<TABLE id=msgUN border=0 cellSpacing=3 cellPadding=0 width="100%"><TBODY><TR><TD id=msgUNsubj vAlign=top>
Coffeeshop Chit Chat - Flood: danger spots difficult to predict</TD><TD id=msgunetc noWrap align=right>
Subscribe </TD></TR></TBODY></TABLE><TABLE class=msgtable cellSpacing=0 cellPadding=0 width="96%"><TBODY><TR><TD class=msg vAlign=top><TABLE border=0 cellSpacing=0 cellPadding=0 width="100%"><TBODY><TR class=msghead><TD class=msgbfr1 width="1%"> </TD><TD><TABLE border=0 cellSpacing=0 cellPadding=0><TBODY><TR class=msghead vAlign=top><TD class=msgF width="1%" noWrap align=right>From: </TD><TD class=msgFname width="68%" noWrap>CPL (kojakbt22) <NOBR>
</NOBR> </TD><TD class=msgDate width="30%" noWrap align=right>Dec-4 6:26 pm </TD></TR><TR class=msghead><TD class=msgT height=20 width="1%" noWrap align=right>To: </TD><TD class=msgTname width="68%" noWrap>ALL <NOBR></NOBR></TD><TD class=msgNum noWrap align=right> (1 of 5) </TD></TR></TBODY></TABLE></TD></TR><TR><TD class=msgleft rowSpan=4 width="1%"> </TD><TD class=wintiny noWrap align=right>25376.1 </TD></TR><TR><TD height=8></TD></TR><TR><TD class=msgtxt>Dec 5, 2009
FLOODS
Exact danger spots difficult to predict
<!-- by line --><!-- end by line -->
<!-- end left side bar --><!-- story content : start -->
WE THANK Mr Narayana Narayana ('Floods a freak event, or could we have tracked it?', last Saturday) and Mr Thomas Lee ('Floods - I would have thought such events were well within our ability to prevent or minimise', Tuesday) for their letters on the Bukit Timah flood.
The heavy rain in the Bukit Timah area on Nov19 was exceptionally intense. In just two hours, 110mm of rain fell, of which 92mm fell from 1.20pm to 1.50pm. This was equivalent to about 40 per cent of the rainfall for the entire month of November falling within the half an hour.
The National Environment Agency (NEA) issued a warning at 12.45pm that day to alert the public to expect heavy rain in the afternoon over many areas of Singapore. However, the exact locations where exceptional rainfall is expected are difficult to predict in any weather forecast. PUB also issued flash-flood advisories to residents and shop owners in low-lying areas in October and to the media on Nov 16 as part of its monsoon preparations.
The huge amount of rain within such a short time that day caused Bukit Timah Phase 1 Diversion Canal to fill up and overflow. However, Bukit Timah Phase 2 Diversion Canal which channels stormwater from the middle part of Bukit Timah to Marina Reservoir via Kallang River did not overflow.
PUB had already initiated plans to deepen and widen Bukit Timah Phase 1 Diversion Canal before this incident. While this upgrading work was intended primarily to cater to increased stormwater runoff from new developments in the next 10 years, it will also help to mitigate the extent and severity of flooding of other intense storms. Works on the first stage are slated for completion by 2012.
Ten fast-track projects were also recently completed to alleviate flooding in flood-prone areas, and five major flood-alleviation projects are ongoing. Flood-prone areas in Singapore have been reduced from 3,200ha in the 1970s to about 79ha today.
In land-scarce Singapore, it will not be cost- effective to build a large and extensive drainage system that caters to all extremities. A balance is needed between setting aside more land for such infrastructure and other requirements for Singapore's development.
PUB will regularly review and improve drainage infrastructure across Singapore to ensure an effective drainage network. Such continuous efforts will help further mitigate the risk of floods.
Tan Nguan Sen
Director (Catchment and Waterways)
PUB
Ms Wong Chin Ling
Head (Operational Services Department)
Meteorological Services
National Environment Agency
[email protected]
</TD></TR><TR><TD> </TD></TR></TBODY></TABLE></TD></TR></TBODY></TABLE>
FLOODS
Exact danger spots difficult to predict
<!-- by line --><!-- end by line -->
<!-- end left side bar --><!-- story content : start -->
WE THANK Mr Narayana Narayana ('Floods a freak event, or could we have tracked it?', last Saturday) and Mr Thomas Lee ('Floods - I would have thought such events were well within our ability to prevent or minimise', Tuesday) for their letters on the Bukit Timah flood.
The heavy rain in the Bukit Timah area on Nov19 was exceptionally intense. In just two hours, 110mm of rain fell, of which 92mm fell from 1.20pm to 1.50pm. This was equivalent to about 40 per cent of the rainfall for the entire month of November falling within the half an hour.
The National Environment Agency (NEA) issued a warning at 12.45pm that day to alert the public to expect heavy rain in the afternoon over many areas of Singapore. However, the exact locations where exceptional rainfall is expected are difficult to predict in any weather forecast. PUB also issued flash-flood advisories to residents and shop owners in low-lying areas in October and to the media on Nov 16 as part of its monsoon preparations.
The huge amount of rain within such a short time that day caused Bukit Timah Phase 1 Diversion Canal to fill up and overflow. However, Bukit Timah Phase 2 Diversion Canal which channels stormwater from the middle part of Bukit Timah to Marina Reservoir via Kallang River did not overflow.
PUB had already initiated plans to deepen and widen Bukit Timah Phase 1 Diversion Canal before this incident. While this upgrading work was intended primarily to cater to increased stormwater runoff from new developments in the next 10 years, it will also help to mitigate the extent and severity of flooding of other intense storms. Works on the first stage are slated for completion by 2012.
Ten fast-track projects were also recently completed to alleviate flooding in flood-prone areas, and five major flood-alleviation projects are ongoing. Flood-prone areas in Singapore have been reduced from 3,200ha in the 1970s to about 79ha today.
In land-scarce Singapore, it will not be cost- effective to build a large and extensive drainage system that caters to all extremities. A balance is needed between setting aside more land for such infrastructure and other requirements for Singapore's development.
PUB will regularly review and improve drainage infrastructure across Singapore to ensure an effective drainage network. Such continuous efforts will help further mitigate the risk of floods.
Tan Nguan Sen
Director (Catchment and Waterways)
PUB
Ms Wong Chin Ling
Head (Operational Services Department)
Meteorological Services
National Environment Agency
[email protected]
</TD></TR><TR><TD> </TD></TR></TBODY></TABLE></TD></TR></TBODY></TABLE>
