The Southland Times. PUBLISHED EVERY MORNING. Luceo Non Uro. TUESDAY, MARCH 17, 1925. COSTS AND PUMPING.

Southland Times, Issue 19502, 17 March 1925, Page 6

The Southland Times. PUBLISHED EVERY MORNING. Luceo Non Uro. TUESDAY, MARCH 17, 1925. COSTS AND PUMPING.

In another column a correspondent ventures on some criticism of the comparison we made on Monday morning between the costs of the Dunsdale scheme and the burden which will be put on the Borough if the pumping system is retained. Our correspondent states that the Power Board’s offer to the Council for electricity represents .65d per unit at the switchboard, and suggests that our contention that there will be no reduction from the charge of 1.25 d per unit now being charged at the Waterworks is incorrect. The Board, so far as we are aware, has not made any offer of .65d per unit, but this figure is probably obtained by a deduction from the present switchboard cost at the power station of .9d per unit. This reduction is made on the assumption that the Board will take over part of the cost of the Corporation generating plant as a stand-by, but it must be realised that this reduction is fictitious so far as the Waterworks is concerned, because if this rebate is granted by the Board the Council must pay it away and the charge at the switchboard remains unaltered. In other words, if the Board took over that portion of the plant it would charge the Corporation .9d per unit, and that actually is the effect of the arrangement. Our correspondent has absorbed this reduction charge twice. This disposes of his first point. His second point has to do with a pumping scheme under consideration in Christchurch, and he uses the estimates in connection with this scheme to support his suggestion that the pumping charges in Invercargill are inordinarily high, and are either incorrectly stated by the Town Engineer or can be largely reduced. He states that the cost of current for the Spreydon sub-station, pumping 840,000 gallons a day, is £320 per annum, and adds that the station has to pump against a 250 feet head. It is doubtful if the head at Spreydon is 250 feet, but our correspondent has erred, we think, in stating that the £320 is the cost of pumping 840,000 gallons a day. It is clear from the report on the Christchurch scheme that 840,000 gallons a day is the maximum of the plant. The Christchurch engineer states in setting out this and the other quantities that “allowance has been made for the requirements of the- several districts over the term of the loan for 25 years.” It is clear, therefore, that the station is not to be asked to work at its full capacity at once. Again, if the Christchurch sub-station is pumping with current at one-sixth of a penny per unit it is working on night load, and if night-pump-ing is to be used, it will be impossible for the Corporation to store the water these four stations will use, to say nothing of the output from the present station at the Cashmere Hills. No reservoirs are provided at any of the sub-stations, and the reservoir on the Hills would be filled with a third of the output of the sub-stations to spare. Simple calculations will demonstrate that this Spreydon station cannot be pumping 840,000 gallons a day against a 250 feet head with current at one-sixth of a penny for £350 per annum, the obvious explanation being that 840,000 gallons is not the output guaranteed for £320. These snb-

stations are some miles from the reseryoir, and it is difficult to see how they can be pumping against a 250 feet head in the circumstances. The pumping charges at Invercargill are complicated by the double lift involved in drawing water from the wells and raising it to the tower, the head against which the water has to be pumped being probably in the neighbourhood of 220 feet, allowing for losses through the double lift and for corrosion in the pipes. When the water is pumped to reservoirs and then to the mains, the head is well up to 120 feet, allowing for losses due to the double lift. The air compressor pump, which costs £574 in current per annum is used to raise the water to the pump in the No. 1 Bore, the level having been lower in recent years. If this pump is discarded the main pump in the bore will need to be lowered to the water level. The Invercargill costs for current must be shown on the Corporation’s books, and there can be no doubt that they are paid. In the circumstances we cannot see how our correspendent’s arguments assist the ratepayers in the slightest degree. They afford no basis of comparison with the Invercargill charges, and do not affect our contention that if pumping is proceeded with the cost to the ratepayers will be higher than if Dunsdale is carried. Mr Maxwell’s point about the catchment area is interesting, and the Council must take it into account, but “Good Health” is wrong in suggesting that this land is inhabited by Maoris, or is used by cattle, or that it will be so used. It is a reserve set aside for the benefit ■of Landless Natives, and it will not be necessary for the Corporation to acquire the whole block. The portion it will require has very little bush on it, and it is not valuable land. its acquisition will not be an expensive matter, in spite of the fears of opr correspondent. Both letters, it seems to us, raise bogies, and in one case the bogey is not even filled with straw, wh’ile the other contains very little. The ratepayers need not worry themselves over either points at this stage.