Cleaning Tiritea Dam a long Job

Manawatu Times, Volume LV, Issue 6919, 25 July 1932, Page 6

Cleaning Tiritea Dam a long Job

THOUSANDS OF YARDS OF SILT

When the big concrete dam at Tiritoa was completed the City Council of those days must havo been in a mighty big hurry to see the reservoir full, for some of the scaffolding used in its construction was left as it stood. The recent lowering of the water level brought all this rubbish to light again, and it will have to be removed as part of the present cleaning operations. Maybe some of this timber is helping to block the outlet pipe, the clearing of which is giving tho present council so much trouble.

Tho reservoir, with its accumulation of mud and filth, presents an unwholesome sight at the present time, and nobody will want tho City Council to switch back to this source of water supply until the deposit has been entirely removed. As tho Tiritea stream flows down the centre of this vast bed of mud it is gradually carrying away sediment in solution, with the result that the stream below the dam, right to its junction with tho Manawatu river, is black. A very large quantity of the deposit has been got rid of in this fashion since the resumption of operations last week, but thousands of cubic yards still remain. At the present time efforts arc still concentrated on flic limber in front of tho outlet pipe. The workmen havo been within 12 feet of the valve, but at that level tho silt on each side of tho narrow cleft cut by tho stream keeps on collapsing Into the stream and re-blocking the outlet. Then recourse has to be mado to the plunger, which has been erected over the valve, to clear an opening. It seems, therefore, that it will bo some time before flic snags and roots themselves will be reached—not until all the silt immediately around the valve lias been washed through. The city is at present drawing its drinking water from a small dam crocted half a mile further up-stream, and there is more than enough water there just now to meet tho city’s needs. In fact, it is running to waste over the bywash. This water is of crystal clearness nnd presents a marked contrast to the silt-laden liquid that is pouring from the big reservoir.