IRRIGATION SEEPAGE

Press, Volume LXXXIII, Issue 25276, 30 August 1947, Page 6

IRRIGATION SEEPAGE

Mr R. D. Robinson, Ashburton, writes:— “Mr Semple has recently given a broad outline of the policy to irrigate 400,000 acres in Mid-Canterbury, costing £3,000,000. Mr Collins has written articles on the subject of seepage but fails to answer the first question he is asked —To get the world’s best advice. The enclosed article is from the “Industrial Bulletin,’ 'published by the New Zealand Departments of Industries and Commerce and of Scientific and Industrial Research. The Bulletin is issued by the authority of the Minister of Industries and Commerce and therefore has his backing. Inside the front page is a paragraph that noth departments are anxious to help, and in bringing this subject under the notice of the public in their April-May, 1947, issue, they are rendering a signal service to the people of Canterbury and in fact the people of N.Z.” (The article referred to is an abstract of an article in the “Engineering News-Record,” by Walker R. Young, chief engineer. Bureau of Reclamation, Denver, Colorado, who discusses the magnitude of the problem of seepage from irrigation channels in the western United States, and describes an investigation into materials and machinery for lining the channels. It .is hoped he says, that progress along these lines will obviate the drainage schemes which are at present necessary, arid lead to extensive economies m irrigation costs.)

‘Analysed this means that after approximately 50 years of irrigation of enormous extent, the chief engineer, Mr Walker Young, appeals to all in the nation to help in a problem of immense proportions. He feels it imperative to conserve water and protect highly productive land from seepage. He says he hopes to develop .ower cost of lining hundreds of miles of new canals as well as some thousands of miles of unlined canals now m service, which indicates that used irrigation canals will not seal up. The losses he gives from unlined canals a £e of alarming proportions and draws attention to his statement that no small part of an irrigation budget is used for cleaning of canals and drains. Some engineers have shown an embarrassing modesty about the extent of seepage from irrigation and the main electric channel but now the ice has been broken by two Government departments, they may feel it possible to ?? ore J reel y- Surely after the publication of these articles no intelli<*tizen °f New Zealand would be bold enough to say that the main electric channel is not leaking, or that i irr \ gat l°« d 9 es not raise the water level at Seadown with consequent flooding of valuable land. There tn e L ea A safeguard and that is e. elect P c channel with concrete. (Mr Semple promised to do this !JLi ne «^ sary ?, nd to concrete the channel carrying the water to the farms.)”