HARNESSING THE WAIMAKARIRI.

Lyttelton Times, Volume CV, Issue 12421, 9 February 1901, Page 5

HARNESSING THE WAIMAKARIRI.

; AN EXPERT’S VIEWS. AN INTERVIEW WITH MR G. P. WILLIAMS. Yesterday a representative of this journal, hearing that Mr G. P. Williams, at present engineer to the Waimakariri-Ashley Water Supply Board, was able to speak with special authority on the question of the proposed Waimakariri water • scheme, waited on him l , with the idea of obtaining additional information on the subject. “I believe that you have special qualifications to speak as an expert on this question,” said the reporter, “ and that) you are an old member of the Institution of Civil Engineers?” . “ Yes,” replied! Mr Williams,' 1 ' I believe that I am the senior member of the Institution practising in Christchurch. I was elected a member in 1879.” “You said ‘a member.’ Is there any difference between a member and an associate?” “Certainly. The qualifications for a member are higher than those ifor-an as--sociate.” “ What experience have you had in connection with the rivers of Canterbury?” “Well, I can fairly claim -to have had peculiar; experience in this matter. I have been engaged in the construction of bridge works, and the protective works in connection with them,. at all the principal rivers of Canterbury, f including the Hurunui, Rakaia, Waimakariri, Ramgitata, Opihi, Pareora, Waihao and Waitaki. I have had exceptional opportunities for studying the Waimakariri, and as district engineer carried out the construction of two bridges over the river, one being at-the proposed sit© of the intake at the Gorge. In 1880 I made the first survey for a railway, from the Gorge Bridge up the Waimakariri, to the Bealey River, under instructions from the Government. This line was pegged out and levelled! over. For the past three years, I have been constantly watching the river in connection with of our water races, and have had daily measurements made of the depth of water by means of a gauge at our intake, and have recorded the results.”. ,

“ Have you carried out similar works in connection with water-supply in other places?” “Yes, many, including the first public supply for a water race by means oil) head works at the Kowai River, not far from the site of the. proposed works. They were initiated by the Provincial Government, but I took charge of them, and completed) the work,, on 1 behalf of the General Government in 1877-78. They included a concrete dam across the river and a tunnel half a mile long.” “ There seems to be some difference of opinion with regard to the estimates for the proposed scheme. What do you think is a fair estimate of the total cost?” “ That is a very big question, and 1 1 really cannot give an answer off-hand. A complete answer would entail a great deal) of calculation, and considerable time. I may say, however, that I read! Mr Turnbull’s business-like letter, published in the newspapers, and. I certainly think that if the whole scheme, including a constant supply of power/ sufficient Ifor ah installation' of 100,000 eight candle-power lamps; can be completed-ter $126,000, as estimated* it wilU fee /a/remarkably and will< Be ’» great' boon r for ■.Christoßuteh, 'as the, power Mil be'iavailable fot sal©-in the- day tinfe ' for general and municipal purposes. 'When I say this I may add that I have detailed accounts of the expenditure and working of many large installations in England and America, for both lighting and power purposes.” “I believe that, a few years ago, you designed on behalf of. the City Council a scheme for a water supply in Christchurch by pumping into .reservoirs at the Port Hills. Will the power be available for that?”

“ Certainly. It could to usefully employed in that way, in the day time, .and it could also be used for the tramways. I am, however, not expressing an opinion as to whether the scheme will be remunerative. ” “ You spoke about the estimate.” ‘‘ I notice that some correspondents think that it does not matter what the estimates are, because, if the . work is put up to tender the lowest tender .forms the surest estimate. . That is, so,-no doubt’; but tenderers must have a definite scheme to tender 'on. . 'Whore, there ia : a choice of schemes, fan estimate- is' a- guide l asl to the scheme to be placed-bofoi’a the-tenderer. There should also bo borne in mind the all-im-portant fact that the Works have to be maintained forever-by the Council, or the promoters, :-to . ensure,, permanence. of the power. . The’cheaper of tvyo, - alternative schemes might not bo-the better one in the end;- it might, prove to be. ruinous.”

' : “ Could not. a :first*dasa electrical engineer be obtained who would decide the whole question from Ms great special! experience?” “ No, The first question your electrical engineer would ask you would be what herse-power could be guaranteed from the turbine to work his dynamo, as the number of kilowatts obtainable is the basis upon which the output of any installation has to be calculated. The first and most responsible part of the work belongs to the department of hydraulics,: and needs engineers familiar with the special difficulties that have to bo encountered.” “ Could not tenders be called for, guaranteeing; say, 3000 horse-power at a certain point, including all .works and main' itenance?”-'' . . —-

“That is a very fair question t-o ask, and that -would) he a very satisfactory way of settling'the cost if it were a practical one. But ilt must he home in mind that a constant supply of power all the year round would ha an exceedingly difficult subject for a guarantee. Suppose the contractors completed all the necessary works and supplied the power for six months, it might happen that, through a mistake in the calculations, or ignorance of the peculiar habits of the Waimakariri, the supply, of power would stop dead for a week. This would at once destroy perfect confidence in the whole scheme, and spoil the business of supplying light and power in such a way that no matter what fines were inflicted, it would be impassible to compensate the Council. The want of continuity would make the whole thing a failure. Again, the tenderers would require to- make exact plans and calculations for themselves, before submitting estimates. The cost of fliis preparatory work would probably be higher and less satisfactory than similar estimates which the Council could obtain direct', the contractors, of course adding a proportionate amount to their tenders to recoup themselves for this preparatory work, or else allow a wide margin, so that there would be no, saving to the Council.” “May it, then, be gathered from your remarks that you are not quite satisfied with the estimates already put before the Council?” “I have carefully read the summary of Mr Dobson’s report to the Council, and his speech at the meeting in the Exhibition Hall, in which the facts and figures set forth are the same. I gather that ho proposes to develops, by means of turbines, situated one mile from the Gorge intake and working at a fall of twenty feet, sufficient power to transmit and deliver _at least 3000 electrical horse-power at Christchurch., Of course, in that case, the headrace would have to be a very largo one. I have professional reasons for not wishing to discuss this scheme at present, besides, in speaking to you in this general manner my words might’not be so well-weighed as they should bo on so important a question,. But I may that there are some very grave objections to the scheme as formulated by Mr Dobson. lam afraid those objections will militate against the continuous daily supply of the estimated power, except at a cost verv much greater than Mr Dobson anticipates.” “ Could not a greater power be obtained by increasing the fall at the turbines-” “ Certainly.. But that, again, will entail the expense of a longer race, though the dimensions might be decreased. “Do you think that an alternative scheme is feasible at a smaller cost?”

“Certainly not. There are variations of the scheme, however, : whioh present themselves to my mind as being more advantageous, but in order to decide on_the best possible scheme, much careful survey work would have to be done, and thq results carefully balanced.” “You do not despair, then, of a successful scheme being initiated?” “No, but success is a question of cost.” “ But I think you have already made it clear that you are nob altogether satisfied with the present estimates?” - “To tell yon candidly, lam not. One thing I can assure you is that the Waimakaririi is no mean power to contend against. It would be as foolish to underrate it as to underrate the Beers; and it is about as easy to conquer,”-