Modification of River Channels

The major modification to the river channels in Singapore is artificial channelization, which involved the concrete lining of river embankments. In 1968, 27% of the drainage has been changed beyond recognition, 36% was modified, and almost all the remainder was at least slightly modified following the removal of the natural vegetation (Wong, 1968). Currently, most parts of the river channels in Singapore have undergone artificial channelization.

With rapid urban growth in Singapore, the flood risk is heightened. For example, places like Potong Pasir is always prone to flooding in 1950s (Plate I and II). This can be attributed mainly to the tremendous expansion of impervious areas. Thus, drainage schemes with the establishment of efficient stormwater drains and the location of several arterial roads have been implemented to provide drainage infrastructures for new land developments and to alleviate flooding problems (Plate III). Rivers like Rochor River which was once inhabited by fishing villages and tree logs transportation has been channelized (Plate IV). With these drainage plans carried out, floodprone areas in Singapore have been reduced from 3200 ha in the 1970s to 172 ha in April 2003 (Figure 6). Currently, Singapore has been divided into 11 drainage management catchments for effective drainage management and control.

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.:: Plate II ::.

.:: Plate III ::.

.:: Plate IV ::.