NIHOTUPU WATER MAIN.

New Zealand Herald, Volume LXIII, Issue 19418, 28 August 1926, Page 13

NIHOTUPU WATER MAIN.

REPAIRS AT QUINN'S CREEK, TRESTLE BRIDGE COMPLETED. THE CITY SUPPLY RESTORED. Repairs to the Nihotiipu pipe line have now been completed. The severe wash-out which occurred at Quinn's Creek in May last when the city water supplv was cut off has been spanned with a high trestle bridge which carries the 24-inch cast iron pipes connectng the two ends of the broken main. The water has been running through this connection since Sunday last. Quinn's Creek flows in a deep gully between two high ridges on the Mauukau side of the Waitakere Ranges. The big main fiom the Nihotupu reservoir passes thiough tunnels pierced in these ridges and oiiginally crossed over the creek on a deep filling, through which a culvert had been built to take the mountain water. The floods of May carried this filling and culvert away bodily and took out about 140 ft. of the main. Temporary repairs were rapidly effected by laying a connection of smaller pipes round the head of the wash-out and it was decided to construct a trestle bridge across the creek bed to carry the big pipes rather than again trust to a culvert and filling. The bed of the creek was found to be composed of loose and decayed rock and it therefore became necessary to excavate to a considerable depth in order to find a sure baso for the concrete foundations of the bridge in the country rock. It was this part of the work that delayed the construction of the bridge, but onco the solid concrete foundations, were in place the erection of the timber structure occupied less than a fortnight. The new bridge is 140 ft. in length and 50ft. high at the deepest point of the gully. The platform on top has a width of IPfL and this carries the main and fho tramline, which runs parallel with the pipe for the greater part of its length in the hills. The pipes were laid toward the end of last week and the connections were made at the mouths of the tunnels at either end. The water was turned in on Sunday and the Nihotupu supply to the city was then completely restored. Among the damage done during the phenomenal rainfall in May was the destruction of the footbridge across the Nihotupu River above the dam. This has now been replaced with a well-designed bridge just above the measuring table at the head of the fall where the river tumbles into the reservoir.