Case No: HQ11X02516
Neutral Citation Number: [2016] EWHC 156 (QB)
IN THE HIGH COURT OF JUSTICE
QUEEN'S BENCH DIVISION

Royal Courts of Justice
Strand, London, WC2A 2LL

Date: 4th Feb 2016 

Before :

His Honour Judge Reddihough
(Sitting as a Judge of the High Court)
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Between :

	(1)	Bryn Michael Chetwynd
(2)	Joanna Valerie Chetwynd 
	
Claimants	
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	(1)	Barry John Tunmore
                     (2)  Caroline Tunmore	
Defendants	

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Mr Wayne Beglan (instructed by Simon Jackson Solicitors) for the Claimants

Mr Wayne Clark and Mr Joe Ollech (instructed by Mills & Reeve LLP) for the Defendants

Hearing dates:   2-4, 7-11, 14-15 December 2015 

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Judgment
His Honour Judge Reddihough : 
1.	This is a claim for damages and injunctive relief by the claimants against the defendants arising out of their respective ownership of adjoining areas of land in rural Norfolk. In essence the claimants claim that the defendants have excavated lakes on their land which have adversely affected the land owned by the claimants and in particular the water levels in fishing lakes thereon. The dispute giving rise to the claim has a long and involved history and it is necessary to set out some of the background to it.
2.	The claimants jointly own land known as Fen Lakes Fishery (the Fishery), Carleton Rode, Norfolk. The land is an area of approximately 3.5 hectares which has on it six lakes totalling about 1.5 hectares in size. It appears that the lakes have been there since at least the 1970s. This land was purchased by the claimants in December 2004 and their ownership was registered on 15 January 2005. The previous joint owner, Mr Robin Ford, had been operating the Fishery as the Fen Angling Club and through the sale of day tickets to anglers who fished the lakes. The Fishery is situated within Carleton Rode Fen (the Fen), an area of some 12.6 hectares, which has been designated as a Country Wildlife Site. The river Tas flows along the southern boundary of the Fishery.
3.	Adjacent to the Fishery and also in the Fen is an area of about 7 hectares of land of which the defendants are the joint owners. They became the owners of that land on 17 January 1995, having purchased it from the estate of Harry Rush, who had also owned the Fishery before he sold it to Mr Ford and his co-owner in 1992.  The first defendant, Mr Barry Tunmore, has lived in Carleton Rode since 1974. In 1986 he purchased White Lodge Farm and he and the second defendant have lived there since their marriage in 1987. White Lodge Farm is a short distance from their land in question in the Fen, but on the other side of Fen Road which runs to the north of that land and the Fishery.
4.	Subsequent to the purchase of the defendants’ land in the Fen the first defendant excavated four lakes upon it.  For ease of identification in this case the six lakes at the Fishery (each of which has a name) have been designated Ponds A-F (although C and D are joined), and the lakes on the defendants’ land as Lakes 1-4 (although Lakes 2 and 3 form one body of water). The Lakes are to the west of the claimants’ land, with Lake 1 being relatively close to Pond A. There is some doubt about precisely when the lakes on the defendants’ land were excavated but according to the first defendant Lake 1 was completed in 2001, Lake 2 by June 1999, Lake 3 in 2000 and Lake 4, which is on the south side of the River Tas, in 2005/6. Thus all the Lakes except Lake 4 had been completed prior to the claimants’ purchase of the Fishery. The total surface area of the Lakes is approximately 8,200 m². 
5.	In 1989, when Mr. Robin Ford was already engaged in the running of the Fen Angling Club at the Fishery, which at that time was still owned by Mr. Rush, he made a planning application for the excavation of three fishery lakes and a parking area on the land in the Fen now owned by the defendants. It appears that the application was made with a view to increasing the size of the Angling Club by having the three additional lakes. There were various objections to the planning application and it was refused by the South Norfolk District Council (SNDC) in August 1989, the first reason for the refusal being the proposed development would involve the destruction of a nature conservation site of county significance through physical works and alteration in the drainage. It would seem that, by reason of this refusal of planning permission, Mr. Ford purchased only the Fishery from Mr. Rush in 1992 but not the land now owned by the defendants. There is an issue as to whether the defendants knew of this planning application and its refusal before and/or after their purchase of their land in the Fen in 1995. Prior to the excavation of the Lakes on their land, the defendants did not make any planning applications for such works. 
6.	The claimants’ purchase of the Fishery in 2004 was with a view to continuing to run it as a commercial fishery, as Mr. Ford had done. The first claimant had recently retired from the army and had a longstanding interest and involvement in angling. 
7.	The defendants assert that initially the construction of Lakes 2 and 3 arose from the widening and extension of existing dykes and tributaries on their land. Once the Lakes were completed, they did not intend to utilise the land for a commercial fishery but they stocked the Lakes with fish. Initially they were fished by family and friends, but then local anglers became interested and the first defendant formed a members club for anglers at the Lakes and also made day tickets available. The profits of this angling operation, while it continued up to 2010, appear to have been less than £1,000 per annum. 
8.	It appears that, subsequent to the excavation of Lake 1 in 2001, the defendants agreed with Mr. Ford that a pipe be placed between Lake 1 and Pond A so that excess water from Lake 1 would feed into Pond A. This pipe was no longer in position when the claimants purchased the Fishery. 
9.	The local planning authority (SNDC) became aware that the Lakes had been excavated without the required planning permission and in May 2007 resolved to take enforcement action to have the land restored to its original state. The defendants through an agent then made an application for a certificate of lawful use of the land on the basis that the Lakes had existed for more than ten years so that the absence of planning permission was obviated. That application falsely stated that the Lakes had been in existence since 1995. Subsequently, the application for a certificate of lawful use was withdrawn and instead the defendants made two applications in September and October 2007 for retrospective planning permission for Lake 4 and Lakes 1, 2 and 3 respectively. In June 2008, SNDC allowed the applications and granted retrospective planning permission for the Lakes with a number of conditions attached, including a condition that outfall from them should not exceed 20 m³ per day, that being the limit over which a water abstraction licence would be required under the Water Resources Act 1991. 
10.	The first claimant had noted that from June 2005 the water level in the Ponds at the Fishery dropped and that the situation deteriorated over the following years. The first claimant asserts that this reduction in water levels in the Ponds has been caused by the excavation of the Lakes on the defendants’ land. He considered that the retrospective planning permissions for the Lakes should not have been granted and he made an application for judicial review to quash them. The defendants did not participate in those proceedings. The judgment in the judicial review application was delivered by Collins, J. on 13th May, 2010. He quashed the retrospective planning permissions for the Lakes on the basis that the decisions to grant the permissions were inconsistent with environmental policies which applied to the Fen and found that there had been a failure to require an environment impact assessment within the relevant regulations. He also found that the construction of the Lakes gave rise to an abstraction of water from the underground strata and that any outfall or overflow of such water from the Lakes amounted to an abstraction of water for the purposes of the Water Resources Act 1991. The defendants accept that the Lakes do give rise to such abstraction. 
11.	Following the decision in the judicial review proceedings, SNDC asked the defendants to comply with the Environmental Impact Assessment Regulations by preparing an environmental statement. Thereafter, on 29th September, 2010, SNDC issued to the defendants an enforcement notice in respect of the breach of planning control occasioned by the construction of the Lakes without planning permission. The enforcement notice included a requirement for the defendants to submit an environmental assessment in accordance with the Environmental Impact Assessment Regulations, indicating the hydrological and ecological impact of the Lakes; and for them to implement a scheme of works to be approved by SNDC to reduce the total abstraction of ground water from the site to less than 20 m³ per day and to remedy the adverse ecological impacts of the unauthorised construction of the Lakes. The enforcement notice took effect on 29th December, 2010 and compliance was required by 29th June, 2011.  
12.	Thereafter, there has been a great deal of work and monitoring undertaken by Harrison Environmental Consulting on behalf of the defendants and Cascade Consulting on behalf of SNDC regarding the effect of the Lakes on the Fen and the work which is required to remedy the ecological impact of the Lakes. A considerable number of reports and assessments has been prepared by these consultants. There has also been the involvement of the Environment Agency, which on 15th October, 2012, granted the defendants an abstraction licence under the Water Resources Act 1991, to transfer water from Lake 1 to Pond A or into a ditch leading to the River Tas. There have been various extensions of time for compliance with the enforcement notice. Different methods of complying with the enforcement notice, including the infilling of one or more of the Lakes, have been discussed between SNDC and the defendants or their representatives. An offer of compensatory land owned by the defendants elsewhere in the Fen as an alternative to compliance with the enforcement notice was rejected by SNDC. 
13.	By a letter dated 27th November, 2015, a few days before the trial of this claim commenced, SNDC informed the defendants that in order to comply with the enforcement notice, they would be required to infill Lake 1 after a period of a minimum of six months monitoring of Lakes 2 and 3 to determine ground water influences. After such monitoring, SNDC would conclude the overall scheme of work, including the infilling of Lake 1, to be undertaken by the defendants. The defendants have indicated that they will adhere to this requirement and agree also to the infilling of Lakes 2 and 3 if required. 
14.	As mentioned above, the claimants claim that construction of the Lakes has caused a significant decrease in the water levels in the Ponds at the Fishery, which it is alleged has had a detrimental effect on the Ponds and the viability of a commercial fishery there. In December 2010, in a very cold spell when ice formed on the Ponds, a large number of fish died and it is asserted by the claimants that this loss, together with fish losses at other times, was caused by the low water levels in the Ponds.
15.	Having set out some of the background to this matter, it is now appropriate to summarise the basis of the claimants’ claim. The claimants firstly make a claim under section 48A of the Water Resources Act 1991 (as amended). Under that section, the claimants claim in respect of loss and damage allegedly suffered by them as a result of the defendants’ abstraction of water resulting from the construction of the Lakes. It will be necessary to consider in more detail the provisions of section 48A. Further and in the alternative, the claimants claim that the excavation of the Lakes created a nuisance and/or that the defendants acted negligently in excavating the Lakes as a result of which they have suffered loss and damage. The claimants also claim that the defendants are guilty of an economic tort by deliberately interfering with the claimants’ business of running the Fishery business. The claimants claim a mandatory injunction requiring the defendants to execute such works as may be necessary to restore the ground water levels in the Fishery to the levels prevailing prior to the construction of the Lakes on the defendants’ land. The claimants further claim damages for the loss of fish from the Ponds, for loss of income from the Fishery, for the costs of remediating the Ponds, for expenses incurred and for loss of amenity. 
16.	In their defence, the defendants deny that the excavation of the Lakes has caused or contributed materially to the loss of any water supply to the Fishery or caused any loss or damage to the complainants, and assert that any such loss is due to other causes. It is alleged that the claimants refused to accept an offer from the defendants to reinstate the discharge of water via the pipe from Lake 1 to Pond A. The defendants admit that they have abstracted water from the underground strata within the meaning of section 48A of the Water Resources Act 1991, but deny liability under that section. It is denied that the claimants have any claim in negligence or nuisance or in respect of an economic tort. The defendants also claim that because Mr. Ford, the claimants’ predecessor in title, acquiesced in the construction of Lakes 1, 2 and 3, an equitable estoppel or easement arises entitling the defendants to use the Lakes in such manner that interferes with the water supply to the Fishery provided they supply water by pipe from Lake 1. It is asserted that in any event an injunction is not appropriate relief. 
17.	In my view, it is appropriate, before considering the evidence in this case, to rule upon two particular questions of law which arise and which are of fundamental importance to the resolution of issues as to liability and causation regarding this claim. 
18.	The first of those questions of law is in relation to liability under section 48A of the Water Resources Act 1991, which was inserted into the Act by section 24 of the Water Act 2003. Section 48A provides as follows:  
“(1) Subject to sub-section (7) below and to section 79 (including that section as applied by section 79A(9)) below, a person who abstracts water from any inland waters or underground strata (an “abstractor”) shall not by that abstraction cause loss or damage to another person.
(2) A person who suffers such loss or damage (a “relevant person”) may bring a claim against the abstractor.
(3) Such a claim shall be treated as one in tort for breach of statutory duty. 
(4) In proceedings in respect of a claim under this section, the court may not grant an injunction against the abstractor if that would risk interrupting the supply of water to the public or would put public health or safety at risk.
(5) Except as provided in this section, no claim may be made in civil proceedings by a person (whether or not a relevant person) against an abstractor in respect of loss or damage caused by his abstraction of water.
(6) Nothing in this section prevents or affects a claim for negligence or breach of contract.
(7) This section does not apply, and no claim may be brought under this section, where the loss or damage is caused by an abstractor acting in pursuance of a licence under this Chapter and is loss or damage - (a) in respect of which a person is entitled to bring a claim under section 60 below (or would be so entitled if there were a breach of the duty referred to in that section); (b) in respect of which a person would have been entitled to bring a claim under section 60 below but for an express provision (including, for example, section 39(1A) above and section 59(C)(6) below) disapplying that duty; or (c) constituting grounds on which a person is entitled to apply to the Secretary of State under section 55 below (or would be so entitled but for sub-section (2) of that section) for the revocation or variation of that licence, but without prejudice to the application of section 48 above.”
19.	As I have already stated, the defendants accept that the construction of the Lakes has given rise to an abstraction of water within section 48A by reason of there being an outfall or overflow of water from the Lakes or any of them. However, it is submitted on behalf of the defendants that the claimants have failed to prove as a matter of fact that the abstraction has caused any material loss or damage. This issue of fact will largely turn on the assessment of the expert evidence. Secondly, the defendants submit that, under section 48A, the defendants can only be liable for loss or damage, caused by the abstraction, which could reasonably have been foreseen by them. It is argued that even if the statutory provision gives rise to strict liability, the proper interpretation of it is that the loss or damage in respect of which a claim may be made is limited to that which is reasonably foreseeable by the defendants. 
20.	The defendants place reliance by analogy on Cambridge Water Co. -v- Eastern Counties Leather PLC [1994] A.C. 264, where solvent from the defendants’ tannery seeped into the ground and was conveyed in percolating water to the plaintiffs’ domestic borehole 1.3 miles away, causing the water in the borehole to become unfit for human consumption. Whilst strict liability arose under the rule in Rylands -v- Fletcher, it was held that foreseeability of damage of the relevant type was a prerequisite of liability in damages under the rule (see pp. 305H to 306D). Because the plaintiffs could not establish the pollution of their water supply by the solvent was reasonably foreseeable, the action failed. 
21.	The claimants in the present case submit that section 48A was intended to replace any liability there could be in the existing common law where foreseeability may have been necessary and that the scope of the liability under the section is not expressed to be limited in any way by reference to foreseeability or otherwise. Thus it is said once the claimants prove any loss or damage was caused by the abstraction, the defendants are strictly liable for it. 
22.	Counsel have been unable to find any reported case which assists as to the interpretation of section 48A. Although sub-section (3) provides that a claim brought under section 48A shall be treated as one in tort for breach of statutory duty, it is clear in my judgment that the actual breach is not the abstraction of water but the causing of loss or damage by the abstraction. Clerk & Lindsell on Torts (21st Edition) at Paragraph 9-50 states:
“Non-compliance with a statutory duty cannot be actionable unless the injury was of the type which the statute was passed to prevent. If a statute requires something to be done with a view to avoiding one particular type of damage, then, if non-compliance with the statute results in another form of damage, no action will lie, on the basis that the damage which occurred was not within the statute. Each case turns upon the interpretation of the statute, and this factor makes it difficult to formulate any more precise principle. The harm may not be within the ambit of the statute either: (a) because the claimant does not come within the particular category of persons contemplated; or (b) because the type of damage was not that which the statute was intended to guard against.”
23.	In my judgment, the proper interpretation of section 48A is that foreseeability of the loss or damage in question is not required. The words in sub-section (1) are clear: “An abstractor shall not by that abstraction cause loss or damage to another person.” There is no limitation or qualification in relation to the loss or damage or its type. If Parliament had intended there to be any limitation or qualification to the loss or damage which could be claimed by reference to foreseeability or otherwise, then it could have been expressly provided for in the section. There is no reason in my judgment to override the clear words of the section and read into it a necessity for foreseeability of loss or damage on the part of the defendants. The abstraction of water may well cause loss or damage and so section 48A puts the risk on the abstractor: if his abstraction causes any loss or damage he takes the consequences and is strictly liable for all loss and damage caused whether he could have foreseen it or not. There are other statutory provisions which give rise to such strict liability - see e.g. the Animals Act 1971, which provides that the keeper of any animal belonging to a dangerous species is liable for “any damage” caused by that animal, subject to specific statutory defences.
24.	The second question of law to be considered at this stage relates to causation of loss and damage. The central issue in this case is whether the excavation of the Lakes and abstraction of water on the defendants’ land caused a reduction in water levels in the claimants’ Ponds and consequent loss and damage. As will be seen, it is put on behalf of the defendants that there were a number of potential causes of the reduction in water levels of the Ponds. It is submitted on behalf of the defendants that it is for the claimants to prove on the balance of probabilities that the defendants’ abstraction of water by the excavation of the Lakes was the effective cause of the claimants’ alleged loss or damage. It is said that if there are a number of causes of the reduction in the water levels in the claimants’ Ponds, the claimants only succeed if they prove that the defendants’ abstraction was the effective cause of the damage. The defendants argue that it is for the claimants to prove that other potential causes raised evidentially by the defendants did not cause the crucial water level reductions giving rise to loss or damage. Therefore, say the defendants, the proper approach to establishing causation in this case is the “but for” test. 
25.	The “but for” test is described as follows at Paragraph 2-09 of Clerk & Lindsell (ibid):
“The first step in establishing causation is to eliminate irrelevant causes, and this is the purpose of the “but for” test. The courts are concerned, not to identify all of the possible causes of a particular incident, but with the effective cause of the resulting damage in order to assign responsibility for that damage. The “but for” test asks: would the damage of which the claimant complains have occurred “but for” the negligence (or other wrongdoing) of the defendant? Or to put it more accurately, can the claimant adduce evidence to show that it is more likely than not, more than 50 per cent probable, that “but for” the defendant’s wrongdoing the relevant damage would not have occurred. In other words, if the damage would have occurred in any event the defendant’s conduct is not a “but for” cause … It is worth bearing in mind that the “but for” test functions as an exclusionary test, i.e. its purpose is to exclude from consideration irrelevant causes. The fact that the defendant’s conduct is found to be a cause applying the “but for” test, is not conclusive as to whether he should be held responsible in law since the function of the causal enquiry in law is to determine which causes have significance for the purpose of attributing legal responsibility. It is sometimes said that the law seeks the causa causans (effective factor) rather than the causa sine qua non (factor(s) without which damage could not have occurred).”
26.	The claimants submit that it is sufficient to establish causation if they prove that the excavation of the Lakes and water abstraction was a significant cause of or made a material contribution to the reduced water levels in the Ponds and therefore to the consequent loss and damage. So, if there were a number of causes or potential causes of the reduction in water levels, the claimants establish causation if the excavation of the Lakes made a material contribution, i.e. more than de minimis, to the reduction. That is a different approach to the “but for” test and does not involve the claimants having to prove that the excavation of the Lakes made a difference to the outcome in terms of the occurrence of the alleged loss or damage, or having to prove that the loss and damage would not have occurred if it were not for the excavation of the Lakes. 
27.	There are cases where it has been held that, in certain situations, the “but for” approach to causation is not appropriate. This has principally arisen in cases involving claims for industrial disease or in respect of clinical negligence. Thus, in Bonnington Castings -v- Wardlaw [1956] A.C. 613, it was held by the House of Lords that the “but for” test should not apply. The claimant in that case had contracted pneumoconiosis from inhaling air which contained silica dust at his workplace. The main source of dust was from pneumatic hammers for which the employers were not in breach of duty (the innocent dust). Some of the dust (the guilty dust) came from swing grinders for which they were responsible by failing to maintain the dust extraction equipment. There was no evidence as to the proportions of innocent dust and guilty dust inhaled by the claimant. On the evidence, the claimant could not prove “but for” causation, in the sense that it was more probable than not that, had the dust extraction equipment worked efficiently, he would not have contracted the disease. Nevertheless, the House of Lords drew an inference of fact that the guilty dust was a contributory cause, holding the employers liable for the full extent of the loss. The claimant did not have to prove that the guilty dust was the sole or even the most substantial cause if he could show, on the balance of probabilities, the burden of proof remaining with him, that the guilty dust had materially contributed to the disease. Anything which did not fall within the principle de minimis non curat lex would constitute a material contribution.
28.	A not dissimilar case was McGhee -v- National Coal Board [1973] 1 W.L.R.1, where the claimant was non-negligently exposed to brick dust by his employers but they were in breach of duty in failing to provide adequate washing facilities so he had to cycle home caked in brick dust. He contracted dermatitis by reason of exposure to brick dust. It was held that the cycling home caked in dust materially added to the risk of him developing dermatitis and so the defendants were liable because their negligence made a material contribution to the dermatitis. 
29.	Likewise, in Fairchild -v- Glenhaven Funeral Services Limited [2003] 1 A.C. 32, the “but for” causation test was not applied. In that case the claimant had contracted mesothelioma, having been employed by various employers who had all in breach of duty exposed him to asbestos fibres. The evidence established that one fibre actually caused mesothelioma as opposed to all contributing so to do. Even though as a fact only one of the defendant employers would have caused the injury, the claimant could not, because of the inadequacies of medical science, establish which. The House of Lords held that all of the employers who contributed to the risk of developing mesothelioma were liable. 
30.	In Bailey -v- The Ministry of Defence [2009] 1 W.L.R. 1052, the claimant was a patient in hospital who sustained brain damage when, in a weakened physical state and so unable to react, aspirated her own vomit and suffered cardiac arrest. Her damage would probably not have occurred if she was not in such a weakened state. There were two causes of her weakened state, pancreatitis (which was not attributable to the defendants’ negligence) and a period of negligent care for which the defendants were responsible. The claimant could not prove “but for” causation because it was not possible to say, on the evidence, that in the absence of the pancreatitis she would nonetheless have been so weakened by the defendants’ negligence that she would have been unable to respond naturally to her vomit and so to have avoided the cardiac arrest and resulting brain damage. It was argued on behalf of the claimant that the reason she aspirated was her extreme weakness which was caused or materially contributed to by the defendants’ negligence. The Court of Appeal held that there were two contributory causes of the claimant’s weakness, the non-negligent cause and the negligent cause, and since each contributed materially to the overall weakness which caused the aspiration, causation was established. It was said that Bonnington Castings -v- Wardlaw was authority for the proposition that, in a case involving cumulative causes, where the inadequacies of medical science mean that the relative potency of the causes cannot be established, the claimant merely has to establish that the defendants’ breach of duty made a material contribution which means something more than de minimis. The case of Wilsher -v- Essex AHA [1988] A.C. 1074, upon which the defendants relied, was distinguished. That was because Wilsher was a case which did not involve causes cumulatively causing injury but a case where there were distinct causes which operated in a different way and might have caused the injury, but the claimant could not establish which cause either caused or contributed to his injury. At Paragraph 46 in Bailey, Waller, L.J. stated:  
“I would summarise the position in relation to cumulative cause cases as follows. If the evidence demonstrates on the balance of probabilities that the injury would have occurred as a result of the non tortious cause or causes in any event, the claimant will have failed to establish that the tortious cause contributed. …. If the evidence demonstrates that “but for” the contribution of the tortious cause the injury would probably not have occurred, the claimant will (obviously) have discharged the burden. In a case where medical science cannot establish the probability that “but for” an act of negligence the injury would not have happened but can establish that the contribution of the negligent cause was more than negligible, the “but for” test is modified and the claimant will succeed.”
31.	A common feature of these cases where the “but for” test has not been applied appears to be that there was one agent or condition brought about by cumulative or consecutive causes, one of which involved fault on the part of the defendant, which resulted in the disease or injury in question. Even though, because of the inadequacies of medical science or scientific knowledge, it was inherently impossible for the claimant to prove exactly how his disease or injury was caused, the defendant was liable if the claimant proved that the defendant’s fault made a material contribution to it or that such an inference could properly be drawn. Such cases are to be distinguished from the situation in cases such as Wilsher where there were not cumulative causes of the injury but the claimant merely proved that his injury could have been caused by a number of different factors but could not prove which caused or contributed to his injury. 
32.	In the present case, the claimants are saying in effect that a similar approach should be adopted to the disease and clinical negligence cases referred to above, and that even if there were other causes of the reduction in water levels in the Ponds, provided it can be proved on the balance of probabilities that the excavation of the Lakes made a material contribution - more than de minimis - to the reduction in levels, the defendants are liable. 
33.	In my judgment the approach in the disease and clinical negligence cases of only having to establish a material contribution to the injury cannot properly be extended to a case such as the present, where the factual situation is very different. In my judgment the defendants are correct in submitting that the normal “but for” causation test should be applied. The essence of the claimants’ case is that a reduction of the water levels in the Ponds caused their alleged loss and damage. Thus, in my judgment, the claimants must prove on the balance of probabilities that, but for the excavation of the Lakes, their loss and damage would not have occurred. If, therefore, for example, other causes would have resulted in the lowering of the water levels such that the loss and damage occurred in any event, then the Lakes would have made no difference to the outcome and causation is not proved. On the other hand, if other potential causes would only have lowered the water levels to a limited or insignificant degree at most and the claimants prove on the balance of probabilities that the Lakes caused additional lowering of levels such that the loss and damage resulted, they will succeed on causation. In short, I hold that the claimants must prove that it is more likely than not that, but for the excavation of the Lakes, the crucial lowering in the water levels of the Ponds and any consequent loss and damage would not have occurred. 
34.	I now turn to consider the lay and expert evidence in this case, bearing very much in mind the conclusions I have reached on the two questions of law just considered. So far as lay witness evidence is concerned, I have read witness statements from the first claimant, both defendants and Mr. Kevin Greenwood and Mr. David Chadwick on behalf of the defendants. Each of those witnesses gave oral evidence before me and confirmed the contents of their witness statements. It should be noted that the witness statement from the first claimant was extremely lengthy and contained substantial passages setting out his opinions and beliefs about the matters in issue in this claim. Plainly he is not an expert witness and the defendants took exception to large sections of his witness statement which they identified for me. I make it clear that, insofar as the first claimant expressed opinions or beliefs in relation to matters which are more properly in the province of expert witnesses, I have ignored them. 
35.	The expert evidence in this case has consisted firstly of detailed reports and lengthy oral evidence from consultant hydrologists: Dr. Charles Wilson on behalf of the claimants and Mr. Jan Van Wonderen on behalf of the defendants. In relation to the damages claim, I have considered reports and heard evidence from fisheries management experts: Mr. Girdler on behalf of the claimants and Mr. Freeman and Mr. Leeks on behalf of the defendants. 
36.	Much of the relevant content of the witness statements from the first claimant and the defendants relates to the background to this matter which I have already summarised. I propose at this stage to consider such further evidence from the lay witnesses as relates to the issues of liability and causation. In his witness statement, the first claimant describes the purchase of the Fishery for £190,000 in December 2004. He produces the sales particulars which included a description of the Ponds. It gave the average depths of the Ponds which ranged between 4 feet and 5’6”. It stated that the Ponds were predominantly fed via spring water and that there was an artesian well which fed Pond A. The claimants were shown around the Fishery in August 2004 by Mr. Ford’s son. The first claimant noticed that the level of the water in the Ponds was slightly down (approximately 100 mm. in Pond C) but he was assured that this was nothing of concern and normal for the Fen in summer months. This was accepted to be due to seasonal variations in Fen water level. The first claimant was shown the artesian well in the north west corner of Pond A which is close to the boundary with the defendants’ land. The first claimant says at that time the well was producing a good water supply and he was informed that it had never stopped running and in part maintained water levels in the Fishery and he viewed water discharging through the interconnecting pipe between Ponds A and B. He was also shown other springs within the Ponds. He saw the flow passing through the Ponds and in particular through the interconnecting pipe between Ponds B and C. 
37.	Prior to the purchase, the claimants were also informed that some lakes had been dug on the defendants’ land. It was also explained that they had been excavated without any planning permission. The first claimant says there was no reason at all at the time of the purchase of the Fishery to believe that the Lakes had any impact on the water levels in the Fishery Ponds or that they would do so in the future. The first claimant says he also recalls that the Fen was saturated during their pre-purchase visits. The area between Ponds E and F was very boggy. 
38.	The first claimant states that at the time of his purchase there was no pipe feeding Pond A from Lake 1 and there were no indications to him that any such pipe had previously been in existence. At some subsequent stage after the purchase of the Fishery, the first claimant did see the end of a pipe leading from Lake 1 and terminating at a ditch which is near to Lake 1 and Pond A. 
39.	In his statement the first claimant explains how he first began to notice that water levels in the Ponds began to drop in June 2005, and that the situation deteriorated over the following years with water levels continuing to fall year on year. He produced graphs which showed from data collected by him the water levels in the various Ponds between 2007 and 2014. 
40.	During 2006, in response to the falling water discharge level from the artesian well at Pond A and the water levels in the Ponds, the claimant lowered the transfer pipes between his Ponds A, B and C/D. The first claimant says that the springs which are situated in the various Ponds have periodically ceased to operate since he purchased the Fishery. He asserts that when he bought the Fishery the water levels were at 36.445 metres above ordnance datum (AOD) in the Fen with the surplus surface water flows in the Ponds being as follows: Pond A overflowed through a pipe to Pond B which in turn flowed through a pipe to Pond C/D from where any surplus flows were discharged via a pipe into the River Tas. There was also surplus water flow provided to Pond B via a pipe from Pond F and from a trench via a pipe to Pond C. He has produced a further graph with the water levels of the Ponds, taken on a daily basis between October 2011 and September 2014. In his statement the first claimant details on a year by year basis the falls in water levels in the Ponds, particularly in the summer months. This does appear to show a trend of the water levels falling lower on a year to year basis. At times heavy rainfall did raise the water levels in the Ponds for a period of time. 
41.	The first claimant refers to the abstraction licence which was granted to the defendants in October 2012 by the Environment Agency, to which I have already referred. This authorised the defendants to transfer water from Lake 1 to Pond A or into a ditch leading to the River Tas. The first claimant states that he has no intention of accepting any flow of water from Lake 1 pursuant to that licence because of the risk of transfer of disease and parasites to his Ponds. He also considered that the transfer of water from Lake 1 would not compensate for the overall losses of water level in his Ponds. 
42.	In his oral evidence the first claimant described how he measured the depths of the water in the Ponds. He confirmed that the position of the springs in his Ponds were as shown on a map which was exhibited to his statement. He said that when the springs are flowing the bubbles in the water from them can be seen. He agreed that he has no data as to volumes of water produced by those springs. He accepted that his monitoring of Pond A as opposed to other Ponds may only have started in 2011. He confirmed that he had also kept records of rainfall for which charts were produced. He said that the water levels of 36.445 metres AOD referred to in his statement had been established from data from gauge boarding in Pond D. He said that is the level when there is a discharge from Pond D to the river. He also said that level is about halfway up the discharge pipe in Pond A. 
43.	The first claimant was questioned about recharge tests carried out by him whereby water was pumped from the river into Pond C, but he said it was impossible to get up to the discharge point from Pond C. 
44.	During his cross-examination, the first claimant agreed that up until 2006 he had taken water from the river. He said that the Environment Agency said that he could only take 20 m³ per day. The first claimant considered that a de minimis level which would have no effect on the water level in Pond A. In relation to him refusing to accept water piped from Lake 1 to Pond A, the first claimant said that that would have affected his potential claim under the Water Resources Act and also because he was concerned as to whether the supply would continue in the future. In connection with the point he made about the Water Resources Act, he said it was not compensation that he wanted but restoration to 36.455 AOD of his water levels. 
45.	In my judgment the first claimant was a careful witness and I see no reason not to accept his evidence about these factual matters and the accuracy of his data. 
46.	In his witness statement the first defendant confirmed the history of his purchase of the land in the Fen and the excavation of the Lakes. He gave some details about his business interests including commercial property investment. The development of the Lakes was not intended to be a business venture. 
47.	The first defendant referred to the time when Mr. Robin Ford was involved in the running of the Angling Club at the Fishery, and his subsequent purchase of the Fishery. The first defendant said that sometimes he and his son would fish at the Ponds, the level of which was always up and down and never more than about two or three feet deep. He said that after Mr. Ford had purchased the Fishery in 1992, he bought three or four tons of Siltex to put in the Ponds to disperse the leaf matter and other vegetation at the bottom of them. The first defendant said he knew Mr. Ford very well and they used to drink together four or five nights a week. Despite this, he asserted that he had no knowledge of the planning application which Mr. Ford had made in 1989 in respect of excavating three lakes on what is now the defendants’ land, and that he did not know that such planning application had been refused. He said that when he purchased the land in the Fen in 1995, he did not recall the reference to Mr. Ford’s planning application in the local land charges search.
48.	He said that when the defendants’ land on the Fen was purchased it was always very wet and boggy. There was an occasion when a digger became stuck and also another occasion when a deer became stuck in the Fen where Lake 1 now is. He described how he began to clear land and excavate the Lakes. He said that Mr. Ford never made any complaint to him about them.
49.	In 1996 the defendants became involved in a countryside stewardship scheme run by the Ministry for Agriculture Fisheries and Food. A management programme was set down for their land in the Fen, including digging out and restoring the existing ditches. The first defendant says that he did not fully understand the implications of joining this scheme and as he did not require funding from MAFF the defendants subsequently withdrew from it. However, MAFF appeared content with the work which the defendants were doing on their land in the Fen. The first defendant claims that because of this he did not realise that he would need any planning permission for the widening and extension of ditches and dykes and the subsequent excavation of the Lakes. Of course, he did become aware that planning permission was required once SNDC brought it to his attention after the Lakes had been excavated. 
50.	The first defendant gives details of the excavation of the individual Lakes and the dates when he thinks that occurred. He says that when Lake 1 was dug out in about 2001, there was a spring in the land in that area and water bubbled up out of it and filled the Lake. He says Mr. Ford was well aware of all the work being carried out. He says that in a very dry spell in 2001 Mr. Ford came to see him and said he had problems and wanted to pump water from Lake 1 into Pond A. The first defendant said he saw the fish in Pond A were all on top of the water gasping for air. He therefore agreed that a pipe should be installed between Lake 1 and Pond A so that the water from the Lake and the spring in it would feed into the Pond. He said Mr. Ford bought the pipework and installed the pipe. He thought this pipe was removed by Mr. Ford at about the time when he put the Fishery on the market in 2004. The first defendant at that time offered £70,000 for the Fishery, although it was being marketed at around £200,000. In making that offer the first defendant informed the agent that he was supplying water to the Ponds from his Lakes and that the water level would drop considerably if that supply was cut off. Apparently the response from Mr. Ford was that the Fishery was not dependent on the water supply from Lake 1. The first defendant said he made his offer of £70,000 because he considered that £50,000-£60,000 would be required to dredge the Ponds. 
51.	The first defendant confirmed that, although he stocked the Lakes with fish, it was never intended as a commercial venture, but he did eventually run it as a members club with day tickets available, but, as I have already mentioned, the profits appear to have been very modest indeed.
52.	The first defendant gave his account of how, once it was clear to him that planning permission was required for his Lakes, he made the application for a certificate of lawful use. The first defendant admits in his witness statement that in making that application he wrongly stated that the Lakes had been in place since 1995. He said he very much regrets making those false representations but says that he had suffered a heart attack in 2006 and was still recovering and “really just wanted everything sorted out”. Having withdrawn that application, he then made the applications for retrospective planning permission for the Lakes. He then confirmed the subsequent history of the matter to which I have already referred.
53.	He said that following the judicial review proceedings, the first claimant had asked for the pipe from Lake 1 to Pond A to be reinstated on a temporary basis. The first defendant said this was not possible at that time because he did not have a water abstraction licence which was required. Although subsequently he was granted such licence, the first claimant has never agreed to take any supply of water from Lake 1. 
54.	The first defendant made reference to land to the north of the claimants’ land from 2001 being changed from arable use to growing willow trees for biomass fuel production. Apparently this was approximately 30 acres of land. The first defendant further refers to a flooding diversion scheme from nearby Hargate. 
55.	When he was cross-examined, the first defendant accepted that there were supporting letters for the application for the certificate of lawful use, including one from his wife, the second defendant, falsely stating that the Lakes had been excavated in 1994/5. His agent’s letter to SNDC had said that the authors of these letters would be prepared to confirm them on oath. The first defendant agreed that this was stated on his instructions. Although at one stage the first defendant appeared to be saying in the witness box that he had not done this deliberately, he did soon concede that he had been prepared to be deliberately misleading and was sorry about that. 
56.	He conceded that he knew that the Fen was a wetland environment which would be sensitive to changes. After some prevarication the first defendant conceded that he did have a relatively good knowledge in relation to planning permission because of his commercial property business. However, he maintained that he never knew at the time of excavating his Lakes that planning permission was required for that. He agreed that he had never approached the planning authority for informal advice about his proposals. He continued to maintain that he never knew of the 1989 planning permission application by Mr. Ford or its refusal. He said wrongly that he had only first heard about that a few days before, when plainly he had in fact referred to it in his witness statement in November 2014. Again, the first defendant maintained that he could not recall his solicitor bringing it to his attention when he purchased the land on the Fen in 1995. 
57.	The first defendant maintained that there had been no question of the defendants or their consultants deliberately delaying in connection with dealing with the enforcement notice. He accepted that the defendants would comply with whatever they are now required to do by SNDC. 
58.	The second defendant made witness statements dated 14th August and 16th November, 2015. Her first statement dealt with the earlier history of the matter so far as she was concerned, and the second statement with the defendants’ dealing with the enforcement notice and the various proposals by their consultants and SNDC’s consultants. She said that until more recently she had played little part in decisions about the Lakes. She did give her husband some assistance with secretarial matters regarding his businesses. She had little recollection of their purchase of the land in the Fen in 1995. She accepted that she had signed the conveyance but had no recollection of doing so. She said that the land was somewhere to go for walks with their dogs or for picnics. There was no intention to set up a business there. She gave no thought at all, she stated, to the question of whether planning permission was needed for the excavation of the Lakes. When some fees began to be paid for the use of the Lakes by anglers, she kept the accounts relating to that. She has only become more involved in connection with the Lakes following the judicial review proceedings. 
59.	When she was cross-examined, the second defendant accepted that her letter in support of the application for a certificate of lawful use in 2007 was deliberately untrue to deceive the council. She agreed that she had collated some invoices relating to the use of diggers which falsely purported to show the Lakes had been dug in 1994/5. She knew the Fen was a country wildlife site but claims she had no knowledge of the implications of that. Overall she was rather vague in her recollections about the retrospective planning applications for the Lakes. She accepted that, by the time of the judicial review proceedings, she was aware that the Lakes may be having an adverse impact on the Fishery. 
60.	Throughout her evidence she firmly maintained that she was not aware of the 1989 planning application by Mr. Ford and its refusal. She said she never saw reference to that in any of the conveyancing documents when their land in the Fen was purchased. She said it never occurred to her that the Lakes might need planning permission and she never questioned what her husband was doing. She agreed that she knew that their land was boggy when they acquired it. She said at the time when the Lakes were excavated she gave no thought to any possible effect of them, although she said that in hindsight she should have known more. 
61.	On behalf of the defendants, Mr. David Chadwick and Mr. Kevin Greenwood were called to give evidence of their knowledge of the history of the relevant land in the Fen. In his witness statement, Mr. Chadwick said that he is an angler and had always been closely involved with the Fen Angling Club at the Fishery. He knew Mr. Ford very well and they were involved together in the club. He said that after Mr. Ford bought the Fishery some extension work was carried out on the Ponds. He and a Mr. Newitt carried out regular maintenance work at the Ponds for Mr. Ford. He said after the work on the Ponds to extend them, they started to experience problems with the water levels. Because of this they had a pump positioned during the summer to pump water from the river to the Ponds. The pump would be run for three or four hours a day three or four days a week in the summer. In addition to pumping water from the river, a hole was dug out near the Ponds and water would be pumped from that. He said that without the pumping the water levels of the Ponds would not have stayed high enough during summer. 
62.	Mr. Chadwick became aware of the defendant’ excavation of the Lakes. He was involved in the installation of the pipe between Lake 1 and Pond A. He said that avoided them having to run the pump to the same extent in the summer. Mr. Chadwick says that he was instructed to remove the pipe from Lake 1 to Pond A at the time when Mr. Ford put the Fishery on the market. 
63.	In cross-examination Mr. Chadwick said he knew about Mr. Ford’s proposal in about 1989 to build three new lakes, but he was unaware that a planning application was made in relation to that or that it was refused. The angling club committee was simply told by Mr. Ford that it was not going to happen. Mr. Chadwick accepted that he had never made any measurements of the water levels in the Ponds. 
64.	Mr. Greenwood, who is now in his late fifties and is a farmer, stated in his witness statement that he had lived in the area of the Fen all of his life. He remembered when Mr. Rush began digging out the Ponds at the Fishery, he thought in the late 1960’s. As a teenager Mr. Greenwood used to swim in Pond A and at its deepest point the water would have come up to about his waist. He was aware of the artesian well in Pond A and that cold water from it used to bubble up. He remembered Ponds C and D being dug and the spring being between them. He said that those Ponds were never very deep and only wellington boot depth for about six years after they were built. He said that after Mr. Ford purchased the Fishery, he put in the network of pipes taking water from Pond A to the other Ponds. He said that the water levels in the Ponds have always been variable. He thought that the weather had been much drier in the last 8-10 years than it used to be. 
65.	Mr. Greenwood had witnessed the excavation of the Lakes and that the area around the dyke on the defendants’ land was always really wet and that when Lake 3 was started a digger sank out of sight. 
66.	In cross-examination Mr. Greenwood said he knew about Mr. Ford’s planning application for the three lakes in 1989 because his mother was on the parish council. 
67.	He said in relation to his statement that the level in the Ponds had always been variable that that was based on what he had seen, and that his view about the drier weather over the last 8-10 years was based on his observations as a farmer. 
68.	I now turn to consider the expert evidence of the hydrologists in this case, bearing in mind the conclusions which I have reached in relation to the interpretation of section 48A of the Water Resources Act 1991, and as to the issue of causation.  Dr. Wilson on behalf of the claimants and Mr. Van Wonderen on behalf of the defendants are each highly qualified and experienced hydrologists with impressive knowledge. The hydrology evidence is central to the issues in this case and particularly that of causation. The hydrology evidence in the form of the reports from Dr. Wilson and Mr. Van Wonderen and their oral evidence is complex, detailed and covers a number of technical matters. I do not propose to recite every detail of their evidence but I bear all of it in mind and also the extremely helpful and detailed written submissions made by Counsel regarding this expert evidence. However, it will be necessary to consider a number of aspects of the findings and opinions of these two experts.
69.	In his report dated 18th December, 2014, Dr. Wilson discusses the topography and hydrology in relation to the Fen. He says that the Fen is located in the headwaters of the River Tas where three topographical tributary valleys from the north, west and south coalesce to form the main valley of the river. He said that there are extensive peat deposits in the valley bottom which indicate the likelihood of persistent saturated or seasonally saturated soil conditions. He claimed that the hydrological effect of the coalescing of the three valleys would be to channel surface water and near surface water run-off (which he described as interflow) towards the River Tas and through the Fen. He said historically this could be expected to have led to the build up of persistent saturated ground conditions in the vicinity of the Fen. He said that interflow occurs where low permeability horizons occurred in the soil profile which intercept the vertical movement of unsaturated flow through the soil and produce saturated conditions which allows lateral flow to occur down the valley side slopes into the valley bottom, where it saturates the whole soil profile so that the water rises to the surface as return flow and moves down valley as topographically controlled surface water flow. He sought to illustrate this in Figures which he prepared. He said that the combination of surface water run-off and interflow run-off from the hillside and surface water run-off inputs coming from the rest of the catchment area upstream would produce saturated or near saturated conditions across the floor of the Tas valley. During the investigations by the consultants on behalf of the defendants and SNDC regarding the enforcement notice, five shallow three metre boreholes WS1 to WS5 had been sunk in various positions in the vicinity of Lake 1 and Pond A. The logs from these boreholes showed the various layers of material below the surface to a depth of three metres. Dr. Wilson referred to shallow permeable soil layers shown in boreholes WS3 and 5. He said that near surface water run-off or interflow would flow through these soil layers towards the local hydraulic sink, normally the River Tas. However, he said that the claimants’ Ponds are located at a narrowing of the Tas valley between two flat basins. He asserted that this physical restriction would result in an increase in the velocity of water movement or a rise in water elevation in the saturated soil layer and the creation of valley bottom springs and waterlogging. He said this would also prolong the duration of near surface saturated conditions in the vicinity of the Lakes and Ponds. 
70.	Dr. Wilson next considered in his report the suggestion that the Lakes and Ponds and particularly Lake 1 and Pond A were being fed directly or indirectly from vertical flow upwards from the deep chalk aquifer through the strata above it. That this was the case was one of the main opinions of Mr. Van Wonderen and is a central issue between the two experts. Dr. Wilson thought that a vertical flow from a chalk aquifer was not an unreasonable assumption for the Tas valley as a whole some 5 kilometres downstream where the river has cut through the chalky boulder clay (Lowestoft till) and the historic buried channel (which runs west to east through the Fen) is filled with permeable deposits of sand and gravel. However, he said that there had been a lack of hard evidence to support the proposition of such vertical flow from the chalk aquifer in the Fen itself. The WS boreholes did not give any indication of the depth at which the Chalk was situated or the thickness or sequence of superficial deposits above it. However, Dr. Wilson said boreholes at Bunwell about 1.8 km downstream of the Fen showed substantial thicknesses of boulder clay and other deposits above the chalk which was situated in the buried channel between 19 and 28 metres below ground level. He thought that from this it could be reasonably assumed that the top of the chalk at the Fen was likely to be below 20 metres ordnance datum, which would indicate a thickness of superficial deposits of at least 16 metres in the Fen. Because there were likely to be several low permeability layers interdigitated with higher permeability layers, this would result in one or possibly two or three perched aquifers being present in the superficial deposits underlying the Fen. He also said that test pumping which had been carried out at the Bunwell boreholes from the chalk aquifer indicated little or no hydraulic continuity between the shallow water features and the chalk aquifer at that location. 
71.	Dr. Wilson also relied upon the findings there had been at three boreholes drilled as part of the Tas Valley scheme about 600 metres upstream of the Lakes. These also showed that the chalk aquifer was strongly confined by the boulder clay and other deposits above it. 
72.	From the evidence of the Bunwell and Tas Valley boreholes, Dr. Wilson had concluded, in the absence of deep borehole information in the Fen, that it was more reasonable to expect the superficial deposits in the Fen to be more like 20 metres thick and for the chalk aquifer to be strongly confined. He says that this deduction was tested when the first claimant, in the summer of 2013, had a chalk borehole drilled next to Pond B. This showed that the depth of the buried channel in the Fen was much deeper than anticipated and that the chalk layer began at a depth of 25 metres. Dr. Wilson says that the water level in the chalk borehole rose rapidly after it penetrated into the hard chalk and the water level rose to elevations above ground level. He says that this showed that similar to the position at Bunwell, the chalk aquifer was well confined and the deposits above it acted as an effective cap on the vertical movement of water from it. 
73.	Dr. Wilson referred to the argument put forward by Mr. Van Wonderen and others, that because there was a direct hydraulic connection between the chalk aquifer and Pond A, the decline in water levels in the Ponds since 2006 is mainly a reflection of a decline in regional chalk aquifer groundwater levels. Dr. Wilson was critical of the use of a record of the monitoring of chalk groundwater levels at a borehole at New Buckenham (3 to 4 kilometres away from the Fen) because it was in a different groundwater catchment area and subject to different hydraulic controls from those that apply in the upper Tas catchment area within which the Fen is situated. He was also critical of the validity of comparing flow from the artesian well at Pond A with the water levels from the borehole at New Buckenham to support the argument that the Lakes and Ponds are receiving vertical flows of water from the chalk aquifer. He said this approach was dubious because it relied on a careful choice of scales or axes in order to give the best apparent fit between the two data sets and that in any event the correspondence between the artesian well flow and New Buckenham water levels and both deep and shallow water tables was mainly rainfall recharge. 
74.	Dr. Wilson referred to monitoring data from Harrison Environmental Consultants between 2011 and 2014 at various points, including boreholes WS1 and WS3. There were some errors and anomalies in the data but by reference to his Figure 13, having made appropriate corrections, Dr. Wilson said that, looking at the response of the data logger of water levels to daily rainfall amounts in relation to boreholes WS1 and WS3 show an example of a classic surface water run-off and interflow response to rainfall at the Fen. He said that the response of water levels in the boreholes to rainfall also gives an indication of the nature of the water bearing deposits at those points. In Dr. Wilson’s Figure 14, he says it is clear that WS5 exhibits a daily rise and fall in water levels which begins in spring and continues becoming more pronounced through summer until October, and that this is the effect of diurnal evaporation and such diurnal changes are absent from the chalk borehole water levels. He also argued that there is a virtually constant difference in elevation both in winter and summer between water levels measured in the chalk borehole and water levels in borehole WS5. He said this suggests that vertical flow of chalk groundwater into Lake 1 and/or Pond A is unlikely. 
75.	In further support of his contention that at the chalk borehole near Pond B the chalk aquifer is strongly confined by the superficial deposits, he relies upon a comparison between barometric pressure changes and short term changes in the chalk borehole groundwater elevations.
76.	The point was made by Dr. Wilson that Meteorological Office data regarding rainfall showed overall greater than average or average effective rainfall between 2000 and 2010. He said the conclusion that might be drawn from this is that, during the period of the construction of the Lakes, effective rainfall was above average and by inference the construction of the Lakes was the explanation for the drop in the level of the Ponds. 
77.	Next, Dr. Wilson dealt with what has been referred to in the case as the Lake 1 test. This occurred between September and October 2011 and in November 2011, when the level of Lake 1 was deliberately lowered and then raised and then lowered again. This was intended to determine any hydraulic connection between Lake 1 and Pond A. There was a rapid response by way of a change of flow in the artesian well feeding Pond A. Dr. Wilson accepted that, if there was a hydraulic connection with Pond A, one would have expected a similar change in water levels in Pond A to be produced but this did not occur. He put this down to the fact that Pond A was shallower and probably sedimented and therefore partly sealed. 
78.	Various overall conclusions were set out by Dr. Wilson in his report. In his opinion, a strong argument could be made in favour of the proposition that the Lakes had altered the local hydrology of the Fen so that they became a significant cause of loss of water from the perched water table. He thought that the water level measurements taken by the first claimant indicated that the Ponds are finely balanced regarding obtaining a sustainable water supply to maintain water levels and that they are likely to be reliant on shallow water bodies and rainfall run-off to maintain the levels. He said there was no doubt that the creation of the Lakes will have diverted some natural water flow away from the Ponds with the possible exception of Lake 4. Again, he said this was due to the interception of surface water run-off and shallow interflow moving generally down valley and the reduction in head in perched aquifers. He said that if the main water inflow to the Ponds came from surface water run-off, interflow run-off or flow from a shallow perched aquifer rather than vertical flow upwards from the chalk aquifer, the impact of the Lakes on the Ponds would be expected to be significant. If the inflow to the Ponds did come from vertical leakage from the chalk aquifer then the potential impact would still occur if the Lakes had better and wider hydraulic contact with the upwelling chalk groundwater. Dr. Wilson accepted that it is often difficult to be categorical about the source of water entering shallow excavations such as the Ponds, but considered on the information available a surface water or shallow soil origin seems more likely as the source of water for the Ponds. He considered that it was easily foreseeable by a drainage engineer, hydrologist or hydrogeologist or a farmer familiar with the maintenance of drainage ditches that the excavation of the Lakes was likely to affect the Ponds to some degree. He said that if he had been asked by the first defendant for advice prior to the excavation of the Lakes, he would have advised him to discuss the project with the first claimant and to enter discussions with the Environment Agency. 
79.	He repeated again that he considered the excavation of the Lakes would have intercepted shallow lateral water flows from the south (Lakes 2 and 3) and west (Lake 1 and possibly also Lakes 2 and 3) which would otherwise have gone to Pond B. Dr. Wilson said in his view it was not possible to give a definitive judgment on the specific impact of individual Lakes on the Ponds. He pointed out that there are no baseline water level or flow data available for the time before the excavation of the Lakes began. He also considered that the modelling undertaken by the various consultants had been too narrowly focused on the immediate vicinity of the Lakes. Significantly, Dr. Wilson’s final conclusion was that the construction of the Lakes will have affected in an adverse way the Ponds and particularly Ponds A and B. However, he said, given the question regarding datums, locations measured and elevations in regard to water level monitoring undertaken at the Fen, and the limited focus and duration of the monitoring that has been undertaken particularly on the defendants’ land, “it is still not possible in my view to be categorical with regard to the precise impact on” the Ponds or the exact processes involved.
80.	In his oral evidence in chief, Dr. Wilson expanded upon and explained a number of the findings and views expressed in his report. He said in relation to the confinement of the chalk aquifer in the Fen that, if there is a thin layer of boulder clay above the chalk, the chance of seepage upwards is greater but if it is a thicker layer of boulder clay there is less chance of seepage upwards. He emphasised that the barometric pressure tests carried out in relation to the chalk borehole by Pond B showed that the chalk was quite strongly confined. He made the point that, in his view, only a small proportion of rainfall penetrates through to the chalk and so there would be a great deal of water flow laterally in the superficial deposits. He said that in relation to the hydrology of the Fen, an overall catchment area of 16 km2 should be considered. I will refer in due course to matters put to Dr. Wilson in cross-examination, after I have referred to the report and evidence in chief of Mr. Van Wonderen. 
81.	At the beginning of his report dated 12th December, 2014, Mr. Van Wonderen helpfully describes some basic hydrological and hydrogeological concepts. He explains that the rate of groundwater flow is a linear function of the groundwater gradient (groundwater level difference between two points divided by the distance between those two points), and the water transmitting property of the aquifer (the transmissivity). This function is referred to as Darcy’s law. Put more simply, it is a function of the slope of the groundwater level and the porous or fissured nature of the aquifer. He said that it is important to understand the water movement in the Tas valley in places where the groundwater is close to the ground surface. The shallow groundwater table condition results in the marshy conditions typical of fen areas. If the groundwater table is close to the ground surface, there is potential for upward capillary flow from the groundwater table to the surface. He explained the geology in the Fen in similar terms to Dr. Wilson and in particular referred to the chalk aquifer being overlain by a variety of glacial and recent deposits which are influenced by a west to east buried valley. He referred to the fact that buried valleys are characterised by heterogeneity at local scale through the complex deposition of materials in a riverine environment due to which there may be preferential paths that allow the groundwater to move rapidly both laterally and vertically. He says that the nature of these preferential flow paths is such that they cannot be considered as defined channels. By pathways he means areas of porous mineral or soil through which water is able to flow with ease. 
82.	He notes that the British Geological Survey map for the area indicates that at the location of Pond A, the top of the chalk is some 12 metres below ground surface. However, the chalk borehole drilled for the first claimant in 2013, showing that the top of the chalk is some 26 metres below ground surface, implies that the deep part of the buried valley extends further east than indicated on the BGS map. 
83.	Mr. Van Wonderen refers to the land use on the hill slopes adjacent to the Fen as being predominantly arable. He noted that, in the area to the north of the Ponds, in the previous ten years there had been a change from arable use to biofuel cropping using willow trees in an area of about 12 hectares. He said this can have an impact on ground water flow. He also said that drainage for arable farming can have a similar effect. He referred to the effect of transpiration whereby water is extracted from the root zone by crops and natural vegetation and the evaporation of water from the soil surface. The combination of these two effects is referred to as evapotranspiration. He observed that, on the basis of Meteorological Office data for the Fen area, the difference between rainfall and evapotranspiration can be significantly negative. 
84.	Mr. Van Wonderen’s view of the hydrological features of the Fen was that minor streams are fed from groundwater that emerges at the western limit of the Fen where the flat fen meets the upland areas. These streams (referred to also as dykes) naturally flowed to the river: they now flow into Lakes 2 and 3 and from there overflow into the river. He considered that outflow from Lake 1 is also to the river. He considered the catchment area for the Fen was some 1.5 km2. He described the various subsurface layers of sands and gravels and Lowestoft till above the chalk. He accepted that the upper layer would allow for lateral transfer of groundwater but it would be in small amounts due to the limited thickness of the permeable sand and gravel layers. He referred to an Environment Agency modelling study which included the Fen area, showing that groundwater flow is maintained by recharge to the chalk through the overlying drift deposits. He said that groundwater modelling has indicated that this amounts to some 50-70 mm./year on average. It is constrained by the ability of the Lowestoft till to transmit water downward to the underlying chalk aquifer. He said that for the catchment area in question, the total average recharge would range from some 160-250 m3 per day, so that given the convergence of groundwater flow in the chalk aquifer towards the Fen an equivalent discharge from the chalk to the surface environment has to take place. He said that groundwater discharge from the chalk is through upward flow through the drift deposits that overlie the chalk. He said that the artesian conditions in the Fen demonstrate that this upward movement is possible. This upward flow he said will occur in areas where the Lowestoft till is extensive and contiguous and that more localised concentration of outflow occurs where permeable pathways from the chalk to the surface exist, such as at Lake 1 and the artesian well at Pond A. He says that these outflows would have occurred before the construction of the Lakes and the Ponds. 
85.	Mr. Van Wonderen said that the upward flow from the chalk aquifer ensures the permanent wet conditions in the Fen which would have been prevalent prior to the construction of the Ponds and Lakes. 
86.	So far as surface water run-off is concerned, he said that this may occur when rainfall is intense but that such run-off would generally be captured by ditches and dykes and find a direct route to the River Tas. He disagreed with Dr. Wilson that there was significant lateral groundwater flow through the superficial deposits from a west to east direction. Lateral inflow from the hill slope areas to the north he thought was likely to be more significant. 
87.	He said that there are two significant points of groundwater discharge in the Fen, the first being the artesian well in Pond A and the second the outflow from Lake 1. He considered that the outflow from the artesian well originates mainly from the chalk aquifer and possibly to a much lesser extent from the superficial deposits. The discharge from the well over the period 2007 to 2014 ranged from 2.5 to 39 m3 per day. The outflow from Lake 1 was monitored as being between 70 and 120 m3 per day during 2011 and 2012. The water inflowing to Lake 1 he asserted originated from groundwater and that in his view it is beyond doubt that most of this inflow originates from the chalk aquifer through a preferential path through the deposits that overlie the aquifer. He said that before the construction of Lake 1, water emerged where the north east corner of that Lake is now. This emerging groundwater would flow overland towards the River Tas and was the cause of the very wet and marshy conditions in that area. 
88.	Mr. Van Wonderen described the Ponds and how the overflow between them would occur. He noted that the Ponds all showed a seasonal variation in water level, with lowest levels during the summer and highest during the winter. He also observed that the water level in the River Tas is significantly lower than the adjacent Ponds which represents a potential driving force for seepage loss from the Ponds to the river. He also observed the evidence of Mr. Greenwood and Mr. Chadwick about the historic Pond levels. 
89.	The construction and nature of the defendants’ Lakes were described and it was noted that, since the excavation of Lake 1, water has continuously discharged from it in significant quantities and that when Mr. Ford owned the Fishery this surplus water was discharged by pipe into Pond A which negated the need for pumping of river water into the Pond during dry summer periods. Since the claimants’ ownership of the Fishery, the surplus water from Lake 1 has been conveyed to the River Tas. 
90.	In his Figure 6, Mr. Van Wonderen indicated his views as to the groundwater flow directions which occurred prior to the construction of the Lakes. He considered that the inflow to the Ponds area is mainly from the north. He said there would not have been a groundwater inflow from the area where Lake 1 is now located towards the Ponds because the gradient was uphill in that direction. So far as the area where Lakes 2 and 3 are now located, previously surface water there would have been carried by the dykes and ditches directly to the river and had no influence on the water levels in the Ponds. His overall view therefore was that the evidence is clear that there are no surface water links between the defendants’ land and the Fishery that could have a bearing on the Ponds. He also considered that the evidence is clear that the groundwater flow in the superficial deposits was such that no connection of any significance between the two properties would have been possible. He said it is evident that the groundwater in the chalk aquifer emerges on both the defendants’ and the claimants’ land through both diffuse upward flow through the drift deposits that overlie the chalk and through more localised flow paths. 
91.	Mr. Van Wonderen then set out what he considers were a number of possible causes of the variation in level in the Ponds, which included climate variability, water levels in the River Tas and seepage from the Ponds to the river, the land use change by way of the growing of willow trees in the area to the north of the Ponds, drainage diversions to limit the flooding risk along Fen Road and the impact of the Lakes. By reference to rainfall data and the dry winters of 2010 to 2012, Mr. Van Wonderen was of the opinion that there is no doubt about the influence of climatic variation on both groundwater discharge from the artesian well at Pond A and groundwater inflow from the superficial deposits to the north and therefore on surface water levels in the Ponds. 
92.	Secondly, he considered that seepage losses from the Ponds to the River Tas would be significant and increase rapidly with rising Pond levels. Thirdly, the area of about 12 hectares to the north of the Fishery where willow trees were grown from about 2005 would have resulted in reduced groundwater levels, as willow trees consume greater amounts of water than arable crops. This would give rise to a reduction in groundwater flow from the north towards the Ponds. Therefore he thought this potential land use changed could not be ignored. 
93.	Next, he referred to flood diversion works which had been carried out at Hargate some 0.5 km to the north west of the Fen. These works included diversion of surface water that would normally flow in the ditch along Fen Road. Again, he said the impact of this flood diversion could not be ignored as having a potential impact on the wellbeing of the Ponds and the Fen in general. 
94.	In considering the impact of Lake 1 on the Ponds, he referred to the outflow rate which had been measured from 70 - 120 m3 per day. Again, he maintained that the majority of the groundwater entering Lake 1 is from the underlying chalk flowing through a permeable yet undefined flow channel. He said that if this flow originated mainly from the superficial aquifer, such aquifer would have to exhibit extraordinary hydraulic properties. The outflow from Lake 1 will be a function of the groundwater level in the underlying chalk, the level in the Lake and the hydraulic conductance of drift deposits underlying the Lake. For a controlled and fixed Lake level the outflow will be directly proportional to the groundwater level in the chalk. Thus flows would be at a minimum during summer periods and would show longer term decline during extended drought periods. Again, he referred to the controlled Lake 1 test which showed a rapid impact on the outflow from the artesian well. 
95.	He also referred to the comparison which could be made between the chalk groundwater levels from the chalk borehole on the claimants’ land and outflows from the artesian well. He said a remarkable correlation is evident and to him it proved beyond doubt that outflow from the artesian well mainly originates from upward flow from the chalk aquifer. Using the correlation between the chalk groundwater levels in the chalk borehole and outflow from the artesian well allowed for backdating of chalk groundwater levels at the chalk borehole location. It thus allowed those levels to be related to the impact of change in Lake 1 water levels on outflow from the artesian well. The analysis, which was shown in Appendix 4 to Mr. Van Wonderen’s report, he says indicates that lowering or raising the water level in Lake 1 results in a quantifiable change in outflow from the artesian well. He said that the significance of this impact can be determined to a reasonable degree of accuracy. He therefore calculated that, by reason of Lake 1, the reduction in outflow from the artesian well would have been some 3.4 to 6 m3 per day. However, he said that during 2011 and 2012, when the water level in Lake 1 was at its lowest, the reduction in outflow from the artesian well could have been as high as 13 m3 per day. Thus a high Lake 1 level will minimise the impact on the artesian well. 
96.	He accepted that this impact on the artesian well outflow has a direct impact on the water level in Pond A. The lowering of the water level in Pond A would reduce the time during wet periods when the water level in Pond A reaches the overflow level and thus the flow of water from Pond A into Pond B and from there into Ponds C and D. In his opinion, the water level in Pond A would not have risen to the level required for overflow into Pond B during the 2010/11 and 2011/12 drought winters even without the impact of Lake 1 on outflow from the artesian well. 
97.	As far as Lakes 2 and 3 are concerned, Mr. Van Wonderen said they received most of their inflow from minor water courses that enter those two interconnected Lakes from the west. Outflow from the Lakes is directly to the River Tas. Because there is a groundwater gradient in the superficial aquifer towards the south from the area around Lake 1 to Lake 2, this causes groundwater flow in the same direction. Because the groundwater table is shallow and has not significantly changed from pre-Lake conditions, and because groundwater does not move up gradient, he concluded that Lakes 2 and 3 do not influence the water situation in the Ponds. In relation to Lake 4, he said it has no surface water inflow and outflow and the water table in Lake 4 is a direct extension of the groundwater table in the surrounding superficial deposits. The water level monitoring data he said clearly indicates that the River Tas forms a groundwater divide and therefore separates the shallow groundwater systems on the two banks of the River Tas so that it is physically impossible for Lake 4 to have any influence on the Ponds. Thus his overall opinion was that the evidence is clear that Lakes 2 to 4 do not impact on the wellbeing of any of the Ponds. 
98.	Mr. Van Wonderen then summarised the foregoing views in the conclusions section of his report. Again, he said that “Pond A receives without doubt groundwater from the chalk aquifer in the form of outflow from the artesian well.” Thus he said the outflow is strongly influenced by variation in the chalk groundwater levels which were low during the late summers and early autumns of 2010 and 2011, which would have a direct impact on flow from the artesian well. He also said that there should be no doubt that the flow from the artesian well would have been reduced during previous drought periods such as those in the early and mid 1990s and also in 2005/6. 
99.	He said that the Ponds located to the east of Pond A received their majority of water from groundwater inflow from the hill slope areas to the north and would only receive water from overflow from Pond A during very wet winter periods when the Pond level rises to some 36.45 metres AOD. 
100.	Mr. Van Wonderen’s final overall opinions were that the impact of Lake 1 levels on flow from the artesian well into Pond A is the only man-made impact directly related to the construction of Lake 1. There would be an indirect impact on Ponds B, C and D due to reduced time of overflow from Pond A into Pond B. However, the climatic variation is a much stronger influence and other anthropogenic changes to the nearby area could also have exerted influence on the wellbeing of the Ponds. He said that it was beyond doubt in his opinion that Ponds B to F are not directly impacted by the development of the Lakes. Ponds B to D would have greatly benefited from diversion of Lake 1 outflow to Pond A from which water would have flowed into Pond B and subsequently Pond C and D via the existing overflows between the Ponds. 
101.	Like Dr. Wilson, in his oral evidence in chief, Mr. Van Wonderen expanded upon and explained his findings and conclusions in his report. He was doubtful that there were perched aquifers in the Fen as postulated by Dr. Wilson. He emphasised that the topography at the Fen was important as shown by the LIDAR (Light Detection and Ranging) data and map sheets for the area. He said that the fact that the groundwater table in the Fen is close to the surface is a reflection of the topography. He maintained his contention that surface water is not a source of water for the Ponds. He again emphasised that, because the groundwater remains high even in summer in the Fen, the source of the water for that must be an upflow through the Lowestoft till from the chalk aquifer as the chalk has a higher head than the ground surface. He stressed that his catchment area of 1.5 km² was the groundwater catchment area as opposed to the surface catchment area referred to by Dr. Wilson. 
102.	He rejected the suggestion that the ditch along Fen Road which is mostly dry is a plausible explanation for the discharge from the artesian well. He thought it was highly significant that, according to the evidence from Mr. Chadwick, when Mr. Ford was running the Fishery, the Pond levels had to be kept up by pumping water from the river. 
103.	In October 2015, Dr. Wilson and Mr. Van Wonderen prepared a joint statement setting out the matters which they agreed, including that Lake 1 has had and can continue to have an effect on water levels in Pond A and that increasing the water level elevation in Lake 1 results in an increase in ground water flow from the artesian well which discharges into Pond A. They also agreed that if, as seems likely, Ponds A and B have become shallower because of sedimentation and leaf fall, this would make the Ponds potentially more sensitive to external influences that might affect Pond water levels. 
104.	When he was cross-examined, Dr. Wilson conceded that he had not inspected the defendants’ Lakes and had only inspected the Fishery and the drains on Fen Road. He agreed that it was only recently that he had prepared and disclosed an estimate of the groundwater flow through the shallow permeable layer at the Fen using the Darcy’s law calculation. He said he had reason to doubt the accuracy of the data used by Mr. Van Wonderen in the preparation of his Figure F showing historic groundwater movement at the Fen. He did concede that the lie of the land from Pond A was downward to the south. He conceded that the springs which had been identified on the claimants’ land were likely to be from flow of water from the north elevation. He maintained that in his view there were three water sources for the Ponds: surface water run-off, interflow and flow from shallow perched aquifers. He said that the surface water run-off would normally run in the leaf litter level of the soil. He did not necessarily accept an observation in a British Geological Survey paper that land drain and ditch infrastructure was likely to account for the majority of lateral flow from run-off, land drainage and flow in the upper more permeable zone of the till deposits. He had only looked at the Fen Road drains and was not familiar with the land drains on the surrounding land. 
105.	He did not accept that the infiltration capacity of the surrounding catchment area would always be sufficient to prevent run-off. He maintained that Lakes 2 and 3 would interrupt water flow to the east. He accepted that surface water would not flow up hill but said it was not necessarily correct that surface water going towards Lakes 2 and 3 would not have been received by Pond A. He said that interflow is below surface flow in the upper horizons of the soil and that is distinct from flow through perched aquifers. He said he had not calculated the volume of water that was flowing towards the Ponds from interflow. He said that it was to him pretty obvious that there are perched aquifers in the Fen area. By reference to the WS boreholes, he indicated where there may be perched aquifers at those levels, but also said that they could be at a level lower than the boreholes.  At one point he appeared to accept that in practical terms there was negligible lateral flow above the groundwater level. He maintained that any vertical flow at the Fen from the chalk was limited. 
106.	Dr. Wilson was questioned about his Darcy’s law equation regarding the rate of flow of water through a cross-section of material. The equation involves three elements: the hydraulic gradient, the width and depth of the material through which there is the flow, and the hydraulic conductivity of the material, i.e. the permeability of it. His calculation had taken a cross-section of an assumed shallow deposit medium of 100 metres with a 1 metre thickness and a hydraulic gradient derived from the Harrison Consultants report. For the hydraulic conductivity, he had taken a factor of 8.64 metres per day. He said this was the appropriate figure for sand and gravel. This resulted in a flow rate of 6 m3 per day with the lower hydraulic gradient figure from Harrison Consultants. If the higher hydraulic gradient was taken, it gave 14.26 m3 per day. However, he said that this in each case would be doubled if the thickness of the material was 2 metres rather than 1. 
107.	Harrison Consultants had carried out some falling head tests in the WS boreholes which gave hydraulic conductivity figures for the materials there of less than 0.5. Obviously, using those very low hydraulic conductivity figures, as Counsel for the defendants demonstrated by producing such calculations, the flow rate would be considerably less than 0.6 m3 per day. Dr. Wilson considered that these hydraulic conductivity figures from the falling head tests were not reliable and were very low for the materials in question.
108.	Whilst Dr. Wilson conceded that not all the water flow from the defendants’ land to the claimants’ land would go into the Ponds, he did not accept that all the flow from Lakes 2 and 3 would go to the river. 
109.	When Dr. Wilson was asked how, when Pond A was 1½ metres in depth, there could be a vertical flow to it from sandy layers lower than 3 metres, he said that hypothetically this was possible and the water would travel vertically by pressure head. He said that it was a realistic possibility that there was a source head higher than Pond A up the river valley.
110.	Dr. Wilson accepted that, with the flow rates calculated from the permeability levels from the falling head tests, to explain a 100 m3 per day discharge from Lake 1, one would need some other source of water than flow through the permeable layers. He would not accept that this must be from the chalk aquifer and said he thought it was more likely to be other sources of rainwater run-off. He then said it was possible that lateral flow could give the 100 m3 per day from Lake 1. 
111.	He did appear to concede that there was a substantial correlation between the artesian well flow and the chalk borehole. He was asked what pressure generated the head in the artesian well of about 20 cm. above the Pond A water level. He postulated that it may be by reason of the elevation of the ditch along Fen Road which was higher than the artesian well so that pressure was generated by the slope from the ditch. He said this could be the case even if the difference in elevation was only the .08 metres suggested to him. 
112.	When he was questioned about the Lake 1 test, Dr. Wilson accepted that there was no change in the level of Pond A but maintained, as he had mentioned in his report, that this was probably because Pond A was sealed or partly sealed by an impermeable layer or sedimentation.
113.	Dr. Wilson conceded that Mr. Van Wonderen’s proposition, that Lakes 2 and 3 do not influence the water situation in the Ponds, was a plausible proposition. He also conceded that Lake 4 is unlikely to have any impact on the Ponds. He agreed that the river is the principal hydraulic “pull” in the valley. He therefore agreed that there would be a degree of seepage from the Ponds to the river. Dr. Wilson accepted that he was unaware of the 12 hectares where willow trees have been grown to the north and had been unable to obtain any information about the drainage work at Hargate.
114.	When he was re-examined, Dr. Wilson retreated a little from any concession he had made in relation to Lakes 2 and 3. He said prior to the excavation of Lakes 2 and 3 some of the water in the saturated valley bottom would have been available to go towards the Ponds. 
115.	When Mr. Van Wonderen was cross-examined, he agreed that the environmental impact statements from the defendants’ consultants should have looked at the considerations in his report, such as the area of willow trees, and should have covered a larger area including the northern boundary of the catchment area some 500 metres to 1 km away. He agreed that he had not done any calculations as to the influence of land use change or drainage. He agreed that the outflow from Lake 1 of 70-120 m³ per day was significant. He estimated that the outflow when Lake 1 was not there would have been some 30-40 m³ per day. However, he maintained that the only significant source of water to Lake 1 was upward flow from the chalk aquifer. He reiterated what he had said in his report, that the quantity of any inflow through superficial deposits was considerably less than the upflow from the chalk, by which he meant not more than a couple of m3 per day compared with the 70-120 m³ per day from Lake 1. He said that he could not concede that the outflow from the artesian well could arise from superficial materials by lateral flow. He said that his Figure 10 comparing the chalk borehole groundwater levels and the artesian well outflow was instrumental in his conclusions. He said it showed the discharge from the artesian well correlates exactly with peaks in the chalk borehole. He maintained his argument that there is a preferential pathway from the chalk aquifer to the artesian well and other pathways through the clay layer to allow some further flow from the chalk aquifer. He said that the hydraulic heads in the chalk aquifer are well above the surface level heads at Lake 1 and the artesian well. He said he accepted as the maximum reduction in flow from the artesian well as a result of Lake 1 as 13 m³ per day. He said he was not in a position to say what the impact was of such reduction to Pond A in terms of the wellbeing of the Ponds. 
116.	Mr. Van Wonderen argued that he was correct to refer to the groundwater catchment area rather than the surface catchment area. He said he confined his attention to potential sources of inflow to the Fen. That is why he looked at the groundwater catchment area. He said the area north of the Ponds was the catchment area relevant to them.
117.	He was criticised for not considering, as had Dr. Wilson, the hillside topography and hydrological effect of the coalescing of the three valleys, but he said that was not necessary. He said he had taken regional groundwater models produced by consultants who spent two years preparing it in order to derive the 50-70 mm. per year groundwater flow by recharge to the chalk. He conceded that the permeability factor in the model was an a priori assumption. 
118.	He agreed that he does place a heavy reliance on the topography and it was reasonable to rely upon the data from Harrisons Consulting and LIDAR. He said that, in his view, the boreholes were accurate regarding the contours to give or take 5 cm. 
119.	It was put to Mr. Van Wonderen that, by reason of the thickness of the confining clay over the chalk, there could not be upward flow of water from the chalk. He disagreed and said that there can be a preferential pathway through the confining layer however thick it is. He said there was no evidence in the literature of there not being preferential pathways by reason of the thickness of the confining layer. 
120.	When he was questioned about the relevance of barometric pressure to the confinement of the chalk, he was not entirely consistent in his answers. However, he said that the barometric pressure tests would indicate that at least the chalk was semi-confined. Again, however, he said that the fact that there was confinement or semi-confinement of the chalk did not exclude a preferential pathway for the water to flow upward from the chalk aquifer. He accepted that, where the chalk borehole was sunk, the chalk aquifer was semi-confined at that point, but there could be preferential pathways elsewhere in the area. 
121.	He accepted that there was confinement of the chalk at the Bunwell and Tas valley boreholes but that did not affect his overall view about preferential pathways or diffuse upper flow through the clay layers. He was criticised for not dealing with the confinement of the chalk in his report, but he said it was unnecessary in the context of his investigation as to the impact of the Lakes on the Ponds. He said he had taken notice of the regional modelling studies to determine the movement through the clays and transfer from the chalk layer. He said the evidence from the Bunwell and Tas boreholes had been taken into account in the groundwater models. 
122.	In relation to whether there were perched aquifers in the Fen, Mr. Van Wonderen said that they could not be there because of the layer below the clay being fully saturated. He said if there is water in the superficial layer above the clay, it is an aquifer but not a perched aquifer. So he did agree that there are aquifers at upper levels which can flow laterally in the saturated part of that aquifer. 
123.	In relation to Dr. Wilson’s suggestion that there could be permeable flow in the layers below 3 metres, he said it was speculation but was possible. However, to give rise to the amount of water coming out of Lake 1, there would have to be tens of metres of layers with low permeability. In connection with the Darcy’s law calculation, he said that even if the permeable layer was very wide, the flow would only reach some 10 or 15 m³ but not 100 m³ per day.
124.	It can be seen from the detail of the hydrologists’ expert evidence to which I have referred that the assessment of the hydrology of the Fen and the impact of the Lakes, if any, on the Ponds is a complex matter, and that there are substantial differences of opinion between the two experts. It was submitted on behalf of the claimants that the evidence of Dr. Wilson was measured and thoughtful, whereas that of Mr. Van Wonderen had about it the flavour of advocacy and was expressed in trenchant terms. In my judgment, the experts were both impressive in their particular ways. I reject the suggestion that Mr. Van Wonderen embarked on advocacy in his evidence. In my judgment he was at pains to seek to ensure if possible that the court understood the complex and technical issues which arose and did so in a helpful and emphatic manner. Overall, by and large, I found the findings and opinions of Mr. Van Wonderen more persuasive and more supported by objective evidence than Dr. Wilson’s. 
125.	Therefore, in relation to the central issue between the two experts, I find that the main flow of water to Lake 1 and the artesian well at Pond A is by way of upward flow through preferential pathways from the chalk aquifer and possibly some diffuse vertical flow from that aquifer. I consider that the Lake 1 test provides strong evidence in support of that conclusion. I accept that, at the chalk borehole by Pond B, and in the boreholes at Bunwell and the Tas valley, there is clear evidence that the chalk at those points is strongly confined. However, in my judgment, by reason of the nature of the materials in the buried valley in the Fen, there can be preferential pathways to allow a flow upwards from the chalk aquifer at different points such as at the position of Lake 1 and the artesian well at Pond A. I consider it unlikely that, as was suggested by Dr. Wilson, a source of water for Lake 1 and the artesian well is water being driven vertically from sandy layers lower than three metres, which would require a head to force it upwards which was higher than Pond A up the river valley. I find equally unpersuasive the theory which Dr. Wilson raised in his evidence, that the pressure to generate the head in the artesian well related to the elevation of the ditch on Fen Road. It seems to me that at times, particularly in the summer, there would have been little or no water in that ditch, particularly following the Hargate flood diversion works. Dr. Wilson was not really in a position to indicate accurately the hydraulic gradient between the ditch and the artesian well, which he says gave rise to the head at the artesian well. I do not accept that lateral flow through the superficial deposits could give rise to the head at the artesian well or the volumes of water being discharged from Lake 1 or the artesian well. 
126.	In terms of the sources of water for the Ponds, I accept that one source would be surface or near surface water run-off (interflow) and lateral groundwater flow. However, in my judgment, such source is a limited source. There is little evidence of surface water run-off and insofar as there was such run-off, much of it would be removed by drainage within the locality. Equally, in my judgment, near surface flow or interflow would be limited and Dr. Wilson appeared to accept in cross-examination that lateral flow above the groundwater level would be negligible in practical terms. 
127.	So far as lateral groundwater flow through the shallow deposits is concerned, I also find that such flow would be limited. This is highlighted, in my judgment, by the Darcy’s law equations which were considered in the course of Dr. Wilson’s oral evidence. Even on Dr. Wilson’s calculation of a 1 metre thickness of material with a high hydraulic conductivity factor of 8.64 metres per day, the result was a flow rate of only 6 m³ to 14 m³ per day. This is to be compared with the 70-120 m³ per day being discharged from Lake 1. Dr. Wilson suggested that the flow would be doubled if the permeable depth of the layer was 2 metres rather than 1 metre. However, there is little evidence that such 2 metre depth existed. He used a thickness (or width) of the layer of 100 metres in his calculation, but there was the suggestion it might be as much as 200 metres. However, in terms of flow to Lake 1, it has to be borne in mind in any event that the boundary of Lake 1 was only about 50 metres. Of course, if the hydraulic conductivity factors produced by the falling head tests in the WS boreholes were used for the Darcy’s law flow equation, the flow rates would be very low. 
128.	I also accept the views of Mr. Van Wonderen that the gradients in the area of Pond A are such that the hydraulic pull is generally away from Pond A. I accept that the topographical data used by Mr. Van Wonderen in connection with this question was appropriate. 
129.	I have already indicated that I accept that, at the chalk borehole and other locations, there was confinement of the chalk and I accept that that was confirmed by the barometric pressure tests referred to by Dr. Wilson. Mr. Van Wonderen was criticised by the claimants for not having addressed the issue of the confinement of the chalk in his report. It was also said that he gave inconsistent answers about the degree of confinement in his oral evidence. However, in my judgment, as I have already found, the fact that there was confinement or semi confinement of the chalk at one point does not mean that there cannot be preferential pathways from it at other points, as stated by Mr. Van Wonderen. The latter was also criticised for using the groundwater modelling which indicated that the groundwater flow was some 50-70 mm. per year on average. However, in my judgment, it was reasonable to use this figure. I further consider that it was appropriate for him to use the 1.5 km² groundwater catchment area to which he referred as opposed to a larger surface catchment area. 
130.	I also accept the evidence of Mr. Van Wonderen regarding regional drying trends and the periods of reduced rainfall or drought between 2009 and 2012. The changes in the discharge levels from the artesian well do seem consistent with seasonal variations, despite Dr. Wilson’s evidence about overall effective rainfall during the period from 2001 to 2012. It must follow from my finding that the chalk aquifer is the main source of the water for Lake 1 and the artesian well at Pond A, that climatic variation is a predominant reason for variability or lowering of the water levels in the Ponds. I also accept the evidence from Mr. Van Wonderen that the Ponds to the east of Pond A receive their majority of water from groundwater inflow from the hill slope areas to the north. They only receive water from overflow from Pond A in wet periods when the Pond level rises to some 36.45 metres AOD. I therefore accept that the growing of the willow trees in the area to the north of the Fishery, and also the Hargate flood diversion works, is more likely than not to have resulted in a reduction of the flow of water from the north to the Fishery, although it is impossible on the evidence available to estimate the extent thereof. I further accept the evidence of Mr. Van Wonderen that there would be a degree of seepage from the Ponds to the river which would contribute to lower water levels in the Ponds. One then has to consider, in the light of all of these findings, the extent of any impact upon the Ponds of the construction of the Lakes. In my judgment, for the reasons explained by Mr. Van Wonderen and contrary to what was suggested by Dr. Wilson, I find that Lakes 2 and 3 had little if any impact upon the Ponds. It is clear in my view that Lake 4 had no impact at all, and indeed Dr. Wilson accepted that it was improbable that it had any impact on the Ponds. One is then left with the degree to which the construction of Lake 1 has affected the Ponds and particularly Pond A. Mr. Van Wonderen accepted that Lake 1 has had an impact on the outflow from the artesian well, which then has a direct impact on the water level in Pond A. However, I accept his calculation that the reduction in flow from the artesian wall would normally only be of the order of 3.4 - 6 m³ per day and at the most about 13 m³ per day. On this basis, it must be the case, as Mr. Van Wonderen said, that in drought periods such as 2010/11 and 2011/12, the water level in Pond A would not have risen to the level required for overflow into Pond B even without the impact of Lake 1. 
131.	What then is the result of these findings in relation to the issue of causation? I have held that the “but for” causation test must be applied, that is that the claimants must prove on the balance of probabilities that, but for the excavation of the Lakes, their loss and damage would not have occurred. In my judgment, by reason of the variety of causes for the variability or lowering of water in the Ponds, and that the main source for Pond A is the chalk aquifer, (so that climatic variation is a main cause of the lowering of water levels in the ponds) the claimants have failed to prove on a balance of probabilities that, but for the excavation of the Lakes, the water levels in their Ponds would not have reduced to an extent where loss and damage occurred. Whilst, as I have said, Lake 1 had a very limited impact, it has not been proved that without that impact the lowering of the water levels in the Ponds to the degree where loss and damage occurred would not have happened anyway. The historical evidence from Mr. Chadwick and Mr. Greenwood, which I accept, is also of some significance when considering the water levels in the Ponds. That evidence indicates that, before the claimants purchased the Fishery, there were times when the water levels in the Ponds reduced to the extent that water had to be pumped into them from the river. Furthermore, in relation to the issue of causation, it should be remembered, as I have already observed, that in his report Dr. Wilson concluded that it was at least probable that there had been an adverse impact on the Ponds from the Lakes, but the data available was insufficient to allow him to be precise about the exact degree of impact. That, in my judgment, comes very close indeed to saying that the “but for” test of causation cannot be satisfied by the claimants, as indeed I have found. Even if I had been persuaded that it was sufficient to establish causation if the claimants proved the excavation of the Lakes made a material contribution to the reduced water levels and the claimants’ loss and damage, it is very doubtful in my judgment if the impact of Lake 1 as calculated by Mr. Van Wonderen could be said to be a material contribution, particularly as the first claimant accepted that, in terms of his Ponds, a supply of even 20 m³ per day would be de minimis.
132.	It must follow that, because the claimants have failed to prove causation, their claim under section 48A of the Water Resources Act 1991, must fail. It must follow for the same reason that any claim in negligence or nuisance would fail. However, I would have found in any event that the claim in negligence or nuisance could not be sustained by reason of the decisions in Langbrook Properties Limited -v- Surrey County Council [1970] 1 W.L.R. 161 and Stephens -v- Anglian Water Authority [1987] 1 W.L.R. 1381, where it was held a landowner has a right to abstract subterranean water flowing in undefined channels beneath his land regardless of the consequences to his neighbours. No doubt, by reason of these decisions, the claim in negligence or nuisance was not pursued strongly on behalf of the claimants. 
133.	The defendants’ conduct in relation to the excavation of the Lakes does them little credit. I found them both to be most unimpressive witnesses. Clearly they lied when making the application for the certificate of lawful use in saying that the Lakes had been constructed by 1995. I find that they must have been aware of the refusal of the planning permission for three lakes on what became their land regarding the application made by Mr. Ford in 1989. I find that they must have known that planning permission would be required for the excavation of the Lakes and particularly because of the first defendant’s previous experience with planning applications. If, contrary to my finding that foreseeability of damage was not necessary in a claim under section 48A, I would have found that it was foreseeable on the part of the defendants that some damage might be caused to the claimants’ land by the excavation of the Lakes. Of course, such foreseeability does not assist the claimants in this case when they have been unable to establish causation. Equally, the fact that the defendants have acted dishonestly, failed to apply for planning permission when they should have done, and were unimpressive witnesses, cannot be a basis for finding in favour of the claimants, particularly in relation to the central issue of causation. If liability had been established, then contrary to the assertions on behalf of the defendants, I would have found that the second defendant was equally liable with the first defendant, as at all times she was a joint owner of the land and was participating to some extent in the decisions being made in relation to it. By reason of their conduct in connection with the Lakes, the defendants are being put to no doubt considerable expense and trouble by reason of the enforcement proceedings against them. It may be that the enforcement action in due course will have some ameliorative effect on the Ponds, but this cannot be known for the same reasons that the claimants are unable to establish causation. 
134.	Although the claimants’ claim has failed, for the sake of completeness I will briefly indicate the findings I would have made on other issues and as to loss and damage had the claim succeeded. I would have rejected any claim by the claimants for economic tort, as there was no basis for saying that the defendants had deliberately excavated the Lakes to cause loss to the claimants, and in the end this claim was not pursued. Equally, I would have rejected the defendants’ defence that there was some equitable estoppel or easement upon which the defendants could rely against the claimants by reference to the conduct of Mr. Ford vis-à-vis the defendants. Again, this argument was not pursued by the defendants. 
135.	Had liability been established, I would at this stage have set out the important factors contained in the first claimant’s evidence regarding his management of the Fishery and the claims for loss and damage. I would also have summarised the effect of the evidence from the three fishery management experts, between whom, in any event, there was a considerable measure of agreement. However, in giving some indication of the further findings I would have made, I simply indicate that I have had regard to all of that evidence.
136.	The defendants asserted that, if they were in breach of duty to the claimants which gave rise to damage, the damages recoverable should be reduced by reason of contributory negligence on the part of the claimants. It was said that the first claimant’s management of the Fishery was at fault in a number of respects. It was said he had not dredged or removed silt from any of the Ponds and the most he did was to rake leaves out of them from time to time. It was said he did not have any form of mechanical aeration available and did not properly monitor the oxygen levels in the Ponds. It was also suggested that the Ponds were overstocked with fish. It is said that he should have done more by way of cutting back vegetation and trees. Whilst the first claimant’s management of the Fishery may not have been perfect, I would not have been persuaded that any of the matters relied upon by the defendants would have amounted to contributory negligence. 
137.	The first head of damages claimed by the claimants was in respect of fish loss. It was said that there had been a substantial loss through the death of fish in the severe winter conditions in December 2010/January 2011. It is alleged by the claimants that the low water levels in the Ponds, together with the low dissolved oxygen levels occasioned by the Ponds icing over, was the cause of these deaths. There was evidence from Mr. Freeman, the defendants’ fisheries management expert, that at that time other fisheries with normal water levels had suffered the loss of fish because of the icy conditions. By a narrow margin, bearing in mind the expert evidence of the claimants’ fisheries management expert Mr. Girdler, who I found to be most impressive, I would have found that it was more likely than not that, but for the low water levels, the fish losses would not have occurred in those icy conditions. 
138.	In my judgment, the claimants’ figures for fish deaths is questionable. Due to the loss of data on his computer, the first claimant was only able to produce details of fish losses totalling a little short of 1,400 lbs. His claim is that some 2,500 lb. of fish died in Ponds C and D, and a little less in Pond B. Originally he was claiming a total loss of fish in the 2010 winter at 5,000 lb. at £10 per pound. The experts put the average cost of a fish at around £5-£6 per pound. The first claimant also claimed that, in the overall period from 2006 to 2014, a further approximately 2,750 lb. of fish died by reason of the low water levels. 
139.	I would have been prepared to find that the claimants were entitled to damages for fish losses, but at a significantly lower level than claimed. On a broad brush basis, I would have allowed for the loss of 3,000 lb. of fish at £6 (including VAT) for the loss in the winter of 2010, which would give £18,000. For other loss of fish due to low water levels in the overall period from 2006 to 2010, I would have allowed for 1,000 lb. of fish at £6, giving a figure of £6,000. In relation to the latter figure, I very much bear in mind that there would have been a number of other reasons for fish losses, including predation, as well as the low water levels. 
140.	The next head of damages claimed by the claimants was in respect of loss of income. This claim was wrongly pleaded on the basis of a claim for loss of turnover rather than loss of profits. It is the claimants’ case that, by 2011, they would have increased the turnover of the Fishery to £25,000 per annum. This would have been arrived at after stepped increases from £15,000 per annum in 2007. Thus it was estimated that the total turnover up to 2014 would have been £175,000. The actual income (i.e. turnover) for those years was £42,107. Thus the claim on the basis of loss of turnover to 2014 was £132,892. On the basis that it would take from now a further five years to restore the Fishery to its proper state and to a turnover of £25,000, there was a claim for future losses of £61,500. 
141.	Mr. Girdler, who has great experience of fisheries of this nature, said that in his opinion the Fishery was well capable of attaining a turnover of £25,000 per annum. When pressed by me to attempt to give a reasonable figure for the expenses of running the Fishery to be deducted from the £25,000 turnover, he said that he would expect expenses to be in the region of £10,000 per annum. On that basis, there would be a profit of some £15,000 per annum, i.e. 60% of the turnover. I am somewhat doubtful as to whether the Fishery could have achieved a turnover of £25,000. However, I would have been prepared to accept that the low water levels in the Ponds had given rise to a loss of income for the claimants. 
142.	Doing my best, again on a somewhat broad brush basis, I would have found as follows. For the three years from 2007 to 2009, I would have allowed a loss of profit of 60% of a turnover of £12,000 per annum, giving a total of £21,600. For the years from 2010 to 2014 I would have allowed 60% of £18,000 turnover, giving 5 x £10,800 per annum with a total of £54,000. That would give a total of £75,600 for the years up to 2014. From this I would have deducted 40% of the actual turnover during those years of £42,107, giving a deduction of £16,843. Thus the award for loss of profit to date would be £58,759.
143.	For loss of income on the basis that it will take three to five years before the Ponds and their banks will be restored to a proper condition, on the assumption that revetment is not carried out, I would allow an average net loss of profit of £8,000 per annum for five years, giving £40,000. 
144.	The next claim by the claimants was in respect of the costs of immediate revetment of the Ponds, that is restoring the banks of the Ponds to a proper sound and restraining state by reason of their deterioration due to erosion and sinking because of the low water levels. These revetment works would be very substantial indeed and I accept as stated by Mr. Girdler that the cost would be some £224,000. However, he accepted that, if full water levels are restored to the Ponds, the banks would gradually become saturated and within three to five years would be in a sound state again. The costs of revetment are as much as or in excess of the overall value of the Fishery. In my judgment, it would be out of all proportion to award £224,000 for the immediate revetment works when, over a period of three to five years, the banks would be restored in any event if the Ponds were full. Thus, on the basis of the principles set out by the House of Lords in Ruxley Electronics -v- Forsyth [1996] A.C. 344, I would only have awarded the current loss of value in the Fishery rather than the revetment costs. I accept from the evidence of Mr. Freeman on behalf of the defendants that that current diminution in value is in the sum of £30,000, and that is the award I would have made to the claimants. 
145.	Next, the claimants claim various expenses. I would have allowed £450 for the purchase of a pump and, say, £300 in respect of the cost of petrol to operate it to aerate the water at the time of the severe winter conditions in 2010, but not to include any amount for the recharge tests conducted in 2012. I would also have allowed the cost of sinking the chalk borehole in the sum of £10,477. The claimants claimed for 49 hours per week for a six week period, plus an additional 25 hours, for recovering and disposing of the dead fish in the winter of 2010/11. The claim was at the rate of £15 per hour, making a total of £4,785. In my judgment, this was an excessive claim and at most I would have allowed the sum of £3,000 in respect of this. Additionally, the first claimant claimed that he had spent at least 1,500 hours of time monitoring the effects of the water loss, liaising with the authorities, reviewing and assessing reports and data supplied by the authorities, and assessing the losses suffered by the business. Again, he claimed at the rate of £15 per hour for this. In my view, this was another excessive claim and at most I would have allowed 750 hours at £10 per hour, giving £7,500.
146.	Finally, the claimants claimed general damages for interference with their use and enjoyment of the Fishery by reason of the low Pond levels. In my judgment, a very modest amount of no more than £750 for each claimant would have been appropriate under this head of damage. 
147.	The defendants argued that in any event there should be a reduction from any damages awarded by reason of the claimants’ failure properly to mitigate their losses. This was on the basis that the claimants had unreasonably refused to accept a piped transfer of water from Lake 1 into Pond A. The first claimant’s reason for this refusal was that it would have prejudiced his potential claim under the Water Resources Act and there would have been no guarantee of such continued supply of water in the future. More recently, supported by the opinion of Mr. Girdler, he said there were biosecurity reasons for not accepting the piped transfer, because of the risk of disease from Lake 1 passing to fish in the Ponds. On balance, I would have held that the claimants’ stance about this was not unreasonable and so would have held that they had not failed properly to mitigate their losses. 
148.	The final issue would have been, if the claimants had succeeded in their claim, whether the court was prepared to make a mandatory injunction against the defendants, requiring them to infill one or more of the Lakes. In my judgment, it would not have been appropriate to grant such relief at this stage. There was the clear possibility, if such an injunction was made, of conflict with the steps being taken by SNDC regarding the enforcement notice. In my judgment, had the claimants succeeded on liability, the appropriate course would have been to adjourn the application for a mandatory injunction pending the outcome of the enforcement proceedings. 
149.	Unfortunately for the claimants, by reason of my finding on the issue of causation, they have failed in their claim and are not entitled to any of the damages which would have been awarded had they been successful. It follows that there must be judgment in this case for the defendants. 
150.	I must finally say that I am extremely grateful to Counsel for the claimants and the defendants for their written and oral submissions which were of a very high standard and of invaluable assistance to me.