POWER FAILURE AND DRAINAGE

Press, Volume LXXIV, Issue 22464, 27 July 1938, Page 6

POWER FAILURE AND DRAINAGE

Effect of Breakdown In City “SERIOUS HEALTH CONSEQUENCES” Report Submitted To Board “Failure of the electric power means a complete breakdown of t' 3 sewerage system in both the city and suburbs, with very unhealthy consequences.” This sentence was one of many in a report, submitted by Mr H. G. Livingstone to last night’s meeting of the Christchurch Drainage Board, which emphasised the seriousness .of any threat of power failure to the city’s health. In a discussion which followed Mr Livingstone’s report it was stated that if a power breakdown lasted for five hours, the city's sewers would be overflowing. The board is now considering, among other schemes, whether to join with other local bodies m erecting a stand-by plant, if considered necessary, or even building a standby plant of its own at an estimated cost of perhaps £50,000. In the meantime, the engineer is to prepare a report on the board’s present position. Mr Livingstone’s report to the board was as follows: "At the request of the chairman I attended a conference with representatives of the Christchurch City Council and Christchurch Tramway Board. The question before the conference was the examination of the position regarding electrical power supply for the sewerage system, water supply, and tramways. “A few weeks ago, after a visit to Lake Coleridge by the Hon. R. Semple, Minister for Public Works, an alarming statement was published which led the public to believe that a leak in the power tunnel was causing grave concern. The statement made it appear that the leak was a new development of a very serious character, and an indication was given to users of electricity that a serious breakdown of the Lake Coleridge supply might occur at any time. The recent mishap to the switchgear at the Lake Coleridge power house also gave the board an unpleasant reminder that a power failure would create a serious problem for Christchurch. Pumps Not Working “During the time when the power was affected our pumps were turtiing over but not pumping, and a few hours in this condition would have created an unpleasant position for Christchurch. So far as the Drainage Board is concerned, failure of electrical power means a complete breakdown of the sewerage system in both the city and suburbs, with very unhealthy consequences. The suggestion of a power failure caused us to face the question of whether the board is justified in erecting a stand-by plant, the cost of which would be in the vicinity of £50,000. but before going further in the matter a conference with other local authorities was arranged. “Between the time of the first alarm on July 7 and the holding of the conference the Minister for Public Works issued a statement, which reads:—T am not as afraid as I was at the first, and it is evident that the danger is not quite as great as was at first feared.’ It is now stated that the announcement by the Minister of the leak from the tunnel refers to a development which may lead to difficulty, but which at present does not affect the plant. The trouble is associated with the second tunnel to be built. Both tunnels are about a mile and a third in length. They pass through country which in part is rock, in part water-bearing, and in part dry shingle, and in part compacted shingle. For part of its length there is water outside the tunnel as well as inside. Both tunnels leak, and have always leaked. The interior of the tunnel has been carefully examined and shows no indication of any changed conditions. "However in examining the power position, we find factors of a serious character which will demand the. attention of all power users. Maximum Supply “The present maximum available supply is 64,500 kilowatts. This winter the demand has increased to 60,520 kilowatts, and.the officers in charge of the various city services consider the margin much too small. The maximum in the winter of 1936 was 44.520 kilowatts; in the winter of 1937 it was 51,860 kilowatts. This year it was 60,520 kilowatts. If this year’s increase is repeated the load for the winter of 1939 would be approaching 70,000 kilowatts. Next Winter’s Peak "Obligations to Otago and Southland will bring in new demands, and it appears certain that next winter’s peak will exceed the plant capacity, even assuming all generating units to be in service and overhauled. "The Public Works Department has called tenders for two additional generating units at Waitaki. each of 15,000 kilowatts. This would bring the normal Waitaki capacity to 60,000 kilowatts installed. The power-house would then, have room for one further unit, making an ultimate total of 75,000 kilowatts nlant capacity. “It is stated, however, that owing to snow conditions there is not sufficient water available,in winter to operate one additional generating unit. The Waitaki is fed bv three lakes and the flow is at a minimum in winter, when the demand is greatest. A really severe winter, with lakes and streams frozen, eould easily cause a power crisis “Any scheme of lake control, will toUg several vears to complete, and will not be n factor as far as the demands of the immediate future arc concerned. “The issues before the board are:— “fl) Should the board expect the Public Works Department to guarantee an and continuous supply of power. “(2) Should the join with the City Council and the Tramway Board and erect a stand-by plant for use in case of a power shortage or breakdown. “(3) Should the board erfect its own stand-by nlant at a cost of approximately £50.000 for use’in case of a failure in power supply. “(4) Should the board connect all pumping stations with special lines for use should electric power be limited and rationed. “At present a few pumping stations onlv have direct lines connexions, and in the event of a sudden rationing of power (lie remainder could not be provided for except through general reticulation. •“These are some of the problems, a discussion of the details and implications'of which will some time. "The position now is that representations have been made to the Public Works Department by the City Council. and it is for the department to say whether it can assu-c the city of an adequate supply. After a preliminary discussion, which brought out

the main factors of the situation, the conference decided to await the reply of tho department to the letter of the City Council. “Mr E. Hitchcock, general manager of the Municipal Electricity Department. has sfated that a power shortage appears certain next year, with increasing gravity for the winter of 1940. “The general situation has serious features, which will require the attention of this board.’’ After the report had been read, a brief discussion among members ended in a decision, in the meantime, to ask the engineer to consider and report on the advisability of connecting separate feeder lines to the board’s stations. At present the stations were not so connected, it was said, and in the event of rationing of power these stations would be in the same circuit as ordinary power for house lighting and heating. Government’s Plan Mr J. S. Barnett said that members perhaps knew of the Government’s scheme to store water in the upper reaches of the Waitaki in the summer to use in the winter. That, however, would take some time to complete. Some years ago, he had heard at Wailaki a lecture by tho engineer in charge of the work at Waitaki. Mr R. H. Packwood, in which he said that for the future it was hoped that the Waipori. Coleridge, and Waitaki schemes, working together, could meet all requirements. Coleridge and Waipori could supply the winter needs, and Waitaki could supply much more power in the summer, and assist in meeting the winter load, too. The crux of the matter, he said, was (hat no one could have foreseen the huge peak load there would be for power. He had attended the conference to arrange for the city’s future supply some months ago. apd even then no one had realised the phenomenal growth in demand that would come in the winter. Closing the discussion, the chairman, Mr E. H S. Hamilton, said that members might prefer to wait for the department's reply to the council before discussing what action they should take. i