36
Three-cell deep culvert under construction
LEGEND
-TWIN TUNNEL
-3-CELL DEEP CULVERT
B-
CU'SHAPE CONC, LINED CANAL
TRAPEZOIDAL CONC. LINED CANAL
PROP. INVERT LEVEL
EXISTING GRD. LEVEL
CHAINAGES
Longitudinal section – phase I
$6. ULU PANDAN
|7 010100LZ1-0296
|9130-| 2200/10171|
ULU PANDAN RD.
1/1500
1/350 1/2000
MILITARY HILL'
1/2000
MALAYAN RAILWAY
HOLLAND RD.
1/350/1/1180
Far East BUILDER, March 1969
due to the scarcity of land, the dis- charge of flood water has to rely in most cases on gravity. In the process of solving the Bukit Timah problem the possibility of using pumps was considered but was ruled out at an early stage.
There remained the possibilities of widening the existing canal or providing diversion channels. The first alternative was abandoned because the canal flows through a heavily populated area and widening the canal would entail costly reconstruction of bridges and buildings.
After a cost comparison study, it was finally decided to relieve the flood menace through the provision of two diversion channels. (Fig. 1). The first, which cuts off the flood flow at 6 m.s. Bukit Timah Road, diverts the flood water from the upper catchment (2,600 acres) to the west coast; the second, which stems off at 31⁄4 m.s. Bukit Timah Road, diverts the flood water from the middle catchment (3,000 acres) through Kallang Basin to the sea.
The scheme is being implemented in two stages, each providing one diver- sion canal.
It is assessed that on completion of the first diversion canal, the flood water overflowing the banks will be reduced by about 60 to 70 per cent under similar rainfall and ground con- ditions. On completion of the second diversion canal, the Bukit Timah valley should be free from all ordinary flood- ings even under a high degree of land
development.
GARLICK AVENUE
BUKIT TIMAH
RD.