Agenda item

Hampstead Heath Ponds Project - Preferred Options Report and Non-Statutory Consultation


The Chairman introduced the report on the Hampstead Heath Ponds Project Preferred Options Report and Non-Statutory Consultation. He noted that the Ponds Project Stakeholder Group (PPSG) existed under the aegis of the Hampstead Heath Consultative Committee and that the PPSG had met on around 20 occasions over the past 12 months, and its members had shown commitment and energy to the task at hand throughout. The PPSG had been given the support and assistance of the Strategic Landscape Architect (SLA) Peter Wilder who had also facilitated a number of PPSG workshops. There now existed two preferred options on each chain of ponds which were detailed within the current report before the committee. He noted that the Corporation was obliged to follow the Institution of Civil Engineers (ICE) guidance on the works required on the Heath dams and that the project costs – over £15m – were not being allocated or spent lightly. He told the committee that the eventual works decided upon would be the minimum required. He concluded by saying the work of the PPSG had been key in informing the project to date, and noted that if works were restricted to the three statutory dams rather than spread across the two pond chains as currently proposed then the resulting impact on the Heath’s natural aspect would be greater.


The Superintendent then took the opportunity to address the committee, and welcomed the Assistant Director of Engineering, the Responsible Officer for the safety and integrity of the Hampstead Heath dams. The Superintendent highlighted the core objective of the project, the prevention of the dams breaching as a result of storm events. He noted that a design philosophy had emerged throughout the project process to date. This philosophy was anchored on the need to preserve the natural aspect of the Heath as well as ensuring the safety of people resident downstream from the dams. These two principles meant that the design proposals attracted a range of views from a variety of stakeholders. The Superintendent highlighted the accepted principle that works should be spread across the two pond chains in order to minimise the impact of works. He then went on to summarise some key issues:


Probable Maximum Flood (PMF)

He noted that it was forecast that the PMF would see 38 tonnes of water per second flow over or around the Highgate Number 1 dam, and that this would be reduced to around 30 tonnes per second under the Preferred Options. He emphasised that the project was anchored on dam preservation, not flood alleviation.


Legal Duty

He recognised that the City of London Corporation (CoL) had a duty to preserve the natural aspect of the Heath in accordance with the Hampstead Heath Act 1871, but this was a qualified duty.


Passive System

He acknowledged that there had been suggestions that, rather than a passive system of dam drainage being installed on the Heath, staff could operate drainage valves to ease pressure on dams in the event of storms. However, the risk to individual staff was unacceptable.


Early Warning

He reported that the Meteorological Office could not commit to providing sufficient early warning of convection storms, the most likely cause of extreme rainfall events. He also referred to recent guidance from the Environment Agency/DEFRA on risk assessment for Reservoir Safety that stated that is was considered unlikely that in the UK context any effective warning would be given.


Preferred Options

He suggested that the PPSG underestimated the influence it had exercised over the identification of the preferred options. He noted that the two options were very similar in character due to the overarching need to follow industry and statutory guidance. He noted that many of the solutions incorporated into the Preferred Options had come from the PPSG and that they had provided a vital scrutiny function.



He noted that the CoL was obliged to carry out works to ensure the dams were not at risk of failure, and failure to do so in a timely fashion would risk the CoL being issued with a s10 notice which would effectively remove the project from CoL control and risk an inappropriate and insensitive solution being implemented. He added that the period of non-statutory consultation would see the CoL asking people what they wanted to see done to the dams. He concluded by saying that the eventual option may be a variant of a Preferred Option.


The Assistant Director of Engineering said that the Superintendent had provided a fair summary of the issues involved. He added that the adoption of early warning would only allow timely evacuation and not ensure the integrity of the dams, which was the issue in question.


The Chairman invited committee members to provide their comments on the report.


Simon Taylor (Hampstead Rugby Club)

He noted that this was only his second committee meeting and therefore did not feel qualified to comment in great detail. He was nevertheless impressed with the level of dialogue carried out by the CoL and the emphasis that has been placed on the preservation of the natural aspect of the Heath.


Ian Harrison (Vale of Health Society)

He noted that despite his recent absence he had remained impressed by the work of the PPSG, and the quality of the paperwork produced by the CoL for this meeting. He felt the project had been heading in the right direction when he was last involved six months ago, and this remained his opinion. He noted that he was unable to comment upon the specific views of the Vale of Health Society but that he would be surprised if they had moved away from the VoHS’s historic support. He made some specific comments of his own.


Regarding early warning – he noted that he was formerly employed in the chemical industry and that his experience told him that it was not appropriate or wise to rely on one safeguard alone – such as early warning –given catastrophic events often arose due to a number of related failures of different safeguards. Regarding ‘Preferred Option’ - he felt it would be more appropriate to refer to the options as ‘Proposed’ or simply ‘Options’.  Regarding consultation – he argued that, subject to the risk of a s10 notice, as much time as possible should always be allocated to public consultation, and that the current timeline looked very tight. Furthermore he argued that consultation material should avoid technical language as far as possible to ensure clarity for the general public.


Jeremy Wright (Heath & Hampstead Society)

He noted that the H&HS had submitted around 5 pages of comments on the Preferred Options which included an issue with the use of the word ‘preferred’,  and the suggestion that ‘proposed’ would be more appropriate. He said that the H&HS agreed that some works need to be carried out and supported the principle of spreading the works over the entirety of the pond chains and increasing the capacity for storage in the central areas of the chains. However, the H&HS cannot support any options that were drawn up on an incorrect interpretation of the law and consequently would damage the natural aspect of the Heath.


The H&HS has issues with the Quantitative Risk Assessment (QRA) used by the CoL. He noted that the QRA states that in the event of dams overtopping during a 1/400,000 year storm, the likely loss of life (LLOL) is currently estimated at 1,100 and at 1,400 in the event of the dams failing, and therefore works would only lead to a residual improvement of 300 in LLOL.


He cited the information provided by Haycock to highlight the experience of the 1975 storm on the Heath,  noting that during the storm it had taken 5 minutes for flooding to occur,, The emergency services very quickly received 2,000 calls for assistance from the public. By comparison it is estimated that in the event of a storm it will take six hours for the dams to overtop. Therefore emergency services will be well aware of the issue of flooding, and will be responding to calls from within the area at risk of flooding well before the dams have overtopped. Therefore, the H&HS does not understand why the CoL is not adopting the principle of Early Warning. He continued by asking if the CoL really believed the content of the QRA. He said that the H&HS had submitted a number of questions on the document with the aim of probing some of the assumptions therein. The recent response that they had received from Atkins did not answer any of these queries. He stated that the H&HS regarded the QRA to be a suspect, factually wrong and misleading document.


He referred to a peer-review by Aecom Engineers which estimated the Bird Sanctuary Dam and the Mixed Bathing Pond dam to be at low risk of failure, and compared this to the completely opposite estimation put forward by Atkins that these dams were at high risk of failure. He said that despite these inconsistencies the CoL had chosen the QRA as the basis for its statement of 1,400 persons being subject to a LLOL in the event of dam failure. He urged the CoL therefore to issue a revised QRA and an acknowledgment, given the 1975 case study, that a storm will provide a natural degree of early warning. He noted that the SLA report was generally accurate. Lastly, he expressed sadness that the consultation will concern two options only.


Richard Sumray (London Council for Sport and Recreation)

He considered the two most significant documents to be the legal position set out jointly by the CoL and the H&HS and the paper outlining the forthcoming information-giving and consultation exercise. He felt that if it was considered to be necessary the judicial review mooted by the H&HS should happen sooner rather than later, given the clear divergence in interpretation of the law, and amount of money already spent by the City Corporation the implications of launching a judicial review once a further round of consultation had taken place. He suggested that further discussion could usefully take place between the H&HS and the CoL to attempt to resolve the difference over legal interpretation. He argued that the H&HS should decide what it wanted to do.


He felt the paper relating to the consultation exercise was well written but problematic. He noted that the process was largely about information-giving, but it was not clear precisely what the public was being asked to consider – if there are only two very similar options, how is the public to make an informed decision? He felt that the term ‘consultation’ was not appropriate as this was not what was really happening. The wording of the material used would be important. and feedback should be given to observations made by the public. Lastly, he said that if the Ponds Project went ahead then the opportunity should be seized to improve the Heath as much as possible as a result.



The Chairman allowed Jeremy Wright to comment upon Richard Sumray’s observation regarding the possibility of a judicial review. Jeremy Wright remarked that H&HS would need to see the final options being considered for a planning application before it was in a position to decide whether or not to embark upon a judicial review. He concluded by saying that the H&HS would rather avoid mounting a judicial review and therefore if there was the possibility to discuss the legal position further or for any friendly action to take place to clarify the position then this would be welcomed.


Ellin Stein (Mansfield Conservation Area Advisory Committee/Neighbourhood Association)

She noted she had been a regular attendee of the PPSG and that she was aware the project was a balancing act between varying dam heights, spillways and impact on the Heath. Nevertheless she felt uncertain over whether, informed as she was by the PPSG process, she could make a decision between the Preferred Options. She recognised that the core principle was dam preservation and not flood alleviation. She felt that examples of consultation material she had seen on the Resources for Change website had a patronising tone, and was too simplistic. Material presented should address real concerns, such as disruption posed by construction, and the effect of new dams on runners, anglers, swimmers etc. It should give an idea of the effect of construction traffic. Fundamentally, it should address why the project is necessary. Lastly, she said the consultation needed to have clarity of purpose – was it genuine engagement or simply a tick box exercise?


Xohan Duran (Representative of People with Disabilities)

He felt that the consultation should fully inform the public, and why the CoL feels it is necessary to spend £15m. He agreed that it should detail the disruption posed by construction, in terms of traffic and the alteration of the landscape. He argued that the end-result should comply with the statutory duty to preserve the natural aspect of the Heath. Lastly, he hoped that a s10 notice could be avoided.


John Hunt

He felt that the public was faced with a common sense versus legal issue conflict. They are faced with two different, well informed legal opinions. Moreover, the number of variables in the project makes it almost impossible to make an informed choice between the options. He voiced admiration for the detailed critique provided by the H&HS. He concluded by saying that the South End Green Association (SEGA) were primarily interested in the lower chain of ponds and therefore did not welcome an increase in the  height of Hampstead No. 1 and 2 dams.


Susan Nettleton

She felt that it was a shame that such fundamental differences remain this far into the project process and that ideally these needed to be resolved. She felt that the public consultation should make it clear the project was about the prevention of dam failure. In terms of project presentation and communication she welcomed the aerial plans but observed that the proposed spillways needed to be included in these, and that similarly a new path near the Boating Pond was not depicted. She noted that no detailed plans existed showing the impact of the spillways despite their significant extent, and that they should be depicted on the plans. Lastly she said that pictorial material of views should depict the dams up close rather than viewed from a distance.




Colin Gregory

He agreed with the issues identified regarding consultation by previous speakers. He was keen to know what the actual question under consideration would be, and emphasised that the process should provide information and invite views. He put forward the example of the construction of the Parliament Hill Staff Yard – none of the original options put forward were considered acceptable after consultation and so a brand new option was put forward. He used the example of consultation over the A1/North Circular – overall the majority of respondents were in favour of none of the proposals, and yet a proposal with only a small percentage of support was chosen simply so the project could proceed. He warned that the CoL risked a credibility issue if it took such an approach. He said that the CoL should make it clear why it had adopted its chosen position. He welcomed the site plans within the agenda pack, and observed that the legal paper focused on the Reservoirs Act 1975 and did not include any analysis of common law liability. He felt that it was key to canvass the views of the contractor that would be carrying out the works. 


The Superintendent replied that it was the CoL’s intention to bring the contractor in early to allow them to gain an understanding of the phasing of the project and the wider issues involved.


Mary Port

She agreed that the legal issue remained a problem. She felt that the technical nature of much of the information would be hard to communicate to the public, and that much of the information failed to reflect how local people related to the Heath –dog walkers, runners etc. were concerned over natural aspect, not safety of dams. She agreed with the decision to focus storage on the centre of the chains of ponds. She felt that many of the diagrams were too technical, and that more explanation was needed over the nature of the spillways, including visual material.


Michael Hammerson

He felt that there was no consensus in the PPSG given it represented such a multiplicity of views. He remarked that some of the works proposed did not seem very well conceived and could be interpreted as ‘window dressing’ – particularly around the Bird Sanctuary dam. He felt that the large size of the spillways – 30-40m – needed to be demonstrated. He felt that the issue was boiling down to whether the work proposed was really necessary or if it was simply a legal issue. He argued the consultation process should aim to convince public why the CoL was willing to spend £15m, and it should avoid giving the impression that the two options were immutable. Visuals of how the Heath would look should be provided, and a description of what the construction process would involve. The CoL needed to get across that the Heath was not going to be developed and would recover over time. He warned that awareness of the project amongst the public at large was minimal – even among regular dog walkers on the Heath.


The Chairman thanked the committee and noted that these comments would be reported to the Hampstead Heath, Highgate Wood and Queen’s Park Committee on 25 November 2013.


The Superintendent took the opportunity to make some comments:



In light of the criticism from the H&HS, he said that the document was not a design tool but something intended to assess impact, and it was usually produced in the civil engineering industry to identify the best outcome for a project.



He argued both sets of options were very similar. .. He agreed that visualisation of the spillways needed to be improved. He said that the information-giving exercise was exactly that – information giving, and that an open ended question would be included to allow the public to comment as widely as possible. The information would set out the project process to date and make clear why the CoL was doing what it was doing. He concluded by saying that the CoL had produced reams of information, none of which provided an alternative to the options in question.


The Chairman emphasised that all comments would be going to the Hampstead Heath, Highgate Wood and Queen’s Park Committee on 25 November 2013, and that the contractor would be engaged as soon as possible to allow early contractor involvement in the design process.


Supporting documents: