servicing

Tell the owner or operator about any concerns you have about the instruments. Consider discussing any significant concerns with the inspecting engineer.

Downstream conditions

Visually assess (where safe and reasonably practicable) the area immediately downstream of the dam. Ask the owner or operator if they know of any changes, actual or proposed, for example knowledge of planning applications. Note any changes downstream that might impact on:

• the ability to safely operate and test reservoir draw down facilities
• the current consequence category for the dam

A change to the consequence category would be cause for calling for an early section 10 inspection.

Flood plan

Review the flood plan and state that it is up to date, or what needs to be updated.

Prescribed Form of Record

Review the PFR and state that it is up to date, or what needs to be updated.

Summary action list

In your summary include the actions from this visit and the actions from the previous written statement. For each action include all of the following:

• the reference – give each one a unique number
• the action required
• its priority assessment – see section on ‘assess the priority of maintenance actions’
• the reason for the action

Examples of reasons for the action are to:

• avoid existing defects progressing
• make legally compliant
• improve records
• reduce, improve or undertake erosion protection
• allow, improve or undertake surveillance
• allow, improve or undertake inspection
• allow, improve or undertake repairs
• allow, improve or undertake monitoring
• allow, improve or undertake investigation

Assess the priority for maintenance and actions

State if the action is necessary to remain compliant with the act. Assess the action or maintenance activity and assign it a priority category. Use the following as a guide to complete the summary action list for your written statement or site visit report:

Priority ‘low’

This action relates to non-urgent matters or could be done as part of wider planned works. The owner or operator should be informed and the action completed with other ongoing planned works.

Priority ‘high’

This action will directly affect safety or the ability to examine the reservoir if not resolved. Supervising engineers should assess the urgency of the action and state a recommended timescale for starting and completing it.

If you have significant concerns or are in any doubt you should consult the inspecting engineer or recommend an early section 10 inspection.

Send your written statement to the Environment Agency

For reservoirs in England, email or post your written statement to the Environment Agency.

Email reservoirs@environment-agency.gov.uk

Reservoir Safety Team  
Environment Agency  
Manley House  
Kestrel Way  
Exeter  
Devon  
EX2 7LQ

Published 27 June 2022
Last updated 23 February 2024 + show all updates

1. 23 February 2024

   Added 'you should remind your undertaker that they should appoint different people to carry out the roles of inspecting, construction and supervising engineer'.

2. 27 June 2022

   First published.