FLOODED AREAS (Reasons for, and preventive measures)

Mr P. Govindaswamy asked the Minister for Law and National Development if he can state the reasons for the recent floods in areas which were not subject to floods some years back, and what steps will be taken to prevent further flooding in such areas.

Mr Barker: The main reason for the widespread recent flooding in areas which were not subject to floods some years back was the exceptionally heavy rainfall. About 8.4 inches of rain were recorded over a period of 24 hours on the 11th of January this year. This was followed by 6.4 inches of rain over a period of six hours on the next day. Again, about 7.4 inches of rain fell over a period of 24 hours on the 17th of February this year. These figures exceed the maximum rainfall of not more than 4 inches per day recorded in Singapore ever since 1931. This exceptionally heavy rainfall coincided with high tide and caused the floods.

Other reasons for the flooding were:

The outlet drains at Bukit Timah Canal, Sungei Whampoa, Sungei Kallang, Geylang Serai and New Bridge Road/South Bridge Road areas are inadequate to serve the catchment runoff.

Previously many low-lying areas and vacant lands served as ponding and storage areas for heavy rainfall. But these areas have been filled and developed, and thus cause greater run-off into streams and drains which become inadequate to cope with this additional discharge.

In the densely populated areas, rubbish and other waste materials are dumped indiscriminately into the drains, thus preventing the free flow of water especially in covered drains.

Measures have already been taken to alleviate the flooding in Bukit Timah, Sungei Whampoa and Sungei Kallang catchments by (1) the Bukit Timah flood alleviation scheme, Phase 1; (2) the Sungei Whampoa improvement scheme; and (3) the Sungei Kallang improvement scheme. Work on all three schemes is already in progress.

New measures to alleviate flooding are being planned for 1968 in the Boon Tat Street and Alexandra Canal catchments. The Public Works Department has had a drainage scheme to alleviate flooding in Geylang Serai since 1960, but has not been able to implement it because of squatters. The Ministry of Health and the Public Works Department are together taking action to remove the concrete slabs covering some drains in the city areas to prevent these drains from being choked with rubbish.