CO129-402 - Governor Sir May - 1913 [7-8] — Page 43

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Conclosure !..

CITY & HILL DISTRICT WATER WORKS.

Tytam Tuk Scheme

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Second Section.

1.

Report and Estimate.

When the Tytam Tuk Soheme was under consideration

in 1903-04, Site No. 1 (vide enclosed plan) was adopted as

the most suitable for the proposed dam because it was con- sidered important to secure the largest possible drainage

area in order to ensure the filling of the large reservoir

contemplated. The gauges which were fixed in 1903 in the

Tytam Valley show however that, in years of average rainfall,

the quantity of water available will be sufficient to fill a

reservoir capable of containing, say, 1,500 million gallons,

though the drainage area be curtailed by constructing the

dam at a higher point and accordingly the site which is

marked No. 3 on the plan was thoroughly investigated with

the result that it was found to be a very suitable site for

a masonry dam, which would, if constructed to a height of

120 feet above Ordnance Datum,- practically stream-bed level,-

possess the capacity stated,- namely, 1,500 million gallons.

The principal advantages of Site No. 3 over No. 1 are that

a dam on the former will cost less and that its construction

can be carried out by Chinese Contractors whereas a dam on

the latter would necessitate the employment of European

Contractors of good financial standing.

2. To ensure the filling of the reservoir during years

of low rainfall, it is proposed to construct a short catch-

water, as shown on the plan, thus intercepting the drainage

of an important valley and conducting the water into the

reservoir. By so doing, nearly the whole of the drainage

area secured by the adoption of Site No. 1 is rendered avail-

able though the full yield of that portion intercepted by

the catchwater will not be secured as it would not be