THE PROPOSED WAITAKI CANAL.

North Otago Times, Volume XI, Issue 359, 30 October 1868, Page 3

THE PROPOSED WAITAKI CANAL.

Bjr fho comrboBj u/* Mi- Hillary ,~ O.-K77 weTiave'lraa an opportunity of inspecting some very elaborate and carefully-drawn plans by that gentl'etnan, showing the works proposed for making tho brewery lagoon a tidal basin. Mr Hillary proposes to cut through the shingle-bank which separates the lagoon froin the sea at a point nearly in a line with the Post-office j the channel to be 50 feet wide, and to be flanked by retaining-walls, built of Oaraaru stone, and faced with hydraulic asphalte to high- water mark, the walla on the seaward side being from this point faced with concrete. From low-water mark the walls to be entirely of concrete, and to run out 70 feet farther, terminating in buttresses facing north and south. The total length of the concrete wall will be 240 feet, and of the Oainaru stone portion 130 feet on either side of the channel. It is then proposed to convert the lagoon into a dock 300 feet square, surrounded by a retaining-wall of Oainaru stone. It is also intended to place two pairs of gates — one at low-water mark and one at the dock entrance, convex respectively to the waters of the lagoon and sea, thus forming a lock which would contain about 3000 tons of water. It is proposed so to construct the lower gates as to admit of their being lifted, in order to flush away any shingle brought up by tho tide. In order to greatly increase tho volume of water in the creek, it is proposed to cut a canal from the Waifcaki, about 14 feet wide and 4 feet deep, starting from a - point about 16 mile9 from the mouth of that river, nearly in a straight line to the Big Hill — a tunnel about a quarter of a mile in length being shown through a spur of tho hill, which, however, can be avoided by a slight detour. Passing through a small gorge from this point, it will be taken by tunnel through the hill at the head of tho Oamaru Creek, into which it then empties. This tunnel, again, may bo avoided ; but to do so would involve a considerable deviation. This plan would have the advantage of providing for the future watersupply of the town, as at the Devil's Bridge a reservoir is now naturally formed, and a very little labor would give an abundant supply of water with a vertical pressure of 150 feet, the level being 150 fee* above that of the town. Were this work carried out, the water in the creek could be raised sufficiently high to float vessels into a dry-dock> which it is suggested ultimately to construct In the hollow near the Post-office. The Waitaki would also thus be rendered navigable up to the Hau-hau Lakes ; and this alone would be an immense advantage to the upcountry district. Another plan, which possesses fewer advantages though it would be a much less expensive work, proposes lo cut the canal from a point about four miles from the mouth of the Waitaki, thence running nearly parallel to the road into the creek, just above the Thames-street bridge. This would provide an ample supply of "water for tho dock alone. Mr Hillary estimates the cost of the whole works, if the shorter canal be adopted, at about L50.000 ; and if the larger canal bo adopted a 1 about L70.000. There appears to be no sort of doubt of the practicability of tho scheme, which is, in an engineering point of view, exceedingly feasible. We understand that the plans hare been laid before tho Superintendent and the Executive, and that Mr Hillary has been, instructed to pi'epare all the necessary data, to bo laid before the Council at the next session.