The Evening Star MONDAY, JANUARY 20, 1873

Evening Star, Issue 3095, 20 January 1873, Page 2

The Evening Star MONDAY, JANUARY 20, 1873

It has been announced that the City Council are about to consider the subject of the drainage of Dunedin, and as a preliminary step they instructed their Surveyor to submit to them a report, which has been, sometime since, printed and circulated. If that report were intended to show that a system of underground drainage is possible, neither the Surveyor’s time nor labor was necessary; a plan was presented some years ago by an engineer whose experience is far beyond that of-the City Surveyor, and wo think that, at any rate, the two should be submitted to competent authority, that their comparative merits may bo tested. But apart from engineering considerations. we object to the City Surveyor’s proposition to discharge the sewage of the City into the Bay, as being fraught with danger to the health and lives of t he inhabitants. He offers no nrgumeid in support of his proposition ; and only cites two examples, both of which point to the extreme danger of the course he advises. The first example is that of a country town in England, Bishop Stortford, in Hertfordshire, iu .which the authorities, through interfering with the underground drainage lost the River Stort should be polluted, rendered the old plan of a weekly clearing of closets necessary; and as Bishop Stortford only contributed two tons a week of solid refuse, it is presumed that Dunedin would supply six tons weekly, which we are gravely told is “a most insignifieont quantity running into a large harbor like ours.” Next is instanced the drainage of London, with an outfall at Woolwich, fourteen miles distant; and those two examples are cited to shew that the sewage of Dunedin should bo discharged at once into (lie buy, If those two examples prove anything, they point to the danger likely to result from such a course. Both the Btort and the Thames are rivers in the true sense of the term ; and the latter pours a vast volume of water, running at great velocity into the sea. Yet fji spite of that it was found necessary, for sanitary purposes, to carry the sewage to a areal distance below the City to avoid the pollution of the water, and the consequent Mife.el4v.ii $ the air. What the peculiarities of Bishop Stortford are wc do not know. At any rate it is evident that it has been eonsidereJ advisable to abandon underground divdftHge, although a running stream is close at h/md to carry off the sewage. But the bay at Dunedin differs from these. It has no current to earry off what may—nay, what must—be de r posited there, if the City is drained into it. The fact of the continual warping up of the harbor points i,n the absence of scour. It is thereforc evident, --hon'd t* lo outfall of our drainage be into the harW, each tide deposit* a stratum ,of Trt?sh

matter, to putrify and decompose and taint the air ; to disseminate far and wide the seeds of disease and death. '» 0 should have been glad to have been spared commenting somewhat severely on the City Surveyor’s report; but it will not do to pass over the onesided treatment the subject has received at his hands. He quotes from the report O£ the Sanitarv Commission or 1000, m which the Commissioners reported m favor of drainage into the harbor; but lie omits to state" the conditions on winch ! that recommendation was made. iN oc o not hesitate to say we think the rccomi mendation of the Commissioners based upon mistaken views, but the City bm- ! veyor has not done them justice ; he Has I stopped short in his quotation at a veiy important point. Wo will, therefore, reprint the passage in full On tilc subject of outfall, your Commissioners are therefore drawn to the same practical conclusion as Mr Balfour, viz., that the tfewatre outfall will be into the harbor ; ami m stating this, they at the same time must again asK attention to the plans of harbor improvement designed by the Marine Engineer, winch your Commissioners consider eminently calculated benefit the health of the City by sweeping away all injurious matter, and by the minute subdivision of the sewage, rendering it compaiatively innocuous.” In seeking for a supenoi , lan to this, your Commissioners can only suggest that the outfall be taken at least half a mile into the ocean, an alternative they conceive opposed by difficulties of_ the greatest magnitude. Having stated their conclusions that the outfall of the sewerage should he into the harbor, '.our Commissioners, in support ot their decision, may cite the example of the City of Loudon, with its three millions ot inhabitants. This City, nndei the advice of the most eminent men of the age, has the outfall of its sewerage into the Thames, at place a little below Woolwich, where the tidal stream is on y 500 yards broad. Seeing this to be the case, it would appear to be hypercritical to raise objections agdnst a City of only, 1«.000 inhabitants, making ready use of the tidal estuary natuic has provided for them, and the breadth of which is 2.000 yards, or four times that of the 1 names. Your Commissioners are therefore of opinion that all sewers or drains of the City should be designed so as to accommodate their gradients with the harbor improvements suggested by Mr Balfour, of which a copy is appended to this report. Mr Balfot'r’s opinion, as expressed by himself in his report to the Commissioners, was as follows At a distance from the City, and sufficiently removed from a'l habitations, an outfall could be constructed there, discharging directly into the ever-vestless ocean, which, by its constant agitation, would effectually prevent any accumulation of deleterious matter ;, while, on the other hand, when the utilization of sewage conies to be better tuulevstood, find capublc ot being carried out with economic success, there is ample space on the beach itself for the construction of all necessary works. _ That the removal of the sewage outfall to a distance from Dunedin would be most beneficial to its sanitary condition must be self obvious. One has only to approach the shores of the hay, or to stand on any of the jetties at low water, even now, to be satisfied that even the present very moderate discharge of sewage into the harbor is fraught with so ious ov Is to the community. Were the whole sewage of the City at once hurried into the bay by a complete system of drains, the effect would certainly be to render the tidal beaches pestilential in the extreme-dangerous enough to those only who had occasion at times to approach them, but fraught with deadly poison to those who were constrained to dwell in their vicinity. I assume then, im of course, that if the sewage of Dunedin is to be discharged into the bay, certain works must be undertaken to protect the City from its injurious effects ; and it becomes a question whether these works could be more economically carried out construction of a great outfall sewer. The works la the hay would have, however,, collateral advantages as shall be afterwards pointed out. .Should it, however, he decided, for the present at least, not to carry the sewage to the ocean, it will probably be only a temporary delay, and I should in consequence recommend that the possibility of future extension be kept in view ; and the main drains of the City laid out in such a manner as to admit of their being afterwards, at a comparatively moderate expense, intercepted by a great sower, the line and levels of which had been carefully studied and arranged from the first.

Tiro works that ATr Balfour considered necessary to render drainage into the harbor innocuous were certain training walls in the centre of the harbor, and reclamation at such points as to secure a tidal scour on the Dunedin side. The cost of these ho estimated at £01,550. From the quotations we have given it is evident that, without these complementary works, he considered the discharge of sewage into the bay fraught with danger, and in this he js eoido'nied by medical opinion. Dr Hockkx whs examined as follows : Q : Do you think it would be ante to carry the sewage of the town into the bay immediately in front of the town?-- A. ; In my opinion it would be extremely unsafe, inasmuch as I believe the ebb-tide would merely carry it two 'or three miles down the baj r , and not into the sea, and it would, if such were the case, partly be returned with the flood-tide. (f { Can yon give any instances of towns becoming unlmalithy from such a cause A. : Instances of the kind af.e cytremedy numerous. We trust the City Council will jycigli these opinions well, and not rashly rush into a vast expense that, instead of rendering the City healthy as intended, can only have the effect of converting the bay into a nursery for miasma, and Dunedin into a charnel house. Drainage is necessary. but it must bp thorough. Dunedin has already paid too mu.oh for ill-consid-ered schemes. The Council are considering the propriety of assuming a responsibility opposed to the most able engineering anti medical evidence and the widest experience. It is dangerous ground to go upon, and may involve results that can never bo remedied,