The question raised on this appeal is as to the construction of sec. 158 of the Western Australian Health Act of 1898, which provides that in cases where it is necessary for the proper drainage of any land, including private premises, that drains or sewers should be made through or under any one or more private premises, it shall be lawful for the Local Board of Health to make an order on the owner or owners of such private premises requiring them to permit the formation of such drain through or under such premises. And, further, that at the expiration of one month after such notice, the Local Board may form or make through or under such premises, such drains as may, in the opinion of the Local Board, be necessary. The defendants in the action, who are now the appellants, are the Local Board of the City of Perth; the respondent is the owner of certain private premises within the jurisdiction of the appellant Board, and it appears that the appellants, acting as the Local Board, conceived it necessary for the proper drainage of a piece of land described as Perth Town Lot 49, Malcolm Street, and adjoining the respondent's premises, that a drain should be made through them. The appellants accordingly made an order on the respondent to permit the formation of the drain through his premises for the purpose of draining Lot 49, Malcolm Street, and, after the expiration of a month, they proceeded to enter the respondent's land for the purpose of constructing such drains as they thought it proper should be made for that purpose. The respondent thereupon brought this action, claiming an injunction and damages. The case was tried before Mr. Commissioner Roe, who found certain facts. In the course of his judgment, he said: "The evidence adduced by the defendant Board, without going into it in detail, proved, I think, beyond all doubt that the present drain, by following the natural fall of the land and natural flow, took the proper course." The counsel for the respondent has contended that, in order to justify the action of the Local Board in entering upon private land, it must be shown that it was necessary to do so, in the sense that it was not possible to drain the land in question except by going through the particular private premises. For the Board it is contended that that is not the meaning to be assigned to the word "necessary" in a statute of this kind; but that, although the word may have such a meaning attributed to it in some statutes, in a statute of this sort, dealing with the powers of public bodies, conferred and intended to be used for the benefit of the community, the intention is to leave it to the local body to determine what, in the bonâ fide exercise of their judgment, is sufficient evidence of the necessity for any given work. The judgment of the learned Commissioner was appealed against to the Full Court, and they reversed his decision and granted an injunction. The learned Chief Justice in the Full Court said, after pointing out that the land might have been drained in another way, which no doubt was true: - "Now I take it that a thing does not become necessary to be done unless it is unavoidable. It is incumbent upon the Board to show that the construction of this sewer through the plaintiff's land was unavoidable in order to drain the particular premises mentioned." And further he says, "I am of the opinion, upon the evidence before me, that there is nothing to show that the Board could not have taken the drain in another direction had they felt so inclined. They would no doubt have been put to greater expense, but that is not the question." There can be no doubt that the drain might have been made in some other way. It might have been made in an indefinite number of other ways, but it appears that, from the situation of the property and the contour of the surrounding land, the drain, as constructed, follows substantially the natural fall, and it is not suggested that the Local Board, in making the drain in this way, were exercising their powers otherwise than bonâ fide. Then the question is which is the true construction of the section. The first thing to be done is to consider what was the object of the legislature in passing this Act. On that point I will refer to the rule laid down in the Sussex Peerage Case, reported in 11 Cl. & F., 85 at p. 143. In that case Lord Chief Justice Tindal said, "The only rule for the construction of Acts of Parliament is that they should be construed according to the intent of the Parliament which passed the Act. If the words of the Statute are in themselves precise and unambiguous, then no more can be necessary than to expound those words in their natural and ordinary sense. The words themselves alone do, in such cases, best declare the intention of the lawgiver. But, if any doubt arises from the terms employed by the Legislature, it has always been held a safe means of collecting the intention to call in aid the ground or cause of making the Statute." The question in every case is, what was the intention of the Legislature? What then were the ground and cause of their making this statutory enactment? Obviously it was considered desirable that some provision should be made for the drainage of premises in a populous city, and that for this purpose powers should be conferred upon a public body who could be trusted to exercise them for the benefit of the whole community. The condition upon which they were to exercise the power of trespass on private land was that it should be necessary for the proper drainage of adjacent land. Now, in the sense suggested by the present respondent, it would never, or at all events very rarely, be unavoidable to go upon any particular person's land. To take the case suggested in the argument, a piece of land, lying higher than two other adjoining pieces of land, is to be drained. It is on the slope of a hill and cannot conveniently be drained upwards, therefore the drain must pass through one or other of the two lower pieces of land. If the argument suggested by the respondent is the correct one, it is not unavoidable to go through either of the two lower pieces. It is manifest that such a construction of the section would lead to a reductio ad absurdum. Another excellent rule in the interpretation of Statutes is that such a construction should be given as will render the legislation efficacious, and not idle. If any construction would render it nugatory it is primâ facie to be rejected. I will first refer to the case of The Stockton and Darlington Railway Co. v. Brown, [1860] EngR 1043; 9 H.L. C., 246. That was a case in which a railway company had exercised certain statutory powers. Where statutory powers of this sort, involving the entering upon private property, and the diminution of private rights, are conferred, a stricter rule is applied in the case of a private company carrying on business for its own profit than in the case of public bodies which are taking action in the public interest. Another distinction is made, depending on whether, as in the Statute now under consideration, compensation is given. In that case Lord Cranworth (at p. 256), said: - "Some general propositions admit of no doubt. In the first place, I think it clear that when the legislature authorizes railway directors to take, for the purposes of their undertaking, any lands specially described in their Act, it constitutes them the sole judges as to whether they will or will not take those lands; provided only that they take them bonâ fide with the object of using them for the purposes authorized by the legislature, and not for any sinister or collateral purpose. This is the construction to be put on all such legislative powers, whether the language of the Act is that the company may take so much of the lands as is necessary for the undertaking, or so much as is required, or is expedient to be taken, or simply (as in this case) that the company may take lands for the purposes of the undertaking. In such cases the legislature, having provided what it considers sufficient means of securing adequate compensation to the owners of the land, leaves it to those interested in the undertaking to say to what extent it will be useful to them to exercise their statutable powers." That case was decided in 1860. The Statute under consideration in the case of Hargreaves v. Taylor, 3 B. & S., 613, decided by the Court of Queen's Bench in 1863, had provided that when a drain was in bad order the Local Board of Health might give notice to the owner or occupier of the premises, requiring him to do the necessary work, and, if the notice was not complied with, the person upon whom the notice was served was liable to a penalty. It was held that the discretion to determine what work was necessary was vested in the Board. The case was argued before Lord Chief Justice Cockburn, and Wightman, Blackburn and Mellor, JJ. It is true that the argument was only on one side, but in giving judgment Mr. Justice Mellor, at p. 619, said: "Under such circumstances it seems more reasonable to hold that the discretion as to the nature and extent of the works required to be done is vested in the Local Board rather than in the justices at Petty Sessions, and we are therefore of opinion that the justices were wrong in assuming a jurisdiction to review the determination of the Board of Health as to this matter." It was there held that under a statute so worded the Local Board were the judges of what was necessary. Vernon v. The Vestry of St. James, Westminster, 50 L.J. (Ch.), 81, was an action against the respondents, who were a local authority, for carrying out a certain work which was found on the evidence to be a nuisance. The work was one of a class which they were authorized to do, but the learned Vice-Chancellor (Malins) had granted an injunction restraining them from carrying it out on the ground that from its situation it would be a nuisance. The Vice-Chancellor, as reported in 49 L.J. (Ch.) 130, at p. 135, said, "Now, if the question between the parties was merely whether one situation or another (in the mews) was more fit for the purpose, I should clearly be of opinion that that was a question to be decided by the Vestry only; they being authorized by the Act to place these conveniences in situations where they deem them to be necessary." He then referred to some decided cases and went on to say (p. 136), "If the question before me simply were, whether one place in the mews were better than another, I should be able to decide - in conformity with the Act of Parliament and these decisions - that the vestry are the sole judges as to what the situation should be. But vestries, like other public bodies, are liable to be controlled by this Court if they proceed to exercise their powers in an unreasonable manner; whether induced to do so from improper motives or from error of judgment." He then referred to the case of Biddulph v. St. George's Vestry, before the Court of Appeal, and quoted from the judgment of Lord Justice Turner, as follows: - "I am far from thinking that this Court has not power to interfere with public bodies in the exercise of powers which are conferred upon them by Act of Parliament. I take it that it would be within the power and the duty of this Court so to interfere in cases where there is not a bonâ fide exercise of the powers given by Parliament. On the evidence I can see nothing to warrant the Court in imputing to the defendants the exercise of their powers otherwise than bonâ fide." That case (which was affirmed by the Court of Appeal on the question of nuisance) suggests both the true construction and the implied qualification. Ex parte Saunders, 11 Q.B.D., 191, is substantially the same as Hargreaves v. Taylor (supra). The question in Stroud v. Wandsworth District Board, (1894), 1 Q.B., 64, and on appeal (1894) 2 Q.B., 1, arose upon a Statute under which the local authority was empowered to execute any necessary works of repair. The question was whether the Board were the ultimate judges of what was necessary, or whether their judgment could be reviewed by any other tribunal. In that case the Court of Appeal affirmed the decision of the Court of first instance, and held that the Local Board were the final judges. Lord Justice Lindley (p. 4), said: - "Now, the question is, who is to be the judge of the necessity for these works of repair? The answer is to be found by considering the object and purpose of this section. It is, in substance, an addition to a group of sections relating to the paving of streets. Under the earlier Acts there was power to pave streets, but not for doing works of repair before doing paving and other works referred to in those Acts. This section is put in to supplement the defect. In the Acts 18 & 19 Vict. c. 120, s. 105, and 25 & 26 Vict. c. 102, s. 77, it is clear enough that the judges of the necessity of paving are to be the local authority. In this Act it is not stated in so many words who are to be the judges of the necessity of works of repair; but, in my opinion, the true construction is that the persons who are to be the judges of the necessity of doing these works are to be the same as those who are to be the judges of the necessity of doing the works under the former Acts." He then referred to the case of Reg. v. Marsham, (1892) 1 Q.B., 371, and said (p. 6): "The question still remains, In whose judgment? And my answer is, in the judgment of the local authority; but, in order to recover the expenses of the repairs, they must show that the money has been expended in such repairs. ... Any other construction of this Act of Parliament would lead to the wildest confusion." Lord Justice Kay, on the same point, said (p. 8): "Then there remains the question, What did the legislature mean by the word necessary? It must be necessary in the judgment of someone. Was it, or was it not, necessary in the judgment of the Board who did the work? Primâ facie, one would think that a public body like a Local Board who had authority vested in them to repair highways which they have not yet determined to pave must have some discretion vested in them. The case of Reg. v. Marsham clearly shows that the judges in that case considered that a certain amount of discretion was vested in the Board; and I think that this word necessary, though it is used in the Act of Parliament without additional words such as which they shall think necessary, or, which shall appear necessary, may yet be fairly construed to mean necessary in the opinion of the Local Board who have to take on themselves to do the work, pay for it in the first instance, then apportion the expenses among the householders, and then recover the apportionments from them." There is only one other case to which I need refer, Lewis v. Weston-Super-Mare Local Board, 40 Ch. D., 55. I refer to it for the remarks of Mr. Justice Stirling (at p. 61), who said: "Now, as to the first point, it was not contended that the word necessary in the 16th section was to be read as equivalent to physically impossible to do otherwise. What was urged upon me was that the route chosen by the defendants must, according to that section, appear necessary to the tribunal which is to determine the question if raised; that is, I suppose, to the Court of first instance in the first place, and to the Court of Appeal if the decision of the Court of first instance be not acquiesced in, and finally the House of Lords, if that tribunal should be resorted to. Now there are few engineering questions on which it is not found that engineers of the greatest eminence take different views; and if the true construction of the enactment be that contended for by the plaintiff it appears to me to follow that no local authority can act upon a report of the kind in question without the risk of a protracted litigation, the result of which would depend on the view taken by the Court, whose decision was ultimately invoked, of the conflicting evidence of experts. In my opinion the enactment is not to be so construed. Although, apparently, the question now arises for the first time upon this particular Act, analogous questions have often been previously raised on similar enactments in other Acts of Parliament, and it is important to see how such enactments have been dealt with by the Court," and, again, at p. 67: "In such a case it seems to me that necessary may well mean necessary for the efficient discharge of the duties in the way which is most for the benefit of the public." The question in that case was as to the proper route for carrying a water main, very much like the present case, where it is a question of the proper route for carrying a drain. It was urged in that case that the words "appear necessary" should be construed as meaning "appear necessary to the tribunal before which the question is raised," but it was held that they should not be so construed. In my opinion, the Act now under consideration cannot be so construed. I think with Lord Justice Lindley, that such a construction "would lead to the wildest confusion," and the practical result would be that the section would become inoperative. This Act was passed in 1898. Now, it is usual to credit the legislature with a knowledge of the existing law on the subject dealt with, and when we find that such a meaning has been constantly attributed to the word "necessary" in other Acts dealing with similar matters, they may have reasonably expected that the word would in this Act be construed as having the same meaning. Against that construction no authorities have been cited. It has been suggested that the use, in the same sec. 158, of the words "such drains or sewers as may, in the opinion of the Board, be necessary," making the opinion of the Board an express test in the same section in which the word necessary is used without any reference to the opinion of the Board, shows that a more limited construction should be given to the word standing alone. That is, no doubt, an argument entitled to consideration; but, if that construction is adopted, the section will become nugatory, and "will lead to the wildest confusion." The question to be determined in this case is whether a drain on a particular piece of land is necessary to the proper drainage of an adjoining piece. Now, when the local authority is called upon to exercise its statutory powers, it is bound to consider the interests of the whole body of the ratepayers, as well as of the individuals concerned. They have to consider what is proper drainage. There may be various methods of drainage, and one may be better in the abstract than another; but in the particular circumstances it may be impossible. Local authorities are bound to consider practicability in the matter of expenditure as well as in the way of engineering facilities. It might be that an admirable system of drainage might be constructed at a cost of one million pounds, but it might be absolutely necessary for them to do the best they could with £50,000. In this case it was the duty of the Local Board to take all the circumstances into consideration, and if they arrived at their conclusions honestly and bonâ fide, no other tribunal can interfere. There is no suggestion of any want of bonâ fides. For these reasons I am of opinion that the judgment of the learned Commissioner was right, and that the judgment of the Full Court should be reversed.