Sessional_Paper_1906 — Page 671

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The total quantity of water supplied during the year was 1,556,508,000 gallons filtered and 10,800,000 gallons unfiltered, making a grand total of 1,567,308,000 gallons or 277,517,000 gallons more than in 1904.

The average consumption of filtered water, per day during constant supply (243 days) was 4,600,000 gallons, which, with an estimated population of 229,100, gives an average, daily consumption of 20.1 gallons per head for all purposes. During universally inter- mittent supply (30 days), the average daily consumption was 12. 5 gallons per head, equivalent to a total daily supply of 2,872,400 gallons and during partially intermittent supply (92 days) the corresponding figures were 16.7 and 3,832,300 respectively. Taken over the whole year, the average consumption per head per day amounted to 18.61 gallons.

Full details of the consumption, contents of the reservoirs, &c., will be found in Appendices C. and D. The analyses made by the Government Analyst showed that the quality of the water throughout the year was excellent.

The system of supply by Rider Mains, which was brought into operation in certain portions of the City during the latter part of the year, constitutes a new feature in connec- tion with the distribution of water. The Rider Mains, which are being laid throughout the Chinese quarters of the City, are subsidiary mains, to which, speaking generally, all house services are connected. They are fitted with valves close to their points of junction with the principal mains. Thus, the closing of the valves on the Rider Mains deprives all houses connected with them of water, but does not interfere with the circulation of water in the principal mains, with which all the fire hydrants and any premises which, for trade or other The latter are in all cases served purposes, require a constant supply are connected. through meters and, after receiving a certain allowance free on account of the rates paid in respect of them, are charged for any water consumed in excess of such allowance. intended that, in future, when the impounding reservoirs cease to overflow, the Rider Mains should be brought into operation, water being turned on to them daily for such per- iod or periods as may be considered necessary to afford a reasonable supply to the houses connected with them. The supply being thus kept under control, it is believed that it can be regulated so as to obviate the serious risks and inconveniences attendant upon the adop- tion of the intermittent system by shutting off the water from the principal mains.

It is

The work of laying the Rider Mains not being completed, it was only possible to par- tially apply the system towards the end of 1905, about 3,050 houses being thus supplied from the 1st October onwards and about another 1,000 from the 22nd November.

A comparison of the consumption during October with that of the previous mouth, and of the corresponding month in 1904 shows a substantial reduction. The figures are as follows:-

October, 1904,.. September, 1905,

October, 1905,....

.140,058,000 gallons. .144,792,000 .122,367,000

The quantity of water pumped to the High Level District of the City amounted to 59,364,000 gallons over the whole year, equal to an average daily consumption of 162,640 gallons, whilst 25,223,000 gallons were pumped to the Hill District, giving an average daily consumption of 69,100 gallons. As compared with 1904, there was a decrease of nearly a million gallons in the quantity pumped to the Hill District and an increase of 10,363,000 in that pumped to the High Level District. The grand total punped during the year amounted to 84,587,000 gallons, as compared with 75,181,000 in 1904. 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. F. and G.

The new pumping engine and boilers installed at Bonham Road Pumping Station, a description of which will be found under Public Works Extraordinary-"Peak Supply were brought into use on the 7th March and have since been systematically employed in pumping water up to the service reservoir at Victoria Peak for the supply of the Hill District. The engine is designed to pump into the service reservoirs for the supply of the High Level District also, but it was found that the main, through which the water had to pass, was not large enough being laid with 6" cast iron pipes. A new main of larger diameter will be required and, in the meantime, the small rams, which are intended for pumping to the Peak, are operated for the supply of the district referred to.