Sessional_Paper_1907 — Page 1093

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The laying of the Rider Mains in those districts of the City in which they were intended to be laid, namely, the Chinese quarters, was completed by the end of October and, as already mentioned, they were brought into operation on the 1st November.

The total number of houses connected to the rider mains is 7,285, the work of connect- ing them having been performed as the laying of the mains proceeded.

The introduction of these mains, though rendering it possible to distribute the supply more uniformly during the application of the intermittent system, has not tended to simpli- fy the distribution arrangements, the complexity of which may be gathered from the fact that the houses served extend from sea-level to a height of 1,800 feet above it. Among other things, the operation of the rider mains interferes greatly with the working of the motors for pumping water to the high levels.

Owing to the necessity of conserving the contents of Pokfulam Reservoir for the supply of the Hill and High Level Districts, some trouble was experienced during the early part of the year in supplying the Western portion of the City, the distribution of Tytam water over a very extended area rendering it difficult to maintain the necessary pressures.

The quantity of water pumped to the High Levels of the City during the year amounted to 50,997,000 gallons equal to an average daily consumption of 139.718 gallons, whilst 25,037,000 gallons were pumped to the Hill District giving an average daily con- sumption of 68,594 gallons. As compared with 1905, there were decreases of 8,367.000 gallons in the quantity pumped to the High Level District and of 186.000 gallons in that pumped to the Hill District. The grand total pumped during the year amounted to 76,034,000 gallons as compared with 84,587,000 in 1905. Tabulated statements containing particulars of the quantities pumped to the High Levels and Hill District respectively and comparative statements of the quantities pumped during the last 10 years will be found in Appendices E to G.

The wrought iron rising main from Bonham Road Pumping Station to the Peak, which was laid in 1904, having developed some serious defects, the new pumping engine cannot be run with safety at any greater speed than 34 revolutions per minute whereas, in order to raise 100,000 gallons in 12 hours, it should be run at fully 40 revolutions. A new main was indented for in May but had not arrived by the end of the year.

In order to utilize the new pump for pumping water to the High Levels of the City, it was found necessary to obtain a main of larger diameter than that hitherto used and an indent was therefore despatched for pipes of 8 inches in diameter. Some of these arrived towards the close of the year and steps were taken to lay them in position.

All the Motors were kept in a good state of repair during the year.

The number of meters in use at the end of the year was 831 in the City and 163 in the Hill District or a total of 994 as compared with 782 and 156 in 1905, or a total of 938.

The quantity of water supplied by meter was as follows:

Filtered-Trade,

Domestic (City),

""

(Hill District),.

Unfiltered,

Total,

**

Gallons.

.112,075,000

100.298,000

25,037,000

34,304,000

.271,714,000

This shews an increase of 15,630,000 gallons in the quantity of water supplied by meter over 1905.

New services were constructed or old ones repaired, altered, improved or connected to the mains to the number of 685 whilst 46 supplies for building purposes were laid on.

The number of inspections of house services was 3,823 including the inspections made during the construction of the Rider Mains. Most of the defects discovered were within the Rider Main areas and they were dealt with as the mains were being laid.