MAN MAKES A RIVER

Press, Volume LXXIV, Issue 22335, 24 February 1938, Page 10

MAN MAKES A RIVER

RANGITATA DIVERSION SCHEME PROGRESS OF IRRIGATION FOR MAYFIELD HEAVY AND COSTLY WORK AHEAD Man is making, with the aid of machinery, a river to run 40 miles across the downs country north of the Rangitata and the plains lands to the Rakaia river. When completed in 1940 Ihe artificial stream, carrying almost the whole winter flow of the Rangilata, will be used, in the dry seasons, for irrigating suitable land in two blocks of 176,000 acres in the Ashburton CoUnty. and, in the Winter* for driving the turbines Of the future hydro-electric station'on the Rakaia. Slower progress than was at first expected has been made in the development of the irrigation scheme —to cost ultimately £415,000 —because of the decision to carry the diversion race for its full capacity of 1000 cusecs along its whole course to the point of discharge into the Rakaia to provide a water supply, in wifiter, for the proposed power station.

, Authority has been granted for the Hipds-Mayfield area scheme to be developed, and the erection of the cottages and hutmehts on the camp site mid-way between the Rangitata bridge and Hinds is now in hand. The construction of the main race, distributories, and laterals, will be commenced before long. The main race, to carry water id Irrigate 56,000 acres in the big block of 113,000 aereS, will branch off from the large diversion race near the Rangitata, river, and travel nearly ih a straight lirie towards the coast. The schemes, as a \Vholfe, are designed for the fullest use of machinery and a minimum of man-power, arid power-operated dredgers, tractors, and drag-lines are working over a scattered area. Until more machinery is taken to the district, the construction work will be more dr less Of a piecemeal description, with every section taken to the stage where it cab be linked jhto a complete engineering scheme. When a steam drag-line with one and a half cubic feet capacity is taken from Hawkswood, on the -South Island Main Trunk construction work, a start will be made with the cutting of the diversion race—2o feet wide at the bottom and carrying 10 feet of water, in the awkward terrace country from the intake, situated five miles above the camp at KlOridyke. Ofi that section, difficult sidling will be necessary, and the extreme depth of, any cut will be 84 feet: The men at Klondyke are at present working three shifts and the Diesel shovel is now eating its way through a 24-foot cutting on a terrace of the Rangitata below the, camp. , , „ . The heaviest Work, and also the must expensive, lies ahead. The river made by man will have to make six crossings of Nature’s waterways—at the north and south branches of the Hinas, the north and south, branches Of the Ashburton, and .at Bowers and Taylors streams. The earthwork will oe fairly simple, the engineers expect, but extensive ahd costly reinforced cOncrete structures will have to be bin.* to take the water under the rivers.

Headworks Construction The erection of the headworks will bfe. started during the winter. The present plans of the engineers are to construct the intake dam. With a series of eight gates, each 10 Wet wide, arranged hi a caisson in radial style, dn the southern bank of , the Rahgitata, and float it across .the river to the selected site, where the water sweeps on a northerly .bend. • G6bd pihflrhes Is being-made if the Mayfifeld bltidk withi the cons ruction of the main race, already mullt for a lehgth Of 10 miles, and of the distnbu-toi-ies and laterals, of which already 53 miles have beep finished; to convey the water m the individual properties to bfe brought Under irrigation.. Ah inspection df the works m vanon* sections from the intake site to the damp at LytidHUrst Was made terday by the Minister -Jov Labdui^and for EmPlPyment (the Horn IE 1. Ain. strong) who was accompanied by Mr F w Langbeih„6istrict PUbliC EnginStr. thfe GanterhUry.