WATER SUPPLY.

Waikato Times, Volume 121, Issue 20246, 15 July 1937, Page 6

WATER SUPPLY.

POSITION IN HAMILTON. NEW FILTER BASIN. TOTAL COST OF £3500. In the estimates for the waterworks department it will be noticed that a considerable reduction Is budgeted for In the matter of chemicals and in main extensions, commented a report from the borough engineer, Mr R. Worley, tabled at last evening's meeting; of the council. Tho main problem which confronts us at present is the capacity of the filter plant. When this was designed ten years ago provision was ma<m for ten years’ development, and we have now reached a stage when extensions should be considered. In the extraordinarily dry summer of 1934-35 it was very evident that we were close to the limit of our efficient capacity. The two Intervening summers have been extraordinarily wet, and in the meantimo nearly 300 houses have been built in the borough, over 100 more are projected by the Government, and we are providing an adequate supply for over i ’.O houses in the Fairfield and Lake Crescent areas. Thus should we experience a normal summer in 1937-38 it is likely at we may experience difficulty in providing a eient supply of adequately filtered water. Increasing Capacity. The problem of how best to increase our filter capacity has been engaging our attention for several months‘and details of our requirements have been submitted to the four firms doing business in New Zealand. Since llie original pressure filters were installed the increase in the exchange rate, the shipping charges have resulted in very high charges for further filters of this type, on the oilier hand, the technique in the development of gravity Mt‘*rs has very materially improved Another factor which has a big bearing on tlie problem is the alteration In tiic quantity of suspended matter in the river water. Our great silt problem came from the denudation below Arapuni subsequent to the debacle following the diversion of tin* river, and the river has so settled iu next column.)

flown in its new course now that the torpidity of the water Is very nearly back to normal. '

"e thus find it 'practicable to make use of a portion of our settling basin capacity and use it for the installation of gravity fillers. I-ly doing this we can install a gravity inter unit having a capacity of over 50 per cent, of our prosen! unit, thus giving us a llltor capacity of 5,000,000 gallops daily for a total cost of about £.'3500, as against a pressure installation ol' £4500. ibis should provide for our requiremolds until llu; population served by Hie water supply, exceeds as,ooo, at which stage it will be less cnsllv again to install an additional gravity unit A further point in connection "with 'the gravity unit is that of the total estimate nf £5500 the sum of £15115 will be spent locally by the council staff in installation work, of which over £SOO will he in direct labour. H is suggested that IHe installation be iluanced as follows: £ISOO from a, I. £IOOO from reserve fund, £IOOO not payable lo supplying firm until April, 1058. Tho time is not far distant when an dditional pumping unit will have to he considered, but this will onlv invojve a matter of hundreds, and will The engineer's ' recommendations wore approved with the estimates.