UNDERGROUND WATER

Press, Volume XCIII, Issue 27961, 7 May 1956, Page 9

UNDERGROUND WATER

NO EVIDENCE FOUND OF DEPLETION CHRISTCHURCH AREA REPORT Although he has found no evidpnee that the Christchurch metropolitan area’s underground water supply is bein? depleted. Mr L. E. Obom. of the New Zealand Geological Survey, considers that in some heavilypumoed areas mutual interference between wells presents a serious problem for the future, and requires supervision and management of artesian aquifers. He says in a report just released for publication that there is no evidence of pollution of the artesian supplies, nor is this likely: but there is a very real risk of pollution of ground water supplies in areas beyond the artesian svstem boundaries where urban settlements are rapidly expanding and water reticulation and sewerage schemes have not kept pace with housin" construction. Mr Oborn’s report was requested by a meeting of Christchurch local bodies last year held to consider the desirability of establishing an underground „water authority. Now that it has been prepared, it will be considered by a further conference. “The value to Christchurch and Canterbury of the Christchurch artesian system, with its abundance of pure, safe water cannot be over-estimated.’’ Mr Oborn says. He regrets that sufficient statistics are not held, and says it is imperative that some agency should organise the collection of data, leading to the supervision and management of artesian supplies. “To avoid what could w°ll be regarded as a major calamity for Christchurch and Canterbury as a whole, and a most regrettable legacy for future generations, it will be necessary to watch closelv the trends of water levels in wells over the years.” he continues. “This work must not be regarded as an expensive luxury to be tolerated, but as a task as necessary to the management of Christchurch’s water resources as book-keeping is to tho management of a business.” He proposes that regular observations be made on .selected wells throughout the metropolitan area, and that local bodies should sink and arrange for the observation of suitable test wells, the work to be undertaken without delay. There had been wasteful and extravagant water utilisation practices, Mr Oborn says. They should be restricted as much as posible to reduce drainage problems and to prevent interference with wells.

“Ground water is, in the main, free from objectionable imnurities, both chemical and organic,” the report stated. “There certainly are areas where the water is contaminated by excessive amounts of carbon dioxide, iron and sulphuretted hydrogen, but these are very localised and can often be avoided by sinking wells to a greater depth at the same site and casing off the contaminated aquifer.”