AT NIHOTUPU

Sun (Auckland), Volume I, Issue 260, 24 January 1928, Page 7

AT NIHOTUPU

CR. MURRAY’S OPINION OF UPPER DAM SITE

The following letter, written by Cr. W. H. Murray on the subject of a report of proceedings at a meeting of the City Council, held on Thursday evening, has been received by The Sun: Sir, —In common fairness I ask that the gist of my report to the City Council on the condition of the Upper Nihotupu dam be published. The catchment area controlled by the upper dam is in part swampy. Semi-putrid sawdust abounds; and through a portion of it to a depth of some feet the city water in part percolates. Oil from the rotting sawdust or decaying swamp matter exudes and is visible on the surface. Stagnant water in the sawdust area makes its presence pungently undesirable. The water supply, as seen and sampled by my party of four, which included Mr. -H. P. Taylor, vice-president of the City West Ratepayers’ Association, and Mr. J. R. Lundon, a city ratepayer, is most certainly not of inviting appearance or odour. The samples are available for inspection. The condition of the dam demands immediate and effective repair work. Considerable erosion from overflow of escaping waters at both sides of the wings has resulted in the washing away of substantial quantities of soil and decomposed rock, and the foundations of more than one of the abutments have been seriously affected. The disappearance of some of the supporting material calls for remedial treatment. Should that dam be left in the condition which I saw it on the Bth inst., and on a subsequent occasion, disaster may have to be recorded should a heavy and continuous downpour take place this summer, while the water in the lower dam is at low level. On the main track down to the lower dam there is a boiler laying unprotected and depreciating in value, the iron stack is now apparently valueless and rust predominates. The valve gauge is lying unprotected on the ground and nearby are some valuable tip buckets, still visible, though partly covered by a landslip of no recent date. The loss already sustained on this valuable machinery must aggregate some hundreds of pounds. At the lower dam the sill gauge showed less than 79ft., as against 134 ft, to which the water must rise before it can go over the spillway in times of flood. Viewing the down stream side of the big dam many weeps in the concrete are noticeable. What depth of silt there is at the 78ft odd indicated by the gauge should be ascertainable by the engineering department. The water at that gauge on the occasion of my first visit was 36ft below the top of the gauge. On the Bth inst. the water was coming over the spillway at the Upper Nihotupu dam. On my latest visit (still without official permit) it was 2ft down from the spillway, the water having been released to replenish the lower dam, which stood at less than 79ft a week ago, as stated. From my personal inspection of the two Nihotupu dams and the main Waitakere dam, I have formed the opinion that a special committee of capable and responsible citizens should be formed without further ado or delay to investigate the city’s present and future water supply. and to endeavour, aided by the best outside engineering advice, to rectify and make impossible of repetition the blunders of the past, and •' ~s and inefficient of the pres - ninistration. Meantime the City West Ratepayers’ Association, recognising the seriousness of the present state of affairs at Upper Nihotupu dam, recently called for and is now in receipt of a report thereon from Mr. R. F. Moore, registered civil and mining engineer, whose standing in our community as a concrete and constructional engineer is beyond question. That report will, I trust, be handed by that association’s representative to the Press for publication. W. H. MURRAY. Councillor.