WEALTH BY WATER

Evening Star, Issue 17241, 5 January 1920, Page 2

WEALTH BY WATER

PROVISION AGAINST DROUGHT. AUSTRALIA’S BIGGEST DAM. The prolonged drought in Australia has brought home to the people the supreme importance of utilising all possible sources of supply for irrigation, and throws into relief the enormous value of the Murrainbidgee scheme, which, with the completion of the Burrinjuck dam, will transform a vast dry hinterland in New South Wales. Mr N. 0. Staveley, borough engineer of Wanganui, who has returned from a visit to Australia, where he was one of four New Zealand civil engineers to attend a meeting of the New South Wales branch of the Institute of Civil Engineers, gave the Wanganui ‘ Herald ’ his impressions of this great irrigation work. “It is difficult,’’ he said, “in a few words to give an adequate idea of the magnitude of this undertaking, which consists in the application of stored water from the Murrumbidgee River to an area of practically barren desert of 230,000 acres in extent, which is being converted into small farms for the intensive cultivation of fruit and other crops. One thousand five hundred of these farms are now in course of development for a returned soldiers’ settlement, while others are already occupied by selectors. BIGGER THAN SYDNEY HARBOR.

“ The dam itself is a magnificent structure, situated in a gorge of red granite which, besides providing an ideal foundation, supplies excellent material for the concrete, of which there are 400,000 cubic yards in the structure. “Its height is 242 ft, width at bottom 160 ft, and length 765 ft, or lit chains. It is constructed entirely of mass concrete, and will impound ’/71,641 acre feet, or 207,278,157,800 gallons, thus being the fourth largest storage in the world, and one and a-half times the contents of Sydney Harbor. The artificial lake formed by this storage has an area of 20 square miles, and "will back up the river tor a distance of 40 miles. x\t present the spillways of the dam are under contraction, and the water is maintained 60ft below its ultimate level by means of the regulating sluices, backing up the river for 28 miles, and forming a smaller but sufficiently impressive lake. The original estimate for tn© dam itself, for which a contract was let (labor only) some 10 years ago, was £872,000; but it is now expected to cost one and a-quarter millions to complete, partly owing to extra works found necessary. The contract was terminated a few months ago, and the works taken over by the Irrigation Commissioners. It is expected they will be complete in about two years. Incidentally it may be noted that $6 miles of narrow?auge railway had to be constructed from he main line to the dam site, at a cost of £86,000, before work could be started. This line is an object lesson in mountain railway construction, there being no bridges, other than culverts, or tunnels, but curves of one and a-half chains radius and grades of 1 in 25 are fairly frequent.

NETWORK OF' CANALS. “ The object of this dam is to conserve the ■winter run-off of the catchment area —which has an area of 5,000 square milei —for use on the land during summer, and the ’ point of draw-off is 220 ‘miles down stream, at Berembed weir, where the main canal starts, which runs for a distance of 96 miles—to be ultimately 130— to the town of Griffith, with numerous sub-canals and branches, forming an irrigated district as indicated above. It is interesting to note that practically the whole or the excavation, which is 50ft wide hy Bft deep for most of its length, was done with horse scoops, similar <b those we use here for sand shifting and road work. “The irrigation area, which is situated in the western district of New South Wales, about 400 miles from Sydney, contains two main towns, Leeton and Griffith, which are laid out arid in course of construction on approved town-planning lines, and several smaller villages. TTiere are 462 miles of roads formed, principally of earth, t\yo water towers, and a powerhouse, besides canning factories, etc. The total expenditure on the scheme to date is approximately four millions, including one and a-quarter millions for resumption of land. “A secondary use of the stored water at Burrinjuck is for the development of hydro-electric power, a scheme for which is now being prepared. It is expected that 80,000 k.w. will be obtained without drawing unduly on the irrigation re- , quirements. ’