SUPPLY MENACED

Evening Post, Volume CXXV, Issue 149, 27 June 1938, Page 12

SUPPLY MENACED

LAKE COLERIDGE POWER

THREATENING LEAK

MINISTER'S CONCERN

Telettrattli —Press Association.) . CHRISTCHURCH, This ftay. Through the development of a leak in ■rfife adit tunnel leading off the main K tunnel between Lake Coleridge and " the surge chamber at the power-house, a new danger threatens the power supof Christchurch. At present the water coming thrbugh the leak is clear, Indicating that there has been no disturbance of the shingle, but instructions have" been issued by the Minister of Public Works, (the Hon. R. Semple) foV the water to be cut off at the first ■ sign of discoloration in the leak. . The tunnel in which the.leak has developed was built for constructional purposes, and the spoil from the main tunnel was removed through it. Between two and three cubic feet per second are flowing through the leak.

"It is as well that the public should know the truth," said Mr. Semple today. "While the possibility of a breakaway cannot be ignored, there has been no indication yet that the country through which the tunnel has been pierced has shifted. So long; as the water coming through the leak remains clear there will be no immediate dangler, but if the water should come away in a rush through the shifting of shingle we will be faced with a calamity. There is no saying what amount of damage could be done.

• "In the meantime the leak must be regarded as a safety barometer. It must be watched day and night. While it remains clear it will be safe to, carry on, but the moment it becomes discoloured the sensible thing to do will be to cut off the water."

The Minister added that serious errors had been made in the construction of the tunnels. Cracks had developed in the main tunnel soon after the power-house had been put into operation. This could have been prevented if the tunnel had been lined "with reinforced concrete. The cracks had been grouted with cement, but though this had overcome the trouble temporarily, it could not give any lasting security.

"With the expenditure of so much public money and so much depending on the successful and continuous operation of the power-house, I amazed that steps were not taken to obtain the maximum of security," added Mr. Semple. "This is an engineering blunder. of the greatest magnitude." •