HIGHBANK POWER STATION

Press, Volume LXXXVI, Issue 26126, 31 May 1950, Page 6

HIGHBANK POWER STATION

PROTECTION MEASURES SUCCESSFUL WORK ON HYDRO-ELECTRIC SCHEMES Work done in the bed of the Rakaia river by the Ministry of Works proved, in the week-end floods, that the Highbank power station is in a safer position than ever before. Protection work done six months ago in anticipation of possible dif.;culties from floods were fully test< d. “The performance was even ben r than we expected,’’ said Mr J. O. Riddell (assistant-district engineer) yesterday. Boulder and netting groynes about 80 feet long were built out ;it right angles from the southern bank of the Rakaia river. They diverted the flood waters away from the bank and the powerhouse and built up a barrier of shingle.

Nine feet of flood waters are now stored in Lake Pukaki. The earth wail is completed up to the right wall of the spillway, finished last October. Th" contractor for the spillway has plac d a large portion of the lett bank w. il and also slabs—3ooft wide —in the floor of the spillway. When the spillway is built, the Ministry of Works will put in the earth filling behind wall. In the meantime, the coffer dam around the front of the spillway, which is almost as high as the main dam. has been completed and it impounded the flood waters. Work at Tekapo The steel sheet-piling tor the coffer dam at the site of the intake structure at Lake Tekapo has been driven and pumping-out of the water will be n soon. The engineers will tnen : e the kind of excavation they will h...? to deal with. The power-house is !■ t taking shape and electrical machinery is being installed and the erection f towers to carry the transmission lines has begun at the works. The contra - tor has begun the build.ng of the surte chamber and the building of the pc: - stock from the power-house up to the chamber is under way. The greater part of the final concrete lining inside the concrete blocks in the tunnel ha. been done and the forcing of grouting into the country behind the blocks to prevent water leaks along the country has been completed. The power-hous ■ end of the tunnel has boon steel lin< d for 600 feet and the liner continue s underneath the surge chamber and links up with the penstock. Preparations for a camp site are advanced at Waitaki Hydro and tenderclose next week for the building f several houses. Tenders have not ’ t been called for the b new power station, in which add.tinr I plant of 30.000 k.w. win be installed, on the Otago bank of the river.