SI ELECTRIC POWER

Grey River Argus, 18 January 1940, Page 5

SI ELECTRIC POWER

EXPANSION PROGRAMME New Rakaia Scheme [Per Press Association], CHRISTCHURCH, January 17. The increase to 60,000 kilowatts ol the capacity of the Waitaki hydroelectric power station, the development of the Rangitata-Raka ; a scheme at Highbank to make it available by the winter of 1941 and the pushing ahead of the Tekapo scheme to produce power by 1943 —that, in short, is the Government’s immediate plan for power supply for the South Island. “It is somewhat far off to say definitely what will happen after these works are completed, but it is probable that the fifth and last unit of 15,000 kilowatts will be installed at Waitaki, and additional water stored in Lake Ohau and, possibly, in Lake Pukaki,” said the Minister for Public Works (the Hon. R. Semple> in an interview yesterday with “The Press,” in which he made special reference to the significance of the Highbank and Tekapo development works. The development at Tekapo to

provide additional storage for Waitaki and a new station near the present township, entails the piercing of a tunnel more than a mile long between the lake and the Tekapo river.” When that is done, it will be possible to generate power,” said the Minister, "and by so. doing, to reduce the level of the lake until the bed of the stream flowing from I the lake is virtually exposed. A *7 regulating dam will then be built at • ii# a sit to be chosen. At present it is not quite clear what type of dam will be used for this purpose, but boring tests to determine the depth and quality of the foundation materials are now in hand. It is hoped soon to be in a position to design the dam and to define its position.” FOR WAITAKI. Of the main stations in the South Island, Waitaki is, as yet, only partially developed. Both the Lake Coleridge and Waitaki stations ob- { tain most of their water from the high country and, consequently, the low-water seasonal flow is in the winter when the demand for power is greatest. Of necessity, provision for storing water for the winter season has to be made. Lake Coleridge itself has been indispensable on that account.

The full development of Waitaki to produce 75,000 kilowatts entails storing water in at least two of the three lakes —Tekapo, Ohau, and Pukaki—in the Mackenzie Plains. As planned, a third unit of 15,0()0 kilowatts was to be added to Waitaki’s first equipment of 30,000 kilowatts and it was then proposed to build-a storage dam at Tekapo and. at the same time to make provision for a 20,000 kilowatt power station at that point. The demand for power has grown so sharply that two additional units are now being installed.

The expectation that a moderate ply of power may also be developed at Highbank during the summer months, especially in the earlier years before irrigation reaches its fullest development, is held by the Government. The prosecution of the huge irrigation project using water from the Rangitata river to irrigate the country between the river and the Rakaia made possible the development of a substantial block of power by continuing the irrigation race to the banks of the Rakaia. A development of 25,000 kilowatts continuously during the winter, or peak demand season, is planned. “Such a block of power being readily available, the development of Lake Tekapo could be delayed for several years,” remarked the Minister, who, however, went on to explain the Government’s developmental policy, with emphasis on the course of the plans at Tekapo. It is 25 years since Government power supply activity began in the South Island with the opening of the Lake Coleridge station, the resources of which were gradually increased to 34,500 kilowatts. In 1934, Waitaki be gan operations with a 30,000 kilowatts plant. In 1936, the Monowai station of 6,000 kilowatts was resumed from the Southland Power Board and in 1937 the Government resumed the Arnold river station from the Grey Valley Power Board. A stand-by-Diesel plant (of motors from a wartime German sumbarine) was established at Lyttelton and later moved to Dobsqn, on the West Coast. GROWTH OF LOAD. “The growth of load has been very rapid during the last five years,” said the Minister, who gave the latest figures, as follows —1934-35: Maximum demand, 32,500 kilowatts; units generated, 149 millions; 1935-36. Maximum demand, 36,700 kilowatts, units generated, 171 millions; 193637: Maximum demand, 44,500 kilowatts, units generated 205 millions. 1937-38: Maximum, demand, 58,200 kilowatts; units generated, 274 millions. 1938-39: Maximum demand, 69,600 kilowatts: units generated, 326 millions. 1939-40: Maximum demand, 76,100 kilowatts; units generated, incomplete. The very rapid growth in 1937-38 and 1938-39 was due to the addition of the Monowai and Arnold river stations to the system.