In Gaekwar Sakar of Baroda v. Gandhi Kachrabhai[9] the Privy Council applied the principle to a case such as the present where a railway embankment constructed under statutory power caused flooding. "The embankment was designed with so little skill" said Lord Macnaghten "that no proper provision was made for the passage of surface water ... Powers of this sort are to be exercised with ordinary care and skill and with some regard to the property and rights of others."

Under sec. 33 (2) and (3) of the Crown Suits Act 1898, the Crown became liable for any wrong independent of contract done in connexion with any railway. The effect of sub-sec. 4 of that section in combination with sec. 36 of the Government Railways Act 1904 is to make the commissioner the party who is to be sued on behalf of the Crown upon such a cause of action. The fact that railways are vested in the minister on behalf of the Crown (sec. 4), that the commissioner is a corporation (sec. 8) and that the railways are placed under his management, maintenance and control (sec. 16) does not, in my opinion, either distribute the legal responsibilities arising from the conduct of the railway system, or separate the previous performance of the duties of care in the construction of railways from the present fulfilment of the obligations of maintenance. The railways remain the railways of the Crown, and, although the commissioner is the proper person against whom to enforce the liability, it is the Crown which is finally liable for wrongs committed in connexion with railways in the course of their construction and management. Further, I think it is immaterial that the construction of a railway took place before the imposition upon the Crown of a liability for tort. The cause of action now sued upon arose only when damage was suffered, and the Crown Suits Act appears to me to have deprived the Crown of its former immunity from liability for civil wrong in all cases where the cause of action became complete after its enactment.

The embankment in the present case was, in my opinion, constructed without a proper and sufficient provision for the escape of water, the natural flow of which it obstructed. The water flowed in a defined channel on either side of which it spread in times of heavy rainfall. The aggregate size of the culverts was increased in 1914, but, in spite of the fact that the country is not one which often experiences prolonged and intense falls of rain, the provision afforded by the culverts appears to have remained altogether inadequate.

Reasonable care in the construction of a railway requires that precautions should be taken to avert damage which the works might be expected to cause in extraordinary conditions as well as that arising in ordinary conditions. The constructing authority, or the operating authority, is not called upon to provide against events which, although imaginable, are so removed from the facts of experience that no reasonably prudent person would foresee and guard against them. But skill and care must be exercised by the authority to prevent damage arising from the works in events which may be uncommon or even hitherto unknown, if they are of a kind and degree that may be expected sometimes to occur.

In cases of the present description it is not accurate to say that, in order to escape liability for damage which as a matter of physical causation appears to be connected with the existence of its works, the authority must show that the substantial cause was an "act of God."

In the case of Baldwin's Ltd.[10] Atkin J. says, at p. 1774: - "I do not think that in a case of this kind it is strictly correct to introduce the notions connoted by the phrase act of God. The term is appropriate where liability is sought to be imposed upon a person who, by reason of his calling or otherwise, such as that of a common carrier, has assumed an absolute liability to see that the plaintiffs' property is left free from harm. Such absolute liability may be subject to an exception in respect of damage caused by act of God, which would ordinarily be defined as such an operation of the forces of nature as reasonable foresight and ability could not foresee or reasonably provide against. But where the liability sought to be imposed arises only from negligence it becomes necessary to consider whether all the requirements of the above definition have been fulfilled. All that is necessary for the defendants is to negative the plaintiffs' allegation that there has been an absence of reasonable care and skill on the part of the defendants. To show that the injury was caused by an act of God would no doubt establish the defendants' case, but it seems to me they may succeed without undertaking so heavy a burden. What I have to consider is whether the damage was caused by a storm of such magnitude that, under the circumstances, the defendants could not reasonably be expected to provide against its consequences."

His Lordship expresses a further view which qualifies, or at any rate amplifies, the last statement. He says, at p. 1774: - "It was contended by counsel for the plaintiffs that, even if the rainfall reached such a height that the defendants could not reasonably have provided against it, yet, inasmuch as a much smaller storm would, by reason of the defendants' negligence, have damaged the plaintiffs' goods, the plaintiffs can recover, for the damages are agreed if any part of the injury done was due to the defendants' negligence. It becomes unnecessary to decide this point; but I think the facts warrant the application of the reasoning of the Court of Appeal in the case of Nitro-Phosphate and Odam's Chemical Manure Co. v. London and St. Katharine Docks Co.1(1878) 9 Ch. D., at p. 527., and that the plaintiffs' contention herein is well founded."

The railway embankment in the present case is a physical feature of the land, constituting a chief cause of the flooding on its western side. The escape of pent-up waters at the northern end of the embankment, occurring, probably, at some time shortly after nine o'clock in the evening, was the direct and actual cause of the inundation of places on the eastern side where some of the plaintiffs dwelt. It is, I think, quite clear that openings in the embankment might have been provided which would have discharged during heavy rainfall a quantity of water many times greater than that flowing through the existing culverts. If the capacity of the opening had been thus multiplied, a great part of the imprisoned water would have escaped without contributing to the damage of which the plaintiffs complain. What is the minimum capacity which would have satisfied the obligation resting upon the commissioner of exercising due care to provide for the escape of water may be difficult to determine. But I have no doubt that the actual provision falls far short of that minimum. Prima facie, therefore, the insufficiency of the waterways left by the railway is a cause of the damage suffered. In arriving at the conclusion that an authority charged with the construction or maintenance has failed to provide a sufficient waterway, a court is not bound to undertake the difficult engineering task of specifying precisely what flow of water should be allowed for and what means should be adopted for letting the water pass under or through the works constructed. No doubt before such a conclusion is reached, some opinion must be formed as to the catchment, the rainfall to be expected, the run off and also as to the practicability of dealing with the flow of water. In the present case, the most important consideration, that upon which views most differed, is the run off to be provided against. In my opinion the ten per cent run off allowed for by the railway engineers is shown to be a mistaken estimate. The source of error probably lies in a failure to allow for intensity of downpour supervening upon a period of rainfall in which the ground has become saturated.

The commissioner relies upon a combination of answers to the prima facie case of liability arising from the facts I have stated. He emphasizes the unusual amount and intensity of the rain that fell in the watershed on 8th March 1934. He contends that it was so unprecedented that no reasonable man would have foreseen it and provided against it, and that it so far exceeded the rainfall which any constructing engineer would have allowed for that no substantial damage would have been averted whatever provision had been made unless the provision went far beyond that with which a prudent engineer would be content.

The duration of steady rain and the intensity of that falling late in the day does appear to have been for the locality very great indeed. The proof that it was unprecedented is not satisfactory. The records of previous rainfall given in evidence were confined to one place. In judging of such a matter a wide area should be considered and reasoning from analogy should play a part. But, in any case, the obligation of care resting on a constructing authority which, in the exercise of statutory powers, obstructs the natural flow of water is not fulfilled unless the authority provides not only against a repetition of what has previously happened but also against such variations of events found to be recurrent as might reasonably be expected to happen even if very rarely.

On the occasion now in question, the weather experienced was not of an unfamiliar kind. It was unusual only in degree, and the difference in degree arose apparently from the circumstance that heavy rainfall took place after saturation of the ground. I do not think the occurrence is one against which no prudent engineer would have provided. I am not prepared to say affirmatively that, if after due investigation, a construction had been adopted which made provision that had proved more than sufficient for every previous rainfall, the commissioner would have been liable as for negligence if some banking back of the waters had occurred on the day in question. But the actual facts are opposed to such assumptions. No proper investigation of the conditions appears to have been made. The openings in the embankment did not succeed in discharging previous rainfall. And I think it is reasonably certain that, if openings had been made large enough only to cope with a recurrence of what had previously occurred, a great deal of the damage would have been avoided. Accordingly the burden seems to me to lie upon the defendant of establishing clearly that, even if he had taken all precautions which could reasonably have been demanded of him, a thing which, in my opinion, he failed to do, yet no substantial part of the damage suffered by each plaintiff would have been escaped because the water flowing to the basin so far exceeded that for which the supposed precautions would provide. The evidence does not, in my opinion, establish this fact, or anything like it.

The contention that the flow of water was an unprecedented phenomenon which no reasonable outlet would receive was combined with the further contention that almost three and a half feet of the height of water which rose behind the embankment was to be accounted for by the conditions on the other side of the embankment. It was said that no adequate means were provided on the eastern side of the embankment for taking the water discharged by the railway culverts under or across the streets which lie on that side of the railway. For that reason and because of the grade and state of the channels and ground on the east, the commissioner asserted that a large part of the imprisoned water represented or reflected the retardation of the flow by conditions existing down stream for which he was not responsible. In many of the steps involved in this contention I agree. I think that the state of affairs existing on the eastern side of the embankment would raise the waters on the western side to a certain degree if the water flowing in on the west and reaching the mouth of the existing railway culverts were exactly equal to their present capacity. It is very difficult to measure or estimate the height to which the waters would be so raised. We had the advantage of a close and careful examination, by counsel on each side, of the levels and other considerations which govern or affect the question. My conclusion is that a level of about two feet would be reached as a result only of the retardation or banking back of water after the point of discharge from the railway culverts, assuming the inflow into the basin formed by the embankment and the discharge therefrom by the existing culverts were equal.

Further, I agree with the view that the outburst of water through the northern end of the embankment, where it crosses a road called Macartney Street, did not account for the water held back across the course of the channel leading from the railway culverts. The water discharged by the break in the bank at that point, in my opinion, could not have contributed to the damming back. Again, I do not think that this contention of the commissioner is met by the fact of the discharge of water through the two cattle pits which stand respectively over and somewhat north of the culverts in the middle of the embankment. That discharge involved no destruction of the embankment and no sudden outburst of pent-up water. The rate of discharge from the cattle pits could not exceed the rate of intake into the basin on the west. Consequently, although operating at a higher level than the additional culvert, the cattle pits may be considered as really serving the purpose of affording just such a means of allowing waters to pass under the railway line as the commissioner should have provided at a lower level in the embankment. Nevertheless, I do not think that the operation of the conditions east of or down stream from the embankment relieves the commissioner from responsibility for any of the damage. So far as it affects the plaintiffs on the west, it does not do so because, in my opinion, the additional two feet by which the water might have been raised by such conditions cannot be regarded as an independent cause of the inundation they suffered. If the conditions downstream had not existed and a completely satisfactory discharge for all water sent under the railway had been maintained, the water in the westerly basin would have risen to the same height. This is shown to be the case by the outburst of water at Macartney Street which accounted for a great volume and by the continued flow through the cattle pits. I do not think that the commissioner can claim that, even if he had fulfilled his duty of care, yet if no corresponding reform had been made by the road authority some damage would or might have been suffered, when in fact the situation was that his actual means of taking off the water were insufficient to prevent the water rising to the full height of his embankment and so doing the very same damage as occurred even if conditions downstream had caused no rising of the waters on the westerly side.

Further, it does not appear that any ascertainable or separable part of the damage actually done by the retention of such a huge body of water as mounted to the full height of the embankment could be ascribed to the first or preliminary rise of two feet.

Different considerations affect the commissioner's liability to the plaintiffs whose property is on the east side of the railway. It may be said that, but for the additional two feet, the water might not have spilt over the embankment at Macartney Street and so cut it back and caused a breach in it through which the imprisoned waters burst and flowed over the premises of those plaintiffs. It is difficult to say whether it would have done so or not. But I think that even so the plaintiffs on the east are entitled to complain of the embankment and the insufficiency of the culverts through it. For they would not have received the water they did but for the existence of the embankment which imprisoned it. A rise of two feet in the water behind the embankment would not have affected them. The cause of the damage suffered by them was the impounding of a volume of water sufficient to cause the outburst.

For these reasons I think the appeal should be dismissed with costs.

I agree that the appeal should be dismissed. The cause of action sued upon was negligence. It is obvious that the water naturally flowing from Cut Hill to the Avon River in the two water courses and over the low-lying lands crossed by the embankment would be obstructed if provision were not made to avoid this result. The embankment from the lowest point is 11 feet high and it runs for about 1,000 feet from above Macartney Street as far south as South Street, and Grey Street crosses it by means of a ramp between these two streets. The houses of the plaintiffs on the west side were flooded by waters obstructed by the embankment, and the houses of the plaintiffs on the eastern side were flooded by a volume of water which broke through the embankment at Macartney Street.

The learned trial judge found that the culverts in the embankment did not give a sufficient outlet for waters which would be expected to be dammed back by the embankment. Counsel for the appellant and the respondents respectively attacked and defended this finding in elaborate arguments based on the evidence of the expert witnesses and proved facts. The finding is amply supported by the evidence and in my opinion was right. While maintaining that the culverts running through the embankment were sufficient according to standards which could be deduced from a combination of practical experience and engineering theory, appellant's counsel sought to account for an estimated height of water on the western side of the embankment by obstruction downstream on the eastern side caused by culverts constructed by the local authority and by other causes impeding the flow of the water for which the railway authority was not responsible. In any case it was contended that the torrential and unprecedented downpour which happened on 8th March 1934 in the locality was a deluge due to an "act of God" and for this reason the defendant should be excused for the totality of the damage.

It may be true that the flood would not have risen to the height which it attained despite the insufficiency of the railway culverts if there were no cause of impedance down stream. But the appellant's argument, which is combated with at least equally cogent theories by the respondents' counsel, has not established, in my opinion, that, but for such causes external to the railway works, the embankment would not have dammed back sufficient water to cause damage to the respondents. The disproof of the learned judge's finding, that the water which broke through the embankment at Macartney Street did not join the water issuing from the railway culverts, does not remove the doubt as to the correctness of the appellant's estimate of the height of water not attributable to any deficiency in the railway culverts. For it is evident that the waters flowing from the culverts at the eastern side of the embankment were very considerably increased by the water which flowed through the cattle pit on the railway line nearer to Grey Street.

Culverts of the dimensions which the respondents' witnesses said were demanded by all the factors necessary to be considered would not, it was pointed out by the appellant's counsel, have coped with the waters which came down the water courses on this occasion and spread to the plaintiffs' properties. But again it is not shown that the inadequacy of the culverts did not cause a big enough accumulation on the western side and a sufficiently concentrated flow over Macartney Street, where the water did not naturally flow, to cause damage to the plaintiffs on both sides of the embankment. It was not a necessary consequence of the exercise of the statutory authority under which the works were constructed that this damage should follow. This damage could have been avoided by the provision of a sufficient outlet for the waters which would be reasonably expected to flow against the railway works that had been erected. There was no duty of absolute insurance against damage arising from the exercise of the power but there was a duty to exercise it with due prudence and caution. I agree with the conclusion that the rainfall on 8th March was not a deluge of such magnitude and intensity that it should be classed as an "act of God." The culverts should have been capable of dealing with the most prolonged and intense downpour of rain which in the climate of Western Australia might be expected, though perhaps rarely, to occur; the rain on this occasion did not exceed this standard (Cf. Great Western Rail. Co. of Canada v. Braid[12]). Prima facie the damage done to the respondents was the reasonable and probable result of the default of the constructing authority in the observance of its duty to provide sufficient culverts, and the appellant has not discharged the onus of showing that the damage was due to other intervening causes. In any event it would not be possible to distribute the damage due to the default and the damage, if any, due to other causes beyond the reasonable prevision of the responsible authority (Cf. Fry J. in Nitro-Phosphate and Odam's Chemical Manure Co. v. London and St. Katharine Docks Co.[13]).

I agree that upon the proper construction of the Government Railways Act 1904, secs. 35 and 36, and the Crown Suits Act 1898, sec. 33 (4), the appellant is the party liable to be sued for the damage caused to the plaintiffs by this breach of duty in the execution of the work.

Solicitor for the appellant, A. A. Wolff K.C., Crown Solicitor for Western Australia.

[1] [1910] VicLawRp 65; (1910) V.L.R. 385; 32 A.L.T. 48.

[2] [1910] VicLawRp 65; (1910) V.L.R. 385; 32 A.L.T. 48.

[4] (1876) 1 C.P.D. 423, at p. 441.

[8] (1916) 85 L.J. K.B., at p. 1771.

[9] (1903) L.R. 30 Ind. App. 60, at pp. 63, 64.

[12] [1863] EngR 252; (1863) 1 Moo. P.C.C. (N.S.) 101.