WAIMAKARIRI RIVER

Press, Volume LXXXVII, Issue 26395, 13 April 1951, Page 8

WAIMAKARIRI RIVER

CATCHMENT BOARD’S PROGRAMME PROTECTIVE WORKS FOR FIRST ATTENTION As part of a scheme costing £lll,OOO to build up defences against the Waimakariri river so that it will take a 200,000-cusec flood, a list of works that can be done before the renewal of the railway bridge was considered at a special meeting of the North Canterbury Catchment Board last evening. The preliminary works were estimated to cost £15,305. The money will be raised as follows:—£33lo from the Waimakariri Maintenance Account, £490 from the Ministry of Works, and £11,505 which is expected to be received by way of a £2 for £1 Government subsidy. The works were listed as follows:

Changing over the rainfall recording system at Arthur’s Pass, already put in hand at no cost; construction of box formation for about 25 chains, forming a lew flow channel above the highway bridge, and beginning at the discharge end of pilot tunnel (£3600); reinstatement of the bank at Jury’s (£700); new loop bank at the south end of cross-bank (£880); bank replacement at Harewood and closing of channels leading to the cross-bank (£490); clearing and levelling of berms at Wright’s cut for about 72 chains (£1500); reinstatement of protection at Eyreton—rope protection and tree-planting (£2400); overflow at Halkett rifle range and blocking of old channel (£275); preliminary strengthening of the bank at White’s bridge (£2850); and clearing of willows on Goat and other islands (£2610).

The board decided to add to this list the raising of the bank at Bruce’s.

RIVER CLEARING PROPOSAL

REMOVAL OF SHINGLE SUGGESTED The scooping of shingle out of the bed of the Waimakariri river and the building up of banks on either side with the material were proposed as a permanent means of protection by Mr A. J. Smith at a special meeting of the North Canterbury Catchment Board last evening when a £lll,OOO scheme to strengthen defences against the river was under consideration. Mr Smith suggested that the problem should be tackled in such a manner in spite of the cost Expenditure in the past, he said, had been virtually washed out to sea. The fact that the board was telling people at Kainga to shift under threat of a calamity showed what confidence it had in its protective works. Mr W. F. Young said that the suggestion was one way of dealing with the oroblem, but in America where it had been followed stopbanks were continually being raised and rivers were chasing them up. The aim behind the scheme before the board was that the water in the river should be so channelled that it would mould the shape of the river so that it would carry the shingle out to sea. On the Otaki river £150.000 had been spent to scoop out about one and a half miles, and although the river had been straightened it was now attacking the side. From a financial noint of view the nronosal was not so good as the scheme before the board, said Mr Young. The chief engineer (Mr H. W. Harris) said that one of the problems would be the disposal of shingle. If four feet were taken from each reach of 25 chains it would cover 36 acres of land to a depth of four feet, and further up the river as the banks widened out the quantities of shingle would become greater.