VICTORIA CHANNEL

Otago Daily Times, Issue 17687, 26 July 1919, Page 10

VICTORIA CHANNEL

■plans for deepening. DEPTH OP 22 FEET DECIDED ON. At tho meeting of tho Otago Harbour Board last night a report by tho board's engineer (Mr Wilkie) on tho deepening of tlio Victoria Channel was considered. Tho report was as follows:-— 'As instructed by the board I submit tho following figures in connection with tho dredging, required to deepen tho upper harbour channel to 22ft and 25ft respectively and to a width of 20Qft.— 22ft deep. 2511; deep. Locality. Chib. yds. Cub. yds. Islands to beginning of "Victoria channel ... ... 30,551 143,930 Victoria channel _ ... 357.G33 903,896 Swinging area oil Victoria wharf and Victoria wharf berthage 1 0ff,700 270,000 Totals 513,730 1,328,831 Time for channel ._ _. 2 years. B years. Time lor swinging area ._ 9 months. l"j years. Oosfc for channel ._ ... £20,000 £50,000 Cost for swinging area ... 7,500 15,000 "The Victoria Channel is at present marked by piles on either sido of tho channel, driven originally in 18ft of water. No uniformity of width has been observed, between tho piles varying from 340 ft to 203 ft. An examination of the sounding plans, made during 1918, shows tho channel between tho 18ft contours to vary from 400 ft to 160 ft. During dredging operations the piles are naturally taken as defining tho width of channel to be dredged, and much unnecessary work has been expended in widening the channel in places already sufficiently _ wide. To reduce tho cost of dredging it is necessary first dehrately to decide upon the minimum width of channel, and then re-drive the guiding piles so that they define a channel of the width decided upon. With regard to the dredging of a swinging basin of? the Vietona wharf, although the cost is based trnon bucket dredging, it is not suggested that t-n*i.s would be the most satisfactory way of dealing with tho soft material at tho upper end of tho harbour. As the trad© of the port expands it will bo necessary to nrovido additional berthage, and the wharves would naturally extend along tho south endowment walL To provide deep-water berthage, and sufficient swingin-g room, many acres at the upper end of the harbour would require to bo deepened. Wlien it is considered thai the spoil from every ttcrro dredged to 25ft deep at tho upper end of tho harbour would fill, roughly, two acres of the south endowment reclamation area, tho necessity of conserving the reclamation areas is at once appreciated. It has been stated that the board's reclamation areas are insufficient for future developments, and if the port of Otago is to bo maintained as a first-class port, it is strongly advnsed that tho board conserve tho reclamation areas for channel dredeincrs only."

Tli© board decided to adopt tho loffler of the two schemes involving the deepening of the channel to 22ft at an expenditure of £27,500, the work to be prosecuted as soon as the deepening of the lower harbour is complete.