Maraetai Hydro Scheme Advances

Chronicle (Levin), 2 April 1949, Page 2

Maraetai Hydro Scheme Advances

Ministry of Works engineers Duilding hydro-electric stations in the North Island saw the opening 3f the up-stream endi of the diverflon tunnel at Maraetai recently, as [irtle more than an incident in the vast project of drawing the maximum electric power from the Waikato River. To meet the North Island's rapid-Ly-expanding demand, new works must be begun as soon as men and equipment become available from stations already Pudding. For instance, when, in two or three weeks, Ihe diversion tunnel at Maraetai is finished, the tunnels will be shifted to Whakamaru, further up-stream, the site of the next station. There they will be employed, either in building another tunnel similar to that at Maraetai, or in iiewing an open cut. It has not yet been decided1 which will be used. The same procedure will'be followed throughout the Waikato scheme of 10 stations, and tools will have little chance to grow cold aftkr coanipletihg! one job before they are moved to the next. As a result, Whakamaru station will toe well on the way by the time Maraetai is operating. At Maraetai the project is coming along much according to the revised schedule laid down a year ago. Provided there are no unexpected hitches, excavations for the_ dam and powerhouse should begin in about six months' time. First, the two coffer dams have to be built, and then the area between thflm freed of water by pumping. At this stage the engineers may face the problem of leakage from the surrounding country. So they have anticipated it by enclosing the area in a grouted box in which a mixture of water and cement has been punnped down 200ft. at centres 10ft. apart to act as a seal.