CITY WATER SUPPLY

Wanganui Chronicle, Volume 88, Issue 125, 27 May 1944, Page 4

CITY WATER SUPPLY

CONSUMPTION INCREASING EACH YEAR NEW PUMPS AT KAI IWI An indication of the large volume of water required in Wanganui annually lor domestic and industrial purposes was given by the city engineer, Mr. L. R. Row, in nis annual report to the I Wanganui City Council. Mr. Rowstated the total consumption durin" the twelve months ended Marcn 31 last, was £923,830,000 gallons, a figure which was steadily increasing each year. Of this, 769,138,000 gallons were drawn from the Okehu dam, 143,42,000 gallons came from the Kai Iwi springs, and 11,250,000 gallons wen,i supplied by Virginia Lake. The average weekly consumption during the year was 17,750,000 gallons, and the highest total reached ior any one week was 22,000,000 gallons. 'The average daily consumption was 2,520,000 gallons, and the record for any one day was 3,600,000 gallons. On this basis Wanganui consumed an average of 150,000 gallons of water an hour, the highest total for any one hour being 196.000 gallons. Mr. Row added that while it was difficult to make P xact comparisons, because of fluctuations in rainfall and the intermitten: application of hosing restrictions, there was every evident-’ that the annual demand was steadily I increasing. This was shown by the fact that in 1934-35, when hosing restrictions were enforced during the .summer months, the total consumption ws 640,000,000 gallons, compared with 921.000,000 gallons last year, when! there were no hosing restrictions. | “It should be noted that the weeklyi flow from the Kai Iwi springs is 13.3 J million gallons,” Mr. Row stated. “Up to 1940 this would have been sufficient to meet the demand during the greater part of the year. During the past three jears, however, the weekly demand has been in excess of the spring capacity throughout each year. “Hosing restrictions were not imposed last summer, but this does not indicate that an ample supply was always available to the city. On the' contrary, there was often less than one ( day's supply in the Westmere reservoir, and Virginia Lake had to be used for short periods on a number of or- 1 cas’.ons. Ther e was always a good margin of supply available at the com-1 .. bined Okehu and Kai Iwi spring!

sources, but the main pipe lines are not of sufficient capacity to bring this water to the city fast enough to meet periods of maximum consumption. In view of thp steadily increasing demand, it will be necessary to install an additional pipe line from Kai Iwi springs to the Westmere reservoir in the near future. “After a delay of four years, th e two turbine pumping units arrived, and were installed and tested at Kai Iwi at the end of December. A large amount of pipe connection work and alterations to the suction well were necessary, and 1 his was done by the waterworks staff. The building, started in 1940, was also completed. The council's workshop staff installed the machinery, and official tests, covering a wide range of line-pressure conditions, were successful in every way. Tley conformed to specifications drawn up in this office in 1939. “When both sets are operating at full capacity under normal head, they are capable of pumping 78,000 gallons of spring water per hour hour and in doing so they use approximately the same quantity of Okehu water to drive the turbines. The total cost of the whole installation was £4136, made up of £1844 for th P turbine pump sets, and approximately £BOO for the building. £l2OO for pipes and fittings, and £292 for plant erection and incidentals. “The electric pumps have both been used intermittently throughout the year. The motor on No. 2 pump burnt out whil e operating unattended and the cost of re-winding was £144 The No. 1 pump unit is badly worn and should be replaced as early as possible. The lota] spring water pumped was I 113,442.000 gallons made up as follows: No. 1 pump (electric), 335 hours. 22,707.400; total. 143,442,000 (electric). 2134 hours. 96,030.000; No. 1 water turbine unit. 63J3 hours, 22.707.000; No. 2 water turbine unit, 630' i bourne; and two daughters, Mrs. C. j gallons. ' “The operating cost for electric ! Dumping was £5 16s 6.4 per million gallons (excluding cost of re-winding J motor), while the cost of pumping by water turbines was a nominal .sum only consisting of lubrication and wages for half an hour each day for the pipe patrol man.” Mr Row added.