Corporate report

Biennial report on reservoir safety: 1 January 2019 to 31 December 2020

Updated 26 July 2023

Applies to England

Executive summary

This report is a comprehensive review of reservoir compliance and enforcement over the last 2 years. It provides data and analysis of regulatory compliance for reservoirs in England. It includes comparisons to previous years. It describes the work of the Environment Agency’s reservoir safety team, as the regulator. It also explains the actions we have taken to protect the public and ensure compliance with the Reservoirs Act 1975. Reservoir undertakers are responsible for ensuring the safety of reservoirs.

We take a risk-based approach to dealing with non-compliance, with public safety being our priority. We have seen improvements in many areas of non-compliance over the last 2 years. Main improvements include:

• maintaining high compliance of engineer appointments
• taking quicker, firmer enforcement action
• closer collaboration with reservoir undertakers on safety measures to drive improvements and maintain compliance
• maintaining high standards of safety and compliance during the coronavirus (COVID-19) pandemic

The Environment Agency will use this data and analysis to help prioritise our efforts for future years – see ‘The future’ section.

The data and results provided in this biennial report should be considered in light of COVID-19. This affected all regulated sectors, including reservoir safety. It tested the resilience of the regulatory regime and the role of reservoir undertakers and engineers.

Despite COVID-19, we have kept non-compliance in England low. We developed a temporary Local Enforcement Position (LEP) to account for the potential difficulties. This combination of advice and adjustments to compliance and enforcement has been well received. The approach is now used by several European countries. See appendix 2 for more details.

Over the period of this review most reservoir incidents have been limited in scale and were well managed by the undertakers. None of these incidents has resulted in a complete failure of the dam or reservoir.

The highest profile incident from this period is the one at Toddbrook Reservoir in Derbyshire (see appendix 3). The government commissioned an independent review that reported in 2020. The Canal and River Trust (CRT) published its own investigation report as the reservoir undertaker at the same time. The Environment Agency considered both reports before sharing a lessons learned technical bulletin.

The events at Toddbrook Reservoir, recent flooding and the threat posed by a changing climate show that we cannot be complacent. It is crucial for all infrastructure to be fit for the future. We will continue to work with all those involved in reservoir management to improve safety and compliance. We will do this using:

• intelligence from these reports
• learning from incidents
• international collaboration
• research and development (informed by climate science)

This will ensure we continue to manage the safety of England’s reservoirs to the highest possible standards. These measures will help:

• mitigate the impact of climate change
• the growing role reservoirs will play in wider water management
• secure more climate resilient places

1. Background

Reservoirs in England have an excellent safety record. The last reservoir failure that led to loss of life in England was more than 100 years ago. It was the death of 21 people after the failure of two dams in North Wales in 1925 that led to the passing of the Reservoir (Safety Provisions) Act 1930.

Parliament updated and superseded this act with the Reservoirs Act 1975. Parliament amended this later act to create the Flood and Water Management Act 2010. There have been no recent reservoir failures that have resulted in loss of life.

The Water Act 2003 transferred the responsibility for enforcing the Reservoirs Act 1975 in England and Wales from local authorities to the Environment Agency. On 1 April 2013, Natural Resources Wales (NRW) became the enforcement authority for large raised reservoirs (LRRs) in Wales.

On 31 December 2020 there were 2097 LRRs in England covered by the act. LRRs are those that can hold at least 25,000 cubic metres of water above ground level. This means they must operate to strict conditions set by the act to ensure high levels of safety. Reservoir operators and owners (undertakers) are responsible for ensuring the safety of reservoirs. The Environment Agency, as the regulator, ensures undertakers comply with the legal safety requirements.

We are active members of an international network of dam safety experts. Together we share learning and apply international best practice - to help improve safety standards. We work with the devolved administrations to do this here in the United Kingdom as well.

2. Our role

The Environment Agency, as the regulator, makes sure undertakers follow the legal safety requirements of the act. We track compliance at all the LRRs in England. NRW does this in Wales. In Scotland the Scottish Environmental Protection Agency works to the reservoirs (Scotland) Act 2011. But our role is much wider than compliance tracking and enforcement, we:

• engage with the British Dam Society (BDS) and Institution of Civil Engineers (ICE) to build knowledge and capability in the industry
• work with Department for Environment, Food and Rural Affairs (Defra) on the review and reappointment of engineers
• work with undertakers to provide advice and guidance so they can operate their reservoirs safely
• advise Defra on policy
• lead and inform research and development projects
• adapt regulatory approaches to maintain safety, for example, during COVID-19

There are 2,097 LRRs in England covered by the act. Of these, the Environment Agency operates 219. Of the 219, 17 are under the supervision of a construction engineer, the rest are in operation.

Under the act we:

• maintain a register of all reservoirs
• ensure that undertakers follow the act by monitoring compliance and engaging with them
• ensure that undertakers appoint a construction engineer to design and supervise the construction or alteration of LRRs
• designate reservoirs as ‘high risk’ if an uncontrolled release of water from the reservoir could endanger human life
• make sure that undertakers appoint a supervising engineer for their high risk reservoirs
• make sure that undertakers have their high risk reservoirs inspected by inspecting engineers
• make sure undertakers carry out any safety measures recommended by inspecting engineers
• appoint engineers and commission safety work when an undertaker does not comply with the act - we charge undertakers for this
• protect people and property against an escape of water from a reservoir
• appoint engineers and take any other action necessary in an emergency
• make sure that undertakers report reservoir incidents and share lessons learnt from them
• ensure that we observe and follow with the requirements of the act for our own reservoirs

Section 4 – ‘The future’ describes the work we will be doing over the next 2 years.

3. A risk based approach to enforcement

The Environment Agency continues to focus on reservoirs that pose the greatest risk to public safety.

Our priority is to make sure that reservoirs always have a construction or supervising engineer appointed. Not having an engineer appointed at the right time poses a significant risk of safety to that reservoir. A construction engineer will supervise the reservoir while it is being built or altered. On completion, they will issue a final certificate. The undertaker must then appoint a supervising engineer.

The supervising engineer will supervise the reservoir at all times once it has been built. This is a continual appointment. They will visit the reservoir and carry out an inspection of its condition at least once a year. The supervising engineer is also the undertaker’s key point of contact should a problem arise with the reservoir.

We ensure that the undertaker appoints an inspecting engineer at the appropriate time. An undertaker employs an inspecting engineer to carry out a statutory inspection at least once every 10 years. The inspecting engineer will produce a report and certify when the undertaker has completed any safety measures. The appointment of an inspection engineer is not continual.

The main causes of non-compliance are where an undertaker has not:

• appointed a supervising engineer to oversee ongoing safety
• appointed an inspecting engineer to carry out the Section 10 inspection
• completed safety measures identified by the inspecting engineer by the date specified in the Section 10 inspection report

With any non-compliance, we provide clear advice and guidance on how to comply. We do this in writing or by meeting the undertakers. If this is unsuccessful, we will escalate to take formal enforcement action. In doing this we follow the Regulators’ Code. We apply the following principles:

• act proportionately
• be consistent
• be transparent
• target enforcement action
• be accountable

Risk designation of Reservoirs

The Environment Agency assigns a risk designation (classification) to each large raised reservoir in England. The designation level is based on risk to life in the event of an uncontrolled release of water from a reservoir. The two designation levels are ‘high risk’ and ‘not high risk’.

High risk LRRs must fulfil all the requirements of the act. Those designated not ‘high risk’ have specific requirements to fulfil also.

Section 2C of the act states that a reservoir is high risk if “the appropriate agency (the Environment Agency) thinks that an uncontrolled release of water from the reservoir could endanger human life”. It is important to note that this paragraph reflects the intention of Parliament when it made the law.

LRRs that are not classed as high risk do not need a statutory inspection or supervision. But, undertakers must:

• register these reservoirs
• report any incidents, changes or information that may alter the risk designation

Changes could include downstream development or alterations to the reservoir.

There will always be reservoirs for which we have not yet determined a risk designation. These could be newly registered reservoirs or those under construction. There will also be those with a provisional designation. We give provisional designations when the undertaker has requested a review or appealed the designation.

Table 1: Reservoir risk designation status

Status on 31 December 2020	Number of reservoirs
Reservoirs under construction (before designation)	133
Provisional high risk	63
High risk	1525
Not high risk	261
Not yet determined	115
Reviews	0
Appeals	0

Of the 133 reservoirs under construction, 108 have received a section 7(1) certificate. The certificate confirms the reservoir has reached a stage of construction where it can be filled with water. There are 25 reservoirs which have not yet reached this stage of construction.

Compliance status

Since the last report the Environment Agency has seen a slight improvement in compliance. There are more improvements that we continue to work on. We provide more detail in table 2.

Over the last 4 years we have seen a reduction in the number of reservoirs without a supervising engineer appointed. If the undertaker has not appointed a supervising engineer, we serve formal notice as soon as this non-compliance occurs. The notice requires the undertaker to make the appointment within 28 days. As of 31 December 2020, there were 5 reservoirs without a supervising engineer. We compare this to 3 on 1 January 2019 and 8 on 1 January 2017. We attribute the slight increase to the restrictions in place during the pandemic.

We have also taken other formal enforcement action. We’ve done this when undertakers have not appointed an inspecting engineer to carry out a statutory inspection by the due date. Again, in such cases we served a notice on undertakers to appoint an inspecting engineer within 28 days.

On 31 December 2020 there were 3 reservoirs with an inspection due, but no inspecting engineer appointed. Of those without an inspecting engineer appointed, all 3 have an engineer supervising the operation of the reservoir. This compares to 8 as at 31 December 2018.

Compliance rates do fluctuate across time. Formal action on appointing engineers has improved compliance since 31 December 2018.

Table 2: Reservoirs non-compliant on 1 January 2019 and 31 December 2020

Non-compliant status	Situation on 1 January 2019	Situation on 31 December 2020
Number with no supervising engineer appointed	3	5
Inspection due, and no inspecting engineer appointed	8	3
Section 10 inspection overdue by more than a year, but an inspecting engineer has been appointed	6	5
Measures in the interests of safety that have not been completed by the deadline set by the inspecting engineer	55	65

Until we give notice of a final high risk designation, the provisional high risk designation may change.

Reservoirs with no supervising engineer appointed could increase to 15. This is because it does not include 10 reservoirs that are waiting for a final risk designation.

There are 5 reservoirs with an overdue section 10 inspection where the undertaker has appointed an engineer. This does not include 2 reservoirs that are waiting for a risk designation review.

There are 65 reservoirs with outstanding safety measures. This does not include 10 that are waiting for a risk designation.

There were 5 Section 10 inspections overdue by more than a year where the undertaker had appointed an inspecting engineer. Section 10 inspections may be ‘overdue’ because the act allows 6 months for engineers to finalise their report. We do not consider the inspection ‘complete’ until we receive the report. In some cases, the engineer has done the inspection, but has not submitted their report within 6 months. These cases are under investigation.

Table 3: Reservoir information recorded between 1 January 2019 and 31 December 2020

Reservoir information recorded	Number of reservoirs
Number of newly constructed reservoirs	33
Number of supervising engineers appointed by or on behalf of the undertaker	569
Number of inspecting engineers appointed by or on behalf of the undertaker	404
Number of certificates issued after the satisfactory completion of an inspection under Section 10 of the Act	429
Number of these certificates which contained measures to be taken in the interests of safety	167
Number of Section 10(6) certificates showing that measures to be taken in the interests of safety had been satisfactorily completed	135

Of the 33 newly constructed reservoirs recorded during the period of the report, all but 2 had a preliminary section 7 (1) certificate. A section 7(1) certificate confirms that the reservoir has reached a stage of construction where it can be filled with water.

Table 4: Breakdown of risk designations of newly constructed reservoirs by undertaker type

Undertaker type	Not yet determined	Not high	Provisional High	High
Registered charities	2	0	0	0
Environment Agency	6	0	0	1
Farms	2	0	5	0
Industrial and commercial	2	0	0	0
Local authority	3	0	0	0
Private landowners and trusts	5	0	1	0
Universities, colleges and schools	1	1	0	0
Water companies	5	0	1	0

Serving enforcement notices

If the Environment Agency is unable to persuade undertakers to comply with the act, one option is to serve an enforcement notice. The notice gives undertakers a deadline to appoint an engineer or complete the safety measures. Table 5 shows the number of notices served (57) under sections of the act.

Table 5: Number of notices served 1 January 2019 to 31 December 2020

Section of the Reservoirs Act 1975	Non-compliance	Number of notices served
8(1)	No construction engineer appointed	1
10(7)(a)	No inspecting engineer appointed	7
10(7)(b)	Safety measures not carried into effect	23
12(4)	No supervising engineer appointed	25
16(4)	Emergency powers	1

Table 5 shows the Environment Agency served 23 notices under section 10(7)(b) of the act. This compares to 65 reservoirs with outstanding measures in the interests of safety shown in table 3. The difference in these figures is because:

• some reservoirs will have had a LEP in place – more information can be found in Appendix 2
• some were still under investigation at 31 December 2020

Table 6 shows the number of notices served by undertaker type. Appendix 1 gives more detail about notices we have served between 1 January 2019 and 31 December 2020.

Table 6: Number of reservoirs by undertaker type where we have served notices, 1 January 2019 to 31 December 2020

Undertaker type	Examples	Total number of undertakers
Private landowners and trusts	Individuals, estates, developers	20
Farms	Farms and fish farms	21
Industrial and commercial	Manufacturers and other businesses with reservoir assets	9
Local authority	County councils, borough councils	6
Government	Government departments	1

Other enforcement action

The Environment Agency issued 3 formal written warnings to undertakers between 1 January 2019 and 31 December 2020. There are 15 reservoirs under investigation. Depending on the investigation outcomes we may take further enforcement action.

In some cases, we have considered how to secure the right outcome for safety, and we have applied a risk-based approach. This means we have used our professional judgement, to take appropriate action. That action could be to issue advice and guidance or could go as far as carrying out emergency works. During the period of this report, we have carried out emergency works at one reservoir.

This approach is to achieve safe outcomes in line with the Regulators Code. It is not always appropriate for us to take punitive enforcement action if a reservoir becomes non-compliant.

Environment Agency Reservoirs

All Environment Agency reservoirs were compliant during 2019 and 2020.

Incident reporting

Reservoir undertakers are responsible for ensuring the safety of reservoirs. As the regulator, the Environment Agency ensures undertakers follow the legal safety requirements. We track compliance at all the LRRs in England. This includes collecting and recording information from reservoir undertakers on incidents. We use this information to improve safety by:

• investigating incidents where appropriate
• informing the reservoir industry of any trends and important lessons identified
• contributing to research into reservoir safety and incident analysis

Publishing our annual post incident report means, those involved in reservoir safety can learn from past incidents. By sharing experiences, we can improve safety for the future. This document covers incidents reported at reservoirs in England only.

Undertakers of small raised reservoirs in England can continue to report incidents on a voluntary basis. Small raised reservoirs have a capacity of less than 25,000 cubic metres of water above ground level. They are not covered by the legislation.

Table 7: Incidents reported between 1 July 2013 and 31 December 2020

Reported incidents	2013 to 2018	2019 to 2020
Incidents at large raised reservoirs	43	26
Incidents at small raised reservoirs	3	2
Total number of reported incidents	46	28

We have not taken enforcement action to get incident reports, although we have issued reminders to undertakers where a report is due. Compliance with the regulations on incident reporting is generally seen to be good and improving.

4. The future

Reservoir undertakers are diverse in type and include:

• the Environment Agency
• water companies
• businesses
• farmers
• fishing clubs
• individual landowners

Not all undertakers have the same level of legal and technical understanding of their responsibilities under the act. The Environment Agency will continue to focus its communication on undertakers who may need extra guidance. We will continue to focus more effort on those undertakers that have a poorer track record of compliance.

We will continue to work with the reservoir engineering profession. We will look to strengthen relationships with the BDS and ICE to build capability and promote safety and standards. Engineers have an important role to play in working with undertakers to achieve compliance.

In 2019, government ministers appointed Professor David Balmforth to undertake an independent review of the incident at Toddbrook Reservoir. His report concluded with 22 recommendations, 14 of these were placed on the Environment Agency. More detailed information about this is in appendix 3.

After the Toddbrook incident report was published, ministers appointed Professor Balmforth to carry out a further independent review. This focussed on the wider legislative and regulatory framework. We expect this review to be published in March 2021.

We will work with Defra and its stakeholders to complete Professor Balmforth’s recommendations. This will be a significant piece of work which will take several years.

Learning from the Toddbrook Reservoir incident emphasises the importance of having an on-site emergency plan.

In 2021 Defra will issue a new ministerial direction requiring undertakers to prepare and maintain emergency on-site flood plans. They must do this for all the reservoirs they are responsible for. On-site flood plans will describe the type of reservoir and details about everything on site. This will enable a rapid response to manage any on-site incidents and related flood risks.

The plans will contain details of essential personnel. They must include clear actions the undertaker will take to prevent or control and mitigate an uncontrolled release of water. The plans will reference areas that are at risk from flooding off site. This is important as the public living downstream of reservoirs may be unaware of the risk posed by reservoirs upstream. Undertakers must test these plans, as directed by their appointed engineer. We will provide training for undertakers and their engineers on how to apply this new guidance.

To enable undertakers to review any off-site flood risk, existing flood maps are being updated and improved. The new maps will be available to emergency responders by summer 2021 and on GOV.UK later in the year.

Defra is carrying out a review of the threshold for LRRs in England. At present the threshold is 25,000 cubic metres above ground level. NRW regulates all reservoirs that can hold 10,000 cubic metres or more of water in Wales. If government decides to lower the threshold, this change may come into effect within the period of the next review. We will continue to work with Defra on developing this proposal and on the completion of outcomes of the review.

5. Next steps

The reviews contained recommendations. We are working with Defra to turn these recommendations into an implementation plan. Some recommendations relate to undertakers and engineers acting now to improve:

• inspection
• supervision
• operation
• maintenance

We will produce 7 new guidance documents in 2021:

• spillway design guidance
• spillway examination guidance
• spillway failure mechanisms research
• guidance on a well-structured package of information on the reservoir
• guidance for inspecting engineers
• guidance for supervising engineers
• guidance for owners

You can view the following associated publications:

• Government independent review of the Toddbrook Reservoir incident [2019]
• Canal and River Trust detailed investigation report into Toddbrook
• Environment Agency’s technical bulletin
• Terms of reference for reservoir review – part B for the wider review of legislation and regulation

Appendix 1 – Reservoir data and statistics 2005 to 2020

The Environment Agency refers to sections of the act in appendix 1.The notices listed refer to:

• section 8(1) ‘Powers of enforcement authority in event of non-compliance with requirements as to construction or enlargement of reservoirs’ – the offence is failure to appoint a construction engineer
• section 8(3) ‘Powers of enforcement authority in event of non-compliance with requirements as to construction or enlargement of reservoirs’ – the offence is failure to carry out safety recommendations contained within the Section 8(2) report by the date required
• section 10(7)(a) ‘Periodical inspection of large raised reservoirs’ – the offence is failure to appoint an inspecting engineer
• section 10(7)(b) ‘Periodical inspection of large raised reservoirs’ – the offence is that the latest Section 10 report contains safety recommendations and a date by which these must be done and the work has not been done as required or by the date required
• section 12(4) ‘Supervision of large raised reservoirs’ – the offence is failure to appoint a supervising engineer
• section 16(4) ‘Emergency powers’ – this notice tells the undertaker what measures we are taking in exercising our emergency powers
• section 21A ‘Power to require information’ – this notice gives the undertaker at least 28 days to provide information specified in the notice

Data protection

The Environment Agency have listed those undertakers that are limited companies and public sector organisations. The Data Protection Act 1998 does not permit us to publish the names of private individuals - including partnerships and sole traders.

Steps taken by the enforcement authority to ensure that undertakers observe and comply with the requirements of the act

Alexandra Lake – St Helens, Merseyside

Undertaker: Northern Star (Pilkington) Limited.

Undertaker type: industrial and commercial.

Relevant section of the act: section 12(4).

Offence: failure to appoint a supervising engineer.

Other Enforcement action: notice served.

Compliance status at 31 December 2020: compliant.

Ardingly - Haywards Heath, Sussex

Undertaker: South East Water Limited.

Undertaker type: industrial and commercial.

Relevant section of the act: section 10(7)(b).

Offence: failure to carry safety measures into effect by the due date.

Other Enforcement action: advice and guidance (delayed certificate).

Compliance status at 31 December 2020: compliant.

Auberies Farm - Sudbury, Suffolk

Undertaker: Auberies Estate Farms Limited.

Undertaker type: farms.

Relevant section of the act: section 12(4).

Offence: failure to appoint a supervising engineer.

Other Enforcement action: notice served.

Compliance status at 31 December 2020: compliant.

Babraham – Cambridge

Undertaker: Cheveley Park Farms Limited.

Undertaker type: farms.

Relevant section of the act: section 12(4).

Offence: failure to appoint a supervising engineer.

Other Enforcement action: notice served.

Compliance status at 31 December 2020: compliant.

Bedgebury Park Great Lake - Tunbridge Wells, Kent

Undertaker: Columbia International SA.

Undertaker type: industrial and commercial.

Relevant section of the act: section 12(4).

Offence: failure to appoint a supervising engineer.

Other Enforcement action: notice served.

Compliance status at 31 December 2020: compliant.

Birkacre - Chorley, Lancashire

Undertaker: Chorley Borough Council.

Undertaker type: local authority.

Relevant section of the act: section 10(7)(a).

Offence: failure to appoint an inspecting engineer.

Other Enforcement action: notice served.

Compliance status at 31 December 2020: compliant.

Boscathnoe No. 2 - Penzance, Cornwall

Undertaker: South West Water Limited.

Undertaker type: industrial and commercial.

Relevant section of the act: section 10(7)(b).

Offence: failure to carry safety measures into effect by the due date.

Other Enforcement action: advice and guidance (delayed certificate).

Compliance status at 31 December 2020: compliant.

Brooke End Irrigation - Northill, Bedfordshire

Undertaker: FB Parrish & Son Limited.

Undertaker type: farms.

Relevant section of the act: section 12(4).

Offence: failure to appoint a supervising engineer.

Other Enforcement action: notice served.

Compliance status at 31 December 2020: compliant.

Burghley House - Stamford, Lincolnshire

Undertaker: Burley House Preservation Trust Limited.

Undertaker type: private landowners and trusts.

Relevant section of the act: section 12(4).

Offence: failure to appoint a supervising engineer.

Other Enforcement action: notice served.

Compliance status at 31 December 2020: compliant.

Carburton - Welbeck, Nottinghamshire

Undertaker: The Welbeck Estates Company Limited.

Undertaker type: private landowners and trusts.

Relevant section of the act: section 10(7)(b).

Offence: failure to carry safety measures into effect by the due date.

Other Enforcement action: notice served.

Compliance status at 31 December 2020: compliant.

Carburton Forge - Welbeck, Nottinghamshire

Undertaker: The Welbeck Estates Company Limited.

Undertaker type: private landowners and trusts.

Relevant section of the act: section 10(7)(b).

Offence: failure to carry safety measures into effect by the due date.

Other Enforcement action: notice served.

Compliance status at 31 December 2020: compliant.

Chard - Chard, Somerset

Undertaker: South Somerset District Council.

Undertaker type: local authority.

Relevant section of the act: section 10(7)(b).

Offence: failure to carry safety measures into effect by the due date.

Other Enforcement action: advice and guidance (delayed certificate).

Compliance status at 31 December 2020: compliant.

College Farm - Duxford, Cambridgeshire

Undertaker: Russell Smith Farms Limited.

Undertaker type: farms.

Relevant section of the act: section 8(1).

Offence: failure to appoint a construction engineer.

Other Enforcement action: notice served.

Compliance status at 31 December 2020: compliant .

Cowhill Belt Pond - Woburn, Bedfordshire

Undertaker: Bedford Estates Nominees Limited.

Undertaker type: private landowners and trusts.

Relevant section of the act: section 10(7)(b).

Offence: failure to carry safety measures into effect by the due date.

Other Enforcement action: notice served.

Compliance status at 31 December 2020: compliant then discontinued.

Culford Park Lake - Bury St Edmunds, Suffolk

Undertaker: Culford School.

Undertaker type: private landowners and trusts.

Relevant section of the act: section 10(7)(b).

Offence: failure to carry safety measures into effect by the due date.

Other Enforcement action: notice served.

Compliance status at 31 December 2020: compliant.

Docking Farm - Oulton, Norfolk

Undertaker: Saltcarr Farms Limited.

Undertaker type: farms.

Relevant section of the act: section 12(4).

Offence: failure to appoint a supervising engineer.

Other Enforcement action: notice served.

Compliance status at 31 December 2020: compliant.

Douster Pond - Crawley, West Sussex

Undertaker: West Sussex County Council.

Undertaker type: local authority.

Relevant section of the act: section 10(7)(b).

Offence: failure to carry safety measures into effect by the due date.

Other Enforcement action: notice served.

Compliance status at 31 December 2020: compliant.

Eastwell Lake - Boughton Lees, Kent

Undertaker: RLG Farms Limited.

Undertaker type: farms.

Relevant section of the act: section 12(4).

Offence: failure to appoint a supervising engineer.

Other Enforcement action: notice served.

Compliance status at 31 December 2020: compliant

Ecclesbourne - Hastings, East Sussex

Undertaker: Shearbarn Holiday Park Limited.

Undertaker type: industrial and commercial.

Relevant section of the act: section 10(7)(b).

Offence: failure to carry safety measures into effect by the due date.

Other Enforcement action: notice served.

Compliance status at 31 December 2020: compliant

Fish Pond, Ascot Place - Winkfield, Berkshire

Undertaker: Donford Limited.

Undertaker type: private landowners and trusts.

Relevant section of the act: section 10(7)(b).

Offence: failure to carry safety measures into effect by the due date.

Other Enforcement action: notice served.

Compliance status at 31 December 2020: compliant

Frog Farm - Havant, Hampshire

Undertaker: Langmead Farms Limited.

Undertaker type: farms.

Relevant section of the act: section 12(4).

Offence: failure to appoint a supervising engineer.

Other Enforcement action: notice served.

Compliance status at 31 December 2020: compliant

Frog Farm - Havant, Hampshire

Undertaker: Langmead Farms Limited.

Undertaker type: farms.

Relevant section of the act: section 10(7)(a).

Offence: failure to appoint an inspecting engineer.

Other Enforcement action: notice served.

Compliance status at 31 December 2020: compliant

Great Lake - Welbeck, Nottinghamshire

Undertaker: The Welbeck Estates Company Limited.

Undertaker type: private landowners and trusts.

Relevant section of the act: section 10(7)(b).

Offence: failure to carry safety measures into effect by the due date.

Other Enforcement action: notice served.

Compliance status at 31 December 2020: compliant

Great Sir Hughs - Chelmsford, Essex

Undertaker: GSH Farming Limited.

Undertaker type: farms.

Relevant section of the act: section 10(7)(a).

Offence: failure to appoint an inspecting engineer.

Other Enforcement action: notice served.

Compliance status at 31 December 2020: compliant

Holly Heath - Saxthorpe, Nortolk

Undertaker: EF & GW Harrold Limited.

Undertaker type: farms.

Relevant section of the act: section 12(4).

Offence: failure to appoint a supervising engineer.

Other Enforcement action: notice served.

Compliance status at 31 December 2020: compliant

Lady’s Pond - Brentwood, Essex

Undertaker: The Church Commissioners for England.

Undertaker type: private landowners and trusts.

Relevant section of the act: section 10(7)(b).

Offence: failure to carry safety measures into effect by the due date.

Other Enforcement action: notice served.

Compliance status at 31 December 2020: on schedule to complete by Spring 2021

Lake Superior - Charlbury, Oxfordshire

Undertaker: Cornbury Estates Company Limited.

Undertaker type: private landowners and trusts.

Relevant section of the act: section 12(4).

Offence: failure to appoint a supervising engineer.

Other Enforcement action: notice served.

Compliance status at 31 December 2020: compliant

Lower East End Farm - Colesden, Bedfordshire

Undertaker: RA Gibson (Colesden) Limited.

Undertaker type: farms.

Relevant section of the act: section 12(4).

Offence: failure to appoint a supervising engineer.

Other Enforcement action: notice served.

Compliance status at 31 December 2020: compliant

Marshland Farm - Sudbourne, Suffolk

Undertaker: Peter Waring Limited.

Undertaker type: farms.

Relevant section of the act: section 12(4).

Offence: failure to appoint a supervising engineer.

Other Enforcement action: notice served.

Compliance status at 31 December 2020: compliant.

Mote Park Lake – Maidstone, Kent

Undertaker: Maidstone Borough Council.

Undertaker type: local authority.

Relevant section of the act: section 10(7)(b).

Offence: failure to carry safety measures into effect by the due date.

Other Enforcement action: advice and guidance.

Compliance status at 31 December 2020: compliant.

Orchardleigh - Frome, Somerset

Undertaker: Orchardleigh Estates Limited.

Undertaker type: private landowners and trusts.

Relevant section of the act: section 12(4).

Offence: failure to appoint a supervising engineer.

Other Enforcement action: advice and guidance.

Compliance status at 31 December 2020: compliant

Overstone Park Lake - Northampton

Undertaker: Overstone Park Limited.

Undertaker type: industrial and commercial.

Relevant section of the act: section 10(7)(b).

Offence: failure to carry safety measures into effect by the due date.

Other Enforcement action: advice and guidance.

Compliance status at 31 December 2020: non-compliant

Pitt Dene - Elsworth, Cambridgeshire

Undertaker: Agreserves Limited.

Undertaker type: farms.

Relevant section of the act: section 12(4).

Offence: failure to appoint a supervising engineer.

Other Enforcement action: notice served.

Compliance status at 31 December 2020: compliant.

Poynton Pool - Poynton, Cheshire

Undertaker: Cheshire East Council.

Undertaker type: local authority.

Relevant section of the act: section 10(7)(b).

Offence: failure to carry safety measures into effect by the due date.

Other Enforcement action: notice served.

Compliance status at 31 December 2020: compliant.

Quadring - Spalding, Lincolnshire

Undertaker: R Bratley (Quadring) Limited.

Undertaker type: farms.

Relevant section of the act: section 10(7)(b).

Offence: failure to carry safety measures into effect by the due date.

Other Enforcement action: notice served.

Compliance status at 31 December 2020: compliant.

Reservoir A - Kirby in Ashfield, Nottinghamshire

Undertaker: partnership.

Undertaker type: farms.

Relevant section of the act: section 12(4).

Offence: failure to appoint a supervising engineer.

Other Enforcement action: notice served.

Compliance status at 31 December 2020: compliant.

Reservoir A - Kirby in Ashfield, Nottinghamshire

Undertaker: partnership.

Undertaker type: farms.

Relevant section of the act: section 10(7)(a).

Offence: failure to appoint an inspecting engineer.

Other Enforcement action: notice served.

Compliance status at 31 December 2020: compliant.

Reservoir B - St Helens, Merseyside

Undertaker: private individual.

Undertaker type: private landowners and trusts.

Relevant section of the act: section 10(7)(b).

Offence: failure to carry safety measures into effect by the due date.

Other Enforcement action: notice served.

Compliance status at 31 December 2020: claimed compliant but no Section 10(6) certificate received yet.

Reservoir C - Braintree, Essex

Undertaker: partnership.

Undertaker type: farms.

Relevant section of the act: section 12(4).

Offence: failure to appoint a supervising engineer.

Other Enforcement action: notice served.

Compliance status at 31 December 2020: compliant.

Reservoir D - Kirby in Ashfield, Nottinghamshire

Undertaker: private individual.

Undertaker type: private landowners and trusts.

Relevant section of the act: section 10(7)(a).

Offence: failure to appoint an inspecting engineer.

Other Enforcement action: notice served.

Compliance status at 31 December 2020: compliant.

Reservoir E - Paddock Wood, Kent

Undertaker: private individual.

Undertaker type: private landowners and trusts.

Relevant section of the act: section 12(4).

Offence: failure to appoint a supervising engineer.

Other Enforcement action: notice served.

Compliance status at 31 December 2020: compliant.

Reservoir F - Feltwell, Norfolk

Undertaker: partnership.

Undertaker type: farms.

Relevant section of the act: section 12(4).

Offence: failure to appoint a supervising engineer.

Other Enforcement action: notice served.

Compliance status at 31 December 2020: compliant.

Reservoir G - near Yeovil, but in Dorset

Undertaker: private individual

Undertaker type: private landowners and trusts

Relevant section of the act: section 10(7)(b)

Offence: failure to carry safety measures into effect by the due date

Other Enforcement action: notice served and warning letter sent

Compliance status at 31 December 2020: compliant

Reservoir H - Bolton, Lancashire

Undertaker: private individual.

Undertaker type: private landowners and trusts.

Relevant section of the act: section 10(7)(b).

Offence: failure to carry safety measures into effect by the due date.

Other Enforcement action: notice served.

Compliance status at 31 December 2020: compliant.

Reservoir J – Diss, Norfolk

Undertaker: private individual.

Undertaker type: private landowners and trusts.

Relevant section of the act: section 12(4).

Offence: failure to appoint a supervising engineer.

Other Enforcement action: notice served.

Compliance status at 31 December 2020: compliant.

Reservoir K - Sudbury, Suffolk

Undertaker: partnership.

Undertaker type: farms.

Relevant section of the act: section 12(4).

Offence: failure to appoint a supervising engineer.

Other Enforcement action: notice served.

Compliance status at 31 December 2020: compliant.

Reservoir L - Boughton Monchelsea, Kent

Undertaker: private individual.

Undertaker type: private landowners and trusts.

Relevant section of the act: section 12(4).

Offence: failure to appoint a supervising engineer.

Other Enforcement action: notice served.

Compliance status at 31 December 2020: compliant.

Reservoir M - Withnel, Lancashire

Undertaker: private individual.

Undertaker type: private landowners and trusts.

Relevant section of the act: section 12(4).

Offence: failure to appoint a supervising engineer.

Other Enforcement action: notice served.

Compliance status at 31 December 2020: compliant.

Reservoir M - Withnel, Lancashire

Undertaker: private individual.

Undertaker type: private landowners and trusts.

Relevant section of the act: section 10(7)(a).

Offence: failure to appoint an inspecting engineer.

Other Enforcement action: notice served.

Compliance status at 31 December 2020: compliant.

Reservoir N - Whittlesey, Cambridgeshire

Undertaker: partnership.

Undertaker type: farms.

Relevant section of the act: section 12(4).

Offence: failure to appoint a supervising engineer.

Other Enforcement action: notice served.

Compliance status at 31 December 2020: compliant.

Sandhurst Lower Lake - Camberley, Surrey

Undertaker: Secretary of State for Defence.

Undertaker type: government.

Relevant section of the act: section 10(7)(b).

Offence: failure to carry safety measures into effect by the due date.

Other Enforcement action: advice and guidance (delayed certificate).

Compliance status at 31 December 2020: compliant.

Slade Brook Balancing Pond - Kettering, Northamptonshire

Undertaker: Kettering Borough Council.

Undertaker type: local authority.

Relevant section of the act: section 10(7)(b).

Offence: failure to carry safety measures into effect by the due date.

Other Enforcement action: notice served.

Compliance status at 31 December 2020: non-compliant due to unplanned ecological issues followed by COVID-19 restrictions. Work has restarted.

Spring Lodge - Methwold, Norfolk

Undertaker: OW Wortley & Sons Limited.

Undertaker type: farms.

Relevant section of the act: section 12(4).

Offence: failure to appoint a supervising engineer.

Other Enforcement action: notice served.

Compliance status at 31 December 2020: compliant.

Springslade Pool - Cannock, Staffordshire

Undertaker: KGL Estates Limited.

Undertaker type: private landowners and trusts.

Relevant section of the act: section 10(7)(a).

Offence: failure to appoint an inspecting engineer.

Other Enforcement action: notice served.

Compliance status at 31 December 2020: compliant.

Sun Paper Mill - Blackburn, Lancashire

Undertaker: Blackburn Waterside Regeneration Limited.

Undertaker type: industrial and commercial.

Relevant section of the act: section 10(7)(b).

Offence: failure to carry safety measures into effect by the due date.

Other Enforcement action: notice served.

Compliance status at 31 December 2020: works underway to discontinue the reservoir.

Ward’s/Blue Lagoon - Blackburn, Lancashire

Undertaker: Blue Lagoon Heritage Limited.

Undertaker type: industrial and commercial.

Relevant section of the act: section 10(7)(b).

Offence: failure to carry safety measures into effect by the due date.

Other Enforcement action: notice served.

Compliance status at 31 December 2020: non-compliant – independent engineer’s site visit arranged.

Ward’s/Blue Lagoon - Blackburn, Lancashire

Undertaker: Blue Lagoon Heritage Limited.

Undertaker type: industrial and commercial.

Relevant section of the act: section 16(4).

Offence: failure to carry safety measures into effect by the due date.

Other Enforcement action: notice served.

Compliance status at 31 December 2020: non-compliant, actions taken to make r reservoir safe.

Update on other third party non-compliant cases in England in appendix 1 of our 2017 to 2018 biennial report

Barcombe - Lewes, East Sussex

Undertaker: South East Water Limited.

Undertaker type: water company.

Relevant section of act: section 10(7)(b).

Offence: failure to carry safety measures into effect by the due date.

Enforcement outcome: under investigation.

Compliance status at 31 December 2020: non-compliant.

Fenham Service - Newcastle Upon Tyne

Undertaker: Northumbrian Water Limited.

Undertaker type: water company.

Relevant section of the act: section 21A.

Offence: failure to register a reservoir; failure to appoint panel engineers; failure to report an incident.

Enforcement outcome: notice served.

Compliance status at 31 December 2020: compliant, but under investigation.

Folkington - Eastbourne, East Sussex

Undertaker: South East Water Limited.

Undertaker type: water company.

Relevant section of act: not applicable.

Offence: failure to carry safety measures into effect by the due date.

Enforcement outcome: safety measures completed, no further action.

Compliance status at 31 December 2020: compliant.

Great Barr Lower Lake - Walsall, West Midlands

Undertaker: BCG Lakes Limited.

Undertaker type: private landowners and trusts.

Relevant section of act: section 10(7)(b) and section 16(4).

Offence: failure to carry safety measures into effect by the due date.

Enforcement outcome: notices of entry served for intervention action.

Compliance status at 31 December 2020: safety measures are complete.

Hallington West - Colwell, Northumberland

Undertaker: Northumbrian Water Limited.

Undertaker type: water company.

Relevant section of act: section 10(7)(b).

Offence: failure to carry safety measures into effect by the due date.

Enforcement outcome: no further action.

Compliance status at 31 December 2020: compliant.

Marlbrook Quarry - Bromsgrove, Worcestershire

Undertaker: Link Property Developments Limited.

Undertaker type: private landowners and trusts.

Relevant section of act: section 8(3).

Offence: failure to carry safety measures into effect by the due date.

Enforcement outcome: failure to carry into effect measures in the interest of safety contained within the Section 8(2) report.

Compliance status at 31 December 2020: non-compliant, under investigation

Mariden No.2 - Coventry, West Midlands

Undertaker: Severn Trent Water Limited.

Undertaker type: water company.

Relevant section of act: not applicable.

Offence: late inspection under section 10.

Enforcement outcome: investigation, advice and guidance.

Compliance status at 31 December 2020: compliant.

Mariden No.3 - Coventry, West Midlands

Undertaker: Severn Trent Water Limited.

Undertaker type: water company.

Relevant section of act: not applicable.

Offence: late inspection under section 10.

Enforcement outcome: investigation, advice and guidance.

Compliance status at 31 December 2020: compliant.

Oldbury No.1 - Nuneaton, Warwickshire

Undertaker: Severn Trent Water Limited.

Undertaker type: water company.

Relevant section of act: not applicable.

Offence: late inspection under section 10.

Enforcement outcome: investigation, advice and guidance.

Compliance status at 31 December 2020: compliant.

Reservoir F - Harrogate, North Yorkshire

Undertaker: private individuals.

Undertaker type: private landowners and trusts.

Relevant section of act: section 10(7)(b).

Offence: works delayed by COVID-19.

Enforcement outcome: ongoing.

Compliance status at 31 December 2020: non-compliant.

Reservoir G - Wolverhampton, West Midlands

Undertaker: private individuals.

Undertaker type: private landowners and trusts.

Relevant section of act: section 10(7)(b).

Offence: failure to carry safety measures into effect by due date.

Enforcement outcome: works completed.

Compliance status at 31 December 2020: compliant.

Reservoir J - Potton, Bedfordshire

Undertaker: private individuals.

Undertaker type: private landowners and trusts.

Relevant section of act: section 10(7)(b) and section 16(4).

Offence: failure to carry safety measures into effect by due date.

Enforcement outcome: notices of entry served for intervention action, Undertaker to discontinue reservoir.

Compliance status at 31 December 2020: non-compliant; discontinuance incomplete.

Stanford - Rugby, Warwickshire

Undertaker: Severn Trent Water Limited.

Undertaker type: water company.

Relevant section of act: section 10(7)(b).

Offence: failure to carry safety measures into effect by due date.

Enforcement outcome: advice and guidance.

Compliance status at 31 December 2020: compliant.

Tilgate Lake - Crawley, West Sussex

Undertaker: Crawley Borough Council.

Undertaker type: local authority.

Relevant section of act: section 10(7)(b).

Offence: failure to carry safety measures into effect by due date.

Enforcement outcome: works completed.

Compliance status at 31 December 2020: compliant.

Whittle Dene Great Southern - Newcastle upon Tyne

Undertaker: Northumbrian Water Limited.

Undertaker type: water company.

Relevant section of act: section 10(7)(b).

Offence: failure to carry safety measures into effect by due date.

Enforcement outcome: safety measures complete; no further action.

Compliance status at 31 December 2020: compliant.

Whittle Dene Lower - Newcastle upon Tyne

Undertaker: Northumbrian Water Limited.

Undertaker type: water company.

Relevant section of act: section 10(7)(b).

Offence: failure to carry safety measures into effect by due date.

Enforcement outcome: safety measures complete; no further action.

Compliance status at 31 December 2020: compliant.

Whittle Dene Northern - Newcastle upon Tyne

Undertaker: Northumbrian Water Limited.

Undertaker type: water company.

Relevant section of act: section 10(7)(b).

Offence: failure to carry safety measures into effect by due date.

Enforcement outcome: safety measures complete; no further action.

Compliance status at 31 December 2020: compliant.

Whittle Dene Western - Newcastle upon Tyne

Undertaker: Northumbrian Water Limited.

Undertaker type: water company.

Relevant section of act: section 10(7)(b).

Offence: failure to carry safety measures into effect by due date.

Enforcement outcome: safety measures complete; no further action.

Compliance status at 31 December 2020: compliant.

Environment Agency reservoir compliance

All Environment Agency reservoirs were compliant during 2019 and 2020.

Statistics, engineer appointments and safety measures

Table 8: Number and type of English reservoirs from 31 March 2005 to 30 December 2020

Description	31 Mar 2005	30 Mar 2007	2 Apr 2009	5 Apr 2011	5 Apr 2013	2 Jan 2015	31 Dec 2016	31 Dec 2018	31 Dec 2020
Total number of LRRs	1,715	1,799	1,889	1,913	1,944	2,001	2,020	2,055	2,097
Number of under construction reservoirs	93	99	102	115	131	167	145	118	133
Number of abandoned reservoirs	not applicable	3	3	4	3	3	3	4	2
Total number of discontinued reservoirs	not applicable	175	191	210	219	225	235	253	262
Number of proposed reservoirs	not applicable	14	19	37	47	59	64	78	76
Total number of undertakers	431	644	691	708	736	772	847	839	838
Total number of LRRs for which the Environment Agency is the undertaker	124	161	180	189	198	209	211	214	219

In table 8:

• LRRs are reservoirs that are in operation, abandoned, and under construction
• under construction reservoirs - includes both new reservoirs and those being modified
• abandoned reservoirs – although empty, an abandoned reservoir is still capable of holding at least 25,000 cubic metres of water above natural ground level
• discontinued reservoirs – the discontinuance of a dam, requires an undertaker to reduce a reservoir’s capacity to a volume that is less than 25,000 cubic metres
• proposed reservoirs - are locations at which a large raised reservoir may be constructed in the future
• Environment Agency reservoirs - comprises those reservoirs that are in operation, abandoned, and under construction

Table 9: Supervising engineer appointments

Description	31 Mar 2005	30 Mar 2007	2 Apr 2009	5 Apr 2011	5 Apr 2013	2 Jan 2015	31 Dec 2016	31 Dec 2018	31 Dec 2020
Number of LRRs with no supervising engineer	44	40	6	4	10	8	8	3	5

In table 9 the figures for 2020 do not include 10 LRRs awaiting a risk designation

Table 10: Inspecting engineer (IE) appointments

Description	31 Mar 2005	30 Mar 2007	2 Apr 2009	5 Apr 2011	5 Apr 2013	2 Jan 2015	31 Dec 2016	31 Dec 2018	31 Dec 2020
Number of LRRs for which the next section10 inspection (S10) report is overdue	115	166	138	46	12	76	91	105	70
Number of LRRs for which the next S10 inspection report is overdue, for which an inspection and report is underway	not applicable	129	134	45	0	62	78	97	67
Number of LRRs for which the next S10 inspection has been overdue for at least one year	51	29	64	10	0	14	11	12	6
Number of LRRs for which the next S10 inspection has been due for at least one year, for which an IE has NOT been appointed	not applicable	1	3	0	0	0	4	0	1
Number of LRRs for which the next S10 inspection has been due for less than one year for which an IE has NOT been appointed	not applicable	not applicable	1	1	12	14	9	8	2

In table 10:

• all high risk reservoirs have to be inspected periodically by an IE, at intervals no greater than 10 years
• the figures may include reservoirs awaiting a risk designation
• where the number of LRRs for which the next s10 inspection report was overdue (70), 67 had an IE appointed

Table 11: Measures to be taken in the interests of safety (MIOS)

Description	31 Mar 2005	30 Mar 2007	2 Apr 2009	5 Apr 2011	5 Apr 2013	2 Jan 2015	31 Dec 2016	31 Dec 2018	31 Dec 2020
Number of LRRs with MIOS, including those within the ‘target period’ set by the IE	278	277	303	267	199	172	272	196	268
Number of LRRs with MIOS that are still outstanding even though the target period has elapsed	not applicable	49	40	41	35	36	57	49	65
Number of LRRs with MIOS for which there is no target date, but which have been outstanding for at least 5 years	not applicable	5	5	1	3	0	2	0	0

‘Measures in the interest of safety’ (known as MIOS) are essential works identified by an inspecting engineer during part of a section 10 inspection. The undertaker is legally required to implement MIOS.

The figures above for MIOS do not necessarily represent non-compliance. They represent the total number of reservoirs that have safety measures identified. Not all these safety measures are outstanding beyond their target date. The figures will vary according to how often engineers are identifying works that need doing at reservoirs - we have no control over this. It is not necessarily a figure to be concerned about unless the work is not done in time.

In table 11:

• number of LRRs with MIOS that are still outstanding even though the target period has elapsed - plus 7 provisional high risk and 3 not yet determined
• if MIOS are still outstanding 5 years after the section 10 report then it is quite likely that they have not been implemented ‘as soon as practicable’

Statistics on Reservoirs by dam category

Although not legally required, a reservoir construction or inspecting engineer should assign a dam category to a large raised reservoir as best practice. The category the engineer assigns depends on potential consequences of a dam breach. The dam category assigned is based on ICE guidance and takes a risk-based approach to reservoir design and inspections.

Table 12: distribution of dam category as at 31 December 2020

Dam category	Number of LRRs	% of total number of LRRs
A	829	39.5
B	359	17.2
C	471	22.5
D	208	9.9
Not assigned	70	3.3
Unknown	160	7.6

In table 12:

• category A dam - where a breach could endanger lives in a community
• category B dam - where a breach could endanger lives not in a community or could result in extensive damage
• category C dam - where a breach would pose negligible risk to life and cause limited damage
• category D dam - special cases where no loss of life can be foreseen as a result of a breach and very limited additional flood damage would be caused
• ‘not assigned’ - in some cases, engineers have not assigned a dam category yet to some non-impounding and service reservoirs

Before July 2013 engineers did not need to submit to us section 10 reports that did not contain safety measures. The ‘unknown’ category refers to where dam categories may not be available for all reservoirs. This category also includes reservoirs under construction where designation is yet to be determined. Over time this number is reducing as we receive new reports.

An impounding reservoir has a dam built across a river or stream to create a body of water behind the dam. A non-impounding reservoir has embankments all around it to hold water. A service reservoir stores fully treated drinkable water and is operated by water companies.

Statistics on reservoirs by undertaker type

Table 13: distribution of undertaker type as at 31 December 2020

Undertaker type	Number of LRRs	% of total number of LRRs
Water company	663	31.6
Private landowners and trusts	397	18.9
Farms	314	15
Environment Agency	219	10.4
Local authority	164	7.8
Industrial and commercial	115	5.5
Canal and River Trust	70	3.3
National Trust	44	2.1
Other government agencies	38	1.8
Registered charities	38	1.8
Recreational clubs and associations	16	0.9
Fish farms	9	0.4
Universities, colleges and schools	6	0.3
Other/unknown	4	0.2

Appendix 2 – Operating reservoirs safely during COVID-19 restrictions

The Environment Agency recognises the difficult circumstances due to COVID-19. We received reports of delays to engineering works and limits to contractor or staff availability. We adjusted our regulatory approach by applying LEPs.

The act’s priority is to ensure the structural stability of reservoirs and to protect the public living in downstream areas. Due to public safety, we expect undertakers and engineers to comply with the act even with COVID-19 restrictions in place.

Examples of conditions placed on the undertaker in the LEP include:

• the supervising engineer must certify that in their absence an alternative engineer is available
• calling for a new Section 10 inspection if the supervising engineer is unable to certify an alternative engineer
• producing a revised surveillance programme
• doing a desktop assessment if the inspecting engineer could not attend the site for a section 10 inspection

The inspecting engineer must consult a supervising engineer when doing a desktop assessment. The desktop assessment must be for the last section 10 report. They must also certify that the inspecting engineer can delay an inspection by up to 3 months.

We considered each case according to individual circumstances. We did not grant a LEP in all cases. In some cases, we advised the undertaker to make alternative arrangements to comply with the act.

In total, 33 undertakers applied for LEPs. We granted 19, giving specific conditions in each case, and granting extensions of up to 3 months. We will keep this approach under review.

Appendix 3 – Toddbrook Reservoir incident, August 2019

At the end of July 2019, following a period of heavy sustained rainfall, water began to cascade down the auxiliary spillway of Toddbrook dam. The dam undertaker is the CRT. On 1 August 2019 this flow of water triggered the partial collapse of the concrete slabs forming the spillway chute.

Over 1,500 people were evacuated from their homes and businesses in Whaley Bridge, Derbyshire. Emergency works started to prevent further damage and avoid any potential catastrophic failure of the dam wall. This was the first major incident involving a UK dam in over a decade.

The CRT, supported by a multi agency team, worked to reduce the water levels in the reservoir. Over 500 one tonne bags of aggregate were installed to shore up and stabilise the spillway. This work meant people could return to their properties within a week.

Government ministers appointed Professor David Balmforth to undertake an independent review of the incident at Toddbrook Reservoir. Professor Balmforth produced a report which included 22 recommendations. The Environment Agency delivered 3 of these recommendations shortly after its publication. We completed recommendations:

• “20. the EA should urgently seek to identify any reservoirs with potentially similar spillway characteristics to those at Toddbrook
• “21. where these are identified, Owners (undertakers) urgently arrange for detailed inspections to be undertaken, with any necessary precautionary measures put in place to ensure they remain safe whilst any remedial work is undertaken
• “22. the EA urgently produces a technical note on the Toddbrook Reservoir incident to inform all reservoir engineers and owners of the lessons learnt from the incident”

We are working with the reservoir sector to deliver the remaining 11 recommendations placed on us. The CRT also commissioned a separate technical investigation into the incident. This investigation formed part of their legal obligations under the Reservoirs Act.

Both reviews concluded that poor design was a main factor in the partial collapse of the spillway. Water getting under the top of the spillway and through joints and cracks in the spillway slabs caused erosion. The reviews identified that this erosion contributed to the collapse.