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tenance of the work. Such special rate and general rates should be levied over such portions of the district only as will, in the opinion of the Board, be likely to drain into or to benefit by the existence of the sewer or main drain, and in making such rates the Board should have power to make differential rates as between lands (a) directly benefited, (b) generally benefited, and (c) benefited only to a small degree, and to exclude lands that do not benefit. (6.) The Board should also have sufficient and ample power to prevent any local authority, person, or company from allowing foul liquid from its district or from his or its premises to enter the stream, and the Board should be empowered to obtain an injunction or mandamus of the Supreme Court or otherwise to restrain any of these things from being done. (7.) These recommendations, so far, are intended in the first place to apply only to surface drainage and household sewage and to provide some means whereby the stream will not be polluted thereby, but they could afterwards be applied to foul liquid from the factories. The principal source of pollution at present is, however, from the factories, and these require special treatment, because, unless a vastly increased water-supply is provided, it will be impossible, for reasons already given, to allow the water used for manufacturing purposes to be placed in the sewer. (8.) The comon law on the subject briefly is that every riparian owner has a right to use the stream for watering animals and for domestic and many other purposes so long as he uses it in such a manner as not to prejudice other riparian owners below him. He may therefore use the water for manufacturing purposes, and for such purposes he may even consume a reasonable quantity of the water, provided he does not thereby impede the flow or sensibly diminish the volume of the streams, but he must return the water he does not consume to the stream after he has done with it in the same state of purity in which it came to him. If he turns water into some other channel, or if he does not return it again to its original stream, or if he consumes an unreasonable quantity according to the size of the stream and thereby causes loss or thereby does something that may cause loss to a riparian owner lower down, he is liable to such lower riparian owner, and his action may also be restrained by process of law.. (See Coulson and Forbes on Waters, 2nd edition, cap. iii; and Angell on Watercourses, 7th edition, cap. iv.) (9.) If therefore the Board is to escape liability, it must be able to throw the onus of purifying the water on the manufacturer who pollutes it, and it should be distinctly provided in any Bill to give effect to this report that the Board shall not be liable to any riparian owner for anything done by the Board or ordered to be done by it in connection with the water, somewhat in the same way as is provided in " The Taieri Land Drainage Act, 1908." The manufacturers are, for the most part, the people who pollute the water, and these are the parties who by law ought to be made to return the water to the stream in as pure a state as it is in when they receive it. (10.) The Board should therefore, in my opinion, be empowered to make rules and regulations providing for the purification of the water, and to enforce a penalty for the breach of such regulations, and also if necessary to obtain an injunction or mandamus of the Supreme Court to compel the various manufacturers to adopt such measures as the Board may from time to time consider to be necessary to purify the water by means of such septic tanks, filter-beds, or chemical treatment, or otherwise as will in each case render the effluent as pure as it was when it entered the manufacturing works from the stream, and the onus of proving that the effluent is as pure as the water was when it came into the manufacturer's premises should be on the manufacturer. This purification will no doubt be a difficult and somewhat expensive thing to undertake in some cases, but no manufacturer has a right to pollute the stream to the detriment of his neighbour, whether that neighbour be a manufacturer or a private person. All I suggest is that the Board should have the power to enforce the common law on behalf of all the riparian owners, but I do not suggest that the right of riparian owners should be taken away, otherwise than as may be absolutely necessary in the interests of all. What is required is not absolutely