The Evening Star TUESDAY, AUGUST 1, 1871.

Evening Star, Volume IX, Issue 2638, 1 August 1871, Page 2

The Evening Star TUESDAY, AUGUST 1, 1871.

The drainage of the City is one of the subjects most prominently insisted upon by the inhabitants of Bell Ward. It was mooted at the huntings, and has been made the subject of questioning by different ratepayers at the election meetings. It is, however, one of those social arrangements that cannot be very easily dealt with. The drainage of cities has always been a difficulty, not only on account of the expense, but because if sufficient care be not taken, the evil sought to be removed from one district may be transferred to another. The drainage of this City should not be undertaken in sections without reference to one general plan, towards the completion of which every drain constructed must be made to tend. And it is this unity of purpose that has to be borne in mind by each successive Corporation elect. This is the chief difficulty with representative bodies, the members of which are elected for short terras of office. The labors of their predecessors are forgotten. New men with new projects in their minds are brought forward, and the work of those who propounded general plans are set aside or forgotten. Whenever this occurs, waste and expense result from the alteration. Brains already formed, are found not to suit the level of those projected, or an alteration in the direction of sewage renders them unserviceable beyond their merely local agency. Bor this reason there should be in all Corporations a sort of personal identity, by which the one plan should be perpetuated through each succession of members, just as in the case of an individual, a settled purpose is carried forward from youth to age, notwithstanding the alteration in form and structure, the waste and renewal of substance that has been going on. We are not aware whether our Corporation has acted upon this precaution in the few drains already made. We know some years ago plans were prepared by the City Engineer of the day, and if we are not mistaken they were presented free to the Council, for the benefit of the City : but we do not know whether they were ever personally adopted as_ the basis of a system of drainage. The advisability of some such measure must however force itself upon attention, when it is considered that thus far the sewage of the City has been allowed to run into the Bay. What else to do with' it under present circumstances is a serious difficulty ] but it is hardly less how to avoid the consequences. For a time no very serious evil may arise j but that such a system will eventually prove dangerous to the health of the inhabitants, will be evident, from the following well-considered remarks of Mr Swyer, then Provincial Engineer, in his report to the Sanitary Commission in the year 18G5 :

The third conditio# is one of the greatest importance in a sanitary poi#t of view. In towns which discharge the content? ,o£ their sewers into tidal rivers or harbors, tire inhabited low portion of the town is liable to injury from the refuse being pent up iu the; sewers during high-water ; and more especially from the accumulation of filth at the outlets, and along the high-water mark. If sewers must discharge into, the -• treams, rivers, or harbors, the outlets should be at such a distance below the town as would render the refuse innoxious—that is, the outlet from the sewers should he placed at such a point that the contents of the sewer would certainly be carried beyond injurious tidal influence ; or, in other words, that there would be no probability of refuse once discharged into the river or harbor being redelivered into the sewers at the return of the tide.

The position of Dunedin with respect to its harbor and the tidal influence is one which will require the most careful .consideration with respect to this view of the question. The distance from one extremity of Otago Harbor to the other is about 1,3 miles, and the flow of the tide as taken from Admiralty charts is on an average 14 miles per hour, therefore any refuse discharged into the Harbor at Dunedin at high water would, under favorable circumstances, have travelled 9 miles before the turn of the tide, or 4 miles less than would be required to discharge it into the ocean, the consequence would be that all the solid portions of the sewage would be deposited on the numerous banks within the Harbor, or along the high-water mark, the sewage in solution being retained in the waters of the Harbor, which, in the course of time, would be reduced to? a gigantic cesspool, an I would become fouler and fouler every year. The disposal of the sewage without allowing it to find its way into the harbor, is not a difficult problem to solve. The application of sewage water for agricultural purposes is now acknowledged to he productive of the greatest benefit; and there is a large tract of land between Dunedin ond Saddle Hill which would be greatly benefited by the regular application of sewage water, and by a aeries of pumping engines even the whole of the Taieri Plain might participate iu the advantages of such a system of fertilization. In this report it will not be necessary toenter into details connected with the irrigation of lands as proposed, but in order to show the value of sewage it may be stated as a fact that eight tons of sewage water are equal to 15 tons of farm yard manure, and agricultural chemists in England estimate the value of sewage from a town at the rate of 18s per head per annum. To throw away materials of so much value would be unpardonable, and to lead the sewage into the Harbor would be not only creat.

ing a source of continually increasing evil ; but would at the same time be throwing as it were thousands of pounds inti the sea.