NB This is the second part of the formal court judgement. The first part appears in previous release. We have had to divide them for technical reasons, and this has changed the numbering of the Judge's numbering below, which should read 88-103. Apologies. 

1. The histories of the Heath shed some light on its condition in 1871, and why Parliament made provision for the Board to “drain, level and improve” it. The valleys were naturally marshy because of the springs and streams. When the steams were dammed to create the ponds, the land dried out to some extent, but there remained marshy areas in the vicinity of the streams and the ponds. In addition, the Heath had been extensively excavated for sand and gravel quarrying by its private owner, which had destroyed trees and vegetation. Its appearance was described in the Illustrated London News in September 1871 (quoted in Farmer: Hampstead Heath (1984)) as:

“a dreary desert prospect of hideous pits and shapeless heaps as far as the view extends over the hill itself, with a few miserable furze-bushes here and there, a ragged tuft of dusty ling, or some wretched weed content to grow in its degraded situation, but without one square yard of verdant turf for a baby to roll upon…. The very body of the earth had been cut away to an amazing depth… holes are scooped out …. thirty feet or forty feet deep….”

2. In my judgment, the proposed works fall within section 15 as they both ‘drain’ and ‘improve’ the Heath and its ponds. In so far as they involve ‘building’ on the Heath in parts which were ‘unbuilt’ in 1871 (e.g. the new dam at the Catchpit and the creation of spillways), the power in section 15 overrides the prohibition in section 12, which is subject to the other provisions of the Act.

3. The material parts of section 15 are also to be found in section 39 of the Wimbledon and Putney Commons Act 1871. In Evans v Wimbledon & Putney Conservators [2013] EWHC 3411 (Admin), Wyn Williams J. held that section 39 empowered the Conservators to build mounds to prevent unauthorised vehicle access on to the common. Although the mounds were not themselves used for purposes of health or recreation, they had the beneficial purpose of preventing unauthorised access by vehicles thereby enhancing the aim of providing unrestricted exercise and recreation on the common (at [56]). This analysis was not considered when the case went to the Court of Appeal ([2014] EWCA Civ 940).

4. Applying the same reasoning to this case, the proposed works at the ponds have the beneficial purpose of preventing the collapse of the dams (which would destroy the ponds), and protecting the Heath and its visitors from sudden flood, thus ensuring the continued safe use of the ponds and the Heath for “health and unrestricted exercise and recreation”.

5. Section 18 gives the Defendant power to erect “convenient or ornamental buildings … for the accommodation of Heath keepers, constables, or other officers, or for other public or useful purposes”. The building of a structure such as a dam or a spillway seems to me to be so far removed from the original intention behind section 18, and the type of building envisaged, that I am unable to agree with the Defendant’s submission that it authorises the proposed works.

6. The Claimant submits that the proposed works breach section 16, which requires the Defendant to “preserve as far as may be the natural aspect and state of the Heath…” In Evans v. Wimbledon and Putney Commons Conservators [2014] EWCA Civ 940, the Court of Appeal considered the meaning of the expression “as far as may be” which was contained in s. 36 of the Wimbledon and Putney Commons Act 1871. S. 36 imposed a duty on the Conservators which was expressed in similar terms to the duty under s. 16 of the Heath Act: “the Conservators shall at all times preserve, as far as may be, the natural aspect and state of the Commons, and to that end shall protect the turf, gorse, heather, timber and other trees, shrubs and brushwood thereon”.

7. The appellant contended that the expression “as far as may be” meant that the Conservators had to preserve the natural aspect of the Commons “as far as possible”. Patten LJ rejected this construction, saying [21]:

“The judge did not accept this construction of the Act and neither do I. Section 36 is specifically concerned with the preservation of the natural state of the commons and in particular with the grassland, gorse, heath and trees which grow there….But s.36 is essentially ancillary to s.34 in that any encroachment or building on the Common will necessarily interfere with the existing landscape. It would be odd if any powers which the Conservators may have under s.34 are nonetheless absolutely excluded by the provisions of s.36. One would expect the legislative scheme to be that which the Conservators should be under a duty to preserve the natural state of whatever parts of the Common they are obliged to maintain as open space under s.34. It seems to me that the natural construction of the words “as far as may be” in s.36 is “ as far as required under the Act”. I do not accept Mr McCracken’s argument that s.36 provides an independent, absolute, and unrelated duty which would have the effect of making the scheme under s.34 largely irrelevant.”

8. In my judgment, Patten LJ’s analysis in Evans is equally applicable here. Section 16 was not intended to operate so as to prevent any works which could lawfully be carried out pursuant to section 15, on the grounds that the works would alter the “natural aspect and state of the Heath”.

Other emergency provision for floods

9. Both the London Borough of Camden and the Defendant are required to plan for emergencies, including flooding, under the Civil Contingencies Act 2004. The London Borough of Camden has responsibility for managing flood risks on the Heath, under the Flood and Water Management Act 2010. There are significant potential flood risks as a result of run-off of surface water from the heights of the Heath down to the plain below.

10. None of these provisions reduce the extent of the obligations under the RA 1975. The Defendant’s proposals address one discrete issue: the risk of the dams breaching.

11. In Camden’s flood risk management strategy it states that the risk of the ponds breaching is “unlikely” while noting that the impact of a breach could be “extremely severe”, and that the Defendant is taking steps to improve the ponds’ defences. The Borough’s Risk Register lists the Reservoirs Act 1975 and regular statutory inspections as controls in place for major reservoir dam failure. Thus, Camden acknowledges that dam breach is a risk which is governed by the RA 1975.

Warning times

12. In ground 2, which I have set out in some detail above, the Claimant submitted that the Defendant had adopted an irrational approach to risk because it failed to take account of the fact that, in a probable maximum flood, residents downstream of the ponds would already be flooded by surface water running off the hill and overflowing sewers before the dams breached, and emergency warnings and evacuation would already be in place.

13. This ground must fail since I have already held that the purpose of the RA 1975 is to prevent the escape of water from large raised reservoirs, not to mitigate the effects of an escape by flood warning and evacuation strategies. The evidence from Dr Hughes, which I accept, was that it is difficult to predict how quickly a dam will fail, but that once overtopping started, a dam could fail very quickly. Even if the residents downstream were already flooded by surface water and overflowing sewers, they might not have evacuated in time. The escape of thousands of gallons of water from the ponds would be likely to have a catastrophic effect on people and property situated below the ponds.

The Defendant’s decision

14. In my judgment, the Defendant’s decision to approve the proposals and seek planning permission for them was lawful. In light of Dr Hughes’ advice, and the studies obtained from other engineers, the Defendant was entitled to conclude that preventative action should be taken now.

15. The claim was arguable, and therefore I give permission to apply for judicial review.

16. However, for the reasons set out above, the claim is dismissed.

Ends. NB The numbering above has changed from original document and '16' should read 103 etc.