Q 107
164. Shing Mun Valley Scheme :—
P.W.E. New Kowloon
(a) Reception Reservoir, Shek Lei Pui, for Shing Mun Water.—This work was referred to in paragraph 224 (J) of last year's Report.
Owing principally to labour troubles, the completion of these works was delayed, but by the close of the year the contract had been fulfilled and the dams satisfactorily tested.
In addition to the storage provided the reservoir is intended to regulate and to a certain extent clarify, the delivery through the Shing Mun Tunnels which discharges directly into it.
The following data is given for record purposes:
Direct Drainage area 96 acres.
Top Water Level 480.00 A.O.D.
Volume available through draw-offs 33.15 Mill. Galls.
Additional volume available through Wash-out ....17.00 ""
Area at Top Water Level 9 acres.
The works consist of:-
(1) A Draw-off Dam with Valve House.
(2) An Overflow Dam.
(3) An Overflow Channel.
(1) The Draw-off Dam has an overall length of 228 ft. and a maximum height of 48 ft. from the lowest foundation level to foot path level, which stands at 482.50 A.O.D.
The inner face of the dam up to 466.25 A.O.D. is of plain 4 to 1 cement concrete and above that level it is of ashlar masonry backed with 4 to 1 cement concrete. The hearting consists of 8 to 1 displacer cement concrete and the outer facing is of granite rubble in regular courses. The Valve Tower and House project from the inner face of the dam and are faced above 466.25 A.O.D. with granite ashlar. The draw-offs are designed to deal with the ultimate capacity of the Shing Mun Valley Scheme and are four in number each 18" in diameter. Two draw-offs are at 472.00 A.O.D. and two at 465.00 A.O.D. The Wash-out pipe, although situated outside the Valve Tower, is controlled from the Valve House. It is of 18" diameter and its level is 450.00 A.O.D.
The following materials were used in the construction of the dam and Valve Tower:—
1,380 C. Yds. Fine Cement Concrete.
967 " 8 to 1 Lime concrete.
111 " Ashlar masonry.
17 " Rubble
218 " Granite
172 " ...