Tunnel Seepages At Lake Coleridge

Manawatu Times, Volume 63, Issue 160, 9 July 1938, Page 6

Tunnel Seepages At Lake Coleridge

NO IMMEDIATE DANGER Per Press Association. CHRISTCHURCH, July 8. The Minister ot Public Works, xnc Hon. R. Semple, is having the closest watch kept on the situation at the Lake Coleridge power station where seepages in a tunnel have caused some alarm. It has been decided to take remedial measures as soon as possible, but in the meantime it appears that the supply is in no immediate danger providing the seepage and leakage does not increase. That was the impression gained by a reporter who received permission from Mr. Semple to make a survey of the system and the points where the trouble is occurring. The serious view which the Minister himself takes cf the trouble, particularly inside No. 1 tunnel, is shown by his decision to make a special trip to the lake last week-end. The Minister arrived from Wellington on Sunday, motored immediately to the lake, had the water shut off in the tunnel (which is the newer of two tunnels supplying water from the lake), and made a thorough inspection. The Chief Public Works electrical engineer, Mr. F. T. M. Kissel, and the Hon. G. R. Hunter, M.L.C., accompanied the Minister, who went far into the tunnel examining the extensive seepages. The party made a thorough survey. It is now stated that as soon as the present high load on the Lake Cole-ridge-Waitaki system drops, the Minister intends to have the water shut off in the tunnel again so that extensive remedial measures can le taken along sections where the seepages occur. This will probably be in the middle of September, when the demands on the system are not so high and the generators from No. 1 tunnel can be stopped without inconveniencing the public through any shortage. The effecting of repairs will be an extensive undertaking and may take some time. All day long a man stands along a staging above the No. 1 surge chamber above the power-house at Lake Coleridge watching closely the behaviour of the water as it passes from No. 1 tunnel (where tho seepages are occurring) into the chamber and then into the great pipe-lines leading down ne hill to the turbines. This man has orders to watch closely the level of the water, and its colour. Any wide divergence of the level or the slightest discoloration of the water he must report immediately to the station. A telephone is installed in the surge chamber house and the watcher is in periodic communication with the station superintendent. This careful watch for discoloration is maintained because it might indicate some serious erosion in the tunnel. Then the water would be cut off immediately at the intake on the edge of the lake, a mile or so away, to prevent any further cutting away of the tunnel sides.