England and Wales Court of Appeal (Civil Division) Decisions

IN THE SUPREME COURT OF JUDICATURE
COURT OF APPEAL (CIVIL DIVISION)
ON APPEAL FROM THE SOUTHAMPTON COUNTY COURT
HIS HONOUR JUDGE IAIN HUGHES QC
4SO04320

		Royal Courts of Justice Strand, London, WC2A 2LL
		30 July 2007

Lord Justice Lloyd:

Introduction

1. The Bitterne Stream was once a natural stream running westwards from Humm Hole to the River Itchen. What now exists, from the same starting point, is a channel through which water flows, passing through Bitterne, effectively a suburb of Southampton, and eventually flowing out into the Itchen. For much of its length it is covered over, and the whole bed of the stream is lined with concrete. Part of one of the open stretches runs along the southern boundary of the Claimant's property at 60-64 Cobbett Road, the present buildings on which were constructed in 1998. This area is prone to flooding. Several occasions of flooding occurred in 1999. In these proceedings the Claimant seeks to establish that one or other of the Defendants is responsible for the maintenance of the channel, and responsible for making good any damage caused by failure to maintain it properly.
2. The Claimant contends that the damage to its property caused by the flooding gives rise to a claim in nuisance against the party responsible for the section of the channel which is adjacent to its property. Given that both Defendants deny such responsibility, the Claimant sought declarations as to both the ownership of the relevant section of the channel and responsibility for its maintenance. DJ Ainsworth directed that a preliminary issue be determined as to whether "the culvert" is a sewer and whether the Second Defendant, as sewerage undertaker, has statutory responsibility to maintain it. In this context the culvert means the section of the channel adjacent to the Claimant's property. I will describe it more precisely later in this judgment.
3. HH Judge Iain Hughes QC heard the preliminary issue, with evidence from four witnesses, over three days, and made a site visit on a fourth. He handed judgment down on 14 March 2006, and on 25 May 2006 he heard submissions as to the order to be made. His order, made on that date, answered the preliminary issue by saying that the culvert was a surface water sewer, but not a public sewer. He refused permission to appeal to both the First and the Second Defendants. Only the Second Defendant pursued the question of permission to appeal, which was refused on paper by Jonathan Parker LJ, but granted on oral renewal by the Chancellor.
4. The issue before us is whether the judge was right to hold that the relevant part of what was once a natural watercourse (the Bitterne Stream) has become a sewer. It appears to be accepted that other parts of it have become a surface water sewer, but that is not accepted as true of the relevant part.
5. Debate on this subject involves the use of terminology which may be open to confusion. A flow of water, or the channel along which it flows, may be a watercourse or a sewer, but according to the correct use of legal language it cannot be both. Therefore, to use the word watercourse risks begging the question, even if it might be a natural word to use as a description of a particular feature, according to the ordinary use of language. There may also be confusion between the physical structure along which the water flows, on the one hand, and the flow of water itself, on the other: the container and the contents. That might not matter but for the argument for the Appellant that the only thing which is relevant is the character of the flow, and that the physical characteristics of what it flows through or along is irrelevant.
6. The judge used two phrases: "the channel" referred to the entire course of what used to be the Bitterne Stream from Humm Hole to the Itchen, and "the culvert" meant that part of the channel which is immediately adjacent to the Claimant's property. Part of this stretch is open and part, at the western end, is covered. I will use the same phrases, and will seek to make it clear, if it is necessary to make the distinction, whether I am referring to the flow of liquid along the relevant stretch or to the physical structure.

The facts

7. The judge found that the channel is what used to be the Bitterne Stream, originally a natural watercourse. I will summarise what the judge said about its present course.

i) At the eastern end, at Humm Hole it is still partly open. According to the Public Sewer Map (PSM), which the judge saw, and which was the only map shown to us, it then passes through a covered section going westwards, part of which is along Beech Avenue. Part of this stretch was piped (by the Borough of Southampton) in order to assist in the draining of an area which was a boggy marsh, and which is now occupied by Beechwood Junior School.

ii) From there, it emerges into an open section. At this point the channel is joined by another, both of them issuing into the single channel with which this appeal is concerned. The open section continues as far as Midanbury Lane, it passes under that road, and then it is again open for a stretch which includes the culvert, just to the south of the Claimant's property, before becoming covered again just before it goes under Cobbett Road, which marks the western end of the Claimant's property. The judge noted that the covered stretch adjacent to the Claimant's property was shown as covered over on the 1949 ordnance survey map, and he inferred that this was done to allow for the construction of what became 62 and 64 Cobbett Road, properties which were eventually demolished and replaced by the Claimant's property (see paragraph 52 of the judgment).

iii) From that point on, the channel remains covered for some distance, passing under what is now a gyratory road system involving Cobbett Road and Buller Road. The construction of the gyratory system, in the early 1960s, seems to have involved changes to the course of the channel, so that it now has several right angle bends. The judge held that the major works to the channel in the area of the gyratory system were undertaken by the Borough in its capacity as the statutory sewerage undertaker, in order to deal with surface water (paragraph 67).

iv) West of the gyratory system, the channel goes under Bitterne Road West and under the railway lines just south of Bitterne Station. Part of the work involved in this area was the subject of an agreement dated 27 December 1951 between the Borough of Southampton and the British Transport Commission, which refers to "a 45 inches internal diameter Surface Water Sewer" to be constructed under the Commission's land in a given position. The Borough, predecessor in title of the City Council, undertook to maintain and repair the sewer.

v) Further west from the railway, the channel passes in a covered section as far as just north of Bitterne Manor School. There it becomes open again, and remains open, apart from passing under Quayside Road, until it reaches the Itchen.

8. The stretch of the channel which lies east of the point at which it emerges into an open section near Beech Avenue is shown on the PSM as being a public sewer. The stretch to the west of that point used to be so shown, but was removed from the PSM by the Second Defendant in 2001.
9. The judge recounted the changes in the course of the channel which appear from successive Ordnance Survey maps. In 1878 the whole channel was shown as a natural stream, the only interference with which was the construction, by then, of a single track railway. In the first part of the 20^th century the channel was piped in part to the west of the culvert, and also to the east, near Beech Avenue. In the 1960's or thereabouts the gyratory system was put in, and more piping was done. By the 1949 edition, the culvert is shown sinking in order to allow for the construction of 62 and 64 Cobbett Road, later demolished. At that stage the whole culvert was shown as within the curtilage of 64 Cobbett Road, whereas now it is in the property to the south, from which the judge inferred that the line of the culvert had been moved a little to the south.
10. The judge said that the 1949 edition was the first which showed the culvert, and (at paragraph 116) that there was no evidence as to who had built the culvert (meaning, here, the container – the concrete lining along which the water flows). He was satisfied that parts of the channel to the east and to the west had been constructed by the City Council or its municipal predecessor, which was at the time responsible both for foul and for surface water sewers, but he could make no finding as to who had constructed this part. He accepted that there was no record that the City Council had done so (paragraph 25).
11. As for the flow along the channel, he found that in 1878 it was still a natural stream. At that stage therefore it carried both natural ground water and surface water. According to the evidence there is still a continuous clear water flow in dry weather. The judge said that he had no evidence as to the source of this water flow, though he referred to one witness' statement that the constant base flow of clear water in dry weather showed that ground water was entering the conduit at many points and that it was acting as land drainage for the catchment area. However, the judge said that this water flow had not been tested to see whether it was natural ground water, leaks from water supply pipes, discharges from domestic or commercial premises, run-off drainage, or a combination of these. The culvert is in a natural valley, which will naturally receive surface drainage from both north and south.
12. In addition there are some points in the channel upstream of the culvert at which there is a CSO – standing for combined sewage overflow [or consented storm overflow^[1]]. These are locations at which the regulator (the Environment Agency) has given permission for a foul sewer to overflow into "controlled waters" at times of flash flood (see the Water Resources Act 1991, section 88). As the judge said, as a result, at times of high rainfall, foul sewage will flow through the channel, including the culvert, together with the surface water. These CSOs are known to exist, because they are shown on the PSM, but their terms are not known, as the relevant documents were not in evidence. Mr Darton submitted that they show that the channel downstream is a watercourse, because a surface water sewer is not within the definition of "controlled waters". I agree with the judge that, in the absence of sight of the consents, this is not a point which can be relied on (paragraph 83).

The law

13. Rights and obligations in respect of sewers, and in particular public sewers, have been regulated by statute for a very long time. The Public Health Act 1936 is one of the significant stages in the evolution of statutory regulation in this area. More recently the legislation relating to the privatisation of the water industry (the Water Act 1989 and subsequent Acts, including the Water Industry Act 1991 and the Water Resources Act 1991) has affected the position. However, we were referred to few statutory provisions. Instead, as before the judge, Counsel's submissions focussed on a number of decided cases.
14. In George Legge & Son Ltd v Wenlock Corporation [1938] AC 204 the House of Lords held that the discharge of sewage into a natural watercourse since 1876 could not convert the stream into a sewer, because the discharge of sewage was unlawful under the Rivers Pollution Prevention Act 1876. Lord MacMillan pointed out at page 213 that a channel may be a sewer though it may carry no sewage and its contents consist solely of innocuous surface drainage. Since any natural stream or watercourse which is still open will almost always contain some surface water, at any rate in or after wet weather, the fact that a flow of water does contain such surface water cannot show that it is a sewer, and cannot transform what was once a watercourse into a sewer.
15. In Shepherd v Croft [1911] 1 Ch 521, at 526-7, Parker J said that "the mere fact that a natural watercourse is culverted or piped by the several owners of the lands which are intersected by it does not make it a drain or sewer so as to vest it in the local authority", under the Public Health Act 1875. Shortly afterwards, in A-G v Lewes Corporation [1911] 2 Ch 495, Swinfen Eady J had to consider a converse case, where crude sewage was discharged by the local authority into an intermittent stream, partly tidal. He said at page 508:

"The question then arises, is the culvert a sewer? The plaintiffs contend it is. The defendants dispute it. The mere pollution of a natural stream or watercourse by turning sewage into it does not convert it into a sewer. On the other hand, if the watercourse has become substantially a sewer, the fact that at certain periods of the year clean water flows into it will not in my opinion prevent it from being a sewer. The question is one of fact and degree in each case. See Falconar v. South Shields Corporation (1895) 11 TLR 223. In that case Lindley L.J. pointed out that the stream had changed its character completely and had become a sewer in the ordinary sense of the word, i.e., a channel for the reception and carrying away of sewage. It was a dirty, filthy sewer."

16. The principal modern case on the point is the decision of the Court of Appeal in British Railways Board v. Tonbridge and Malling District Council (1981) 79 LGR 565. Oliver LJ gave the judgment of the court. The question was whether a culvert under a railway carried a sewer or a watercourse. It appeared that the construction of the railway had interrupted three ancient natural channels or watercourses which drained a large catchment area, and the culvert was constructed in order to carry the water from the ancient watercourses away despite the obstacle created by the railway embankment. If it was a sewer the Board could seek to have it vested in the local authority under section 17 of the Public Health Act 1936, but this did not apply if it was not a sewer but a watercourse. At page 572 Oliver LJ said:

"Granted that in certain circumstances that which started life as a watercourse can become a sewer, that is not easily established where all that has happened is that water, whether surface water or foul water, has been made to flow through an outfall into an existing natural stream. One has to ask whether the circumstances are such that the stream has substantially lost its original character and taken on the character of a sewer and that does not occur simply because the stream is made to carry a quantity of sewage."

17. Later, at page 573, he went on:

"What is clear is that something very much more than the mere discharge of sewage into a stream (and, a fortiori, the mere discharge of pure surface water) is required before its status is changed to that of a sewer (see, for instance, Glasgow, Yoker & Clydebank Railway Company v. MacIndoe (1896) 24 R. (Ct. of Sess.) 160). Thus, for instance, if circumstances are such that what was originally an agricultural stream comes to carry sewage in such substantial quantities that its character is completely changed (as occurred in Falconar v. Corporation of South Shields (1895) 11 T.L.R. 223) it may no doubt become a sewer within the ordinary meaning of the word."

18. He then cited a passage from the speech of Lord Maugham in the George Legge case and went on to say this, at pages 574-5:

"In the instant case there has been nothing approaching the situation envisaged by Lord Maugham in the passage I have read. All that has happened is that outfalls have been constructed channelling the surface drainage of the built-up area into the existing streams so as to increase to some extent the flow of surface water which they carry away; and it is, Mr Nugee submits, quite impossible to say that these streams have become, as a result of such increased flow of surface water, "sewers" within the ordinary meaning of the word.

We find Mr Nugee's argument persuasive. On the facts as found or agreed at the trial it is, in our judgment, clear that there has been no alteration in the essential character of the three watercourses and the culvert since 1840 and the mere fact that the surface drainage of the built-up area has been collected and diverted into them through a number of outfalls so as to produce a significant increase in the volume of water carried off, cannot possibly constitute them, either individually or collectively, sewers or a sewer within the ordinary meaning of that term."

In that case no question arose as to works done by a statutory authority which might have been done in the capacity of a sewerage undertaker, and might therefore have had a bearing on the status of the resulting works. All the work had been done by the railway company under its own statutory powers.

19. We were shown a more recent decision of the Court of Appeal where such a question did arise, Sefton Metropolitan Borough Council v United Utilities Water Ltd [2001] EWCA Civ 1284. That case concerned part of Maghull Brook, which passed under the densely populated centre of Maghull, in Merseyside, in an enclosed culvert constructed in about 1958. The question was whether this part had become a sewer before 1 April 1974, because of the culverting work. The question arose indirectly. The British Transport Commission was successor to the Leeds and Liverpool Canal Company. The Leeds and Liverpool canal passed over this part of the Maghull Brook, by way of an arch or tunnel constructed under statutory authority, which the Commission was bound under the same statute to maintain. West Lancashire Rural District Council (the RDC) was, before 1974, the relevant local authority for the area, and was also the sewerage authority for the area under Part II of the Public Health Act 1936. In 1961 the Commission and the RDC entered into a deed under which each of them accepted responsibility for half the cost of repairing maintaining and renewing the arch and channel under the canal. In 1974 Sefton Metropolitan Borough Council became the relevant local authority but North West Water Authority became the sewerage undertaker. The question was which of these two authorities (or rather its successor in the case of the sewerage undertaker, namely United Utilities) was responsible for the liabilities of the RDC under the 1961 Deed. This turned on the question in which capacity the RDC had acted when it entered into the deed. In turn this depended on the capacity in which the RDC had done the work of culverting in 1958. Had it been done under Part II of the 1936 Act, which applies to local authorities' functions and duties in respect of sewerage, or was it under Part XI of the Act, which set out a number of miscellaneous powers of local authorities? The trial judge had held that the relevant stretch of the Maghull Brook had always been a watercourse, and had not changed its character as such. Sefton appealed and argued, among other grounds, that the judge was wrong not to hold that the character of this part of the Maghull Brook had changed to a sewer before 1 April 1974, but this argument was not pursued on appeal. The appeal focussed instead on the evidence as to the basis on which the culverting work had been undertaken in 1958. Robert Walker LJ said that the references in the minutes were not all one way, but that overall he was satisfied that the work had been undertaken under Part XI of the 1936 Act, under general local authority powers, and not under Part II, under powers conferred on a local authority in respect of sewerage. Given the different focus of the arguments in that case, on the fact that the culverting work was done by a particular authority which had two capacities, and on finding out in which capacity it had acted, it is not surprising that attention was given not to the flow along the relevant channel but to the construction work undertaken, and to the basis on which it was undertaken. Robert Walker LJ referred to the British Railways Board case, which had been cited to the judge, though not to the Court of Appeal because of the abandonment of the ground of appeal to which it was relevant. It does not seem to me that the Sefton case adds to or qualifies what was said in the British Railways Board case, save to demonstrate that construction work done in relation to a channel may make a difference, depending on who did it and in what capacity.
20. It seems to have been common ground that the Maghull Brook was still a natural watercourse both upstream of the culvert, in a small undeveloped area east of Maghull, and also downstream towards its junction with the river Alt. This fact seems not to have been regarded as being incompatible in itself with an intermediate part of the Brook having become a sewer, by virtue of works done under a particular statutory authority, but since the decision was that the work had been done by the RDC under general powers, not under sewerage powers, the point did not arise for decision as to whether it is legally possible to have a flow which is a watercourse for part of its length and a sewer for another part, with all or part of the watercourse downstream from the sewer.

The judge's decision

21. Judge Hughes decided that the culvert had become a sewer, but not a public sewer. He posed the question "whether the character of the natural stream has changed to such an extent that the channel has become a sewer in the ordinary, non statutory sense of the word": see paragraph 41, based on the BRB case. Later, at paragraph 46, he formulated the test as "whether there has been so substantial a change in the character of the channel as to transform it into a sewer", as a question of fact and degree in every case in the light of the guidance given by the BRB case, and said that it was not an easy test to satisfy.
22. The judge then reviewed the facts, and came to consider their effect, starting with the evidence as to a continued flow of ground water. He rejected this, on the basis that Southern Water had not proved that the continued flow of clear water in dry weather (which he accepted there was) was attributable to ground water (paragraphs 88 to 90).
23. The factors which he did regard as relevant were these. First, the complete change in the structure of the channel; secondly the change in the route of the channel; thirdly the change in the nature of the flow; fourthly the fact that the channel is used for the drainage of buildings and yards appurtenant to buildings; fifthly the fact that many tributary conduits are themselves sewers properly so called; sixthly the description given to the channel in documents from 1951 onwards; next the capacity of the channel, and last the occasional presence of foul sewage in the channel.
24. He went on to consider the second question, whether the sewer was a public sewer. Although there is no appeal against his decision that it was not a public sewer, it is pertinent to note what he said on this point. Under section 219(1) of the Water Industry Act 1991 it was a public sewer only if it was a sewer vested in a sewerage undertaker in its capacity as such, whether vested in that undertaker pursuant to a scheme under provisions of the Water Act 1989 or the 1991 Act (which provided for the transfer of functions, assets and liabilities in relation to privatisation of the water industry) or under section 179 of the 1991 Act (which it was not) "or otherwise". The judge said that, to be so vested, it would have to have been a public sewer at the date of the transfer of the property rights and liabilities of the Southern Water Authority, the former sewerage undertaker, to the Second Defendant as part of the privatisation process under the Water Act 1989. In order to qualify in that way, he said that it had to come within statutory requirements of section 20 of the Public Health Act 1939^[2]. This offered three possibilities:

i) The sewer was constructed prior to 1 October 1937;

ii) The sewer was built as a sewer by the municipal predecessor of the City Council after 1 October 1937, or acquired by it;

iii) The sewer had been the subject of a specific declaration of vesting on the part of Southern Water or its municipal predecessor under section 17 of the 1936 Act.

25. He rejected the first of these, on the basis that the channel was not constructed in its present form before 1937, and in particular the culvert was first shown to exist as such in the 1949 ordnance survey. He rejected the second because there was no evidence that the municipal predecessor had done anything to the culvert (unlike to other parts of the channel). There was no evidence of any declaration of vesting, so the third possibility was also irrelevant. Accordingly, given that he had held that it was a sewer, it followed that it was a private, rather than a public, sewer.

Discussion

26. Mr Darton, for Southern Water Services Ltd (Southern Water), the sewerage undertaker, submitted that most of the factors relied on by the judge for his finding that it was a sewer rather than a watercourse are irrelevant in law, and that the only relevant matter is the nature of the flow, basing this submission on the BRB case, and that the change in the nature of the flow along the culvert was nothing like substantial enough to satisfy the test set out by Oliver LJ in that case.
27. Mr Chapman, for Raglan, supported the judge's approach and conclusion, in particular submitting that more factors than just the nature of the flow were relevant to be considered in addressing the question of fact and degree as to whether the nature of what had been a watercourse had changed so that it was a sewer. Mr Burns, for Southampton City Council, the relevant local authority, submitted that the only issue before the court was as to the status of the culvert, rather than the rest of the channel, and made common cause with Mr Chapman in supporting the judge's approach on the evidence.
28. The judge's order relates only to the status of the culvert, not to the whole channel, even though the judge made findings as to what had happened to other parts of the channel. Mr Burns is therefore correct in pointing out that the appeal is therefore only concerned with the culvert as such. It does not follow that because one part of the channel is a sewer, another part of it is. It seems to me that, logically, the status of a stretch downstream from the culvert is unlikely to be relevant to the status of the culvert itself. It might seem odd to find that a section of the channel which is upstream of the culvert was a sewer, but that the culvert itself was a watercourse. It may be less odd if one remembers that a flow may be a sewer even though it carries no foul sewage, but only surface water. I note that at several points in his judgment the judge did pose the question in relation to the status of the channel as a whole: see paragraphs 41, 46 and 109. Expressing his conclusion in paragraph 109 (quoted in full below at paragraph [34]) he said:

"I am satisfied on this evidence that there has been so substantial a change in the character of the channel, and therefore the culvert, as to transform it into a sewer."

29. Where the question for decision is as to the status of a particular stretch of a stream or flow, such as the culvert in the present case, I would not regard evidence as to what has happened to other parts of the stream or flow as being irrelevant, but it does seem to me that the question needs to be addressed by reference to the specific stretch at issue, rather than the stream or flow as a whole. Otherwise there is a risk that matters relating to other parts of the stream will be regarded as having more significance than they should.
30. The judge found that two parts of the channel downstream from the culvert were the subject of works done by the relevant sewerage undertaker as such: see paragraphs 55 to 58, and 64 to 67. That applies to the length under and near the railway, and that under the gyratory system, immediately to the west of the culvert.
31. So far as the culvert itself is concerned, part of it is piped and covered, and the rest of it is lined in concrete. The judge had no evidence as to who had done this work over the length of the culvert, nor when (except that the piped section was created by 1949) or on what basis (see paragraph 116). Of course, by itself the fact that a watercourse is lined, or is piped and covered over, does not make a difference to its status (see Shepherd v Croft, quoted at paragraph [15] above).
32. The judge referred to a different point at paragraph 94, namely the fact that, in addition to the pipe carrying the flow along the line of the original watercourse, a second pipe discharges into the channel, by a junction created upstream of the culvert, which, as the judge said "has nothing to do with the original stream but is intended to assist with the removal of surface water sewage and, on occasions, foul sewage". It seems to me that this point goes with other aspects of the change in the flow through or along the channel. He said at paragraph 98 that "the channel now receives flow from a number of other sewers, principally surface water sewers but also on occasion foul sewers". At paragraph 99 he continued: "the evidence suggests that the primary function of the channel is now surface water sewage. Most of the surface water sewers in the area discharge directly or indirectly into it." He mentioned the fact that the significant part of the channel which runs under Beech Avenue is still shown on the PSM (maintained by Southern Water) as a public surface water sewer, and said that, since that part of the channel is no different in character from the part which lies downstream, it is difficult to see why one part should be treated differently from the other in terms of legal classification.
33. Mr Darton submitted, on the basis of the BRB case, that the fact that a watercourse carries away surface water cannot make it a sewer (see paragraph [17] above). The judge also relied on the fact that the channel (including the culvert) carries foul sewage on occasion, pursuant to the CSOs already mentioned, at times of flash flood. At paragraphs 107 and 108 he said this:

"107. The mere presence of foul sewage cannot alter the character of a watercourse. However the channel passes through a densely populated area of Southampton and for three lengths (excluding Humm Hole) flows in an open culvert. The risk of flooding is at its greatest at the very times when the presence of foul sewage is most likely.

108. On the evidence of past history flooding will take place at the property where the channel sinks. On the other side of the culvert at this point is another development of residential flats. I consider the occasional but deliberate discharge of foul sewage into a channel of this nature, with these characteristics, to be significant and quite different in nature and effect to a discharge of foul sewage into a river or watercourse in a rural area. I consider it proper to take this into account when considering this issue because of the impact of a flood including foul sewage on a population that did not exist when the channel was Bitterne stream."

34. However, his conclusion, at paragraph 109, was that the channel, including the culvert, had become a sewer, but a surface water sewer. He said:

"109. The effect of these various features is cumulative, although some are plainly more important than others. Considering the features I have identified and the channel as a whole it no longer can sensibly be called a stream or a watercourse without undue strain to the ordinary meaning of those terms. I am satisfied on this evidence that there has been so substantial a change in the character of the channel, and therefore the culvert, as to transform it into a sewer. More precisely, it has become a surface water sewer."

35. Among the factors to which he referred was the change in the route of the channel. The significant changes in this respect were all downstream from the culvert. It does not seem to me that these can affect the proper view of the status of the culvert itself. He also referred to the fact that the channel was described, from time to time, as a sewer in formal documents. Again, these references were to stretches downstream from the culvert. For these parts of the channel the description may have been significant, because they showed the basis on which the work was done. In my judgment they do not affect the position upstream. He also referred to the fact that the capacity of the piped section of the channel is much greater than would be necessary to cope with only natural flow. That applies to sections both downstream and upstream from the culvert. It seems to me that it goes with the fact that the channel now does carry away a lot of surface water.
36. Thus, taking the various points together, there are three main separate factors, or groups of factors, which the judge regarded as relevant: (i) the channel as a whole, and the culvert in particular, is now piped or at least (where it is open) lined in concrete; (ii) the flow includes a great deal more surface water than it used to, including surface water brought to the channel by way of conduits which are or include surface water sewers, and it might be said, therefore, to form part of the surface water sewer network; (iii) the channel, and in particular the culvert, carries foul water on occasion, at times of flash flood, pursuant to consents given under the relevant legislation.
37. Mr Darton's submissions on those factors, based on the BRB case, are clear and simple: piping or lining a flow of water does not affect its status; adding more surface water to a watercourse makes no difference; and the presence of foul sewage is not sufficient to change a watercourse into a sewer unless the quantity of sewage is very substantial, which clearly it is not in the present case.
38. Given that, as the George Legge case showed, the discharge of foul sewage into a natural watercourse could not convert a watercourse into a sewer, because the passing of the 1876 Act made such discharge illegal, it seems to me that, nowadays, the effect of the discharge of foul sewage into anything other than a foul sewer is likely to depend on the statutory provisions under which it is done. If it is not done with consent, then the position would be the same as under the 1876 Act. If it is done with consent (as in the case of the CSOs referred to above in the present case) then it will depend on the terms of the consent and of the provision under which the consent is given. The judge was not shown the consent, nor, I think, was he taken to the statutory provisions under which the consent may have been given. In those circumstances, it seems to me impossible to base any conclusion on the discharge of the foul sewage into the channel. It is fair to say that, from the terms of his conclusion in paragraph 109, it does not seem that the judge did rely on this aspect to any substantial extent.
39. By itself, it must be right that to put a flow of water into a concrete lining, or even a pipe, is irrelevant to the status of the flow. So the real point is whether the fact that the culvert now receives surface water to a much larger extent than before, brought to it by way of surface water sewers, so that it can be said to form part of the local network of surface water drainage for the area, makes it a surface water sewer itself. It lies downstream from a number of surface water sewers, and further downstream from it parts of the channel appear, from the judge's findings, to have been the subject of works carried out by the sewerage authority as such, so that these parts are therefore presumably also sewers. (I should record that Mr Darton did not accept that the mere fact that a sewerage undertaker does works of construction to the channel of an existing flow, as opposed to constructing a new channel for a new flow, makes it a sewer if it is not one already.)
40. Where work has been done to the structure of a channel through or along which a watercourse flows, the statutory authority for the work could be such that it changes the character of the flow from that of a watercourse to that of a sewer. Whether it does will depend on the facts of the given case and the terms of the statute. No such point arises in the present case as regards the culvert, because it is not known who did such work as has been done to the culvert itself, as distinct from other parts of the channel, and therefore it is also not known whether there was any relevant statutory authority for it. There is no evidence which connects the work done with the City Council, so on the evidence it was not done by a relevant authority. If it had been, it might have qualified as a public sewer.
41. What is left, therefore, is the fact that the culvert, as part of the channel, now carries a great deal more surface water than it did originally, and the question whether it still carries any ground water.
42. The channel carries a continuous base flow of clear water in dry weather, but the judge had no evidence as to the source of this flow. He commented that Southern Water had not tested the water flow to determine whether or not it was natural ground water. He regarded it as possible that it was attributable to one or more of leaks from water supply pipes, discharges from domestic or commercial premises or run-off drainage, rather than natural ground water. He held that this point was not decisive, because if a channel is a sewer, then the fact that it does receive some natural ground water, even on a continuous basis, does not alter its status as a sewer. I agree with that proposition, but it is also true that, if it is a watercourse, the fact that it receives some, or even a great deal of, surface water does not change it into a sewer. Moreover the judge's proposition does beg the question: if it is in issue whether the flow is a sewer or a watercourse, the fact (if it be so) that it continues to carry a flow of natural ground water, as it did historically, is relevant to answering the question. If there were no natural ground water, then it could be much easier to establish that it was now a sewer, because it would only be carrying surface water, rather than carrying such water as an unavoidable addition to natural ground water. The judge approached this question on the basis that it was for Southern Water to show that there was still a continuous flow of natural ground water. I respectfully disagree. Since it is clear that the channel was originally a watercourse, the burden of proof of relevant facts, where in dispute, would be on the party seeking to show that the situation has changed, that is to say on Raglan rather than on Southern Water.
43. The judge may have been influenced in this by the view he took of the Second Defendant's decision, without having gone through the procedures it had laid down for itself to follow, to remove the part of the channel west of Beech Avenue from the PSM. As the judge said (at paragraph 71) this was not determinative, because although a sewerage undertaker is under a statutory duty to maintain a PSM (see Water Industry Act 1991, section 199), the contents of the PSM do not define what is or is not a public sewer. It is not of the same significance as a definitive map of rights of way under the Wildlife and Countryside Act 1981, for example. Nevertheless it is striking that the Second Defendant did remove this part of the channel from the PSM shortly after the first letter from the Claimant's solicitors. The judge may have felt that, before taking such a step, the Second Defendant ought to have tested the clear water flow to assess its source or sources.
44. The judge also paid regard to the evidence of Mr Rawson Burns, a retired chartered engineer who had worked for Southern Water and previously for Havant Borough Council, who gave evidence (among other things) as to the practice about making corrections to a PSM. The judge referred to the criteria which Mr Rawson Burns mentioned in this respect (see paragraph 85), and considered the Second Defendant's decision to remove part of the channel from the PSM in the light of those criteria (paragraph 86). It was in that context that he made the comments referred to above as to the absence of tests on the part of the Second Defendant as to the source of the clear water. Those comments seem to me entirely legitimate in the context of considering the Second Defendant's decision to remove part of the channel from the PSM. They do not necessarily reflect the correct legal approach to the issue which the judge had to decide.
45. However, the judge went on to say (at paragraph 91) that he was not prepared to determine the case solely on the basis of the existence of a significant clear flow during periods of dry weather. I agree that it would not have been appropriate to decide the case solely on such a basis. The main question is as to the significance of the largely increased flow of surface water, emanating from the different sources mentioned by the judge, including a number of upstream tributaries, some of which appear to be surface water sewers.
46. In relation to this, Mr Darton relied heavily on Oliver LJ's words in the BRB case, quoted above at paragraph [17]:

"What is clear is that something very much more than the mere discharge of sewage into a stream (and, a fortiori, the mere discharge of pure surface water) is required before its status is changed to that of a sewer."

47. The judge's decision is based on a number of matters, not all of which I would regard as being of equal relevance. The increase in the amount of surface water in the stream is one of the most important aspects of his reasoning. But it can fairly be argued that he did not proceed on the basis of a mere discharge of surface pure water into the stream. The discharge is, in part, the result of substantial works done by the sewerage undertaker upstream of the culvert, for the drainage of the surface water in what seems likely to be a wider catchment area than that of the original stream. That produces a curious result, on the judge's finding. The stretches of the channel upstream (as well as downstream) where the then sewerage undertaker did works under statutory authority may have become sewers (they were not directly in issue, and I do not say they necessarily did, though clearly the judge thought they did). If so it seems likely, at lowest, that they would have become public sewers which would be the responsibility of Southern Water as sewerage undertaker. By contrast, the judge's conclusion that the culvert had changed from a watercourse to a sewer is largely based on work done elsewhere in the channel by the sewerage undertaker, but because there is no evidence that the then undertaker did any work to the culvert as such, that part of the channel, if it became a sewer, remained a private sewer and is not the responsibility of the sewerage undertaker. Whose responsibility it is remains to be decided: Raglan argues that the City Council is responsible but the Council denies this. I find it surprising that work done by the sewerage undertaker elsewhere in the channel should have had this side-effect as to the status of the culvert to which the sewerage undertaker did nothing in terms of construction, and for which it (rightly, according to the judge) accepts no responsibility in terms of maintenance.

Conclusion

48. I have found the issue on this appeal difficult to decide. I see the force of the judge's comments about the change in the nature of what used to be the natural and open Bitterne Stream, and about the oddity, on Southern Water's contention, of having a fairly short stretch of watercourse in the channel with extensive stretches of what appear to be sewers (and probably public sewers at that, even if only or mainly for surface water, not foul sewage) both upstream and downstream of the part in question. On the other hand, I also find it curious, as I have said, that work upstream and downstream under statutory authority can have not only whatever effect it has on the parts of the channel to which the work was done, but also an incidental effect on the status of the culvert, and what is more, a different effect, because it makes it a sewer but not a public sewer.
49. I would pay tribute to the judge's judgment, which is a model of clarity and deals very fully with the issue before him, in what were clearly far from ideal circumstances, as regards the identification of the preliminary issues, and the manner in which they came before him for decision, including the serious underestimate of the time required. I have, however, come to the conclusion that the judge's decision is wrong, and that the culvert is still a watercourse, not having become a sewer. My reasons for disagreeing with the judge are these.
50. First, I consider that there are some errors in his reasoning. He ought not to have regarded it as being for the Second Defendant to prove that the continuous base flow of clear water in dry weather still included natural ground water. On that point the burden of proof was the other way. He ought not to have taken into account (to the extent that he did, which may not have been great) the discharge of foul sewage under the CSOs. I do not regard the fact that the course of the stream now lies over or through concrete culverts or pipes as a matter which, by itself, can have any relevance to the decision. The circumstances in which the construction works could be relevant, if they were done under statutory authority, but none were relevant to the culvert. The change in the route of the channel is also irrelevant of itself, especially since almost all the significant changes are downstream from the culvert, and matters downstream seem to me to be inherently of little or no relevance to the status of the culvert. I would not attach any importance to the descriptions used in relation to parts of the channel, especially as none applied to the culvert itself (as the judge said, in relation to the second issue, at paragraph 116). It seems to me, also, that the judge approached the question wrongly by considering the status of the channel as a whole, rather than that of the culvert, albeit in the context of the rest of the channel so far as relevant.
51. What certainly is relevant is the nature of the flow through the culvert. The stream started as a watercourse, carrying natural ground water, as well as, inevitably, some surface water. It still starts in the same place and is still partly open there. It seems to me that, in those circumstances, the natural assumption should be that it still carries natural ground water. If Raglan or the City Council wished to contend otherwise, it seems to me that the burden of proof would have been on them. There having been no evidence on the point, it seems to me that the matter should proceed on the basis that the channel still carries some natural ground water. It has not changed in that respect.
52. Clearly it also carries surface water, and no doubt a lot more than it used to. It does occasionally carry some foul sewage, but I do not regard that as relevant, because of the absence of evidence as to the terms and basis of the CSOs. So one is left with the large increase of surface water, the fact that there have been substantial works upstream which presumably add to the flow of surface water, and that some of what there is upstream, by way of tributaries, so to speak, does seem to have the status of sewers, and apparently public sewers.
53. If the question is posed specifically in relation to the culvert, it seems to me that the only relevant change that has occurred is the addition of a great deal more surface water to the flow along that part of the channel. Nothing has happened to change the status of the culvert in terms of works done under statutory authority. The sewerage undertaker has done nothing to that stretch of the channel which can affect its status. Therefore if there has been a change, it must be by virtue of the change in the flow, because the fact that the flow is now channelled and partly piped is not sufficient. It seems to me that, viewed in that light, and by reference to the culvert itself, there is no sufficient change to constitute the flow a sewer rather than a watercourse. I come back to the words of Oliver LJ in the BRB case, quoted at paragraph [17] above. There is no relevant discharge of foul sewage, and though there is an increased discharge of surface water, something very much more than that is needed. In my judgment, on the true analysis of the facts concerning the culvert, there is nothing more than that increased discharge which can be relied on. Accordingly, the status of the stream as it flows through the culvert as a watercourse has not changed, however much its appearance may have changed in that part, and whatever changes there may have been to its character and even its status elsewhere in the channel, both upstream and downstream.
54. For that reason, I would allow this appeal.
55. The judge was understandably critical of the way in which public bodies had incurred substantial cost in pursuing expensive and time-consuming litigation, rather than coming to "a sensible negotiated settlement of what is in reality a relatively minor local issue". It may be, however, that, particularly at a time when flooding is at risk of becoming more prevalent, the issue raised in this appeal has a wider potential significance for sewerage undertakers and others. Whether this decision itself is of wider relevance remains to be seen. Given the extensive flooding experienced in many parts of England in June and July 2007, the importance of issues of this kind is all too plain. I hope that, if such a question arises in future, the court will not have to decide it (as the judge had to in this case) without knowing the statutory basis on which any relevant works of construction were done or even that of the known consents to the occasional discharge of foul sewage.

Lord Justice Toulson

56. HH Judge Hughes QC expressed the view at the beginning of his judgment that the preliminary issue he was being asked to try was inappropriate. I agree, but I am not sure that the judge appreciated the full extent of the problems which it created. I say that in no spirit of criticism, because I too did not appreciate the full extent of the problems until I came to preparing this judgment with the benefit of reading in draft the judgment of the Chancellor. I will come back to this subject but will begin (with the benefit of Lloyd LJ's full summary of the background and the facts) by considering the arguments advanced on behalf of the appellant water authority by Mr Darton.
57. The primary submission made by Mr Darton can be summarised as follows: in considering whether a watercourse has become a sewer, (a) the court is concerned only with what flows through the channel, and not with any questions about how, why or in what circumstances any changes had been made to the construction of the channel, and (b) a watercourse can only become a sewer if the contents of the flow consists so substantially of lawfully deposited foul sewage that it has become essentially a foul water sewer.
58. I reject that submission. It goes further than anything said in the judgment of Oliver LJ in British Railways Board v Tonbridge and Malling District Council (1981) 79 LGR 565 or in the cases cited by him, and it is inconsistent with Sefton Metropolitan Borough Council v United Utilities Water Limited [2001] EWCA Civ 1284.
59. In both British Railways Board v Tonbridge and Malling District Council and Sefton Metropolitan Borough Council v United Utilities Water Limited the courts had to consider whether a natural watercourse had become a sewer within the meaning of the Public Health Act 1936. Section 343 of that Act provided:

" "Drain" means a drain used for the drainage of one building or of any buildings or yards appurtenant to buildings within the same curtilage,"

and

" "sewer" does not include a drain as defined in this section but, save as aforesaid, includes all sewers and drains used for the drainage of buildings and yards appurtenant to buildings."

60. Materially identical language appears in earlier and later statutes dealing with the same subject matter.
61. During the argument the language used by Oliver LJ in British Railways Board v Tonbridge and Malling District Council was subjected to analysis of the kind which would be more appropriate if it appeared in the statute. Arising from Oliver LJ's acceptance of the submission advanced in that case by Mr Nugee QC that the critical question was "whether the circumstances are such that the stream has substantially lost its original character and has taken on the character of a sewer", we heard argument whether the word "stream" in that sentence should be construed so as to include the bed or be confined to the flow.
62. The important point is, as summarised by Robert Walker LJ in Sefton Metropolitan Borough Council v United Utilities Water Limited at [16], that the authorities

"indicate that a natural watercourse can become a sewer within the meaning of the 1936 Act (which I will refer to as a statutory sewer) and that whether this has occurred is a question of fact and of degree."

63. In considering what might or might not bring about a change from a watercourse to a sewer, Oliver LJ said in British Railways Board v Tonbridge and Malling District Council at 573:

"What is clear is that something very much more than mere discharge of sewage into a stream (and, a fortiori, the mere discharge of pure surface water) is required before its status is changed to that of a sewer (see, for instance, Glasgow, Yoker and Clydebank Railway Company v MacIndoe (1896) 24 R(Ct of Sess) 160). Thus, for instance, if circumstances are such that what was originally an agricultural stream comes to carry sewerage in such substantial quantities that its character is completely changed (as occurred in Falconar v Corporation of South Shields (1895) 11 TLR 223) it may no doubt become a sewer within the ordinary meaning of the word."

64. That passage provides authoritative but not exclusive guidance. It does not in my judgment provide a platform for the argument that the only circumstances in which a watercourse can become a sewer is where it has come to carry substantial quantities of foul sewage.
65. If that were so, it would mean that Robert Walker LJ was tilting at a windmill for most of his judgment in Sefton Metropolitan Borough Council v United Utilities Water Limited. In that case part of a watercourse had been enclosed in a mile long stretch of culvert, constructed between 1958 and 1959, under what had become the densely populated centre of Maghull. It received surface water drainage (and some unintended contamination from foul water) from many houses and other buildings in the area, as well as flows from other sources (including undeveloped land and highway drains). In other words, it primarily carried surface water from an urban area and any element of foul water was accidental. On Mr Darton's argument, the culverted stretch could not be a public sewer. That is not how the Court of Appeal approached the matter. It identified the issue as being whether the culverting of the stream had in the relevant circumstances the legal effect of causing the culverted watercourse to become a sewer. The culverting had been done by West Lancashire Rural District Council acting under statutory powers under the 1936 Act. West Lancashire was not only a local authority but a sewerage authority. It therefore had the powers of a sewerage authority under part II of the act and miscellaneous powers as a local authority under part VI. The Leeds and Liverpool canal crossed over the culverted section. After the culverting works have been done, West Lancashire contracted with the canal authority to share the cost of maintaining the crossing. Under a later local government reorganisation, Sefton Metropolitan Borough Council became West Lancashire's successor as local authority, and West Lancashire's rights and liabilities as sewerage authority became vested in the North West Water Authority. The question arose whether the new local authority or the new sewerage authority was responsible for West Lancashire's contractual obligations in relation to the crossing of the culvert with the canal. For this purpose it was necessary to consider whether the culverted section had become a public sewer.
66. Robert Walker LJ in his judgment, with which Henry and Rix LJJ agreed, noted at [21] that in British Railways Board v Tonbridge and Malling District Council the court did not enquire into the statutory power under which part of the natural watercourse had been piped, but that in the instant case both parties had recognised that the essential issue was whether in carrying out the culverting work West Lancashire had been acting as a sewage authority under it part XI powers. The judge had held the latter, and his decision was upheld. Accordingly the work had not been done by West Lancashire as a sewerage authority and in those circumstances the works did not convert the watercourse into a public sewer.
67. Robert Walker LJ observed at [41] that both parties were agreed that West Lancashire could not have been exercising powers under both part II and part XI simultaneously. He added:

"It is not obvious to me why a pipe substituted for a watercourse under s 262(1) might not in some circumstances be a statutory surface-water sewer from the time of its construction, if at that time the watercourse was already receiving flows from other surface-water drains and sewers, and might not be a public sewer if constructed by a sewerage authority. But that line of argument was not adopted by experienced counsel on either side."

68. The observation was obiter, but it is instructive to note in what respect. Robert Walker LJ was there saying that he could see no reason why if a sewerage authority (which was also a local authority) installed a pipe for surface water in place of a watercourse already receiving surface water, this might not be a public sewer, albeit that the statutory power used for the construction of the pipe was under s 262(1), i.e. within part XI. The point "not adopted by experienced counsel" was that a sewage authority could use part XI powers in that way, as distinct from proceeding under part II. If, however, the court had held that West Lancashire had been using part II powers to construct the culvert (and nobody suggested that it could not have done so), it is clear that the court would have held that the culverted section would in those circumstances have become a public sewer, although it was predominantly for surface water.
69. In the present case there was no evidence before the judge who built the section of culvert adjoining the claimant's premises. But upstream of that section the local authority had undertaken substantial work piping what had originally been the watercourse in order to take surface water from urban development and also to permit combined sewage overflows. A combined sewage overflow or "CSO" is a connection between a foul and surface water sewer in order to relieve pressure on foul sewers during periods of high rain fall. The judge found as a fact that the City Council's predecessor constructed the channel under Beech Avenue to provide a surface water sewer. He was entitled so to find (although I note as a matter of detail from the Public Sewer Map that the channel beneath Beech Avenue also appears to have a number of CSOs).
70. Mr Darton submitted that this was wrong. He submitted that even where a sewerage authority in purported exercise of statutory powers laid pipe work in order to take surface water along the line of a previous watercourse, however small the previous flow may have been and however large the subsequent flow might be, the resulting work could not be a sewer in law; and that in so far as Robert Walker LJ's approach in Sefton Metropolitan Borough Council v United Utilities Water Limited suggested otherwise, that approach was wrong. I do not accept that.
71. Mr Darton further argued that if he were wrong in that submission, the matter is of no relevance when considering the status of the culvert adjacent to the claimant's property. This brings me to what I regard as the really difficult part of the case, and it is a novel point. Taking it as an established fact that the channel under Beech Avenue was constructed as a sewer under statutory authority, what is the effect on the culvert with which the judge was concerned? The judge recorded that the two pipes beneath Beach Avenue had diameters of 450 mm and 800 mm. Their contents flowed into the culvert adjacent to Raglan's land and on a common sense view must have constituted the vast majority of what entered the culvert.
72. As the Chancellor points out, the judge was not asked to determine the status of the culvert within a statutory context. The Chancellor has referred in [79] to the definition of sewer in s 219 of the Water Industry Act 1991 (which is substantially the same as in the 1936 Act) but, as he observes, the judge did not consider that section to be of assistance. It is not satisfactory to decide a difficult point of law on an ill drafted preliminary issue. I also suspect that the real issues between Raglan and the defendants involve wider considerations. Raglan is concerned about the risk of flooding. If a sewerage authority constructs a sewer in such a way that it is liable to cause flooding of land in the proximity, I can see that it may be liable at common law for the damage caused, whether the water issues directly from the authority's sewer or floods the bed of a natural small watercourse and so floods the neighbouring land. But none of this falls within the preliminary issue.
73. I have real doubts about the appropriateness of the exercise which the judge was asked to carry out. However, I am also conscious that the parties have already incurred considerable expense, much of which will fall on the public. So with those reservations I proceed to give my view on the question whether the judge was entitled to find that the relevant culvert is a sewer (using the word as interpreted in previous authorities under statutes containing a similar definition to that in the 1991 Act).
74. If the channel immediately upstream of the section adjacent to the claimant's property has been turned into a public sewer to accommodate principally surface water in much increased quantity, but also some foul water when the occasion requires, the impact of those changes on the section by the claimant's property is in my view properly to be taken into account in considering whether that section has changed its character. Whether there has been such a change is ultimately a question of fact and degree. Mr Darton submitted that it would be ludicrous that a change in the character of one part of a channel should necessarily produce a change several miles away. I agree. A common sense view has to be taken on the particular facts. The fact that the water authority's own Public Sewer Map showed the relevant section as a public sewer until the present dispute arose, and the water authority issued a new version showing it not as a public sewer, was material which the judge was entitled to take into account as evidence of how the authority itself regarded the relevant section at the time when the map was originally prepared.
75. In his careful and thorough judgment, after reviewing the authorities the judge summarised the basis on which he had to proceed as follows:

"I proceed on the basis that the correct test is whether there has been so substantial a change in the character of the channel as to transform it into a sewer. This is a question of fact and degree in each case, taking into account the above guidelines. The authorities make it plain that the test is a high one."

76. He then proceeded to set out the facts in full and careful detail. In my judgment he was entitled to conclude that at the relevant time the culvert with which he was concerned had become but a section in a network of a public sewerage system, predominantly but not exclusively for surface water, and that its character had therefore changed to the extent that it had become a sewer. I would therefore dismiss the appeal.

The Chancellor

77. The issue before HH Judge Hughes QC was "whether the culvert is a sewer and whether Southern Water have the statutory responsibility to maintain the same". The culvert was described by the judge as "adjacent to [60-64 Cobbett Road, Bitterne, Southampton] and running along the southern boundary but not within Raglan's ownership". By his order made on 25th May 2006 the judge declared the culvert to be "a surface water sewer but....not a public sewer within the statutory meaning of the same". Lloyd LJ has described both the culvert and the channel of which it forms part and I gratefully adopt his descriptions.
78. The judge described the circumstances in which the issue arose in paragraphs 8 and 9 of his judgment. Thus, Raglan argued that the culvert was a sewer, whether public or not, and not a watercourse in its endeavour to impose liability for its flooding on one or other of Southampton City Council or Southern Water Services Ltd. The City Council contended that the culvert was a public sewer so as, it hoped, to shift any liability on to Southern Water. Southern Water argued that the culvert was either a watercourse or a non-public sewer so as to divert any liability back to Raglan as riparian owner or the City Council. In those circumstances the judge considered (paragraph 10) that he should approach the preliminary issue in two parts: "First, is the culvert a sewer at all? Secondly, if the culvert is a sewer is it a public sewer?"
79. The statutory meaning to which the judge referred in his order is that contained in Water Industry Act 1991. S.219(1) contains a number of definitions of potential relevance "except in so far as the context otherwise requires". Thus:

""public sewer" means a sewer for the time being vested in a sewerage undertaker in its capacity as such...."

""sewer" includes (without prejudice to subsection (2) below) all sewers and drains (not being drains within the meaning given by this subsection) which are used for the drainage of buildings and yards appurtenant to buildings;"

""surface water" includes water from roofs;"

""watercourse" includes all rivers, streams, ditches, drains, cuts, culverts, dykes, sluices, sewers and passages through which water flows...."

Though he referred in paragraph 37 of his judgment to the fact that both Raglan and the City Council relied on s.219 to support their respective arguments he concluded that those provisions did not determine the matter (paragraphs 37 and 43).

80. Instead of applying any of those statutory definitions the judge adopted as the proper test, which he understood by the end of the argument to be common ground, that explained by Oliver LJ in British Railways Board v Tonbridge and Malling DC (1981) 79 LGR 565, 572 quoted by Lloyd LJ in paragraph [16] of his judgment. The judge summarised that test in paragraph 46 of his judgment as:

"...whether there has been so substantial a change in the character of the channel as to transform it into a sewer. This is a question of fact and degree in each case, taking into account the above guidance. The authorities make it plain that the test is a high one."

81. In my view that proposition is open to criticism in two respects. First, it looks to the channel as a whole not just the culvert to which the preliminary issue was rightly confined. Elsewhere in his judgment, for example paragraph 10, the judge altered the word 'channel' to 'culvert'. But it does not appear that the use of the word 'channel' in paragraph 46 is a mistake because there are later passages in his judgment where the judge refers expressly to parts of the 'channel' when considering the status of the 'culvert'. As Lloyd LJ has pointed out in paragraph [28] of his judgment, logically the status of a stretch of the channel downstream of the culvert can be of little, if any, relevance once it is accepted that it is possible for different sections of the channel to have a different status. The second error lies in the omission of any reference to the contents of the channel. Whether or not the composition of the contents is the only consideration it is one of the most relevant, as the judgment of Oliver LJ in British Railways Board v Tonbridge and Malling DC (1981) 79 LGR 565 shows.
82. The judge then traced the history of the channel (paragraphs 47 to 91) and summarised the material facts (paragraphs 93 to 108) under the headings (a) "The structure of the channel has completely changed", (b) "The route of the channel has changed to a significant extent", (c) "The nature of the flow has changed", (d) "The channel is used for the drainage of 'buildings and yards appurtenant to buildings'", (e) "Many of the tributary conduits are themselves sewers, properly so-called", (f) "The description given to the channel after the war", (g) "The capacity of the channel" and (h) "the occasional presence of foul sewage in the channel". The Judge's conclusion, expressed in paragraph 109 of his judgment, is as follows:

"The effect of these various features is cumulative, although some are plainly more important than others. Considering the features I have identified and the channel as a whole it no longer can sensibly be called a stream or watercourse without undue strain to the ordinary meaning of those terms. I am satisfied on this evidence that there has been so substantial a change in the character of the channel, and therefore the culvert, as to transform it into a sewer. More precisely it has become a surface water sewer."

83. In my view the focus for the judge's consideration and his conclusion, namely the channel as a whole, was wrong in both the respects to which I have referred in paragraph [81] above. The issue is the status of the culvert. Much of the judge's consideration was devoted to the construction of the channel downstream of the culvert and independently of its flow or contents. As such it was of marginal, if any, relevance.
84. The judge then considered the second issue he had analysed and concluded that the culvert was not a public sewer within the meaning of s.219 Water Industry Act 1991. That depended on the identity of the undertaker in which it was vested. There is no appeal from that conclusion. Thus this court is left in the unsatisfactory position of being expected to determine the first of the issues to which the judge referred, namely whether "the culvert is a sewer at all", by reference to 'the natural and ordinary meaning of the word "sewer"' divorced from a particular statutory context in Public Health Act 1936, Water Industry Act 1991 or any other relevant statutory provision.
85. That, as I understand it, is why all parties have relied on the judgment of Oliver LJ in British Railways Board v Tonbridge and Malling DC (1981) 79 LGR 565. As he made plain on page 571 he was considering, at least in the passages which followed, the natural and ordinary meaning of the word "sewer", notwithstanding that the case itself concerned the meaning of the word in the context of the Public Health Act 1936. Those passages have been quoted by Lloyd LJ in paragraphs [16] to [18] and I need not repeat them. They clearly show that the nature of the contents or flow of the culvert is the most significant factor in the determination of the question whether what was once a natural watercourse has become a sewer. But I agree with Toulson LJ [64] that the decision of the Court of Appeal in that case does not establish that alterations to the bed and banks of the culvert or of an upstream section of the channel are irrelevant to the question. It is easy to envisage cases where the additional flow of sewage is inconclusive but works to the relevant bed and banks resolve the issue.
86. On the other hand I agree with Lloyd LJ that the decision of this court in Sefton Metropolitan Borough Council v United Utilities Water Ltd [2001] EWCA Civ 1284 does not carry the matter much further. As he has explained in [19]-[20], the reference in that case to the decision of the Court of Appeal in British Railways Board v Tonbridge and Malling DC (1981) 79 LGR 565 was only in connection with a ground of appeal which had been abandoned. But the decision in Sefton does confirm that construction work on the culvert and upstream bed and banks may be relevant, at least if who did it and in what capacity is relevant to the issue.
87. I agree with Lloyd LJ that for the reasons he gives [38] – [40] and [50] various considerations the judge took account of have to be excluded from consideration or substantially discounted. Accordingly, as he said in [41], one is left with

"the fact that the culvert, as part of the channel now carries a great deal more surface water than it did originally and the question whether it still carries any ground water."

88. If the question is whether the culvert is a sewer within the meaning of the definition contained in s.219 Water Industry Act 1991 I have quoted in paragraph [79] above then it may be that the presence of surface water in the volume now to be found in the culvert would be enough to alter its essential nature from watercourse to sewer. But I do not understand that to be the question because there is no appeal from judge's conclusion on the second part of the preliminary issue. If, by contrast, the question is whether on the test propounded by Oliver LJ in British Railways Board v Tonbridge and Malling DC (1981) 79 LGR 565 for a change from natural watercourse to sewer is satisfied then the increased flow of surface water through the culvert cannot be enough. Even if one adds the occasional presence of raw sewage pursuant to the CSOs to the natural ground water and surface water the test still cannot be satisfied. Nor, in my view, can it matter if some part of the channel upstream of the culvert is classified as a sewer for some specific statutory purpose unless the statutory test is the same as that propounded by Oliver LJ.
89. For these reasons I agree with the conclusion of Lloyd LJ and respectfully differ from that of Toulson LJ. I would allow this appeal.
90. The fact that, by a majority, we are differing from the conclusion of the judge should not obscure the fact that he was presented with an impossible task and dealt with it as well as any judge could. The preliminary issue should never have been ordered to be tried in the form it was put forward, or, perhaps, in any form. There was no common standard by which the issue "whether the culvert is a sewer" was to be judged. Each party was seeking to establish, avoid or shift liability for the alleged nuisance suffered by Raglan. They sought to establish, avoid or shift liability in a variety of ways to which the issue whether the culvert was a sewer might be relevant but by reference to different meanings of the word. Second the case had not been properly prepared by some or all the parties. Third, the judge was, for whatever reason, given inadequate time to pre-read or hear the case or to finalise his judgment. Fourth, the trial of the preliminary issue has merely increased costs and delay in the resolution of this dispute and was never likely to do anything else. These points are dealt with by the judge in paragraphs 11 to 24 in tones of studied moderation. His moderation should not minimise the ample justification for his criticisms.
91. We will hear further argument on the form of order we should make to give effect to the conclusion of the majority. We shall wish to be addressed on whether we should merely allow the appeal and set aside the order of the court below or whether we should go further and make some declaration of our own and, if so, in what terms. We shall also wish to consider what directions for the future conduct of this action should be given so as to ensure that it is progressed to a conclusion without further delay and at the least expense.

Note 1   [At paragraph 29 the judge gives “combined sewage overflow” as the phrase for which CSO stands. In the Appellant’s skeleton argument, paragraph 10 says the same, but paragraph 4(v) footnote 1 gives “Consented Storm Overflows”: which is correct?]    [Back]

Note 2   [This is what the judge said at paragraph 113, but should the reference be to the 1936 Act?]    [Back]