Appendix
Key Changes to Code of Practice on Surface Water Drainage
Existing Version
Minimum Platform Levels for General
Developments
Revised Version
Minimum Platform Levels for General
Developments
The minimum platform level shall not be
lower than:-
The minimum platform level shall not be
lower than:-
(i)
75 cm above the highest tide level
in the vicinity. For this purpose, the
highest tide level shall, unless otherwise
specified, be taken as follows :-
(i)
104.0 mRL for developments along
the southern coast, and
104.5 mRL for developments along the
northern coast; or
° along the southern coast of Singapore
Island from Tuas to Changi : RL 101.75m
(ii)
30 cm above the adjacent
road/ground level; or
° along the north-eastern coast of
Singapore Island from Changi to
Causeway : RL 102.05m
(iii)
60 cm above the highest recorded
flood level, if any, as advised by PUB; or
° along the north-western coast of
Singapore Island from Tuas to
Causeway : RL 102.35m
(ii)
(iv)
Any other level as may be
specified by PUB;
whichever is the highest.
the adjacent road/ground level;
(iii)
30 cm above the highest recorded
flood level, if any, as advised by PUB; or
(iv)
other level as may be specified by
PUB;
whichever is the highest.
Minimum Platform Levels for
Commercial/ Multi-Unit Residential
Developments with basements
Minimum Platform Levels for
Commercial/ Multi-Unit Residential
Developments with basements
The minimum platform level shall not be
lower than:-
The minimum platform level shall not be
lower than:-
(i)
75 cm above the highest tide level
in the vicinity. For this purpose, the
highest tide level shall, unless otherwise
specified, be taken as follows :-
(i)
104.0 mRL for developments
along the southern coast, and 104.5 mRL
for developments along the northern
coast; or
° along the southern coast of Singapore
Island from Tuas to Changi : RL 101.75m
(ii)
60 cm above the adjacent
road/ground level; or
° along the north-eastern coast of
Singapore Island from Changi to
Causeway : RL 102.05m
° along the north-western coast of
Singapore Island from Tuas to
Causeway : RL 102.35m
(ii)
(iii)
60 cm above the highest recorded
flood level, if any, as advised by PUB; or
(iv)
Any other level as may be
specified by PUB;
whichever is the highest.
the adjacent road/ground level;
(iii)
30 cm above the highest recorded
flood level, if any, as advised by PUB; or
(iv)
other level as may be specified by
PUB;
whichever is the highest.
Minimum Crest Level
Minimum Crest Level
Minimum crest level is required for an
entrance, exit or opening to a basement or
underground structure (basement, tunnel,
underground facility, etc) as follows:-
Minimum crest level is required for an
entrance, exit or opening to a basement or
underground structure (basement, tunnel,
underground facility, etc) as follows:-
(i)
(i)
Basements of General
Developments
Basements
For basements, underpasses and
sunken/underground facilities, the
minimum crest level shall be at least 15
cm above the minimum platform level.
(ii)
Special Underground Facilities
For Rapid Transit underground
stations/tunnels, underground road
networks, depressed roads, and other
special underground facilities, the
minimum crest level shall be at least 15
cm above the minimum platform level
(iii)
Linkage to Special Underground
Facilities
All developments with direct or indirect
links to these special underground
For basements, underpasses and
sunken/underground facilities, the
minimum crest level shall be at least 15
cm above the minimum platform level.
(ii)
Special Underground Facilities
and Basements of Commercial/ MultiUnit
Residential Developments
For Mass Rapid Transit underground
stations/tunnels, underground road
networks, depressed roads, basements of
Commercial/ Multi-Unit Residential
Developments and other special
underground facilities, the minimum crest
level shall be at least 30 cm above the
minimum platform level.
(iii)
Linkage to Special Underground
Facilities and Basements of
Commercial/ MultiUnit Residential Developments
facilities shall comply with the same
minimum crest level requirements.
All developments with direct or indirect
links to these special underground
facilities and basements of Commercial/
Multi-Unit Residential Developments shall
comply with the same minimum crest level
requirements.
Minimum Reclamation Level
Minimum Reclamation Level
For land reclamation works, the minimum
reclamation level shall not be lower than:-
For land reclamation works, the minimum
reclamation level shall not be lower than:-
(i)
RL 103.0m along the southern
coast; and
(i)
RL 104.0m along the southern
coast; and
(ii)
RL 103.5m along the northern
coast; or
(ii)
RL 104.5m along the northern
coast; or
(iii)
Any other levels as may be
specified by PUB.
(ii)
Any other levels as may be
specified by PUB.
Drainage Design Standards
Drainage Design Standards
Major rivers – return period of 50 to 100
years as specified by the PUB
The drainage design standards for new
drains will be increased to cater for more
intense storms The new return periods
used for drainage design are:
Important installations/developments
such as airports and tunnels – return
period of 50 years
Outlet drains and secondary
drainage facilities – return period of 5
years
- 10 years for catchments less than 100
hectares
- 25 years for catchments of 100 to 1000
hectares
- 50 years for catchments more than
1000 hectares (and critical
installations)
Earth Control Measures at
Construction Sites
Earth Control Measures at
Construction Sites
The basin / tank shall have a storage
capacity to cope with the volume of water
from a rain based on a minimum design
return period of 1 in 2 years storm.
The basin / tank shall have a storage
capacity to cope with the volume of water
from a rain based on a minimum design
return period of 1 in 5 years storm.
Intensity-Duration-Frequency (IDF)
Curve Data
IDF Curve Data
Data from 1931-2009
Data from 1931-1989