DIVERSION CUT

Gisborne Times, Volume LXV, Issue 10320, 1 February 1927, Page 3

DIVERSION CUT

EXTENSION OF DREDGING. TO 12 FEET BELOW LOW WATER. ENGINEER SAYS IT IS ESSENTIAL. „ . Whether or not the dredging of the diversion cut should be extended to 12 feet below low water mark entailing 7600 feet out into the *sea It- seemed to him he said. Harbor Board meeting yesterday, but the Engineer assui-etl members that the work was essential. Mr. A. H. Wallis inquired whether dredging was still proceeding in the diversion cut and how far the Engineer intended extending the cut into the ea? It seemed to him he said, that the cut was advanced far enough now it had reached low water mark. He could not see the use ot extending the cut further because any seas coming in from the south east would fill the mouth of the cut with sand immediately. No sooner would the dredge stop, he said, than the cut would be filled up with sand, if the seas were running. Personally he saw no need for the cut to be extended below the natural angle of the river 6 feet below low water mark. He contended that in the old river years ago there was no need to extend the dredging. The Engineer explained that it would be very readily understood that conditions were different to-day from %vhat they were years ago. He pointed out that the dredge was excavating the cut to a depth of 12 feet, and beyond the point to which the dredge had excavated there was no depth of water. In the early stages of the construction the raaxi.mum flood likely to be experienced was taken as a guide and it was calculated what the extent of the cut would have to be to carry that volo of water. This channel was found to be 300 feet wide and 12 feet deep, which was the extent of the diversion cut, which he said would be sufficient o carry away all the water in an "optional flood. It was not possible to stop dredging to 12 feet at low water mark thus leaving a tank in the mouth, of the cut. The excavation to a depth of 12 feet had to he extended beyond low water mai-k to the same level in the bay. He pointed out that, even if the cut was extended to say 6ft. below low water mark, the extension of the cut to the ideal 12ft. below low water mark would cost so little that it was not worth consideration. Mr. C. H. Williams said everyone would assume that a bar would form at the mouth of the cut in bad weather, but he wanted to know if the flood water would scour out such a bank by extending the cut to 12ft. below low water mark. The Engineer explained that that would be the case. Mr. G. Smith suggested that dredging to 12ft. below low water mark might be dispensed with if it was not entirely essential, offering to take the responsibility if the Board adopted the suggestion. The Engineer said that it was necessary to extend the cut'to 12 feet below the low water mark. That ended the argument.