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Dam No. 2,
Pineapple Pass Catch- water
Dam No. 2 A
Dams Nos, 3 & 4
Nortli Conduit
Smugglers' Ridge or
Dam No. 2, T. W. L. 560 O. D., which will have a maximun length of 140 L. Ft. and a depth to stream bed of 162 ft., will impound 900 million gallons. It will have a direct catchment area of 765 acres, but by means of catchwaters running along the whole Southern face of Taimoshan and discharging through Pineapple Pass, an additional Catchment Area of 2,575 acres will be obtained. The total Catchment Area of 3,310 acres will be sufficient to fill this reservoir with 12 inches of effective rainfall.
Inside the direct Catchment Area of Dam No. 2, Dam No. 2A, 250 ft. long and 100 ft. in depth to stream bed, impounding 185 mil- lion gallons, will be constructed.
On the Southern Slopes of Taimoshan inside the Indirect Catch- ment Area of Dam No. 2, there are sites for two small reservoirs, Dams No. 3 & No. 4 at levels of 1,025 O. D. and 1,000 O. D. and impounding 200 million gallons and 137 million gallons respectively. These reser- voirs, as well as providing economical storage, will act as rainfall- equalising reservoirs and will allow of considerable reduction in the carrying capacity and thereby in the cost of the long catchwater dis- charging through Pineapple Pass.
From Dam No. 2 an open conduit approx. 2,800 L. Ft. long at a level of 485 A. O. D. will be constructed along the Western side of the Valley to the North Tunnel Gauge Basin.
The North Tunnel approx. 2,160 L. Ft. in length will pierce Smug. North Tunnel glers' Ridge and emerge in the valley above Giu Drinkers' Bay, dis-
charging into the South Conduit.
South Conduit
Golden Hill
or South Tunnel
Reception Reservoir
Filter Beds
& Service Reservoir
Trunk Mains
to Kowloon
The South Conduit which will be approx. 2,000 ft. in length will connect the South end of the North Tunnel and the North end of the South Tunnel.
The South Tunnel approx. 4,680 L. Ft. in length will pierce the Golden Hill and discharge into a Reception Reservoir situated in the lower Sheklaipui Valley immediately above the Filter Beds and Service Reservoir sites.
Between the Filter Beds Site and the end of the South Tunnel a Reception Reservoir will be formed with an overflow into the Proposed Kowloon Byewash Reservoir thereby making the Shing Mun water available through the existing works.
As the Shing Mun Water is of a high standard of initial purity and there is not sufficient area to install slow sand filter beds, the water will be dealt with by fast gravity or pressure filters and will discharge into a Concrete Service Reservoir of approx, 5 million gallons capacity.
From
Trunk mains will run by way of one of the back streets of the & Hong Kong Shamshuipo Reclamation, Coronation and Nathan Roads to Tsim Sha
Tsui feeding a new Service Reservoir at Pipers' Hill on the way. Tsim Sha Tsui the pipes will cross the Harbour to Jackson Road and then by way of Jackson Road, Parade Ground and Garden Road will reach the Public Gardens where a Service Reservoir with approx. T W.L. of 300 0. D. will be constructed. Considerable alteration will then be required in the City Distribution System.
Gravity
Section of
Scheme
The foregoing or Gravity section of the Scheme will give an aver- age supply of approx. 11 million gallons per day throughout the driest known period and, when this consumption is reached, the low level reservoirs will require to be put in hand.
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Dam No. 5, T. W. L 250 O. D., having a length of 502 L. Ft. and Dam No. 5 a depth to stream bed of 100 ft, will impound 400 million gallons. With a catchment area of 502 acres it will take 35 inches of effective rainfall to fill it without overflow from the upper reservoirs, but, if thought necessary, this area can be nearly doubled by means of a small catchwater.
Dam No. 6 will be situated immediately on the up stream site of Dam No. 6 Tai Wai Village and will have a top water level of approx. 100 A. O. D. It will be 1,740 L. Ft. in length with a total depth to stream bed of 85 ft. and will impound approx. 1,700 million gallons. The direct catchment area available for this reservoir is 1,203 acres, but by means of catchwaters a further 816 acres is made available, making 2,019 acres in all. Approx. 37 effective inches of rainfall are necessary to fill this reservoir without any overflow from the upper reservoirs.
Station & Ris-
The Pumping Station will be situated below Dam No. 6 and the Pumping Rising or Pumping Mains will follow the Access Road along the South ing Mains side of the valley to the gauge basin at the tunnel inouth, a distance of approx. 23 miles.
Bay
In the Gin Drinkers' Bay Valley there are two possible sites for Gin Drinkers a very large reservoir, but surface indications do not promise well for Reservoir foundations at a reasonable depth. If however either site on investi- gation should prove feasible, storage of between two and three thou- sand million gallons could be obtained in a position easily accessible to the main scheme. The water from this reservoir would be pumped to the South Conduit between the tunnels.
An Access Road 16 ft. wide having a maximum gradient of 1 in Access Road 16 will run from the Castle Peak Road at Tsun Wan to Pineapple Pass then down the Shing Mun Valley to join the Taipo Road above Shatin with a branch running North from Pineapple Pass to Dam No. 1. The portion of the road from Dam No. 6 to Dam No. 2 will serve a double pur- pose, as the pumping mains will be laid along it. The total length of this road when completed will be G miles,
The foregoing gives the broad outlines of the Scheme with ap- proximate areas and storage capacities as far as they can be ascertained from the information now available. It is however certain that as the work proceeds and further information is obtained considerable modi- fication will require to be made,
The works will be constructed in the following order: --
Order of Construction
1st. Section. Access Road to Pineapple Pass approx. two miles ist. Section. in length, smali intake dam on Shing Muu River with temporary pipe- line, North Conduit, Smugglers' Ridge or North Tunnel, South Con- duit between tunnels, Golden Hill or South Tunnel, Reception Reser- voir, 1st. section of filter beds, service reservoir, trunk main through Kowloon Peninsula across harbour to Public Gardens, and Service Reservoirs in Public Gardens, Hong Kong, and Pipers' Hill, Kowloon.
2nd, Section. Continuation of Access Road to Dams 2nd Section. Nos. 1 and 2, construction of Dam Nos. 1, 2, and 3A, Catchwaters discharging through Lead Mine Pass, 2nd section of Filter Beds, and Second Trunk Main to Kowloon &c.
3rd, Section Catchwaters draining areas A, B, C, D, & E, on 3rd Section. the Southern Slopes of Taimoshan discharging through Pineapple Pass, Dams Nos. 3 & 4 & 3rd. Section of Filter Beds.
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