THE HARBOR

Gisborne Times, Volume VIII, Issue 574, 19 November 1902, Page 2

THE HARBOR

A SUGGESTION TO THE BOARD.

jTo the Editor of the Times.)

Sin, — It would seem, after some months’ experience, that however well tho dredge may be worked it will bo found quite inadequate to make any permanent improvement in tho harbor. Tho groat difficulty to bo overeomo is tho constantly reforming bar near tho end of the breakwater. It has occurred to uio that other moans might bo used for tho removal of this obstacle, and that in a way which would have many other advantages. I am aware that sand and water in conjunction form one of tho most difficult problems that engineers have to deal 'with, and that all works having to do with such material must bo more or less experimental and risky, but I boliove that Gisborne harbor cun ho greatly improved in a cheaper and more effective way than by tho slow and costly process of dredging. My idea is that a tidal lock should bo built across tho channel, the upper gate of which should be placed near the inner ond of the western groin, and the lower gato from two to three hundred foot furthor down. Tho effect and advantages of this work would, I believe, bo as follows : A permanent high water level would bo kept above tho upper gate, thus making a large and convenient basin for shipping, and doing away with tho necessity of dredging in that locality, except for purposes of berthngo and reclamation. The lock being n tidal ono both gates could bo oponod for from ono to two hours at each high-water, and vossels passing at such times could go in or out without being locked through. At low tides the lock sluices could bo let go us often as necessary for the purpose of scouring out tho channel and preventing tho bar at tho ond of the breakwater from forming. Or if this should he insufficient tho whole body of water in tho upper basin could be used, which would cause a scour that would go near to washing out the hay itself. The whole of the silt, otc., boing thus removed by a Hushing process, the drodgo could be employed entirely in removing rock or other material from tho channel, which would not ho effected by scouring, and in reclamation work in tho upper river. Tho lock would bo provided with sluice, independent of the main gates, by means of which tho lovol of tho upper basin could be absolutely controlled, audit might be found possible to use power derived from these for lighting purposes, but this being a matter of storago batteries and other electrical appliances, may bo left for after consideration.

In time of flood, when the rivers were bringing down silt, the lock would bo opened, so as to allow tho silt laden water to go straight to sea. If by thoso means a deep channel can be mado as far as the lower lock gate, it is obvious that vessels could be looked through into the upper basin, where thoy would have ample room to moor uud swing. In caso of largo steamers landing passengers and mails, tho present road could be extended across tho Waikanao to a landing place for the tenders below tho lower gate or in tho lock itself. The most obvious advantage of this scheme would be the permanent high water in tho basin and rivers. This would greatly add to tho healthfulness and beauty of tho town, and tho increased value of river bank property should go far to defray the cost of the works, besides a large saving being mado in lightering charges for cargo by having large vessels boing ablo to como right up to the wharves. Tho IVaimata and Tarubcru arc at high water beautiful rivers ; at low water thoy afo dirty ditches, and by means of this plan ovon tho filthy Waikanao may be mado a beauty spot.—l am, etc., J.J. Gisborne, November 14. 1902.