122
Kowloon Peninsula.
With the above data, taking into account the increase which has occurred in the two years which have elapsed since the census was taken, the present population and water supply required may be estimated as follows:-
Total gallons per day.
Civil European, land,
Population.
1,000
X
Gallons per head. 20
20,000
Do. Chinese, do.,
...30,000
X
10
300,000
Do. do., floating,
8,000
X
5
40,000
Naval and Military, European,.
300
X
20
6,000
Do.,
Asiatic,
1,200 X
10
12,000
New Territory,...
3,500 X
10
35,000
Total..........44,000
413,000
Taking the average, this will give about 9 gallons a head, which cannot be considered an excessive supply for domestic purposes alone, and it must be borne in mind that the Dock Company's Hung Hom Establishment takes 20,000, and the Wharf and Godown Company's 15,000 gallons a day. In fact, the supply can only be kept within these limits by strict supervision, by metering all private services, and by allowing no private services in Chinese houses. In proof of this it may be stated that during 1898 the domestic supply in Victoria, where water is laid into Chinese houses, amounted to 13.5 gallons per head, while in Kowloon, where it is not, the supply during the same period was at the rate of 6.1 gallons. This latter amount will, no doubt, be exceeded when the distributory system is made equal to the requirements and an ample and constant supply ensured.
It is impossible to estimate the probable increase of a population of this sort-according to the census returns of 1891 and 1897 it increased 33 per cent. in 6 years--and in view of the fact that the works will probably take 3 or 4 years to complete, it is proposed to provide a fair margin over present requirements and to lay out the works in such a way that they may be extended without stoppage of the supply.
Taking all things into consideration it appears advisable to provide at once for a supply of not less than 500,000 gallons a day.
The existing supply amounts to between 200,000 and 300,000 gallons a day.
SUPPLY OBTAINABLE FROM A CATCHMENT Area.
In Mr. COOPER's report on the Water Supply of Victoria, 1896, the following figures are given. as a basis for calculating the yield of a catchment area :—
Rainfall from May to August, 44 inches, of which 50 per cent. is available. Rainfall from September to April, 20 inches, of which 33 per cent. is available.
These figures are the results of the experience gained in working the Tytam and Pokfulam reservoirs.
The gathering grounds on the hills at the back of Kowloon Peninsula are very similar to those at Tytam and Pokfulam, and as the rainfall is not likely to differ largely, the above figures may safely be taken as a basis of calculation. By doing so it will be found that to supply 500,000 gallons a day a collecting area of about 300 acres is necessary.
AVAILABLE SOURCES OF SUPPLY.
An examination of the country from Li-Chi-Kok to the Peninsula east of Kowloon Bay has resulted in 5 available sources of supply being found, in two of which good reservoir sites exist. These are shown on drawing No. 1, and details of the Reservoir Sites from surveys by Mr. XAVIER on drawings Nos. 2, 3 and 4.
Source No. 1-Contains a reservoir site commanding a drainage area of 152 acres, which can be increased by means of a short catchwater to 333 acres. To equalize the rainfall on this area a reservoir of not less than 93,000,000 gallons capacity should be provided. The site surveyed will give, with a data 65 feet in height, a storage capacity of 120,000,000 gallons. The lowest draw off would be 390 feet above Ordnance datum, aud the supply obtainable from the drainage area of 333 acres would be 590,000 gallons a day. This can be further increased by additional catchwaters to the east on both sides of the Shatin Valley.
To
Source No. 2-Also contains a reservoir site which commands a drainage area of 219 acres. equalize the rainfall on this area, storage would be required for 62,000,000 gallons, but a reservoir capable of containing 106.000,000 gallons can be constructed with a dam of only 50 feet in height. In order to utilize the site to its full extent, therefore, a catchwater should be constructed to intercept a large stream to the westward, thus considerably increasing the drainage area. Disregarding this, the natural drainage area of 219 acres will yield a supply of 390,000 gallons a day.