THE HONGKONG GOVERNMENT GAZETTE, 10TH JULY, 1875.
283
Wong-nei-chung Valley, whence emerging again into daylight, the water will be conveyed by means of an open conduit along the hillsides to a point overlooking the eastern side of the Race Course, where it will be received by a syphon of cast iron pipes and be conveyed underground across the Race Course, along Queen's Road East and other streets, into the public tanks of the city actually in use, a certain portion of the water, in search of its own level, finding its way directly into the mains leading to the highest districts for the special accommodation of the latter.
Upon close guaging, the stream in question has been found to yield an average of 300,000 gallons per day during the dry season, and as former calculations have been based upon a possible drought of two hundred and forty days, such having actually occurred in Hongkong, it will only be prudent to adhere to this datum, making the aggregate volume of water 72 million gallons. Three hundred thousand gallons equally divided among 90,000 people gives a daily ration of a little over three gallons and a quarter per head, which may perhaps be supplemented by another quarter gallon from hillside drainage between Wong-nei-chung and the Syphon head, and this is the utmost the project is capable of, for the absence of any favourable site for an impounding reservoir on so high a level renders it like the present Pokfoolum Water Works incapable of future extension or enlargement should the necessities of a future generation of colonists demand it. The entire cost of this project is £39,000, divided as follows:-
Masonry Dam,
Strainer,
18 inch Main from Dam to Strainer, Conduit from Strainer to Guage Basin,
Guage Basin and Tunnel Inlet,. Tunnel,
Tunnel Outlet,
£
s. d. 1,449. 7. 0
375. 11. 0
149. 10. 0
107. 12. 0
187. 8. O
.15,860. 18. 0
388. 18. 0 2,012. 10. 0 .15,000. 12. 0
Conduit,
18 inch Main to Tank,
£35,532. 6. 0
Contingencies, 10 %....
3,553. 4. 0
say £39,000. Q. 0.
£39,085. 10. 0
The Low Level Project.-In this plan will be recognized many of the features of the original project of 1873, the difference being that the quantity of water stored is not sought to be increased between Tytam and Wong-nei-chung by nullah supplies, but is led underground direct to the nearest available point on the northern slope of the island, whence as in the preceding scheme, it is sent for- ward by open conduit to a point on the hill overlooking the "Black Rock" on the eastern side of the Race Course. At this point it is received into one end of a cast iron syphon and poured out from the other end into the public tank below Robinson Road, known as No. 1 Tank. The syphon is two miles long, and is proposed to be laid along the same line as that in the preceding plan, viz., under the Race Course and along Queen's Road East and the upper roads in the direction of the tank. The storage of water at Tytam is proposed to be made in a reservoir impounding 283 million gallons, the dam being built upon a site close to that suggested in 1873. This volume of stored water, which may be slightly increased by hill drainage falling into the conduit between Wong-nei-chung and the Syphon head, will yield an average of thirteen gallons per head of inhabitant during the 240 days dry period of the year. The total cost of the Low Level Project is £122,600, divided as follows:-
Embankment,
Outlet Tunnel, Inlet,
.£
Valve Shaft, Tunnel,
95. 16. 3 6,087. 7. 6
5,423. 5. 0
Outlet,
516. 13. 9
£ S. d. 52,675. 14. 0
12,123. 2. 0
Culvert to Gauge Basin,.
Gauge Basin and Tunnel Inlet,
Overflow Weir and Bye-wash,
·
Tunnel,
Tunnel Outlet,
Conduit,..
18 inch Main to No. 1 Tank,.
Contingencies 10 %.....
say £122,600. 0. 0.
£
167. 18. 0
187. 8. 0
7,812. 13.
0
22,794. 16.
0
799. 6. 0
1,400. 0. 0
13,490. 14. 0
£111,451. 11. 0 11,145. 3. 0
£122,596. 14. 0