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present, when Pok-fu-lam reservoir is depleted, it is often difficult to maintain an adequate supply to the Elliot filter-beds from the Bowen Road Conduit.
An exhaustive examination of Hong Kong island with a view to discovering yet more sites for storage reservoirs has shown that six such sites exist. But to each of them there are serious objections. Three more storage reservoirs might be built in the Tytam valley, two at a height of 750 feet above sea-level and one actually within the flow of the sea in Tytam harbour. The two former would have capacities of 70 million and 40 million gallons, but they would be inside the existing catchment area of the original Tytam reservoir. They would, therefore, impound no new supplies of water and in time of drought the water stored in them would merely diminish the storage in Tytam reservoir. The reservoir site within the flow of the sea would have a capacity of 700 million gallons; but, when investigated in 1904, a rock foundation for the dam was not found until a depth of 65 feet below ordnance datum had been reached. As the site is below sea-level, most difficult and costly coffer-dams would have to be built as temporary erections on both sides of the permanent dam under construction and the expense of the scheme would be out of proportion to the supply gained, the more so as all the water from such a reservoir would have to be pumped to a height of nearly 400 feet, in order to pass through the Tytam Tunnel. An additional reservoir might be built directly below the existing Pok-fu-lam reservoir. It would have a capacity of 78 million gallons; but its construction would necessitate the resumption of the Hong Kong Dairy Farm and is for this reason undesirable. Another natural site for a reservoir is the basin on the south side of the island containing the village of Little Hongkong and bounded on the north by Bennets Hill and Mount Cameron and on the south by Brick Hill, Two dams would here be necessary, one across Stanton Creek near Aberdeen and the other at the brickworks close to Deep Water Bay. This reservoir would have a capacity of 2,500 million gallons; but its catchment would be small for its size, although the overflows from the Aberdeen and Wong-nai-ch'ung reservoirs could be diverted into it. All water from it would have to be pumped; and, in view of the great length of the dams, the considerable resumptions necessary and the heavy contingent works, the reservoir would be costly. Moreover, in the public interest it is not advisable to submerge this valuable area of flat land, the last such area remaining in Hong Kong island. Finally it would be possible to build two additional reservoirs with an aggregate capacity of 114 million gallons in the Taikoo catchment on the slopes of Mount Butler. But the water rights in this locality are held by Messrs. Butterfield and Swire, whose existing reservoirs Government would have to acquire as a preliminary to further development; and, even if resumption were effected, it seems likely that most of the water procurable would be needed for the Taikoo Sugar Refinery and Dockyard and that comparatively little could be made available for public use. The examination of these six schemes has. therefore, led my Government to conclude that all six should
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be postponed until the scheme for providing Hong Kong island with water from the mainland has been put to the test.
Construction work upon this scheme, known as the Sheng- mun scheme, began (as I have already said) in 1923. An access road 16 feet in width and 1.92 miles in length from Ts'ün-wan to Pineapple Pass was completed in 1925. In the same year were also completed the intake dam across the Sheng-mun River above Pineapple Pass, the temporary conduit 6,000 feet in length from this intake to the point where the dam in the Sheng-mun gorge will be built, the North Conduit 2,900 feet in length from this point to the opening of the North Tunnel, and the South Conduit 2,000 feet in length between the North and South Tunnels. In 1926 the North Tunnel 2,160 feet in length through Smugglers Ridge and the South Tunnel 4,689 feet in length through Golden Hill were completed, and so also was the reservoir with a capacity of 33 million gallons in the lower Shek-lai-pui valley, built to receive raw water delivered through these tunnels. In the follow- ing year 150 feet of the North Tunnel were straightened and 3,200 feet of 24" steel main were laid. This trunk main will bring the Sheng-mun water to Kowloon Point and will have a total length of 24,030 feet with a feed to the Kowloon distribution system at Pipers Hill, where a covered reinforced concrete service reservoir with a capacity of 12 million gallons was completed in 1925. Immediately below the reception reservoir in the lower Shek-lai-pui valley is the site of a rapid gravity filteration plant to deal ultimately with 20 million gallons a day. The first section of this plant, capable of filtering five million gallons a day has already been completed and is now in operation. Adjoining these filters, there is under construction a covered reinforced concrete service reservoir with a capacity of eleven million gallons. The expenditure incurred on the development of this Sheng-mun scheme up to the 30th June last was $2,326,490, the whole of which has been charged to the Colony's loan account.
In order that water from the Sheng-mun scheme may be avail- able on Hong Kong island, works estimated to cost $361,602 must still be completed, including the land pipe-line to Kowloon Point, and the pipe-line across the bed of Hong Kong harbour. Of the pipe-line on the mainland 20,280 feet have already been completed, leaving 3,300 feet to be laid at Sham-shui-po and 450 feet across the railway terminus. Eventually there will also be 3,000 feet on Hong Kong island; but it is not proposed to undertake this section of the land pipe-line until late in next year. Instead a temporary connection with the city mains near Statue Pier will be made in the first instance, in order to expedite the delivery of water from the mainland to the island. The drawings and details of the harbour pipe-line have been worked out, submitted to the Consulting Engineers and approved by them. The pipes, which are 12" diameter steel mains, are due for delivery in the Colony at the end of this month, and meanwhile dredging operations along
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