Case No: A2/2000/6372; A2/2000 6473; A2/1999/1242

 
IN THE SUPREME COURT OF JUDICATURE
COURT OF APPEAL (CIVIL DIVISION)
ON APPEAL FROM HIGH COURT OF JUSTICE
QUEEN’S BENCH DIVISION
Mr Robert Owen QC sitting as a 
Deputy High Court judge
Strand, London, WC2A 2LL

Friday 1 December 2000

B e f o r e :

LORD JUSTICE PETER GIBSON
LORD JUSTICE WALLER
and 
LORD JUSTICE JONATHAN PARKER

	Bybrook Barn Centre Limited & Ors		Appellants/Claimants	
	- and -		
	
Kent County Council	
Defendant/
Respondent	

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(Transcript of the Handed Down Judgment of
Smith Bernal Reporting Limited, 190 Fleet Street
London EC4A 2AG
Tel No: 020 7421 4040,  Fax No:  020 7831 8838
Official Shorthand Writers to the Court)

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Mr Howard Palmer QC, Mr Neil Moody (instructed by Williams Davies Meltzer of London for the Appellants/Claimants)
Mr James Dingemans (instructed by Messrs Badhams of London for the Defendant/Respondent)

Judgment
As Approved by the Court

Crown Copyright ©

Lord Justice Waller:
Introduction 	
1.		The First Claimant is the owner of a Garden Centre in Canterbury Road, Ashford Kent.  The remaining Claimants lease retail space within the Garden Centre.  On 12 August 1996 the Garden Centre and the premises of the other Claimants were flooded causing extensive damage to the interior of the premises and to stock belonging to the Claimants.  The cause of the flood was that a stream, known as Bockhanger Dyke, had burst its banks.  That was caused by the fact that a culvert under Cemetery Lane was unable to take the quantity of water flowing down the stream.  The Defendants are the highway authority.  It is common ground that the culvert was part of the highway.  The culvert was constructed and maintained by the Defendants’ predecessors, but it is common ground that the liabilities of the predecessors are the liabilities of the Defendants and that the culvert can be treated as having been constructed, maintained and under the control of the Defendants.  The fact that the Defendants do not own the whole of the soil upon which the highway is found down to the centre of the earth is not important given that they own the highway and they have that control.  
2.		By a judgment delivered on 5 November 1999 Robert Owen QC, sitting as a Deputy High Court judge, dismissed the Claimants’ claim for damages in nuisance as against the Defendant highway authority.  He did so because he felt constrained so to do by a Court of Appeal authority Radstock Co-operative and Industrial Society v Norton-Radstock U.D.C. [1968] Ch. 605.  He found that although the culvert taking the dyke under Cemetery Lane when originally constructed caused some interference with the flows when it was constructed, 
“. . . that evidence. . . does not in my judgment demonstrate that the culvert then gave rise to a nuisance.  In my judgment the evidence as to flooding, both positive and negative, shows that when constructed the culvert was of adequate capacity to carry the natural flow of water within the dyke; and that the flooding in 1993 and 1996 and the continuing risk of flooding of the site agreed by the experts . . . are the result of changes within the catchment area.”
What he had in mind by the changes within the catchment area were activities further upstream, such as the construction of the M20 motorway, which had increased the amount of water that flowed into the dyke and increased the rate of that flow.  He found that although the highway authority became aware in about 1990 that the culvert was no longer able to take the quantity of water flowing down the dyke, on the basis of Radstock the highway authority had no responsibility to increase the size of the culvert.  
3.		This is an appeal brought by the Claimants against that decision.  The point raised by the appeal is an important one.  It raises the question whether a highway authority which have constructed a culvert to take a natural stream under the highway which at the time it was constructed was adequate and thus did not cause a nuisance, and which when built, would not (as I understand the judge’s finding) reasonably be expected to cause a nuisance, become responsible to enlarge the culvert when factors not their responsibility demonstrate that the culvert is no longer adequate and does now cause a nuisance.  
The Facts 
4.		The facts should be expanded a little as follows.  A natural watercourse, Bockhanger Dyke, flows through land owned by the First Claimant, the Garden Centre.  The remaining Claimants are lessees of retail space within the Garden Centre.  There is also a doctors’ surgery on the land close to where the flooding occurred but the doctors are not Claimants in these proceedings. 
5.		The watercourse is interrupted by Cemetery Lane, a highway.  When the highway was laid, or possibly at some later date, a culvert was constructed under the highway through which the watercourse was intended to travel.  The construction it seems was in about 1950 but it was extended or altered in about 1969.  The judge took a date of 1934 which may have been a mistake for the date of 1936 pleaded by Mr Dingemans, for the Defendants, although Mr Dingemans frankly accepted that apart from some reference in one document, he had no evidence for that date.  The Defendants having conceded that they should be treated as the builders of the culvert, the actual date of construction was not an issue before us.  The culvert was a cylindrical concrete pipe running through the highway embankment, some 900 mm in diameter and 20 metres in length.  
6.		As already indicated the judge found that the culvert when built reduced the velocity of flow of water in the watercourse but he found in the words already quoted that at that stage no nuisance was caused.  He further found that in its present condition it created a significant risk of flooding caused by water backing up by virtue of the fact that the capacity of the culvert is such that it cannot take the present capacity of the dyke.  
7.		He found that the significant risk of flooding of the site in recent years was the result of the major developments in the catchment area, in particular the construction of the M20 motorway and a Business Park, both undertaken over 40 years after the probable date of construction of the culvert.  This conclusion was reached by the judge on the basis of the evidence of Mr Burch who was the First Claimant’s Managing Director and who had known the site for many years, and on the expert evidence of Mr Allitt.  
8.		It is common ground that the flooding would not have occurred in August 1996 if the watercourse had been in its natural state and not restricted by the present culvert. Nor would the flooding have occurred if a culvert of rectangular cross-section (1.2 metres x 2.4 metres) had been in place.  As the judge pointed out, just downstream from Cemetery Lane the watercourse passes under Canterbury Road.  There the culvert is a rectangular cross-section of 1.1 metres x 3 metres and appears to give no trouble.  
9.		The judge’s finding was that the Defendants, through Mr Munford who was the area bridge engineer and responsible for the culvert from 1989, must have become aware of the problem with the capacity of the culvert in 1989/90/91.  The basis on which the judge came to that finding appears from pp. 4 and 5 of his judgment and reflects very badly on Mr Munford who, according to the judge, had sought to maintain that he had no awareness of the lack of the capacity of the culvert before the flood in August 1996, the subject of the action.  That contention, as the judge found, 
“became unsustainable in the face of the documentary evidence in his own files, the existence of which only emerged in the course of his cross-examination.  He was eventually forced to concede that it must have been clear to him in 1989/90/91 that there was a problem with the capacity of the structure.”
10.		Mr Dingemans has pointed out that in his witness statement (p. 82 of the bundle) Mr Munford was accepting he had some knowledge of flooding in June 1994, but it is still true that only when documentarty evidence emerged did he concede that he must have known of problems in 1989/1990/1991.  
11.		There was a further unsatisfactory feature of Mr Munford’s evidence.  He maintained that the cost of replacing the culvert with one which would have sufficient capacity was £129,000 plus service diversion costs.  The service diversion costs he stated would be a further £16,500 giving a total cost of £145,000.  But, as the judge found, 
“his own file, undisclosed until the second day of the trial, contained a detailed estimate of the necessary works costed by a project manager employed by the Defendant at a total of approximately £81,000.  The estimate was dated 13th July 1998, four months before the date upon which (Mr Munford’s) first witness statement was signed”.
Submissions 
12.		Both parties have put in detailed submissions.  I shall attempt a summary of the main points.  Mr Palmer QC, for the Appellants, submitted that the judge found as a fact that the culvert originally in place impeded the flow in the dyke and that the Defendants are thus liable for any flooding even caused by unusual factors and even if unforeseeable at the time of the original construction.  He based that submission on Corporation of Greenock v Caledonian Railway Company [1917] AC 556 and in particular the dictum of Lord Finlay LC at 572 where he stated:- 
“It is the duty of any one who interferes with the course of a stream to see that the works which he substitutes for the channel provided by nature are adequate to carry off the water brought down even by extraordinary rainfall, and if damage results from the deficiency of the substitute which he has provided for the natural channel he will be liable.”
He submitted that albeit Greenock represented the law of Scotland, that authority was adopted by the Court of Appeal in Pemberton v Bright & Anr [1960] 1 WLR 436.  In that case the court held that where a culvert had been altered and extended in 1926 and the entrance left uncovered and unprotected, that interference was one which created a potential nuisance in that “heavy rain was always a potential danger unless properly controlled and this at least was a place where a grid would have stopped, or would have probably stopped, debris getting past it.”  Liability thus for flooding which occurred in 1956 was established.  
13.		In the alternative, Mr Palmer submitted that once the Defendants became aware that the culvert was interfering with the flow of the natural watercourse and that that was giving rise to flooding on the Claimants’ land, the highway authority were liable in nuisance for continuing with the same and for failing to take proper steps to prevent such flooding.  For that proposition he relied on Sedleigh-Denfield v O’Callaghan and Others [1940] AC 880 especially Lord Wright at 904-905.  
14.		Mr Palmer’s final alternative was to rely on Allan William Goldman v Rupert William Edeson Hargrave [1967] AC 645 PC and Leakey and Others v National Trust [1980] 1 QB 485.  By reference to those authorities he submitted that an occupier of land owed a general duty of care to a neighbouring occupier in relation to a hazard occurring on his land whether such a hazard was natural or man-made; that the duty was to take such steps as were reasonable in all the circumstances to prevent or minimise the risk of any injury or damage to the neighbour or his property of which the occupier knew or ought to have known.  The judge would have found the Defendants liable on this principle.  Mr Palmer suggested that the judge was right so to do and was wrong to feel that he was constrained by Radstock to come to a contrary view.  
15.		Mr Dingemans submitted that on the judge’s findings that the culvert when constructed was adequate, and that it neither created a nuisance nor was a potential nuisance, the judge was correct to follow Radstock which Mr Dingemans submitted established that if something was not causing a nuisance or a potential nuisance when constructed, the forces of nature could not make the creator of that construction liable for nuisance at some future time.  He submitted that Greenock was not authority for the proposition that if a structure was built in a stream which was adequate to cope with the natural flow even after extraordinary rainfall, the structure becomes a nuisance or the creator of a nuisance because persons upstream have increased the flow and altered “the true state of nature”.  
16.		He submitted that Radstock was consistent with a line of authority which established that “that which is not a nuisance at the time it is done, cannot become so by length of time”.  That quote comes from the headnote to Rex v Bell (1822) 1 LJKB (OS) 42 relied on in Radstock.  He relied further on Moore v Lambeth Waterworks Co. (1886) 17 QBD 462 where the defendants were found not liable when a fireplug lawfully fixed in a highway had become exposed as the road surface had worn.  That authority was approved by the House of Lords in Great Central Railway v Hewlett [1916] 2 AC 511 where the railway company had been empowered to erect in a highway certain gateposts and in a war-time blackout a taxi-driver had run into them.  The company was found not liable for the accident.  It was held that the accident was caused by the post which had been legalised by the empowering act and by the elimination of light due to the exigencies of war.  A mere power to maintain posts did not impose an obligation to warn the public of their existence.  Mr Dingemans further relied on Thompson v Brighton Corporation [1894] 1 QB 332 (CA) where a manhole cover became exposed as the road surface eroded, causing injury, but the Corporation were held not liable.  
17.		Mr Dingemans distinguished Sedleigh-Denfield and Pemberton on the basis that in those cases a nuisance or potential nuisance existed from the outset.  He submitted that Goldman was concerned with a hazard on the land and it supported a duty on occupiers only in relation to such hazards.  He submitted it was thus not of significance that it was not cited in the Court of Appeal in Radstock.  
18.		He further suggested that his submissions were supported by the sewage and drainage cases such as Glossop v Heston & Isleworth Local Board (1879) 12 Ch. D. 102 and Smeaton v Ilford Corporation [1954] Ch. 450 where local authorities were held not liable for damage caused by an overflow of their sewage systems which had been adequate when installed but became inadequate over time.  He very properly pointed to the somewhat different approach in Pride of Derby and Derbyshire Angling Association v British Celanese Ltd. [1953] Ch. 149 where the corporation were held liable for the effluent poured into the river from a sewage system which had become inadequate and where the property or businesses of persons further down the river were damaged.  But he pointed out again how that authority had been distinguished in Dear v Thames Water and Others (1992) 33 Con LR 43.  He suggested that it was of significance that in that case no-one suggested that the culverts had become inadequate for the purpose of carrying the storm water in Pinner or that any liability flowed simply from that inadequacy.
Discussion 
19.		In considering liability for nuisance and the authorities relating thereto the following must be borne in mind.  First, it is well known that the situations in which liability for nuisance has been found to be established vary enormously, and it is not always easy to reconcile the reasoning as to why liability has been found to exist in one situation but not in another.  As Lord Wilberforce in Goldman said at 657:-
“the tort of nuisance, uncertain in its boundary, may comprise a wide variety of situations, in some of which negligence plays no part, in others of which it is decisive.. . . .”
Generally, an action for private nuisance lies in respect of interference with the plaintiff’s enjoyment of his land, arising from something emanating from the defendant’s land, and the plaintiffs indeed seek to show that in this case the culvert was on the defendants’ land.  But the liability for nuisance from flooding from a natural stream where the flow has been interfered with would not at first sight appear to me to require emanation from the defendants’ land, as opposed to the creation of the obstruction or control over the obstruction.  That may be a distinguishing feature of this form of liability.  
20.		Second, where the defendant is a statutory body with statutory duties or statutory powers, often the exact extent of those duties and powers will be important.  Mr Dingemans showed us a passage in Lord Hoffmann’s speech in Stovin v Wise [1996] AC 923 at 958 where he said as follows:- 
“In my view the creation of a duty of care upon a highway authority, even on grounds of irrationality in failing to exercise a power, would inevitably expose the authority’s budgetary decisions to judicial inquiry.  This would distort the priorities of local authorities, which would be bound to try to play safe by increasing their spending on road improvements rather than risk enormous liabilities for personal injury accidents.  They will spend less on education or social services.  I think that it is important, before extending the duty of care owed by public authorities, to consider the cost to the community of the defensive measures which they are likely to take in order to avoid liability.. . . . . . .”
But, it is of equal importance to appreciate that, as Lord Hoffmann made clear earlier in his judgment, statutory bodies do not occupy a special position so far as liability for nuisance is concerned unless statute puts them in that special position.  He said at 946:-
“Since Mersey Docks and Harbour Board Trustees v Gibbs (1866) L.R. 1 H.L. 93 it has been clear law that in the absence of express statutory authority, a public body is in principle liable for torts in the same way as a private person.  But its statutory powers or duties may restrict its liability.  For example, it may be authorised to do something which necessarily involves committing what would otherwise be a tort.  In such a case it will not be liable: Allen v Gulf Oil Refining Ltd [1981] AC 1001.  Or it may have discretionary powers which enable it to do things to achieve a statutory purpose notwithstanding that they involve a foreseeable risk of damage to others.  In such a case, a bona fide exercise of the discretion will not attract liability: . . . .”.  
21.		As Lord Hoffmann then pointed out Stovin was a case where a private person would not have been liable and the question was whether the highway authority should have a duty imposed on it by virtue of its statutory powers.  That is to be distinguished from a situation in which a liability in nuisance would be imposed if the defendant was not a public authority and the question is simply whether the statutory authority should also be liable having regard to any statutory provisions.  
22.		The third matter to bear in mind is that in this area, perhaps more than any other, the law has developed over the years.  O’Connor J (as he then was) in his judgment at first instance in Leakey [1978] 1 QB 849 and Megaw LJ in the Court of Appeal in the same case [1980] 1 QB 845, demonstrated this point in a way material to the facts of this case and I will come back to it.  
23.		It follows from the above that distinctions between cases which seem on the surface broadly similar but which came to what seem to be inconsistent results, are often on the narrowest of grounds.  This is nowhere better demonstrated than by the fact that in Pride of Derby the Court of Appeal could trenchantly find the corporation liable for the nuisance caused to persons down river resulting from the effluent being deposited in the river by the corporation because the sewage system had become inadequate.  But in order so to do the court distinguished cases such as Glossop where the local authority were held not liable for polluting the river causing damage to the business of the occupier of a house within the district of the local board, when that pollution was due to the inadequacy of a sewage system adequate when the defendant local board had taken it over.  Thereafter Upjohn J in Smeaton followed Glossop and found no liability on a local authority where effluent had flooded a garden of a ratepayer because the sewage system had become inadequate to cope as a result of the many other sewers that now drained into that local authority’s system as compared to when it was built.  Later still in Dear His Honour Judge Peter Bowsher QC followed the Glossop line of authority distinguishing Pride of Derby. 
24.		This is not the place for a minute analysis of all these decisions which in my view are of only peripheral relevance.  However, the main distinctions between the situations in Glossop, Smeaton, and Dear as compared to Pride of Derby would appear to me to be as follows.  First, in cases such as Glossop, Smeaton, and Dear, the plaintiffs were members of the public for whose benefit the sewers or sewerage system had been installed, and what the plaintiffs were in effect doing was seeking an order to compel the local authority to carry out their statutory duty to provide an adequate system.  That was found to be seeking a public law remedy and provided one reason why the plaintiffs’ actions in private nuisance could not succeed. (see Lord Evershed MR at 174-175 and Denning LJ at 190 in Pride of Derby; Upjohn J in Smeaton at 463 and Judge Bowsher in Dear at 58-59).  Second, the statutory provisions imposing duties, providing powers, and granting exemptions, were important in those cases.  In Pride of Derby the statutory provision on which the council was relying as protecting them from liability, was found by the court in fact to confirm that there was liability.  In Smeaton the statutory provision was “generously” construed to relieve the statutory authority from liability under the rule in Rylands v Fletcher albeit I accept that was not the basis for relief from the liability in nuisance.  In Dear the case really turned on whether there was liability in relation to the exercise of statutory powers.  Third, as Upjohn J’s judgment in Smeaton showed, it will be a relevant consideration as to whether a defendant should be liable for “continuing” a nuisance created by forces for which that defendant is not responsible, whether it is reasonably practicable for that person to prevent the nuisance continuing.  In Smeaton the finding was that it was not reasonably practicable to do so.  In Pride of Derby it is difficult to discern this point being considered in any detail, but, since an injunction was granted, albeit suspended for a reasonable period, the implication is that it must have been contemplated that prevention was reasonably practicable.  In Dear the finding of the judge was that the defendants did not have immediate physical control of the thing causing the nuisance.  On that basis for example he distinguished Goldman and Leakey (see p. 70). 
25.		Mr Dingemans relied on the way Upjohn J dealt with the question of causation in Smeaton at p. 464 when dealing with the local authority’s liability in nuisance as opposed to their liability under the rule in Rylands v Fletcher.  I should therefore quote it and deal with it. 
“No doubt the defendant corporation are bound to provide and maintain the sewers (see section 14 of the Public Health Act 1936), but they are not thereby causing or adopting the nuisance.  It is not the sewers that constitute the nuisance; it is the fact that they are overloaded.  That overloading, however, arises not from any act of the defendant corporation but because, under section 34 of the Public Health Act, 1936, subject to compliance with certain regulations, they are bound to permit occupiers of premises to make connexions to the sewer and to discharge their sewage therein, and that, excluding the Oaks Lane Estate, accounts for 98 per cent of the sewage in the sewer.  Nor, in my judgment, can the defendant corporation be said to continue the nuisance, for they have no power to prevent the ingress of sewage into the sewer”.  
26.		Mr Dingemans of course suggests that the above passage supports his argument that the cause of the flooding in the instant case was the activities upstream that produced further water as opposed to the size of the culvert.  But my comment on the above passage is as follows.  Causation is a notoriously difficult concept.  It seems to me to depend on how one looks at it if one is to choose between the cause being the extra sewage coming into the system or the inadequacy of the system to cope with the extra sewage.  Both in one sense would seem to be causes.  But it is logical to discount the inadequate system as a cause if it is not something about which the plaintiffs are entitled to complain in a private law action.  That is how I would understand what Upjohn J was saying. 
27.		I should also mention the special position that highway authorities had at common law since this is also something relied on by Mr Dingemans, albeit rightly not much pressed in argument.  Prior to 1964 when statute substantially changed the legal position which is now contained in section 41 of The Highways Act 1980, highway authorities were not liable for non-feasance as far as maintenance of the highway was concerned.  That was a special position so far as those particular bodies were concerned (see Denning LJ in Pride of Derby at 188).  By section 41, highway authorities are liable for non-repair of the highways, but by section 58(1) of The Highways Act 1980 they are provided with a defence in respect of damage resulting from their failure to maintain a highway if they prove that the authority had taken such care as in all the circumstances was reasonably required to secure that that part of the highway to which the action related was not dangerous for traffic.  
28.		Mr Dingemans’ argument recognised that section 58(1) does not apply so as to provide a defence to the highway authority’s position in this case.  He submitted however that the previous common law position should protect the authority in so far as they are carrying out their highway duties because it is only in relation to maintenance of the highway that statute has changed the legal position.  He submitted that the building and maintenance of the culvert are things done in the carrying out of the defendants’ highway duties and that under the previous common law the highway authority would not be liable for non-feasance and should not thus now be held liable.  The difficulty for Mr Dingemans is that there is no authority which establishes that the principle in relation to non-feasance was applied other than in relation to the highway authority’s obligation to maintain the highway.  There is no authority which suggests that highway authorities are protected from a liability in nuisance caused in situations where private individuals would have been held liable.  Indeed Hurst v Hampshire County Council (1997) 96 LGR 27 in relation to trees would appear to be authority against Mr Dingemans’ submission.  
29.		It follows from the above rather lengthy introduction that it is the facts of this particular case on which one should concentrate, and albeit the highway authority are a body with public duties and powers in the general interest of the community, there is not any statutory provision which protects them from a liability in nuisance.  We are concerned with water-damage from flooding.  The cause was the bursting of the banks of a natural stream.  That flooding would not have occurred if the natural stream still existed without the culvert under Cemetery Lane, or if the culvert had been of a larger size.  In one sense it can be said that the cause of the bursting of the banks was that more water was being poured into the dyke by persons upstream.  As it seems to me the inadequacy of the culvert was also plainly a cause and the only question is whether that cause is a cause for which the highway authority are liable.  By 1990 the highway authority knew that the culvert was not adequate to take the new flows, and could have enlarged the culvert so as to prevent flooding by an expenditure of £80,000 at some period prior to 1996 but did not do so.  
30.		On those facts the first question is whether there is strict liability on the basis of Greenock.  On the findings of the judge I would answer that question in the negative.  The facts in Greenock were as follows.  The West Burn  flowed in a channel considerably below the surrounding ground which drained into it and in particular was below the level of Inverkip Road.  In 1908, in order to form a playground for children, the natural channel of the West Burn was altered.  A culvert was constructed and the burn buried.  The surface of the park thereafter sloped down to Inverkip Road, which had become the lowest level and the channel for surface water which formerly drained into the burn.  In addition, the defendants constructed a paddling pool at the mouth of the culvert which obstructed the flow of water and it was admitted that those works obstructed about “half the flow of water which would otherwise go down the culvert”.  Flooding occurred in 1909 and then on the occasion with which the action was concerned in August 1912. 
31.		The question in the case was whether the defendants could establish “damnum fatale” in the law of Scotland, which, as I understand it, would be approximate to act of God in English law.  It was assumed incidentally by Lord Shaw at 579 that there was no difference on the topic between the law of England and that of Scotland.  It was in that context that Lord Finlay held that the appellants had failed to establish any defence.  He continued at 572:-
“It is true that the flood was of extraordinary violence, but floods of extraordinary violence must be anticipated as likely to take place from time to time.  It is the duty of any one who interferes with the course of a stream to see that the works which he substitutes for the channel provided by nature are adequate to carry off the water brought down even by extraordinary rainfall, and if damage results from the deficiency of the substitute which he has provided for the natural channel he will be liable.  Such damage is not in the nature of damnum fatale, but is the direct result of the obstruction of a natural watercourse by the defenders’ works followed by heavy rain”.
32.		In Sedleigh-Denfield Viscount Maugham at 888 having stated that the principle laid down in Rylands v Fletcher did not apply said:- 
“On the other hand there is no doubt that if an owner of land for his own convenience diverts or interferes with the course of a stream he must take care that the new course provided for it shall be sufficient to prevent mischief from an overflow to his neighbours’ land, and that he will prima facie be liable if such an overflow should take place: Fletcher v Smith (1877) 2 App. Cas. 781; as to which see Greenock Corporation v Caledonian Ry. Co. [1917] A.C. 556.  It would be a defence to prove that the overflow was due to a rainfall or a storm so exceptional that it should be regarded as an act of God; no doubt it would also be a defence, subject to a qualification I will mention later, to prove that the overflow was caused by the interference of a trespasser”.
33.		There is no doubt that if a stream is diverted or blocked the liability will be strict.  But, it is interesting to note that Lord Finlay at the conclusion of his judgment in Greenock said:- 
“In the case now under appeal the Lord Ordinary found, and in my opinion rightly found, that the flood could not be regarded as in the nature of damnum fatale, and that the appellants in constructing the culvert ought to have foreseen the possibility of such an occurrence and to have provided against it”.  
The essence of the strict liability which was being imposed seems to me to depend on whether the court takes the view that the defendant “ought to have foreseen the possibility” of what occurred.  That seems to me consistent with Pemberton where the liability was established because the failure to put a grille created a “potential nuisance”.  That view of the strictness of the liability in this type of case is also consistent with Cambridge Water Co. v Eastern Counties [1994] 2 AC 264 where foreseeability of the risk was established as being necessary to establish liability not only in nuisance but under the principle of Rylands v Fletcher.  Lord Goff then approved what he suggested was the tenor of what Blackburne J’s celebrated statement of the law had meant in Fletcher v Rylands (1866) LR 1 Ex 265.  Lord Goff said:- 
“The general tenor of his statement of principle is therefore that knowledge, or at least foreseeability of the risk, is a prerequisite of the recovery of damages under the principle; but that the principle is one of strict liability in the sense that the defendant may be held liable notwithstanding that he has exercised all due care to prevent the escape from occurring”. (see p. 302D)
34.		On the findings of the judge in this case when this culvert was built it did not create a nuisance and it was not foreseeable on the basis of the flow of water which at that stage was coming down the natural stream that it would cause a nuisance.  Nor in my judgment should it be presumed that the constructor of the culvert should have foreseen that further water might flow into the dyke so that the culvert would cause a nuisance. 
35.		Thus if this were a case where persons upstream had increased the flow into the dyke to an unforeseeable extent and a flood had occurred because water could not get through the culvert, I would not have found the highway authority had any liability.  
36.		That then brings me to the critical question.  Once the highway authority were aware that the culvert did not allow the water which was now coming down the stream to flow freely, so that flooding resulted, did they have any duty to enlarge the culvert?  I say straight away that if what one was concerned with was some wrongful pouring of quantities of water into the stream above the culvert, and flooding being caused simply when such wrongful occurrences occurred, different considerations would apply.  But in this instance there is no suggestion that any person upstream had acted wrongfully in any way.  The amount of natural water in the dyke has simply increased due to changes in activities upstream without wrongful conduct by anyone.  The question is whether the highway authority can say that since there was no nuisance, and indeed no potential nuisance, originally, whatever the state of knowledge that flooding is now being caused and whether or not it is practicable to enlarge the culvert so as to abate the nuisance, there is no liability?  
37.		The judgment of O’Connor J in Leakey at first instance and the judgment of Megaw LJ in Leakey in the Court of Appeal trace the development of the law through the authorities so far as it relates to liability for nuisance caused by things naturally on the land.  Those are the circumstances beyond peradventure where the defendant can say the nuisance or potential nuisance was not created by him.  O’Connor J pointed to the change of heart of Lord Goddard between his view that there should be no liability for brushwood causing flooding in a river in Neath R.D.C. v Williams [1951] 1 KB 115 and his decision seven years later in Davey v Harrow Corporation [1958] 1 QB 60 that there should be liability for trees growing naturally.  O’Connor J pointed also to the development in the law in a defendant’s favour.  O’Connor J referred to those cases where the fact that it might be very costly to remove a nuisance cut no ice with the court and pointed to the fact that Lord Wilberforce’s views in Goldman produced a more reasonable result.  O’Connor J ultimately distinguished Radstock.  He noted the lack of citation of Goldman and suggested that only two authorities relating to nuisance were cited.  That may have been a little unfair in that Sedleigh-Denfield was cited but he would have added that although cited it got no consideration in the judgments in the Court of Appeal.  He thought that in any event Radstock was inconsistent with Davey and he preferred thus to follow Davey with which he believed Goldman to be consistent.  
38.		Radstock appears not to have been cited in the Court of Appeal but Megaw LJ expressly approved O’Connor J’s reasons (see p. 513) and it is difficult to contemplate that he did not approve O’Connor J’s view of Radstock that being an important aspect of the judgment at first instance.  
39.		In my view Sedleigh-Denfield does not supply Mr Palmer with a discrete point before as it were one gets to Leakey and Goldman and it is important to see how the law developed before reaching a conclusion on Radstock.  Sedleigh-Denfield was concerned with a nuisance being caused by the act of a trespasser.  It became known, or should have become known to the owner of the land from which water would flow (if the pipe did not take it away), that the grille was inadequately placed.  Furthermore the replacement of the grille into a correct position was an easy matter.  I do not think that the fact that a nuisance was created from the moment the grille was put down made any difference as to the question of liability.  If the grille was not a nuisance or potential nuisance when put down but became a potential nuisance by virtue of factors for which the landowner was not liable but which again were easily rectified, liability, as it seems to me, would have been the same.  What the House of Lords decided was that if a nuisance was being caused or if a potential nuisance became apparent, even if it had not been created by the occupier of the land, the occupier of the land from which the nuisance emanated became at least potentially or prima facie under a duty to his neighbours.  
40.		In Sedleigh-Denfield it was an easy and inexpensive task to remove the cause of the nuisance and thus the court recognised that the potential duty became an actual duty.  It was the ability to abate the nuisance which led to the finding that the nuisance was continued.  That this is so seems to me to be clear from various passages in the judgments.  In particular Lord Atkin said at 897:- 
“It seems to me clear that if a man permits an offensive thing on his premises to continue to offend, that is, if he knows that it is operating offensively, is able to prevent it, and omits to prevent it, he is permitting the nuisance to continue . . . .” (My underlining) 
It is this point that is emphasised by Upjohn J in Smeaton at 462. 
41.		Sedleigh-Denfield is a clear recognition that, even though a defendant may be able to say that this was not a nuisance created by him, he may still have a duty to abate it, at least if it is a simple task so to do.  The dissenting judgment of Scrutton LJ in Job Edwards Ltd v Birmingham Navigation Company Proprietors [1924] 1 KB 341 (CA) was approved and that in turn thus marked with approval the passage in the 5th Edition of Salmond’s Law of Torts p. 260 which said as follows:- 
“When a nuisance has been created by the act of a trespasser, or otherwise without the act, authority or permission of the occupier, the occupier is not responsible for that nuisance unless, with knowledge or means of knowledge of its existence, he suffers it to continue without taking reasonably prompt and efficient means for its abatement”.  
42.	0	The dissenting judgment of Scrutton LJ in Job Edwards as Megaw LJ pointed out in Leakey was itself a turning point in the development of the law.  In my view Goldman and Leakey simply take Sedleigh-Denfield a stage further.  Megaw LJ demonstrated how his view as to the law was dependent on Sedleigh-Denfield.  But, as already indicated, the view of Lord Wilberforce in Goldman added a further dimension by identifying the considerations which come into play for the purpose of deciding whether it is reasonable to impose a duty on a person to abate what he can see is causing or may cause a nuisance.  A defendant is not entitled simply to say that something was not causing a nuisance when it came on his land or when it was constructed and thus no liability can be imposed on him.  A defendant’s duty is to do that which it is reasonable for him to do.  
43.		That approach, which, as it seems to me, is consistent with Sedleigh-Denfield and with Goldman, is inconsistent with the approach of the majority of the Court of Appeal in Radstock.  The decision in Radstock may be right on its own assumed facts.  Those facts were that a sewer was built under the ground over which the stream flowed, that ground belonging to the plaintiff.  It caused no interference with the flow when built.  Natural forces scoured the bottom of the river (i.e. the plaintiff’s land), and the eddying then caused damage to the bank of the river and the foundation of the plaintiff’s bridge.  On the basis of Goldman and Sedleigh-Denfield it was not appropriate to approach the matter on the basis that simply because the sewer was not a nuisance when created it could never become a nuisance thereafter.  The correct approach on those authorities involved recognising that the builder of the sewer might have a liability if the sewer was causing a nuisance depending on other considerations.  In the particular case it would have been difficult to decide precisely what was the cause of the nuisance remembering it was the eddies which were alleged to be causing the problem and those eddies had caused much of the plaintiff’s land to be scoured away.  Was the responsibility on the plaintiff to replace his land scoured away by natural forces or was the responsibility on the constructor of the sewer to remove the sewer?  In any event was it reasonably practicable for the constructor of the sewer to remove the sewer?  On any view in considering the difficult balancing exercise to be engaged in, the starting point would not have been that an unnatural construction had been placed in the river.  
44.		In my view O’Connor J’s attitude to Radstock was entirely right and that view must be taken to have been endorsed by Megaw LJ (with whom Cumming-Bruce LJ agreed, as did Shaw LJ albeit with misgivings) in the Court of Appeal in Leakey.  I take the view that the Deputy judge in this case was wrong to feel that he was constrained in some way by Radstock.  
The Test 
45.		The test to be applied is that set out by Megaw LJ in Leakey at p. 526E in the following terms:- 
“The defendant’s duty is to do that which it is reasonable for him to do. The criteria of reasonableness include, in respect of a duty of this nature, the factor of what the particular man - not the average man - can be expected to do, having regard, amongst other things, where a serious expenditure of money is required to eliminate or reduce the danger, to his means.  Just as, where physical effort is required to avert an immediate danger, the defendant’s age and physical condition may be relevant in deciding what is reasonable, so also logic and good sense require that, where the expenditure of money is required, the defendant’s capacity to find the money is relevant.  But this can only be in the way of a broad, and not a detailed, assessment; and, in arriving at a judgment on reasonableness, a similar broad assessment may be relevant in some cases as to the neighbour’s capacity to protect himself from damage, whether by way of some form of barrier on his own land or by way of providing funds for expenditure on agreed works on the land of the defendant”.  
Conclusion 
46.		The factors which in my view point in favour of liability are the following.  The defendants’ predecessors must have chosen to construct a culvert to put the natural stream under the highway.  It is common ground that the defendants are to be treated as in no better position than their predecessors.  Even if, as I have suggested, it does not place on the defendants a strict liability for all eventualities thereafter, it places on them a high obligation to see that the natural stream can continue to flow under the highway.  This is not a case of an inadequate sewage system and a plaintiff ratepayer seeking to get the local authority to do its public duty.  This is a case where a private landowner has suffered damage from flooding caused by a culvert built by and under the control of the highway authority.  The highway authority had the means of preventing the flooding by enlarging the culvert at some cost, but basically without great difficulty.  It is not a case where it would be right to conduct a general inquiry as to the budget available to the highway authority or as to its backlog.  One reason why that is not required is that under the statutory provisions as analysed by the judge at the end of his judgment, it appears that the highway authority would be liable to do this work if an appropriate notice had been or was served on them.  It would not in such circumstances be an answer for them to say that they did not have the money to do it having regard to more pressing matters.  Mr Dingemans submitted that the statutory scheme enabled contributions to be obtained where appropriate that being part of his argument as to why liability should not be imposed on the highway authority.  Not much argument was addressed to this point but such argument as was addressed to it by Mr Palmer suggested that it was unlikely that the plaintiffs would be contributors.  Furthermore I would have thought that if the highway authority accepted that they should carry out the works and considered that under the statutory scheme some contributions from others could be obtained, there would be no difficulty in persuading the appropriate authority to serve the required notice pursuant to the Land Drainage Act.  
47.		The judge, if he had felt free to do so, would have found that the highway authority were liable on the test above stated.  In my view he would have been right to do so and I would allow the appeal.  I do not believe there to be any dispute as to damages and it appears to be accepted that if liability was established an injunction should be granted.  As to the precise terms of the injunction submissions can be made.  
Lord Justice Jonathan Parker:  
48.		I agree.  
Lord Justice Peter Gibson: 
49.		Although we are differing from the conclusion reached by the Deputy judge in his careful judgment and despite the able arguments of Mr Dingemans for Kent County Council, there is nothing which I would wish to add to the judgment of Waller LJ with which I am in entire agreement.  
Order:		As minuted by Counsel
(This order does not form part of approved judgment)