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and finished in 1871 creating a reservoir of 66 MG.* capacity. The reconstruction of the conduit was next undertaken and completed in 1877, providing a water supply scheme capable of supplying 1/2 M.G. per day continuously or a maximum of about 3 M.G.D.* which is still in use.
This supply however only fed the western end of the town, and the East Point and Happy Valley areas were still dependent on the hill streams, intakes having been built in the Wong Nei Chong and Tai Hang Valleys in 1871, and Blue Pool and Mint Dams built in 1874 provided a small storage. The impossibility of providing for the growing population from the small Pokfulam scheme, particularly as the centre of the town was moving eastward, led next to the development of the Tytam Valley, to the South-East of the Island.
The original Tytam Reservoir was completed in 1883, and by 1889 the first stage of the scheme was complete. This included the Tytam Reservoir of 312.33 M.G. storage capacity, a tunnel through to the Wong Nei Chong Valley 2,428 yards long, followed by a conduit 5,500 yards long winding along the northern slopes of the Island to six slow sand filter beds and a service reservoir of 5.7 M.G. capacity in the Albany Valley. The total storage available was them 378.33 M.G. and the population had reached 194,482. This was the first supply to be filtered and soon after the Pokfulam supply was similarly treated at the West Point Filters which were completed in 1890.
The first Peak supply was the next development. In 1891 water was pumped to parts of the Peak District, which had previously been dependent solely on wells. This was a supply to a small tank at Wanchai Gap, fed by a hydraulic ram pump from the Bowen Road Filters. A draw-off from the Bowen Road conduit was filtered in two slow sand beds and the service reservoir being at a much lower level the drive water for the rams was obtained from the discharge from the filters to the service reservoir a portion of which was thereby pumped to the Wanchai Gap Tank. These pumps are still working as slowly and efficiently as ever but delivering to another tank at the 650 ft. level only.
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In 1892 a City Waterworks Distributing Scheme was completed. It was evidently then possible to supply all urban areas for in 1895 the use of wells was prohibited on Public Health grounds. In the same year the capacity of Pokfulam Reservoir was increased by the device of temporary boards on the overflow weir. By thus raising the overflow level by 2'0" the capacity was increased by 4.4 M.G. The population had by then increased to 248,948 and further resources were required, but in the meantime this temporary measure was resorted to.
* M.G.
Million Gallons.
* M.G.D. — Million Gallons per day.
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By 1897 Tytam Dam was raised 9 ft., which increased its capacity by 72.47 M.G., and again a further 22.2 M.G. was obtained by 2′0′′ boards. In 1899 a new reservoir was completed, the high level Wong Nei Chong Reservoir, with a top water level or 730 ft. A.P.D.* and a capacity of 30.34 M.G., increased to 33.99 M.G. by the use of boards.
The storage of the Island therefore had by that time been increased to a maximum of 511.39 M.G., but still the demand was rising and when a dry year came in 1902 there was another water shortage, with all the familiar difficulties. There was the usual clamour to re-open the wells but this was strenuously opposed by the Sanitary Board. Despite this there was an outbreak of cholera, and 460 cases were reported; water supply was restricted to one hour per day, and water was brought over from the Mainland in junks and pumped into three tanks on the praya. In the words of a Hong Kong Telegraph report dated May 5th, 1902, "arriving at the stand-pipes, one sees that it is a case of first come first served...... until at length the line of carriers grows longer and stretches far away from where the little steam-engines are puffing and panting as they pump the water out of the junks.......
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As a result of that shortage the City was saddled with one most unusual scheme, that of rider mains. In order to make best use of the available water by reducing waste it was proposed to introduce universal metering of supplies. The proposal however, was not well received by the Chinese residents and an amazing compromise solution was reached. Certain streets in the City were to be provided with duplicate mains, one to provide metered supplies and a second, called a rider-main, was unmetered. The reason for the duplication of the mains was that the unmetered (rider main) supply could be shut off during periods when the supply had to be restricted, whereas the metered supplies were not so restricted until the storage position became much more acute. The consumers supplied from the rider mains jointly subscribed $1,000,000 towards the cost and an extra 1% tax to cover maintenance, rather than pay for all water consumed. The scheme was commenced in 1903 and completed by 1906.
On the constructive side however, work was commenced or pushed on for a number of new reservoirs. Two of these were in the Tytam Valley, the Bye-wash completed in 1904 and Tytam Intermediate in 1907, and in addition there was the first Kowloon Reservoir, to which reference will be made later.
The next development on the Island was a true Peak Pumping Scheme, for in 1914 the Pokfulam Road pumping station was com- pleted, which pumped water from the West Point filters to a tank on Victoria Peak with a top water level 1751.88 ft. A.P.D., a total lift
* A.P.D. — Above Principle Datum.
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