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the line across the bed of the harbour have been commenced. We now hope that Sheng-mun water may be brought to Hong Kong early in next year by means of this pipe-line, which is estimated to be capable of delivering 31⁄2 million gallons a day across the harbour.
Here, however, it is necessary to sound a note of caution. The existing waterworks on the island with a total storage of 2,118,414,000 gallons and a total catchment area of 3,278 acres are calculated to have a capacity of 7.25 million gallons a day; but a modest estimate of the full water supply requirements of the island is ten million gallons a day. Thus the estimated supply falls short of the estimated requirements by 2.75 million gallons a day. At first sight it might, therefore, seem that an additioned delivery of more than three million gallons a day through the harbour pipe-line would suffice for our present needs. But two considera- tions combine to make the outlook less favourable. In the first place, Old Kowloon and New Kowloon are growing at an abnormal rate. Now, including that part of the Sheng-mun scheme already completed, the existing waterworks on the mainland have a total storage of 501,750,000 gallons and a total catchment area of 4,270 acres. Their estimated capacity is five million gallons a day, while a modest estimate of the full water supply requirements of Old and New Kowloon is 4.18 million gallons a day. There is, therefore, at present only a surplus of 820,000 gallons a day avail- able on the mainland; and in a few years' time, if the population on the northern shores of the harbour continues to increase, this surplus will have vanished. Then again there is a second considera- tion. The utmost, which the harbour pipe-line now about to be constructed can deliver, is 3 million gallons a day. But bitter experience this year has shown us that in time of drought only one million gallons a day flow down the conduit from Sheng-mun valley; and in time of drought it is, therefore, unlikely that much water from Sheng-mun could be made available on Hong Kong island, unless and until more storage reservoirs have been con- structed on the mainland.
One such reservoir for increasing water storage on the main- land is already under construction, namely the Kowloon Byewash Reservoir. Its site is in the valley immediately below the existing Kowloon reservoir. It has an estimated capacity of 175 million gallons, and it will impound the overflows both from Kowloon reservoir and from the raw water reception reservoir in the lower Shek-lai-pui valley. It requires no contingent works such as filters or pumping plant; and, although not a part of the Sheng-mun scheme, it can be developed economically in connection with that scheme. Its cost is estimated at $600,000. Its construction was approved by resolution of this Council on the 24th January last.
I have now described all the works already sanctioned and actually in progress. But there are further waterworks, which
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we are anxious to take in hand as soon as the schemes for them have been worked out in detail and estimates of their cost prepared. We hope with as little delay as possible to begin the construction of a dam in the Sheng-mun gorge. Its site has already been located, and it is roughly calculated that the reservoir so formed will impound between 1,000 and 1,500 million gallons according to the height of the dam. I shall be prepared to put this scheme before you and invite you to approve it as soon as reliable estimates of its cost are available. Moreover, it is possible that further examina- tion of the Sheng-mun valley may indicate the advisability of constructing a second storage reservoir higher up the stream than the site in the gorge; but the best location of the dam for this second reservoir has not yet been determined. It is also very likely that this Council will be invited before long to approve the construction of catchwaters running along the whole southern face of Tai-mo-shan and discharging through Pineapple Pass into the Sheng-mun gorge reservoir, for it is estimated that an additional catchment area of 2,575 acres would thus be obtained. But the schemes known as the second, third and fourth sections of the Sheng-mun valley waterworks are still in a very rough and inchoate form, though it is safe to predict that in the near future the Hong Kong Government will have to spend about ten million dollars upon waterworks construction additional to that already sanctioned and now in progress. When this has been done, and if the pipeline across the bed of the harbour proves to be a success, the require- ments both of Hong Kong island and of Old and New Kowloon should for a time be adequately supplied.
The possibility of using salt water for fire fighting, for road watering and for flushing sewers has been carefully investigated. It is computed that the quantity of water used for fire fighting has never in this Colony exceeded one million gallons a year; and the amount used for road watering and cleansing side-channels is estimated at 62 million gallons a year. This demand can be adequately met in years of normal rainfall by the use of water from the nullahs and in times of drought salt water can be used, when necessary, in streets adjacent to the sea. For flushing closets and sewers the majority of buildings now obtain their supplies from wells and nullahs; and at the present time only 88 million gallons a year are drawn from the storage reservoirs for this purpose. The total annual demand for these three services is, therefore, less than 100 million gallons and does not warrant the installation of an elaborate and expensive system of piped sea water laid on throughout the city. But the whole question of the development of our nullah supplies to their utmost capacity is now receiving the attention of the Public Works Depart- ment..
The aim of this Government is to give every house connected with the waterworks, both on Hong Kong island and on the main- land, a full supply of filtered water throughout the year. This should become possible in 1932, when the first section of the Sheng-
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