OTAGO HARBOUR

Otago Witness, Issue 3195, 9 June 1915, Page 5

OTAGO HARBOUR

ITS FUTURE AS A DEEP WATER PORT. HARBOUR RATING DISTRICT. DEVELOPMENTS IN TRADE. At a meeting of the Technological branch of the Otago institute on tho 18th, Mr J. Blair Mason, engineer to tho Otago Harbour Board,' read an interesting paper on “ Tho Future of Otago Harbour.” He showed, in the first place, what tho harbour can become, and, in the second place, how revenue may be secured to bring about improvements to meet extending trade. It was safe to postulate ho said, that tho port of Dunedin must be prepared to accommodate tho largest vessels afloat today, with a reasonable margin for increases in length and draft of vessels. It had been demonstrated by eminent _ marine architects'that vessels up to ICCOft in length could be economically constructed, and that tho size of tho largest vessels of the future would be regulated by tho capacity of thentrading ports. Many port authorities, in recognition of this contingency, were deepening their waterways and constructing berths-TOOOft long to take vessels of this class. The Panama Canal was constructed to allow- of the passage of vessels up to 1000 ft long and 40ft draft. The Dominions Royal Commission, which visited New Zealand in 1913, took evidence as to the prospects of tho principal ports of this dominion being made equal to these requirements of depth and berthage. One was able to assure the commission that there would be no difficulty in obtaining and maintaining a depth of 40ft at Port Chalmers when it was wanted, and that when these big ships came along the people of Dunedin would see to it. that this port would be capable of berthing them. In speaking of the port of Dunedin, it should be remembered that the appellation applied to the whole harbour, and included Port Chalmers, tho present terminus for heavy draft vessels. It was the policy of the Harbour Board to develop the whole harbour in such a manner as would serve the best interests of the people of the harbour district. With that end in view, tho lower harbour channel, from tho_ Heads to Port Chalmers, was being continually deepened and improved for the of the largest class of vessel trading to the dominion. Next in importance was the Upper Hai-bour improvement works, consisting of the enlargement of Victoria Channel, deep water basin, and berthage at Dunedin for the reception of the ordinary-sized ocean carriers, which, by proceeding to Dunedin, could land their cargoes in proximity to tho city -warehouses. The minimum depths to-day in the lower harbour were: Entrance channel Taiaroa Heads, 40ft- at low_ water; channel south off Harrington Point, 32ft at low- water; Deborah Bay, 26ft at low water. The low w’atcr depth of the Lower Harbour channel throughout the greater part of its course exceeded 40ft. The mean depth from Port Chalmers for 1 i miles down channel until the 40ft contour was reached, was 34ft. _ The actual bottom to be removed to give a channel 3Coft wide and 40ft deep through the shallow reaches did not exceed 1,000,000 cubic yards, representing a sum not exceeding £40.000 for dredging by the board’s bucket dredges. It should be noted that for vessels of extreme draft it was usual in most places to allow the tide to make and not to seek to navigate harbour channels at low water. By vessels using the channel on a 4ft rise of tide, comparatively little dredging would bo required to bring the port up to the Panama standard of 40ft. The necessary berthage could also be provided at Port Chalmers when it was required. It appeared therefore that hero was a deep water port in the making, under circumstances that would enable the port authorities of the future to cope with every increase in the size of vessels up to the ’scale mentioned —viz., 1000 ft long and 40ft draft.

To give access to the wharves and basin at Dunedin for a draft of 30ft the widening and deepening of the Victoria Channel was necessary. The minimum depth to-day in the centre was 19ft at low water, with a minimum width of 170 ft. The mean depth at low water was 22ft. The objective in the meantime was to obtain 22ft at low water as a minimum, ultimately dredging to 26ft at low water to permit vessels drawing 30ft to pass through at high water. The cost of carrying out such operations would not bo excessive, and the expenditure would be easily met out of the board’s ordinary revenue. _ The works antecedent to dredging a basin and deepening the berthage to, first of all, 25ft, and then to 30ft. at Dunedin, wore now nearing completion. It then but remained to go steadily on with the necessary dredging, limiting the. total expenditure to a sum that the ordinary revenue would stand, which might, for the present, be put down at £20,000 per annum under normal trade conditions.

The Otago dock was already of insufficient dimensions to accommodate the newer steamers of tho Union Company and others, and it would bo a necessity of tho future that tho port should possess a larger dock, capable of taking vessels of any size, which, as already shown, would have no difficulty in entering tho harbour. Harbour improvements at Port Chalmers were carried out to-day on plans that provided for extra dock and slipway accommodation, and for workshops and shipbuilding yards, which, sooner or later in these now lands, must be established. The district commanded by the port of Dunedin contained tho counties of Bruce, Taieri, Peninsula, Waikouaitl. Waihemo, Maniototo, Vincent, Clutha, ana portions of

Lake County and of Tuapeka County. This area was traversed Dy the River Molyneux and the Otago Central railway, and covered a large extent of fertile country, especially along the coastal portions, while the interior in large part promised to be equally fertile when irrigated and developed. Cpon the settlement and development of the harbour district must depend the prosperity of Dunedin and its port ; and need one say that the prosperity of New Zealand as a whole was bound up with opening up and settling a large population on the land? For the purposes of comparison he had attempted to define the districts, and to arrive at the area with the population commanded by tho principal ports of the dominion. The results were as follows:—•

Population District. Area acres. 1914. Auckland 6,764,000 260,000 Napier 3,203,840 40,000 Wellington ... 5,050,000 . 150,000 Lyttelton 5,651,220 143,000 Timaru 4,033,280 42,000 *Duncdin 5,366,500 120,000 Bluff 6,000,000 62,000 * Population of cities, towns, and boroughs, 79,560; of counties, 40,340; —total, 120,000. In tho Dunedin district there were 14.3 persons to every square mile of 640 acres, and deducting those in tho towns, 4.8 to the square mile. Treating it broadly as an agricultural and pastoral proposition, what population should the country be expected to support when in full profit? In 1891 in the old agricultural and pastoral countries of Europe the density of population per square mile was: —Austria, 210 persons; France, 185; Greece, 95; Switzerland, 185; Portugal, 135; Spain, 80. In tho industrial country of Belgium the density was 360,. and in England 500 to tho square mile. Those who had studied the features and resources of these countries, and know our own favoured district, would bo warranted in premising that the land was capable of supporting many times its present population. With a population of a million, the density would be only 119 per square mile, or a little more than onethird of tho density of the United Kingdom. . Mr Fraser, tho Government Statistician, had supplied him with figures, from which, with tho statistics of the Agricultural Department, it was ascertained that "the lands of the Dunedin district were utilized ajiproxiamately as follows during last season (1914): —Area in grain crop, 255,200 acres; fallow land, 26.520 acres; ploughed land, sown in grasses, 691,800 acres; in orchards, 3500 acres; gardens, 1280 acres; forest-tree plantations, 5550 acres; land not ploughed, surface sown, 166,400 acres; tussock and natural grass, 3,860,000 acres; —-total, 4,918,350 acres. The total area, more of less improved, was 1.058,350 acres. Adding up the acreage of land under crop, fallow land, land in orchards and gardens, there was a total of 264,500 acres, which may be termed the cultivated land to-day in tho Harbour district of 5.366,500 acres. The proportion of tho total capable of being brought under cultivation could not be exactly known until some department of State took the matter in hand and systematically classified the lands of the dominion. But from the figures given it was evident that 788,000 acres of cultivated land were ready to hand in the ploughed and surface-sown grassed lands. There wore besides the plains of the interior, which when watered, would bring forth abundantly. The Maniototo Plain, tho valleys of the Ida, Manuherikia, and Clutha were to-day in parts but wildernesses, but all said to be capable by irrigation of high productiveness; and it was now dawning on our people that in sunny General Otago there was a potentiality of wealth in the soil when the waters of the great rivers could he turned on to it. The first irrigation work of magnitude was inaugurated a few days ago at Cromwell, and one looked forward to tho day when the brown, ■ dreary plains would become dressed in greenery, with farm land and fruit land returning their many fold as the result of pouring warer on tho thirsty land. After a reference to tho indebtedness of tho board, and the revenue at its disposal. Mr Blair Mason touched on tho proposal to supplement the board’s income from endowments by raised by rating, say, the capital value of property within the harbour district, so as to return a sum that, together with the rentals, would provide for interest on loans and other incidental charges. As tho rental ir.com" increased. the income from rates would be reduced proportionately, and cease when tho rentals provided the whole income required. To carry out the proposal to-dav would require that the sum of £30,000 (being tho difference between £43,000 interest and charges and £13.000 revenue from endowments), should bo obtained by a rate on property over the harbour district. The capital value of rateable property within tho harbour district is approximately £24,000,000, so that a rate of one-third of a penny in the pound would yield the required sum. This would be a maximum, and subject to reduction as tho income from rentals increased. Tho adjustment effected in the finances by the method suggested would in reality enable the port authorities to carry out harbour improvements entirely out of revenue, provided tho income from dues on goods and shipping previously used to meet tho interest charges could be maintained and used for that purpose. This course would avoid further borrowing and the piling up of interest. As the expenditure on port improvements must be regulated in accordance w-ith tho funds available anv falling-off in such income could be usually anticipated and the expenditure curtailed proportionately.