PUB has accepted the recommendations of the Expert Panel for Drainage Design and Flood Protection Measures and announced today its action plan to strengthen Singapore’s flood resilience.
“Recognising the challenges posed by weather uncertainties and increasing urbanisation, we have put in place a multi-pronged plan that covers the entire spectrum of drainage and flood management. This includes implementing higher drainage design standards and holistic solutions, building new capabilities and working with stakeholders to improve preparedness. Through these efforts, we seek to minimise and mitigate the impact of flash floods in Singapore,” said Mr Chew Men Leong, Chief Executive of PUB, the national water agency.
Implementing higher drainage standards and holistic solutions
Over the next five years, PUB will spend about $750 million to carry out 20 drainage improvement projects to achieve a higher level of flood protection. The capacity of six major canals (Bukit Timah 1st Diversion Canal, Geylang River, Alexandra Canal, Rochor Canal, Sungei Bedok and Sungei Kallang), will be increased by 30 to 45% to meet the higher standards stipulated in the revised Code of Practice on Surface Water Drainage.
In addition, PUB will carry out an in-depth examination of each catchment and implement catchment-specific solutions to achieve the higher drainage and flood protection standards To do that, PUB will adopt a holistic approach that covers the entire drainage system. Recognising that expanding drainage will not be sufficient, especially for areas that are more developed and have site constraints, PUB will go beyond the conventional ‘pathway’ solutions (such as expanding drains/canals and building diversion canals and detention ponds) to developing solutions at ‘source’ (where rainwater falls)1 to better manage stormwater run-off, and at ‘receptors’ (where rainwater flows to)2 to protect buildings at the local level.
Developing guidelines with agencies and stakeholders
PUB will work closely with public sector agencies, developers and professional bodies to introduce new guidelines to facilitate the implementation of solutions at source and receptors. These new guidelines will include managing surface run-off for new developments through the use of features such as local detention ponds and green surfaces. PUB will also work with agencies to improve the flood protection guidelines for buildings. PUB aims to have these guidelines in place within a year.
Reviewing drainage masterplan
In view of the increasing weather uncertainties and urbanisation, PUB will review its drainage masterplan once every three years. The masterplan will be made public by the end of 2013.
Improving flow capacity of Stamford Canal
Specifically for Stamford Canal catchment, PUB will implement immediate measures to maximise the flow capacity of Stamford Canal. These include introducing a polymer lining to smoothen the canal walls and diversion of some services such as sewer and NEWater pipelines. The lining works are expected to be completed in 9 months while the diversion of services will take up to a year. These immediate measures will help increase Stamford Canal’s flow capacity by an estimated 10%.
Longer-term solutions including the construction of a diversion canal and detention ponds are currently being studied, and PUB will finalise these plans by May 2012.
Building new capabilities
To expand its modelling capabilities, PUB will develop 3-dimensional Digital Elevation Maps (DEMs) and link them to our hydrodynamic model. This will allow PUB to validate drainage system performance, measure surface run-off, determine residual flood risks and enhance forecasting of floods. This modelling will be carried out for Marina Catchment, including the Stamford Canal catchment, by end of 2012. PUB plans to do the same for all major catchments by 2013. PUB will be collaborating with the Singapore Land Authority which is leading the effort to develop a national DEM for whole-of-government applications.
Working with stakeholders to improve preparedness
PUB will continue to keep the public informed before, during and after the occurrence of flash floods. To provide timely alerts and updates to the public, various information channels such as the PUB website, smart phone applications, mobile text messages and social media platforms are already in place. We would also like to call on the public to help us by reporting clogged drains and flash floods so that quick follow-up action can be taken.
The public can help by keeping the catchments and waterways clean so that the drains and canals can remain free-flowing. The public has also been forthcoming with their suggestions on drainage improvements. PUB will continue to engage the various stakeholder groups to gather feedback and develop ideas to strengthen flood management in Singapore.
To enhance the warning system on both potential as well as ongoing flood situations, images from selected CCTVs will be made available to the public through PUB’s website by March 2012. In addition, the Meteorological Service Singapore will be enhancing its heavy rain warning service to increase the lead time and allow for earlier warnings to be issued. The enhanced service is expected to be introduced in the later part of the year and will also give the public a better indication of the expected severity of the rainfall. In the next two years, PUB aims to pilot a flood forecasting system based on information from cloud patterns, rainfall and water levels. These initiatives will help to further improve public preparedness.
“Strengthening Singapore’s flood resilience is a long-term and ongoing effort. Stakeholder participation continues to be an important element in our inclusive approach. Moving on, we will work more closely with them to develop solutions and improve public preparedness as part of our overall flood management efforts,” said Mr Chew.
[1] For example, local storage tanks and ponds, green roofs, rain gardens and porous pavements.
[2] For example, raised platform and crest levels and flood barriers.
Please refer to the annexes for the list of major drainage improvement projects from 2012 to 2016 and the executive summary of recommendations by the Expert Panel on Drainage Design and Flood Protection Measures.
About PUB
PUB is a statutory board under the Ministry of the Environment and Water Resources. It is the national water agency, managing Singapore’s water supply, water catchment and used water in an integrated way.
About PUB’s tagline: Water for All: Conserve, Value, Enjoy
PUB has ensured a diversified and sustainable supply of water for Singapore with the Four National Taps (local catchment water, imported water, NEWater, desalinated water).
To provide water for all, PUB calls on all to play our part to conserve water, keep our water catchments and waterways clean and build a relationship with water so we can enjoy our water resources. If we all play our part, we can have enough water – for industry, for people, for life.
