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	England and Wales Court of Appeal (Civil Division) Decisions
You are here: BAILII >> Databases >> England and Wales Court of Appeal (Civil Division) Decisions >> British Waterways Board v Severn Trent Water Ltd [2001] EWCA Civ 276 (2 March 2001) URL: http://www.bailii.org/ew/cases/EWCA/Civ/2001/276.html Cite as: [2001] 3 WLR 613, [2001] NPC 53, [2001] EWCA Civ 276, [2002] EHLR 1, [2001] 3 All ER 673, [2001] Env LR 45, [2002] Ch 25

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IN THE SUPREME COURT OF JUDICATURE
COURT OF APPEAL CIVIL (CIVIL DIVISION)
ON APPEAL FROM THE HIGH COURT
CHANCERY DIVISION
Arden J.

		Royal Courts of Justice Strand, London, WC2A 2LL Friday 2nd March 2001

PETER GIBSON L.J. :

1. The issue raised by this appeal is of some importance both to the sewage industry and also to owners of canals and other watercourses and, if the sewerage undertaker is right, the owners of other land in which a sewer has been laid. It is whether a sewerage undertaker has the right to discharge water from its sewers into such canals and watercourses and onto such land or whether it needs the consent of the owners to do so. Arden J. held that the sewerage undertaker has the right to discharge such water into canals and watercourses as being implicit in the undertaker's express statutory power to lay and maintain pipes. In this test case the sewerage undertaker is Severn Trent Water Ltd. ("STW") which discharged water from its sewers into the Stourbridge Canal. The owner of that canal is the British Waterways Board ("the BWB") which appeals to this court with the leave of the judge.
2. The factual background to this case can be stated very shortly. The Stourbridge Canal was built between 1776 and 1779 pursuant to a private Act of Parliament, the Stourbridge Canal Act 1776. Rights over the canal have been transferred over time to the BWB, latterly under the Transport Act 1962. The BWB was created under s. 1 of that Act. It is a navigation authority.
3. In 1972 planning provision was granted for the construction of an extension to an existing housing estate known as the Poplars at Brierley Hill in the West Midlands. As part of that development, the developers sought permission from the BWB for the discharge of surface water from the estate via a 9-inch discharge pipe into the canal. On 22 April 1976 a licence was granted by BWB to STW's statutory predecessor as sewerage undertaker subject to an annual charge of £29. The licence was terminable on 6 months' notice. By clause 2 (G) the licensee covenanted with BWB that immediately on the termination of the licence it would remove the pipe and reinstate BWB's property.
4. On 26 September 1996 BWB gave notice of the termination of the licence on 31 March 1997. STW claimed that it did not need BWB's consent to discharge water into the canal. BWB claimed that STW did need that consent and wanted a higher charge from STW. The parties were unable to reach agreement.
5. On 21 January 1997 BWB commenced these proceedings. By its Originating Summons BWB sought a number of declarations of which in the event the material declaration was that upon the true construction of s. 159 Water Industry Act 1991 ("the 1991 Act") STW as a sewerage authority had no power or right thereunder to discharge the contents of any sewer or disposal main into any canal or waterway vested in BWB. Before the judge argument was confined to the single issue whether that declaration should be granted. The judge, finding in favour of STW, did not grant BWB the declaration which it sought but declared that STW as a sewerage undertaker had an implied power under s. 159 to discharge surface water from the Poplars Estate into the canal via the pipe the subject of the licence and that accordingly STW was not then and was not on 31 March 1997 when the licence was terminated obliged to remove its pipe or reinstate BWB's property.
6. The 1991 Act is a consolidation Act (with amendments, not material to this case, to give effect to recommendations of the Law Commission). As has recently been reaffirmed by the House of Lords in R. v Environment Secretary, Ex p. Spath Holme Ltd. [2001] 2 WLR 15, the court when construing a consolidation Act will normally seek to ascertain the intention of Parliament by looking only to the way that intention was expressed in the words used in that Act and will not construe that Act by reference to the repealed statutes which the enactment has consolidated. The good sense of that rule is obvious: there would be little benefit in consolidation if the ascertainment of the intention of Parliament required recourse to the antecedent legislation in the hope that that would provide a sufficiently clear indication of the meaning of the statutory language in the consolidating Act. But that rule is subject to exceptions. If there is an ambiguity in the consolidation Act or if the court finds itself unable to interpret a provision in that Act in the social and factual context which originally led to its enactment, then it will be permissible to look at the superseded legislation for such help as it may give (see p. 28 per Lord Bingham, with whom on this point Lord Nicholls and Lord Cooke agreed). The starting point is the consolidation Act itself.
7. The 1991 Act recognises two relevant types of undertakers: a water undertaker and a sewerage undertaker. Such undertakers are companies which are appointed for any specified area (s. 6 (1)). A company may be both a water undertaker and a sewerage undertaker, and STW is such a company, but its functions in relation to each capacity are spelled out in the 1991 Act in elaborate detail.
8. The general duties of water undertakers are set out in s. 37 and other provisions of Part III of the 1991 Act. The general duties of sewerage undertakers are set out in s. 94 and other provisions of Part IV of the 1991 Act. S. 94 (1) reads:

" It shall be the duty of every sewerage undertaker -

(a) to provide, improve and extend such a system of public sewers (whether inside its area or elsewhere) and so to cleanse and maintain those sewers as to ensure that that area is and continues to be effectually drained; and

(b) to make provision for the emptying of those sewers and such provision (whether inside its area or elsewhere) as is necessary from time to time for effectually dealing, by means of sewage disposal works or otherwise, with the contents of those sewers."

9. S. 94 (2) imposes a duty on the sewerage undertaker to have regard to its existing and future obligations to allow for the discharge of trade effluent into public sewers and to the need to provide for the disposal of that effluent.
10. S. 98 imposes a duty on a sewerage undertaker to provide a public sewer to be used for the drainage for domestic purposes of premises in a particular locality in its area if so required by, amongst others, the owner or occupier of any premises in that locality.
11. S. 117 (5) and (6) is in this form:

"(5) Nothing in sections 102 to 109 above or in sections 111 to 116 above shall be construed as authorising a sewerage undertaker to construct or use any public or other sewer, or any drain or outfall -

(a) ....

(b) for the purpose of conveying foul water into any natural or artificial stream, watercourse, canal, pond or lake, without the water having been so treated as not to affect prejudicially the purity or quality of the water in the stream, watercourse, canal, pond or lake.

(6) A sewerage undertaker shall so carry out its functions under sections 102 to 105, 112, 115 and 116 above as not to create a nuisance."

Ss. 102 to 109 and 111 to 116 deal with the adoption of sewers and sewage disposal works, the communication of drains and private sewers with public sewers, other connections with public sewers and restrictions on the use of public sewers.

12. Part VI relates to powers and works of undertakers. S. 155 provides that a relevant undertaker (which means a water or sewerage undertaker) may be authorised by the Secretary of State to purchase compulsorily any land which is required by the undertaker for the purposes of or in connection with the carrying out of its functions. This includes the acquisition of interests in and rights over land by the creation of new interests and rights.
13. S. 158 confers on any relevant undertaker for the purpose of carrying out its functions power to lay a relevant pipe in, under or over any street and to keep that pipe there and certain ancillary powers. References to a relevant pipe are to be construed in this way:

"(a) in relation to a water undertaker, as references to a water main (including a trunk main), resource main, discharge pipe or service pipe; and

(b) in relation to a sewerage undertaker, as references to any sewer or disposal main"(s. 158 (7).

14. S. 159 confers similar powers in relation to pipes in other land.

"(1) .... every relevant undertaker shall, for the purpose of carrying out its functions, have power -

(a) to lay a relevant pipe (whether above or below the surface) in any land which is not in, under or over a street and to keep that pipe there;

(b) to inspect, maintain, adjust, repair or alter any relevant pipe which is in any such land;

(c) to carry out any works requisite for, or incidental to, the purposes of any works falling within paragraph (a) or (b) above."

References to maintaining or altering a pipe are further elaborated on in s. 192 (2), and to laying a pipe in s. 219 (2). By s. 159 (4) reasonable notice must be given to the owner and occupier of the land where the power is to be exercised.

15. S. 165 confers powers on water undertakers (but not sewerage undertakers) to discharge water. By s. 165 (1) where any water undertaker is exercising or about to exercise any power conferred by certain specified sections including ss. 158 and 159 or is carrying out certain other activities in relation to certain specified works belonging to or used by the undertaker, it may cause the water in any relevant pipe or in such work to be discharged into any available watercourse. But s. 165 (2) denies authority for any discharge which damages or injuriously affects the works or property of (inter alios) any navigation authority.
16. S.166 prohibits (except in an emergency) the discharge through any pipe the diameter of which exceeds 229 mm. save with the consent of the National Rivers Authority ("the NRA"), now the Environment Agency, and of any navigation authority which carries out functions in relation to the part of the watercourse where the discharge is made or any part of that watercourse which is less than 3 miles downstream from the place of the discharge. There is no reference to a canal in the non-exhaustive definition in s. 219 (1) of "watercourse," but I shall assume that a canal is an artificial watercourse. S. 167 (1)(b) allows a water undertaker, proposing to discharge water into any inland waters or underground strata, to apply to the Secretary of State for a compulsory works order.
17. S. 168 provides for a relevant undertaker to enter premises for the purposes of carrying out any survey or tests to determine whether and how certain powers (including those in ss. 158 and 159) should be exercised or for the exercise of any such power.
18. By s. 180 and Sch. 12 provision is made for a relevant undertaker to pay compensation to specified persons in specified circumstances. By para. 2 (1) of Sch. 12 if the value of any interest in any relevant land is depreciated by virtue of the exercise by any relevant undertaker of the power in s. 159 to carry out pipe-laying works on private land, the person entitled to that interest is to be entitled to compensation from the undertaker of an amount equal to the amount of the depreciation. Para. 2 (2) and (3) confers further rights to compensation on persons entitled to an interest in that land for other loss or damage or injurious affection attributable to the exercise by the undertaker of that power. Para. 4 requires a sewerage undertaker to make full compensation to any person who has sustained damage by reason of the exercise by the undertaker of any of its powers under "the relevant sewerage provisions". This term, as defined in s. 219 (1), excludes ss. 94, 158 and 159. Para. 6 imposes a duty on every water undertaker to cause as little loss and damage as possible in the exercise of the powers under s. 165 and to pay compensation for any loss caused or damage done in the exercise of those powers.
19. S. 181 requires the Director General of Water Services to investigate complaints with respect to the exercise by a relevant undertaker of any powers conferred on that undertaker "by or by virtue of sections 159 or 161 (2)". If the Director General is satisfied that the undertaker has failed adequately to consult the complainant or by acting unreasonably in the manner of its exercise of that power has caused the complainant to sustain loss or damage or to be subjected to inconvenience, he may direct the undertaker to pay to the complainant an amount up to £5,000 in respect of that failure, loss, damage or inconvenience.
20. S. 184 confers power on the NRA (now the Environment Agency) or the Civil Aviation Authority or any internal drainage board, dock undertakers, railway undertakers or airport operator to take up, divert or alter the level of any sewers, drains, culverts or other pipes which are vested in a sewerage undertaker and pass under or interfere with, or interfere with the alteration or improvement of, any watercourse vested in or under the control of the NRA or that internal drainage board, any property of the Civil Aviation Authority, any river or works forming part of the undertaking, the railway of the railway undertakers or the airport in question.
21. By s. 186 (3):

"Nothing in the relevant sewerage provisions shall authorise a sewerage undertaker injuriously to affect -

(a) any reservoir, canal, watercourse, river or stream, or any feeder thereof, or

(b) the supply, quality or fall of water contained in, or in any feeder of, any reservoir, canal, watercourse, river or stream

without the consent of any person who would, apart from this Act, have been entitled by law to prevent, or be relieved against, the injurious affection of, or of the supply, quality or fall of water contained in, that reservoir, canal, watercourse, river, stream or feeder."

Again by reason of the definition in s. 219 (1) of the term "the relevant sewerage provisions" no reference is made to ss. 94, 158 or 159.

22. The judge in her full and careful judgment ([2001] 1 Ch 32 at pp. 38-39) thought it helpful to keep in mind the distinction that is drawn in the legislation between a pipe-laying power and a discharge power. She referred to ss. 158, 159 and 160 and said:

"One might have thought that the power to lay a pipe automatically carried with it the power to discharge the contents of the pipe at an appropriate place, perhaps a stream or a river, if the water is pure. Here, a sewerage undertaker is given the pipe-laying power on its own, that is without any discharge power. Hence the question which arises here, namely whether the discharge power is conferred by implication."

23. Under the heading "An implied power?" the judge at p. 42 said this:

"Can a discharge power be implied into section 159 in the case of a sewerage undertaker? If one of the primary functions of a sewerage authority is to drain land, it would seem to follow that it should have an implied power to discharge the water so drained, and it would at first sight be odd if water undertakers had that power in right of the pipe-laying power, but sewerage undertakers did not. If, however, there is an implied power in this case, consideration would have to be given to its extent. Does it enable S.T.W. to discharge surface water into any watercourse? Does that include a dock or harbour or tidal waters or other water area not covered by the definition of "watercourse," which applies for the purposes of section 165? Is there any restriction on the volume of water or its frequency? What happens if the power causes loss or damage to the owner of the watercourse? Is there any remedy if the discharge causes flooding or if foul water is discharged? Is there any restriction on the size of pipe that the sewerage undertaker can use (cf. section 166)? Is the implied power exercisable without any person's consent? Does the sewerage undertaker have to give notice before it exercises the power? Can it exercise its power of discharge (if any) on to land as well as into water? The more questions of this nature that there are, and the greater the difficulty in providing satisfactory answers to these questions, the more persuasive will appear to be the argument that it is contrary to the true meaning of section 159 to hold that it confers an implied power of discharge."

24. The judge then turned to consider the rival arguments and the authorities and looked in detail at Durrant v Branksome Urban District Council [1897] 2 Ch 291, a decision of this court under the Public Health Act 1875. This was said to be the main plank in the argument of Mr. Beloff Q.C. for STW. She described the case as compelling. She noted that the 1991 Act is a consolidation Act but said (at p. 46):

"However, in this case, doubt is thrown on the existence of the implied power by the existence of the express discharge power in section 165, and the provisions of Schedule 12. Therefore it is in my judgment necessary to trace the statutory history. In any event, it is necessary to look at the statutory history in order to see whether the decision in Durrant's case is still good authority notwithstanding the changes in the relevant legislation."

Thus the reasoning by which the judge justified looking at the legislative history of the 1991 Act appears to proceed from the premise that the power of discharge should, if possible, be implied; but she regards s. 165 and Sch. 12 as throwing doubt on that. She further finds justification for this historical research in order to see whether Durrant is still good authority.

25. The judge then considered the statutory history, drawing conclusions that ss. 159 and 165 had entirely different origins and that if there was an implied power of discharge, as from 1989 (when the Water Act 1989 changed the law) it ceased to be subject to any duty to compensate any persons suffering loss and damage; another system for compensation and enforcement was then introduced, being compensation at the discretion of the Director General on a much reduced scale and in more limited circumstances.
26. At p. 55 the judge expressed her conclusions:

"First, in my judgment there is an implied power by virtue of section 159 to discharge surface water from pipes vested in a sewerage authority. It is part of the duty of a sewerage undertaker under section 94(1) of the Water Industry Act to make provision for "emptying" sewers, which as stated includes drains for removing surface water. Section 94(2) reinforces this to some extent, though not in the context of surface water, that it is the duty of a sewerage undertaker, in performing its duty under section 94(1), to have regard to the need to provide for the "disposal" of trade effluent. As a matter of first impression it is difficult to see how a sewerage undertaker can altogether avoid emptying surface water from drains into a watercourse. The position of a water undertaker is different. Section 37 refers to the supply of water. It is arguably not incidental to the normal performance of this duty that the water undertaker should discharge water into a watercourse. Hence if a sewerage undertaker has a discharge power by implication, it does not follow that a water undertaker has such a power. On this basis the existence of an implied power in section 159 in favour of sewerage undertakers alone would not duplicate any provision in section 165."

27. The judge then referred to Durrant as "highly persuasive as to the result of this case". She continued at p. 55:

"The fact that there is only a limited right to receive compensation makes it clear that Parliament intended to authorise the acts of the sewerage undertaker under section 159 without a right of full compensation, such as there had been in the Act of 1875. This is therefore a case where the presumption that Parliament did not intend to interfere with private rights must yield."

28. The judge found support in the words of s. 181, "any powers conferred on that undertaker by or by virtue of section 159," for the implication of a power of discharge and possible support from s. 184. She found as limits on the implied power those appertaining to statutory powers in general. Thus the power had to be exercised in good faith, could only be to do what might fairly be regarded as incidental to or consequential upon those things which Parliament had authorised, the manner of its exercise was subject to a degree of control under s. 181, and, because of the limited right to compensation, it had to be exercised with all reasonable regard and care for the interests of other persons.
29. The judge therefore found in favour of STW.
30. Mr. Beloff Q.C. for STW supports the reasoning and conclusion of the judge. He starts from the judge's proposition to which I have referred in para. 22 above, suggestive as it is that a statutory pipe-laying power automatically carries with it by implication a power to discharge the contents of the pipe. As he put it, a duty to drain without power to discharge is unimaginable. He relies on the principle that statutory powers will be construed as impliedly authorising everything which can fairly or reasonably be regarded as incidental to or consequential on the power itself.
31. For my part I have difficulty with the judge's proposition as a starting point for an examination of whether a power to discharge is to be implied into a pipe-laying power in a modern statute: that must depend on whether the statutory language justifies such implication. Still more do I question the reasoning by which the judge justified looking at the predecessor legislation before the 1991 Act. As I pointed out at para. 24, the judge appears to have started from the premise that the power to discharge should be implied, and she found support in Durrant for that implication.
32. Durrant seems to me to have little relevance to the present case. It was a case decided by reference to four sections of the Public Health Act 1875: ss. 15, 16, 17 and 308. By s. 15 every local authority was to keep in repair all sewers belonging to them and to cause to be made such sewers as might be necessary for effectually draining their district. By s. 16 a local authority was given power to carry any sewer through, across or under any turnpike road or any street or place laid out as or intended for a street, or under any cellar or vault under a street and, after giving reasonable notice to the owner or occupier, into through or under any lands whatsoever within their district, and also to exercise all or any of the powers given by s. 16 without their district for the purpose of outfall or distribution of sewage. S. 17 provided:

"Nothing in this Act shall authorise any local authority to make or use any sewer drain or outfall for the purpose of conveying sewage or filthy water into any natural stream or watercourse, or into any canal pond or lake until such sewage or filthy water is freed from all excrementitious or other foul or noxious matter such as would affect or deteriorate the purity and quality of the water in such stream or watercourse or in such canal pond or lake."

S. 308 provided that when any person sustained any damage by reason of the exercise of any of the powers of that Act in relation to any matter as to which he was not himself in default, full compensation should be made to such person by the local authority exercising such powers.

33. The plaintiffs in Durrant owned part of the bed of a river. The defendant local authority built drains to carry rainwater falling on roads into the river, but such water was loaded with sand and silt. The plaintiffs claimed an injunction to restrain the defendants from causing or permitting any water with sand or silt to flow into the river. North J. held that the local authority had a right to discharge the water from the surface drains into the river if they observed the provisions of s. 17, and this court dismissed the appeal from him. Lindley L.J. thought it very important to bear in mind that the plaintiffs, if damnified, could obtain compensation under s. 308. He thought that the inevitable inference from ss. 16 and 17 was that but for s. 17 water could be poured under s. 16 into any natural or artificial stream or watercourse, canal, pond or lake. Lopes L.J. agreed, pointing out that s. 308 met any objection of injustice to the landowner. Chitty L.J. also agreed, saying that the question turned on the four sections. He said that s. 17 might be read partly as a proviso and partly as an enabling clause, but that the better reading was that the power was conferred by s. 16. To my mind it is far from clear that this court would have reached the same conclusion in the absence of ss. 17 and 308.
34. The decision in Durrant was applied in a number of subsequent cases including Hesketh v Birmingham Corporation [1924] KB 620 and Pride of Derby v British Celanese Ltd. [1953] Ch 149. But in those cases as in Durrant the relevant applicable legislation contained the same essential elements of ss. 15, 16, 17 and 308. Under the 1991 Act, whilst to some extent s. 94 might be seen to be the successor to s. 15 and s. 159 to be the successor to s. 16, in relation to sewerage undertakers performing functions under s. 94 or s. 159 there is no equivalent to s. 17. S. 117 (5)(b), which is the equivalent of s. 17, has no application to ss. 94 and 159. Further, it is hard to see that there is any modern equivalent of a provision for full compensation such as was found in s. 308. The provisions of Sch. 12 are very limited and appear only to relate to compensation for owners of the land the subject of the express pipe-laying power in s. 159. Although the judge thought that s. 181 could be taken to be the modern substitute for s. 308, it seems to me to perform a quite different function, viz. to award a modest sum on public law grounds when there is maladministration in the limited ways specified in the section. That is a far cry from the full compensation for loss provided by s. 308. In any event I question the applicability of s. 181 at all to the suggested implied power of discharge. The judge thought the words "by or by virtue of [s.] 159" significant of the existence of an implied power. But when one finds in s. 159 itself two references in subs. (3) to a "power conferred by virtue of" a paragraph of subs. (1), it does not seem to me possible to give to the words "by or by virtue of [s.] 159" in s. 181 (1) the weight which the judge would have them bear as indicating a reference to an implied power in relation to s. 159.
35. I have even more difficulty with what we were told by Mr. Beloff was the judge's own point on s. 184, which she thought might provide some confirmation that an implied power of discharge exists in favour of sewerage undertakers. I do not see that it follows from the power in that section for certain undertakers to alter sewers or drains interfering with certain watercourses or certain rivers that an implied right of discharge from sewers or drains into those watercourses or rivers was recognised. Mr. Beloff did not press this point and I say no more about it.
36. It was common ground between the parties at the hearing before this court that STW needed the implied statutory authority for which it contended, because to discharge water onto another's land would be an interference with private rights, even if the discharge caused no damage. As the judge rightly recognised, there is a presumption that a statute does not give the right so to interfere. However this presumption will yield to a sufficiently clear intention in a statute, as the House of Lords held in Allen v Gulf Oil Refining Ltd. [1981] AC 1001. In that case statutory authority for the construction and operation of a refinery was held to confer immunity against actions in nuisance because the refinery could not be operated without causing a nuisance. Mr. Beloff accepted that the 1991 Act did not authorise a sewerage undertaker to commit a nuisance. That is plainly right: it is not inevitable that nuisance will be caused by a sewerage undertaker performing its statutory functions.
37. Mr. Beloff at the hearing did not challenge BWB's submission that the discharge of water into BWB's canal without BWB's consent would be a trespass unless statutory authority for that discharge could be implied. At the end of the hearing we asked Counsel to investigate this point further. As a result of their helpful further researches, it remains common ground, subject to one qualification, that discharging water onto another's land constitutes a trespass. That is because (a) such a discharge is a direct entry onto land, and (b) the cause of action in trespass does not require damage (see, for example, Clerk & Lindsell on Torts, 18^th ed. (2000) paras. 18-08, 18-09 and 19-02 and Halsbury's Laws 4^th ed. Reissue (1998) Vol. 45 (2) para. 505). It is for the defendant to justify the legality of the entry, whether by the landowner's consent or by legal right (e.g. by prescription, by easement or by statutory authority).
38. Mr. Beloff suggested a qualification in the case of a direct discharge into flowing water. In such a case, he submitted, there would be no trespass, though he accepted that where there is a discharge through the air onto water or onto land a trespass occurs. Mr. Beloff's qualification is not based on any direct authority on the point, but on inferences from cases where it has been held that there has been an interference with incorporeal rights over flowing water, such as fishing and navigation rights. I do not accept those inferences. I cannot see why in principle it should matter whether or not the discharge is directly into the water, given that the land covered by the water is owned by another. In any event, as Mr. Flint Q.C. for BWB pointed out, it is apparent that many discharges by sewerage undertakers will not be directly into flowing water (in the present case the discharge is not made directly into the water of the canal, but into a basin area beside the canal, and at times the basin may be full and at times empty), so that it cannot be assumed that Parliament legislated on the footing that discharges would always take place directly into water so that no statutory authority was required for an interference with private rights.
39. I accept Mr. Flint's submission that the proper place to start consideration of the question whether a power to discharge is to be implied is the actual words of the section into which the power is sought to be implied. The first point of note in s. 159 is that it expressly confers detailed powers on both water undertakers and sewerage undertakers alike. Such powers are not merely to lay a pipe, but also ancillary powers such as to keep the pipe there, to inspect, maintain, adjust, repair or alter a laid pipe and to carry out any works requisite for or incidental to the purposes of works so empowered. The elaboration of the ancillary powers does not eliminate all possibility of the implication of further powers. Thus Mr. Flint accepted that there must be implied power to use the pipe for the performance of the undertakers' functions by causing water to flow through the pipe. But that is a straightforward self-sufficient power easily implied without qualification. The implication of a discharge power, which gives rise to questions such as the judge herself raised, as I have noted in para. 23, is by such elaboration rendered more difficult.
40. That difficulty is considerably increased by the fact that express provision for discharge is made in the same Part of the 1991 Act but limited to water undertakers. Even allowing for the fact that the functions of a water undertaker differ from those of a sewerage undertaker, I regard it as significant that s. 165 expressly gives water undertakers alone the power to discharge water into any available watercourse (and nowhere else) in exercising the power conferred by s. 159 on water and sewerage undertakers alike and that by ss. 165 (2) and (3) and 166 strict conditions are imposed on that discharge. Why should Parliament dispense with the need for the prior consent of the NRA (or the Environment Agency) or a navigation authority or the removal of mud and silt or a limit on the diameter of a pipe for a sewerage undertaker discharging through its pipes when it insists on those conditions for a water undertaker? Why should there be an express reference to compensation for expenditure attributable to a discharge under s. 165 (and therefore limited to a water undertaker's discharge) in para. 6 of Sch. 12, but not to a discharge by a sewerage undertaker unless an implied power of discharge for a sewerage undertaker was not contemplated?
41. Would it defeat the intention of Parliament if a sewerage undertaker did not have an implied power to discharge the contents of its sewers? In my judgment it is impossible so to conclude. S. 94 (1)(b) directly addresses the question of discharge. So far from suggesting that a power should be implied, it expressly imposes on every sewerage undertaker a duty to make provision for the emptying of its sewers and for effectively dealing, by means of sewage disposal works or otherwise, with the contents of those sewers. It can do this by discharge into rivers or the sea (provided that it does not cause pollution or offend environmental controls), by discharge onto its own land (and I have already noted the compulsory purchase power conferred by s. 155 subject to the authority of the Secretary of State), including via its own sewage works, or by procuring the consent of the landowner, such as occurred in the present case until the licence was terminated. There is nothing in the evidence to suggest that the sewerage undertaker is inevitably left at the mercy of an overgreedy landowner. Even in the present case the water now discharged into the canal of BWB could, albeit at some expense, be rerouted to be discharged elsewhere. It is entirely consistent with the presumption against Parliament interfering with private rights that no right to commit a trespass should be implied.
42. There is a further difficulty in the way of the implication of a power to discharge. I find it impossible to see what are the precise limits of such power. This is not a case such as Durrant where it was possible to discern from s. 17 the limits of what was impliedly permitted but for the prohibition in s. 17. Here the prohibitory provisions of s. 117 (5)(b) and s. 186 (3) do not extend to the functions in s. 94 or s. 159 and so offer no guidance on the power sought to be implied into s. 159, read together, as Mr. Beloff submits, with s. 94. Logically, one would have thought, if a power to discharge is to be implied merely because of the power to lay a pipe or because of the drainage or sewerage functions of the sewerage undertaker, the discharge of everything in any such pipe would be impliedly authorised. Yet Mr. Beloff understandably shrinks from putting his case so high, though he has, when pressed as to where the discharge is impliedly authorised to occur, extended the place of discharge to any land where a pipe is laid. The limits which the judge suggested should apply to the implied power, as I have noted in para. 28 above, are surprisingly vague given the detailed conditions enacted for discharge by water undertakers. The imprecise limits of the suggested power of discharge seem to me to be a further indication that no implication should be made.
43. I therefore conclude from an examination of the 1991 Act as a whole that the implication of a power to discharge is inconsistent with the provisions of that Act and cannot be justified. There is no cause to look at the predecessor legislation to this consolidation Act. I note that in the Water Resources Act 1991, which was enacted at the same time and as part of the same group of Acts relating to water as the 1991 Act, express powers are conferred on the NRA (now the Environment Agency) as on water undertakers as to pipe-laying and discharge and that there is provision for compensation. I also note that the Highways Act 1980 conferred on highway authorities the power to lay pipes for draining surface water and an express power of discharge and provision for compensation. All this is consistent with the absence of any implied power of discharge in the 1991 Act for sewerage undertakers.
44. Since writing the first draft of this judgment I have had the benefit of seeing Chadwick L.J.'s judgment. I agree with the further reasons which he gives for allowing this appeal.
45. For all these reasons, I would respectfully disagree with the decision of the judge, allow the appeal, set aside the judge's order, and grant declarations that upon the true construction of the 1991 Act STW has no implied power to discharge surface water from the Poplars Estate into the Stourbridge Canal, and that STW is obliged by reason of clause 2(G) of the 1976 Licence to remove the 9-inch surface water pipe the subject of the 1976 Licence from BWB's property and to reinstate its property to its satisfaction.

Chadwick LJ:

46. From its junction with the Birmingham Canal at Black Delph to its junction with the Staffordshire and Worcestershire Canal at Stourton, the Stourbridge Canal is a cruising waterway for the purposes of Part VII of the Transport Act 1968. The Canal is comprised in the undertaking of the British Waterways Board ("BWB"); having been transferred to BWB when that Board was established by the Transport Act 1962.
47. On 22 April 1976 BWB entered into a licence agreement with The Severn-Trent Water Authority, the purpose of which (as appears from the recital) was to enable the Water Authority to discharge into the Canal surface water from a residential development at Brierley Hill. For that purpose BWB granted the Water Authority a licence, on payment of the annual sum of £29, to discharge clean surface water through a nine inch surface water drain pipe (together with silt trap and outfall). The position of the pipe and ancillary works was defined by a plan. The licence was terminable on notice; and the Water Authority agreed that, on termination, it would remove the pipe and ancillary works.
48. The Severn-Trent Water Authority was a regional water authority established under section 2 of the Water Act 1973. Its functions included sewerage and sewage disposal. Section 14(1) of the 1973 Act was in these terms, so far as material:

"It shall be the duty of every water authority to provide, either inside or outside their area, such public sewers as may be necessary for effectually draining their area and to make such provision, whether inside or outside their area, by means of sewage disposal works or otherwise, as may be necessary for effectually dealing with the contents of their sewers; . . ."

In that context "sewer" included a sewer or drain of every description (other than a drain used for the drainage of one building only) - see section 4 of the Public Health Act 1875, section 343(1) of the Public Health Act 1936 and section 38(1) of the Water Act 1973. It is not, I think, open to doubt - nor is it in dispute - that the Water Authority entered into the licence of 22 April 1976 for the purpose of enabling them to perform the duty imposed by section 14(1) of the 1973 Act.

49. The Water Act 1989 was enacted on 6 July 1989. It provided, at section 4, for the functions of regional water authorities to be transferred to other bodies with effect from an appointed transfer date. The date appointed was 1 September 1989. The functions, including the sewerage functions, of The Severn-Trent Water Authority were transferred to Severn Trent Water Limited ("STW") as the successor company - see section 4(2) of the 1989 Act, Schedule 2 to that Act and The Water Authorities (Successor Companies) Order 1989 (SI 1989/1465). In relation to the sewerage functions transferred to it STW became a sewerage undertaker for the purposes of Chapter III in Part II of the 1989 Act - see section 11(4)(b) of the Act. The duties formerly imposed on its predecessor water authority by section 14(1) of the 1973 Act were imposed on STW (in substantially the same form) by section 67(1) of the 1989 Act.

50. The Water Act 1989 (so far as material) was repealed, on consolidation, by the Water Consolidation (Consequential Provisions) Act 1991 - see section 3 of that Act, and Part I in Schedule 3. The relevant provisions in relation to sewerage are now found in Chapter 1 of Part IV of the Water Industry Act 1991. In particular, the duties formerly imposed by section 14(1) of the 1973 Act and by section 67(1) of the 1989 Act are now imposed by section 94(1) of the 1991 Act. The sub-section is in these terms:

"It shall be the duty of every sewerage undertaker -

(a) to provide, improve and extend such a system of public sewers (whether inside its area or elsewhere) and so to cleanse and maintain those sewers as to ensure that that area is and continues to be effectually drained; and

(b) to make provision for the emptying of those sewers and such further provision (whether inside its area or elsewhere) as is necessary from time to time for effectually dealing, by means of sewage disposal works or otherwise, with the contents of those sewers."

49. The benefit of the licence of 22 April 1976 was transferred to STW (together with other rights comprised in the undertaking formerly carried on by The Severn-Trent Water Authority) by the scheme made and approved under Schedule 2 of the 1989 Act. On 26 September 1996 BWB, as it was entitled to do under clause 4(2) of the licence, gave notice of termination, to take effect on 31 March 1997.
50. STW accepted that the notice of 26 September 1996 was effective to determine the licence of 22 April 1976. It did not accept, however, that it was obliged to cease discharging surface water through the pipe and ancillary works which were the subject of that licence; nor that it could be required to remove that pipe and the ancillary works. In support of its contention that it was entitled to continue to discharge surface water STW relied upon the provisions of the Act of 1776 (16 Geo III c.28) under which the Canal was originally constructed; and, in the alternative, on the provisions in section 159 of the Water Industry Act 1991. It was in those circumstances that BWB sought declaratory relief, by originating summons issued on 21 January 1997. Paragraphs 4 and 5 of that summons, which are the only paragraphs relevant on this appeal, were in these terms:

"A Declaration (4) that upon the true construction of Section 159 of the Water Industry Act 1991 (c.56) the Defendant as a sewerage authority has no power or right thereunder to discharge the contents of any sewer or disposal main into any Canal or other waterway vested in the Plaintiff.

A Declaration (5) that the Defendant is obliged by reason of clause 2(G) of the 1976 Licence to remove the 9 inch surface water pipe the subject of the 1976 Licence from the Plaintiff's property on the 31 March 1997 and thereupon to reinstate its property to its satisfaction."

51. The summons came before Mrs Justice Arden for determination. By an order which she made on 13 October 1999 it was declared:

".... that, upon the true construction of section 159 of the Water Industry Act 1991 the defendant as a sewerage undertaker has an implied power thereunder to discharge surface water from the Poplars Estate at Brierley Hill into the Stourbridge Canal via the 9 inch surface water pipe the subject of the Licence dated 22 April 1976 ... and that accordingly the defendant is not now and was not on 31 March 1997 obliged by virtue of clause 2(G) of such Licence to remove such pipe from the claimant's property or to reinstate the claimant's property."

The judge gave permission to appeal from that part of her order. It is that appeal which is now before us.

52. Section 159 of the Water Industry Act 1991 ("the 1991 Act") is in these terms, so far as material to a sewerage undertaker:

"(1) Subject to the following provisions of this section, to section 162(9) below and to the provisions of Chapter III of this Part, every relevant undertaker shall, for the purpose of carrying out its functions, have power -

(a) to lay a relevant pipe (whether above or below the surface) in any land which is not in, under or over a street and to keep that pipe there;

(b) to inspect, maintain, adjust, repair or alter any relevant pipe which is in any such land;

(c) to carry out any works requisite for, or incidental to, the purposes of any works falling within paragraph (a) or (b) above.

(2) ...

(3) ...

(4) The powers conferred by this section shall be exercisable

only after reasonable notice of the proposed exercise of the

power has been given to the owner and to the occupier of the

land where the power is to be exercised.

(5) Subject to subsection (6) below, in relation to any exercise of

the powers conferred by this section for the purpose of laying or

altering a relevant pipe, the minimum period that is capable of

constituting reasonable notice for the purposes of subsection (4)

above shall be deemed -

(a) where the power is exercised for the purpose of

laying a relevant pipe otherwise than in substitution for

an existing pipe of the same description, to be three

months; and

(b) where the power is exercised for the purpose of

altering an existing pipe, to be forty-two days.

(6) Subsection (5) above shall not apply in the case of any notice

given with respect to the exercise of any power in an emergency or for the purpose of -

(a) laying or altering a service pipe; or

(b) complying with a duty imposed under section 41 or 98 above.

(7) Subject to subsection (2) above [which excludes from

subsection (1) the laying of a service pipe by a water undertaker

save in certain defined circumstances], in this section "relevant

pipe" has the same meaning as in section 158 above."

55. Section 159, as appears from subsection (1)(a), confers pipe-laying powers in or over land which is not, itself, in, under or over a street, Section 158 confers corresponding powers in relation to streets. Section 158(7) defines "relevant pipe" for the purposes of both section 158 and section 159. It is in these terms:

"Subject to section 161(7) below, in this section references to a relevant pipe shall be construed -

(a) in relation to a water undertaker, as references to a water main (including a trunk main), resource main, discharge pipe or service pipe; and

(b) in relation to a sewerage undertaker, as references to any sewer or disposal main."

In that context, "sewer" has the inclusive meaning given to the word by section 219(1) of the 1991 Act:

"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."

and "drain" means a drain used for the drainage of one building. In effect, therefore, the meaning established by the Public Health Act 1875 has survived.

53. I have described sections 158 and 159 of the 1991 Act as provisions which confer pipe-laying powers. The powers are conferred on "every relevant undertaker". "Relevant undertaker" means a water undertaker or a sewerage undertaker - see section 219(1) of the Act. There is nothing in sections 158 or 159 of the 1991 Act which suggests (on a first reading) that those sections are intended to confer powers to discharge onto land not owned by the relevant undertaker whatever it is that is to pass through the "relevant pipe".
54. The view that sections 158 and 159 are not concerned with powers to discharge the contents of the pipe which they authorise and enable the relevant undertaker to lay and maintain in or over the land of another is strengthened by a consideration of section 165(1) of the Act, which gives an express power of discharge (in the circumstances there defined) to a water undertaker. The section is in these terms:

"Subject to the following provisions of this section and to section 166 below, where any water undertaker -

(a) is exercising or about to exercise any power conferred by section 158, 159, 161 or 163 above (other than the power conferred by section 161(3) above); or

(b) is carrying out, or is about to carry out, the construction, alteration, repair, cleaning, or examination of any reservoir, well, borehole, or other work belonging to or used by that undertaker for the purposes of, or in connection with, the carrying out of any of its functions, the undertaker may cause the water in any relevant pipe or in any such reservoir, well, borehole or other work to be discharged into any available watercourse."

Section 161 confers powers on relevant undertakers (that is to say, on both water undertakers and sewerage undertakers) to carry out works needed to secure that water in a relevant water works (that is to say, water mains, resource mains, service pipes, etc. which contain water which may be used by a water undertaker for providing a supply of water) is not polluted or otherwise contaminated. Section 163 confers powers on a water undertaker to fit a stopcock to any service pipe used to supply water to any premises. It is of significance that the power to discharge when a water undertaker is exercising powers under sections 158, 159 and 161 is conferred expressly by section 165(1); but there is no comparable express power conferred on a sewerage undertaker in the same circumstances. Further, the power to discharge conferred on a water undertaker by section 165(1) is subject to safeguards or limitations - see sections 165(2), 165(3) and 166(1).

55. Before turning to the judgment below, it is convenient to refer to the scheme of the 1991 Act; and to set section 159 in its context within that scheme.
56. The 1991 Act is a consolidating Act (as its long title makes clear). It re-enacts much of the Water Act 1989 (which was an amending Act, having as one of its main objects the "privatisation" of the water industry). The 1991 Act is one of a number of enactments relating to the water industry which received the Royal Assent on the same day (25 July 1991). The others were the Water Resources Act 1991, the Statutory Water Companies Act 1991, and the Water Consolidation (Consequential Provisions) Act 1991. Together they comprise a formidable bulk of detailed and complex legislation. The Water Industry Act 1991 itself contains 223 sections and 15 schedules; the Water Resources Act 1991, 225 sections and 26 schedules. The legislation is replete with express powers to cover activities which water and sewerage undertakers might need or wish to undertake. It is, at the least, unlikely that Parliament would have left anything as fundamental as a power to discharge sewage onto another's land to be inferred.
57. The 1991 Act is divided into Parts. In the context of this appeal, the relevant Parts are Part II (Appointment and Regulation of Undertakers), Part III (Water Supply), Part IV (Sewerage Services), Part V (Financial Provisions) and Part VI (Undertakers' Powers and Works).
58. Section 6, in Part II, provides for the appointment of companies to be water undertakers or sewerage undertakers. A company cannot be appointed to be a sewerage undertaker unless it is a company within the meaning of the Companies Act 1985 which is limited by shares - see sections 6(5) and 219(1) of the 1991 Act. The significance of that is that a sewerage undertaker will derive its general corporate powers from its memorandum of association; unlike a statutory undertaking, its powers do not have to found within the enactment by which it is established. There is, for example, no need to seek, within the 1991 Act, powers for sewerage undertakers to acquire rights over land by purchase or prescription. It may be expected that those powers will be contained in the memorandum of association of the company which is appointed to be a sewerage undertaker. It is necessary, however, to look to the 1991 Act for powers of compulsory purchase, or for powers to override the rights of others (with or without the payment of compensation).
59. Section 37, in Part III of the Act, imposes a duty on every water undertaker to develop and maintain an efficient and economical system of water supply within its area. Specific obligations are imposed in relation to the supply and maintenance of water mains, trunk mains, resource mains and supply pipes (to which reference is made in the definition of "relevant pipe" in section 158(7) of the Act). Those are all conduits through which water is supplied; they have no function in relation to drainage or sewage. It may be noted in passing that a "discharge pipe" to which reference is also made in section 158(7) is also a pipe used by a water undertaker - see sections 165 and 192; it has no assigned meaning in relation to sewerage undertakers.
60. Section 94 (to which I have referred earlier in this judgment) is the first section in Part IV of the 1991 Act. It imposes on every sewerage undertaker a general duty to provide a system of public sewers so as to ensure that the area for which it is responsible is effectually drained. It imposes, also, a duty to make provision for emptying those sewers and for dealing with their contents. Sections 102 to 105 provide for the adoption by a sewerage undertaker of existing sewers or sewage disposal works within, or serving, its area. Sections 106 to 109 provide for the connection of drains and private sewers into public sewers. In particular, section 106 gives to the owner or occupier of any premises (or the owner of any private sewer which drains premises) the right to connect to, and to discharge both foul water and surface water into, the public sewer of a sewerage undertaker; save that where separate public sewers are provided for foul water and for surface water, a person may not discharge foul water into a sewer provided for surface water nor (save with the consent of the undertaker) surface water into a sewer provided for foul water. Sections 111 to 114 provide for the sewerage authority to take steps to protect its sewerage system from use which is likely to damage it or to cause a nuisance. Section 115 provides for co-operation between sewerage undertakers and a local authority (in its capacity as highway authority) in relation to the draining of surface water from roads or streets. Section 116 gives the sewerage undertaker power to close or restrict the use of a public sewer.
61. Sections 117(5) and (6) are in these terms, so far as material;

"(5) Nothing in sections 102 to 109 above or in sections 111 to 116 above shall be construed as authorising a sewerage undertaker to construct or use any public or other sewer, or any drain or outfall -

(a) ...

(b) for the purpose of conveying foul water into any natural or artificial stream, watercourse, canal, pond or lake, without the water having been so treated as not to affect prejudicially the purity and quality of the water in the stream, watercourse, canal, pond or lake.

(6) A sewerage undertaker shall so carry out its functions under sections 102 to 105, 112, 115 and 116 above as not to create a nuisance."

It is important to note that section 117(5) does not confer a power to construct or use a sewer, drain or outfall for the purpose of discharging surface water or foul water into a stream, watercourse, canal, pond or lake. Rather, it imposes a restriction on doing that in the case of foul water which has not been treated. But there is nothing in sections 102 to 109, or in sections 111 to 116, which could have the effect of permitting or authorising the discharge of surface water or foul water onto the land of another, or into a stream, watercourse, canal, pond or lake. If a power to do that is conferred by the 1991 Act, it must be found elsewhere. Further, section 117(6) gives no encouragement to the view that any power that may be conferred elsewhere is likely to authorise the commission of a nuisance.

62. Section 142, in Part V of the 1991 Act, confers powers on relevant undertakers (that is to say, both sewerage undertakers and water undertakers) to fix, demand and recover charges for any services provided in the course of carrying out their functions. Section 142(4) enables a relevant undertaker, "except in so far as this Chapter otherwise provides", to fix charges "by reference to such matters ... as appear to the undertaker to be appropriate." It is plain, therefore, that (absent of some restriction imposed under Chapter I in Part V) a sewerage undertaker may, when fixing charges in connection with the provision of drainage and sewerage services, include provision for the costs associated with discharge or disposal. There is no restriction elsewhere in Chapter I upon making provision for the costs of discharge or disposal. For example, it could not be said that STW would not have been entitled to take into account the licence fee payable under the licence agreement of 22 April 1976 when fixing the charges to be paid by customers. It cannot be assumed, therefore, that Parliament must have intended that sewerage undertakings would have power to discharge onto the land (or into the watercourse) of another without payment. The 1991 Act confers power on relevant undertakings to recover the costs associated with carrying out their functions; and those costs will include the costs of acquiring any necessary rights by purchase.
63. Chapter I in Part VI of the 1991 Act contains provisions as to "Undertakers Powers". Sections 155 to 157 are grouped under the cross-heading "Powers in relation to land". Section 155(1) confers power on the Secretary of State to authorise a relevant undertaker to purchase compulsorily any land anywhere in England or Wales "which is required by the undertaker for the purposes of, or in connection with, the carrying out of its functions." Section 155(2)(a) provides that the power conferred on the Secretary of State by section 155(1) includes power to authorise "the acquisition of interests in and rights over land by the creation of new interests and rights". So, if a sewerage undertaker needs to acquire the right to discharge onto the land (or into the watercourse) of another in order to carry out the duties imposed on it by section 94 of the 1991 Act, it can do so compulsorily under the authority of the Secretary of State. But, of course, the exercise of the right of compulsory acquisition will give rise to an obligation to pay compensation under the relevant provisions of the Compulsory Purchase Act 1965 as modified by the provisions contained in Schedule 9 to the 1991 Act - see section 155(5) of the 1991 Act. It is, I think, not without significance that paragraph 2 of Schedule 9 to the 1991 Act makes express provision for the compulsory acquisition of a right by the creation of a new right (for example, under a licence to discharge); and paragraph 3 of that Schedule provides that, in the case of a compulsory acquisition under section 155 of the 1991 Act, there shall be substituted for section 7 of the 1965 Act, the following section (so far as material):

"In assessing the compensation to be paid by the acquiring authority under this Act regard shall be had not only to the extent (if any) to which the value of the land over which the right is to be acquired is depreciated by the acquisition of the right but also to the damage (if any) to be sustained by the owner of the land, etc. . . ." [emphasis added].

The words which I have emphasised replace the words of the section as enacted in the Compulsory Purchase Act 1965.

64. It is clear, therefore, that Parliament has provided, in Part VI of the 1991 Act, for the compulsory acquisition of rights over land (including the right to discharge the contents of sewers onto land or into a watercourse) where those rights are required by a sewerage undertaker for the purposes of, or in connection with, the carrying out of its functions; and has provided, in Part V of the Act, for the recovery by the sewerage undertaker, through charges, of the cost of acquiring such rights. Against that background it is, at the least, unlikely that Parliament intended to confer an implied right to discharge (with or without causing a nuisance) without any obligation to pay compensation.
65. It is said that that implied power is to be found in section 159 of the 1991 Act. Sections 158 and 159 form a group under the cross-heading "Pipe-laying". They are to be read in conjunction with Schedule 12, which makes provision "for imposing obligations for the purpose of minimising the damage caused in the exercise of certain powers conferred on undertakers and for imposing obligations as to the payment of compensation" - see section 180 of the 1991 Act. Paragraph 2 of Schedule 12 is headed "Compensation in respect of pipe-laying works in private land". The paragraph is in these terms, so far as material:

"(1) If the value of any interest in any relevant land is depreciated by virtue of the exercise, by any relevant undertaker, of any power to carry out pipe-laying works on private land, the person entitled to that interest shall be entitled to compensation from the undertaker of an amount equal to the amount of the depreciation.

(2) Where the person entitled to an interest in any relevant land sustains loss or damage which -

(a) is attributable to the exercise by any relevant undertaker of any power to carry out pipe-laying works on private land;

(b) does not consist in depreciation of the value of that interest; and

(c) is loss or damage for which he would have been entitled to compensation by way of compensation for disturbance, if his interest in that land had been compulsorily acquired under section 155 of this Act, he shall be entitled to compensation from the undertaker in respect of that loss or damage, in addition to compensation under sub-paragraph (1) above.

(3) Where any damage to, or injurious affection of, any land which is not relevant land is attributable to the exercise by any relevant undertaker, of any power to carry out pipe-laying works on private land, the undertaker shall pay compensation in respect of the damage or injurious affection to every person entitled to an interest in that land.

(4) ...

(5) In this paragraph "relevant land", in relation to any exercise of a power to carry out pipe-laying works on private land, means the land where the power is exercised or land held with that land.

(6) In this paragraph the references to a power to carry out pipe-laying works on private land are references to any of the powers conferred by virtue of sections 159, 161(2) and 163 of this Act."

66. Compensation is payable under paragraph 2 of Schedule 12 in three distinct situations: (i) where the value of any interest in land, on or in which pipes are laid in the exercise of the pipe-laying power, is depreciated; (ii) where loss or damage (not being the depreciation of the value of an interest in land) attributable to the exercise of the pipe-laying power is suffered by a person entitled to an interest in land on or in which pipes are laid; and (iii) where damage to, or injurious affection of, land (not being land on or in which pipes are laid in the exercise of the pipe-laying power) is attributable to the exercise of the pipe-laying power. It might, perhaps, be possible to argue that the owner of the bed of a river or watercourse (not being land in or over which any pipes are laid in the exercise of the pipe-laying power or at all) is entitled to claim compensation for damage or injurious affection caused by the discharge of surface water or sewage from pipes laid in or over the land of a riparian owner, on the ground that that is attributable to the exercise of the pipe-laying power in relation to the riparian land; but that, to my mind, would be to give to the phrase "attributable to the exercise of [the pipe-laying power]" a meaning which it was not intended to bear. I do not think that Parliament intended, when enacting paragraph 2 of Schedule 12, that the phrase "attributable to the exercise of [the pipe-laying power]" was apt to cover the discharge of surface water and sewage from pipes which had been laid pursuant to the pipe-laying power. But, even if Parliament did intend that, it plainly did not intend the phrase to cover the discharge of surface water and sewage from pipes which were not laid pursuant to any statutory power but under the terms of a contractual licence; or, say, to existing sewers which had been taken over or adopted under section 102 or section 104 of the 1991 Act.
67. The importance of section 180 of, and Schedule 12 to, the Act, as it seems to me, is that they make clear that damage or injurious affection resulting from or attributable to the exercise of the pipe-laying power is to attract compensation. To imply into section 159 of the 1991 Act a power to discharge onto the land (or into the watercourse) of another without giving to the person interested in that land (or watercourse) any right to compensation would be inconsistent with the statutory scheme of which section 159 forms a part. It is impossible to hold that a power to discharge onto the land of another through pipes which have not been laid in the exercise of the pipe-laying power could attract compensation under Schedule 12. And it is unnecessary to strive to do so; the power to discharge (where required) can be acquired compulsorily under section 155 of the Act, upon payment of compensation.
68. But for the fact that the judge reached a different conclusion, I should have regarded the contention that a power to discharge the contents of sewers (whether surface water or sewage) onto the land (or into the watercourse) of another was to be implied by virtue of the provisions of section 159 of the 1991 Act as unarguable. For the reasons which I have sought to give, I cannot see how, as a matter of construction, it can be said that the express powers which are conferred by section 159 of the Act lead to the conclusion that a power to discharge must be implied. Nor can I see how it can be said that such a power must be implied in order to enable a sewerage undertaker to carry out the functions imposed by section 94 of the Act. The fallacy, as it seems to me, lies in the underlying (but unspoken) premise that Parliament must have intended that sewerage undertakers should have facilities to discharge (which, plainly, they do require in order to carry out their functions) without paying for those facilities. Whether or not that premise could have been supported in the context of a public authority charged with functions imposed in the interests of public health, it cannot be supported, as it seems to me, in the context of legislation enacted following a decision to privatise the water industry.
69. The judge, in a judgment which is now reported at [2001] Ch 32, addressed the question whether a discharge power could be implied into section 159 of the 1991 Act in the case of a sewerage undertaker in a passage which begins at page 42D. She observed:

"If one of the primary functions of a sewerage authority is to drain land, it would seem to follow that it should have an implied power to discharge the water so drained, and it would at first sight be odd if water undertakers had that power in right of the pipe laying power, but sewerage undertakers did not."

70. The reference, there, to the water undertaker's power to discharge "in right of the pipe laying power" is a reference to the express power conferred by section 165 of the 1991 Act. But it must be kept in mind that the express power conferred by section 165 is conferred only where a water undertaker "is exercising or about to exercise" the pipe-laying power conferred by section 159; there is no power for a water undertaker to discharge from pipes which are not the subject of a current (or immediately prospective) exercise of the pipe-laying power. The need for a power to discharge from supply pipes into an available watercourse is unlikely to arise unless something is being done (or is about to be done) to those pipes. To state the obvious, the purpose of supply pipes is to supply water to the place where it is wanted. A water undertaker is not in the business of disposing of surplus water. The position of a sewerage undertaker is quite different. It is in the business of disposing of surplus water (in particular, surface water). In the case of a water undertaker, its principal function is to supply water; the laying of pipes is incidental to that principal function; and the power to discharge water from those pipes is incidental to the pipe-laying function. In the case of a sewerage undertaker, its principal function (or one of its principal functions) is to dispose of water; the laying of pipes is incidental to that function; and it would be surprising if it were given power to discharge as an incident of its pipe-laying function. That would be to put the cart before the horse. What might, at first sight, seem an odd distinction is not, on further consideration, in the least odd. What would be odd, would be for a water undertaker to be given an express power to discharge which was not incidental to work which was being done (or about to be done) on supply pipes; or for a sewerage undertaker to be given power to discharge which was incidental to (and only exercisable in connection with) work being done (or about to be done) on sewage pipes. The power to discharge which a sewerage undertaker requires is not a power incidental to the pipe-laying power; it is a power which is exercisable after pipes have been laid. For my part, I would not expect to find the power which a sewerage undertaker requires conferred in the same statutory context as the express power to discharge which is conferred on water undertakers.
71. Nor do I share the judge's view that "it would seem to follow [from the fact that one of the primary functions of a sewerage authority is to drain land] that it [a sewerage undertaker] should have an implied power to discharge the water so drained". It seems to me that the judge may have overlooked the fact that one of the important changes made in the Water Act 1989 (and perpetuated in the Water Industry Act 1991) is that sewerage functions were transferred from public authorities (which derived their corporate powers from the statute by which they were established) to limited companies (which derive their corporate powers from their memoranda of association). The judge referred, at page 9D, to there being no objection in principle to a statutory body having a power by reasonable implication to do that which it needs to do to achieve its object. I agree. It would be easy to find that a power to discharge was included (by implication) in the powers conferred on a statutory undertaking. But a sewerage undertaker is not a statutory undertaking. What STW seeks to assert has been conferred by implication is not a corporate power to discharge (for which it can rely, no doubt, on its own memorandum of association) but a power to discharge without payment of compensation onto the land (or into the watercourse) of another. Again, for my part, I would not expect an implied power of that nature to follow from the fact that a company limited by shares (which, it may be assumed, are to pass out of public ownership in due course, if the objective of privatisation is to be achieved) has been appointed as a sewerage undertaker to carry out the duties imposed by section 94 of the 1991 Act. What I would expect to find (and do find) in the legislation is a power to acquire by compulsory purchase, with the authority of the Secretary of State and upon payment of compensation, the rights which the undertaker needs to carry out its functions.
72. Faced with the obvious difficulties of construction posed by the provisions of the 1991 Act, the judge found support for her view in the decision of this Court in Durrant v Branksome Urban District Council [1897] 2 Ch 291. That was a decision on the Public Health Act 1875. I agree with Lord Justice Peter Gibson, for the reasons which he gives, that the Durrant case is of little relevance to the position as it now is under the 1991 Act. It seems to me that the judge fell into the error of reasoning, from the decision in the Durrant case and the subsequent legislative history, (i) that there must be an implied power for a sewerage undertaker to discharge onto the land of another, (ii) that, because the provisions of the 1991 Act did not appear to support that conclusion, those provisions must be ambiguous, and (iii) that the ambiguity so identified could be resolved by recourse to the Durrant case and the legislative history. That is the wrong approach. The 1991 Act is a consolidating Act. The correct approach is to begin with the provisions of that Act. If they are clear (as I think that they are in the present case) there is no need to ask what the position was under previous legislation. Indeed, where the provisions of that earlier legislation differ from those in the consolidating Act, there is not only no need; it is dangerous to do so.
73. The present case provides an illustration of the danger. There can be no doubt that the law was changed by the Water Act 1989. The judge, herself, recognised that at [2001] Ch 32, 50B-C. The trap, into which, as it seems to me, the judge was led, was to assume that the pre-1989 law remained unchanged save to the extent that changes could be identified in the 1989 Act; and to ask what those changes were. That was the wrong question. The right question is to ask what the law has been since the statutory consolidation in 1991. The answer to that question is to be found in the 1991 Act. It is only if that Act does not provide an answer in which the court can feel confidence that there is any reason to look at earlier legislation - see R v Secretary of State of the Environment, Transport and the Regions, ex parte Spath Holme Limited [2001] 2 WLR 15, to which Lord Justice Peter Gibson has already referred.
74. For those reasons, as well as for the reasons given by Lord Justice Peter Gibson with which I concur, I would allow this appeal.

KEENE L.J.

75. I agree, with some hesitation, that this appeal should be allowed. I can see the force of the arguments advanced on behalf of the respondent, particularly the point that it would be remarkable if Parliament had imposed the duty on sewerage authorities under section 94 "to make provision for the emptying of ... sewers and such further provision ... as is necessary for effectively dealing by means of sewage disposal works or otherwise, with the contents of those sewers", without conferring on them the power to discharge the contents. Yet there is no express power to discharge given anywhere in the 1991 Act to sewerage undertakers.
76. Clearly as a matter of corporate capacity such a power to discharge is implicit in section 94. But it does not follow from that that there is to be implied a power to discharge onto the property of others without consent, thereby overriding private rights. One would expect to see such a power provided in express terms.
77. Moreover, there is a considerable difficulty in implying such a power into section 159 as the defendant contends. It is not confined to the fact that both water and sewerage undertakers are given by section 159 an express pipelaying power with ancillary powers and that only water undertakers are given an express power to discharge by section 165(1). It is also the extent of any implied power so created. The express power conferred on water undertakers to discharge is confined to discharges into watercourses. But the pipelaying power possessed by both types of undertaker by virtue of section 159 is a power to lay a pipe "in any land which is not in, under or over a street". There is no reference to watercourses, canals, lakes or any other specific water feature. That being so, any implied power of discharge to be derived from section 159 would seem to be a power to discharge without the consent of the landowner onto any land over which a pipe could be laid by virtue of that provision. Discharge would not be confined to watercourses or similar features. That, however, would be an even more far-reaching power and one yet more difficult to imply. It would presumably give the sewerage undertaker the power to discharge at any point along the line of the pipe.
78. One recognises that various provisions in the Act seem to imply that in certain circumstances a discharge may be made so long as no nuisance is caused. Section 117(5) provides:

"(5) Nothing in sections 102 to 109 above or in sections 111 to 116 above shall be construed as authorising a sewerage undertaker to construct or use any public or other sewer, or any drain or outfall -

...

(b) for the purpose of conveying foul water into any natural or artificial stream, watercourse, canal, pond or lake, without the water having been so treated as not to affect prejudicially the purity and quality of the water in the stream, watercourse, canal, pond or lake. "

79. The sections there referred to do not include section 159 but comprise such statutory powers as that to adopt an existing sewer: section 102(1). It might be asked why a sewerage authority should implicitly have the power to discharge foul water from an adopted sewer, so long as it does not have the prejudicial effects referred to in section 117(5)(b), and yet not have such a power when dealing with surface water drainage.
80. Likewise, section 186(3) states:

"(3) Nothing in the relevant sewerage provisions shall authorise a sewerage undertaker injuriously to affect -

(a) any reservoir, canal, watercourse, river or stream, or any feeder thereof; or

(b) the supply, quality or fall of water contained in, or in any feeder of, any reservoir, canal, watercourse, river or stream, without the consent of any person who would, apart from this Act, have been entitled by law to prevent, or be relieved against, the injurious affection of, or of the supply, quality or fall of water contained in, that reservoir, canal, watercourse, river, stream or feeder."

The "relevant sewerage provisions" do not include section 159.

81. The answer in respect of both section 117(5) and section 186(3) seems to be that those provisions do not imply that the consent of the owner or occupier of the land on which the watercourse flows is not required. The purpose of those provisions is much wider. They are designed to ensure that those who may be affected by a discharge, but whose consent to the discharge itself is not required in terms of property rights, are nonetheless clearly protected against damage. Into such a category would come those downstream of a discharge who have a right to abstract water of a certain quality or who as riparian owners may be at risk of flooding or of other harm. The provisions in question are there to make it clear that their common law remedies, particularly in nuisance, are not affected by the exercise of the statutory powers referred to. On such a construction, there is no necessary implication that the undertaker can discharge without the consent of the owner or occupier of the watercourse.
82. For these reasons, as well as for those set out in the judgments of Peter Gibson and Chadwick L.JJ., I would allow this appeal.
ORDER: Appeal allowed with costs below, and in the appeal. Permission to appeal to the House of Lords refused. (Order does not form part of approved Judgment)