It accepts expert panel's recommendations, will take steps to tackle floods
Feng Zengkun Straits Times 31 Jan 12;
NATIONAL water agency PUB has accepted the recommendations of an expert panel to tackle floods and will roll out a slew of measures in the next five years.
These include short-term engineering solutions such as increasing Stamford Canal's flow capacity by 10 per cent within a year to reduce floods in the prime Orchard area.
PUB, which announced the measures yesterday, will also spend $750 million over the next five years on 20 drainage projects. It will deepen and widen six other major canals, in places such as Bukit Timah, Geylang and Bedok, to increase their capacity by 30 to 45 per cent.
The panel of foreign and local experts, appointed by the Government last June after a spate of floods here, released its recommendations earlier this month.
It said PUB would need to implement a range of solutions at buildings and along pathways to handle more intense storms and mitigate the effects of increased urbanisation.
PUB should also review its drainage-system planning guidelines as well as improve its flood-warning system, the panel added.
It noted that more data on rainfall patterns and how rain water flows across the land would need to be collected.
PUB chief executive Chew Men Leong yesterday called the new moves 'a multi-pronged plan... to minimise and mitigate the impact of flash floods in Singapore'.
Besides engineering solutions, the agency will also improve flood-prediction and warning systems, such as posting closed-circuit television images of flood-prone areas on its website from March.
By year end, the National Environment Agency (NEA) will roll out an improved heavy-rain alert system.
PUB will also create digital land height maps of the major catchment areas by next year to be used in a new flood-prediction model by 2014.
In Orchard Road, hit by three floods in the past two years, PUB will smoothen the walls of Stamford Canal between Cuscaden and Grange roads to speed up water flow. Pipes in the canal will be removed to increase its capacity.
These projects will be completed within a year.
The agency will decide by May whether to build a diversion canal or water-storage pond or both to ease the canal's burden in the long term. Minister for the Environment and Water Resources Vivian Balakrishnan had said in Parliament earlier this month that the canal would divert rain water to the Singapore River, and the pond would be about the size of two to three football fields.
Other engineering solutions include fresh guidelines for new buildings by the year end.
These may include green roofs that can help slow and retain rain water, and flood barriers at buildings in low-lying areas. The agency said it would consider making the guidelines mandatory in high-risk places and may work with building managers to retrofit existing structures.
In the long term, PUB will update its drainage masterplan every three years, compared with every five years now. This will help the agency keep on top of weather changes and make adjustments or interventions, or change drainage-design standards, said Rear-Admiral (NS) Chew. PUB will publish the masterplan next year.
He added that an inter-agency committee convened in 2010 to tackle floods, comprising PUB, the Housing Board, Singapore Land Authority, Land Transport Authority, Building and Construction Authority, National Parks Board and industrial landlord JTC Corporation, will continue to work on the new measures together.
Head of the expert panel Chan Eng Soon said the agency's solutions are in line with the panel's recommendations. 'These are significant commitments and I am glad to note the emphasis on a holistic approach that covers the entire drainage system in each of the catchments,' he added.
But Mr Chik Hai Lam, building supervisor of Liat Towers which has been hard-hit by floods three times, said increasing Stamford Canal's capacity may not be enough.
PUB has to take care 'of the debris in the canal as well. We went into the canal to have a look ourselves, and there was so much debris - sand, branches', he added.
What PUB will do to fight floods
THE following are the measures to be rolled out by national water agency PUB:
IN THE SHORT TERM
Increase Stamford Canal's flow capacity by 10 per cent within a year to reduce floods in Orchard Road
Set up fresh flood prevention and alleviation guidelines for new buildings, which may include roofs with plants to slow and retain rain water and flood barriers at buildings
Make available closed-circuit television images of flood-prone areas on the PUB's website from March
Roll out an improved heavy-rain alert system by year end. This will be undertaken by the National Environment Agency
IN THE MID TERM
Launch a new flood-prediction model by 2014, which will take into account cloud patterns, rainfall and water levels; digital maps will predict where rain water will flow
IN THE LONG TERM
Expand six major canals in places such as Bukit Timah, Bedok and Geylang, to increase their capacity by 30 to 45 per cent in the next five years
Build a diversion canal or water-storage pond to ease Stamford Canal's burden. The PUB will decide which measure to adopt by May
Review drainage masterplan every three years instead of every five, as is being done now. The PUB will publish a masterplan next year
FENG ZENGKUN
Republic's drainage standards not up to other cities': Panel
Straits Times 31 Jan 12;
SINGAPORE'S drainage-design standards still lag behind those in other places, said an expert panel, despite the standards being raised after the 2010 Orchard Road flood.
The panel, comprising 12 foreign and local experts, was convened by the Government last June to help reduce floods here. It made its recommendations earlier this month.
It noted in its full report - published yesterday on the Environment Ministry's website - that drainage systems here are designed according to the size of the area they serve and the type of installations on the land.
Catchments here have to handle at most storms that are predicted to occur once every 100 years.
In other places such as Britain and Hong Kong, drainage standards are based on land use and are more stringent. Trunk systems in urban areas in Hong Kong, for example, have to handle storms that may occur once every 200 years.
The panel said PUB should review its drainage-design standards and look into a risk-based approach which balances the probability of a flood happening in an area against the damage it would cause.
It said the current standards 'do not explicitly take into account the damage that flooding may cause in terms of... damage to assets flooded and other damages to the economy, such as interruption of traffic'.
It added: 'While PUB has incorporated some elements of a risk-based drainage design and flood management approach, what (it) currently lacks is a systematic approach to tackling flooding that reflects good practice elsewhere in the world.'
The panel noted that many global cities have adopted this risk-based approach and added that it is a cost-effective way to prioritise areas which need investment in flood prevention. It added that future drainage-system guidelines should take into account less than ideal situations, such as hydraulic systems malfunctioning or drains and canals being clogged by debris.
PUB said yesterday that it would review its drainage masterplan once every three years from next year, compared with once every five years previously.
It added that it would carry out 'a systematic analysis of each major catchment and propose a range of interventions to achieve the required level of flood protection'.
FENG ZENGKUN
PUB commits S$750m to fight flooding
Hoe Yeen Nie Channel NewsAsia 30 Jan 12;
SINGAPORE: National water agency PUB has committed at least S$750 million over the next five years to increase the capacity of Singapore's drains by up to 45 percent.
Nearly half the money will be spent on expanding the capacity of six major canals, including Rochor and Bukit Timah canals. Other waterways are Alexandra Canal, Geylang River, Sungei Bedok and Sungei Kallang.
PUB is also studying ways to better manage storm water upstream and is developing a model to predict floods with greater accuracy.
These are among comprehensive measures PUB announced on Monday to cope with increasingly intense rainfall, in response to earlier recommendations by an expert panel.
PUB said that as Singapore becomes more urbanised, its approach to flood management needs to go beyond just improving drainage capacity.
Its chief executive, Chew Men Leong, explained: "We have to take a much more sophisticated approach, where we want to look at a whole range of solutions. That will include managing and reducing run-off at source, as well as better protect buildings and facilities at the receiving end so they can better handle residual risk."
Measures include roof-top canopies and retention ponds to absorb rainwater once it hits the ground.
There will also be new flood protection guidelines for buildings, due in a year's time.
And over the next two years, the agency is also piloting a system to better predict floods, using data on rainfall and the amount of run-off from catchment areas.
But there will still be challenges, as rainfall data is not always accurate.
PUB's director of catchment and waterways, Tan Nguan Sen, said: "...storms in Singapore are tropical storms. It's very difficult to forecast the intensity and the location of where the storms will appear. That is where it's difficult, because without that accurate prediction, the (flood prediction) model will not be able to generate the accurate forecast."
PUB will also review its drainage masterplan every three years, instead of the current five, to ensure the system keeps up with Singapore's needs.
The masterplan, first developed in the 1970s, maps out Singapore's drainage system, and it will be made public for the first time. PUB plans to release the document by the end of 2013.
Recent floods on Orchard Road have been traced back to Stamford Canal. To resolve this in the immediate term, PUB will line the walls of the canal with a polymer coating to reduce friction and increase water speeds.
PUB will also remove sewer and NEWater pipes located in the canal and place them elsewhere.
PUB says these measures will expand capacity by about 10 per cent within the year.
It is also studying more permanent solutions like a diversion canal and detention ponds, and will finalise plans by May.
- CNA/ir
Shops hope anti-flood measures can be speeded up
Sharon See Channel NewsAsia 30 Jan 12;
SINGAPORE: Businesses in Orchard Road have welcomed PUB's latest drainage improvement projects, especially the efforts to increase Stamford Canal's flow capacity.
But some are worried the measures may not come quick enough.
Parts of Orchard Road - like the basement of Lucky Plaza and Liat Towers - have in recent years been victims of flash floods during intense thunderstorms.
The most recent flooding took place just last month.
To reduce such occurrences, national water agency PUB is carrying out improvement works at Stamford Canal, which serves the flood-hit Orchard Road area.
PUB will line the walls of the canal with a polymer coating to reduce friction and increase water speeds.
PUB will also remove sewer and NEWater pipes located in the canal and place them elsewhere.
The agency hopes these short-term measures will increase the canal's flow capacity by 10 per cent within a year.
Steven Goh, executive director of Orchard Road Business Association, said: "We appreciate PUB putting in effort in improving the capacity of the Stamford Canal...I think it does help, but I think 10 per cent is not a lot."
The association is hoping for more long-term solutions from PUB, which is considering building a diversion canal and detention ponds.
Mr Goh said: "We find that detention ponds as well as diversion of the canal will be more urgent to meet the changing weather patterns. There's a piece of land behind Ngee Ann City (that) could be set aside for an underground holding tank, and then above (it) we still can keep...a park...as a recreation (area) for the shoppers of Orchard Road."
But such improvement works could take a few years to complete.
In the next five years, PUB will carry out 20 drainage improvement projects across the island to increase the capacity of its drains by up to 45 per cent.
Many Lucky Plaza shopowners Channel NewsAsia spoke to said they are glad to hear about PUB's flood improvement measures. But owing to the unpredictable weather, some added that they hope to see the works completed within a shorter time.
Orchard Road Business Association's Mr Goh said: "We wish that the government and the PUB will hasten up this programme and make it a priority so that it'll ease our fear of the next flood that may come again."
And shopkeepers say what's also helpful is an enhanced flood alert system which can send out alerts earlier so that they have more time to react.
- CNA/ir
PUB to pump S$750m into drainage projects
But even as measures are being rolled out, businesses want authorities to act even faster
Esther Ng Today Online 31 Jan 12;
SINGAPORE - Over the next five years, national water agency PUB will spend at least S$750 million on expanding canal capacity and other drainage projects.
Under the initiatives, the capacity of six major canals across the island - Bukit Timah First Diversion Canal, Rochor Canal, Alexandra Canal, Geylang River, Sungei Kallang and Sungei Bedok - will be increased by between 30 and 45 per cent.
But even as some measures - such as earlier warnings of heavy rain and making available CCTV images of selected flood prone areas - are set to be rolled out in the coming months, businesses along Orchard Road, which have been hit by flash floods, want the authorities to move even faster.
Orchard Road Business Association (ORBA) executive director Steven Goh said: "We wish that the Government and the PUB will ... make it a priority so that it'll ease our fear of the next flood that may come again."
Yesterday, the PUB said it has accepted the recommendations of an expert panel - which were unveiled earlier this month - which include green roofs, local storage tanks and ponds and rain gardens to better manage surface run-off at source.
Between now and 2017, the PUB will be investing heavily on 20 drainage improvement projects. It will also carry out "an in-depth examination of each catchment and implement catchment-specific solutions to achieve the higher drainage and flood protection standards".
PUB chief executive Chew Men Leong said: "In the past, dealing with drainage was simpler ... but given the trends of increasing urbanisation and higher rainfall intensity, we have to take a much more sophisticated approach."
Over the next two years, the PUB will pilot a flood forecasting system to better predict floods, using three-dimensional digital elevation maps, water level sensors and flow meters in canals, rain gauges and weather data from the Meteorological Service Singapore.
As the flood forecasting system is only a pilot, Mr Chew cautioned that the "accuracy of the data" will be "limited in the beginning".
Unlike Australian storm forecast models, storms in Singapore are tropical, said PUB director of catchment and waterways Tan Nguan Sen. He added: "It's very difficult to forecast the intensity and the location of where the storms will appear … Without that accurate prediction, the model will not be able to generate the accurate forecast."
In the near term, the public can look forward to an enhanced warning system, including earlier warnings - expected to be introduced by the met services later this year - of heavy rain with a better indication of the expected severity of rainfall.
Businesses along Orchard Road - which is served by the Stamford Canal - will also be better protected from flash floods.
By February next year, the removal and diversion of sewer and NEWater pipelines and the coating of canal walls with polymer will increase the flow capacity of Stamford Canal by 10 per cent. The Stamford Canal work is expected to cost around S$2 million, said Mr Tan. Long-term solutions such as the construction of a diversion canal and detention ponds are currently being studied and will be finalised in May.
While he appreciates PUB's efforts, ORBA's Mr Goh noted that "10 per cent is not a lot" and he urged the Government to hasten the longer term measures to improve Stamford Canal.
But Nee Soon GRC MP Lee Bee Wah, who chairs the Government Parliamentary Committee for the Environment and Water Resources, cautioned against rushing the measures. Said Ms Lee: "We are investing in a lot of money on drainage and flood protection. We should not rush and then find gaps in between and have to go back to patch up."
Concurring, Nanyang Technological University civil engineering lecturer Susanto Teng said: "All these proposals sound simple but are not easy to do as they involve engineering work in an urban area."
The PUB said it will make public, for the first time, its drainage masterplan by December next year. The masterplan will also be reviewed every three years, instead of five.
Over the next 12 months, the PUB will work with public sector agencies, developers and professional bodies to develop new guidelines to manage surface run-off for new developments and improve flood protection guidelines for buildings.
Timeline of measures
- By March: Images from CCTVs at selected flood-prone areas on PUB's website
- By May: Long-term solutions finalised for Stamford Canal
- By June: Trial version of flood forecasting system at Marina Catchment areas
- By Oct: Polymer lining to reduce friction of Stamford Canal wall
- By Dec: 3-D terrain mapping and hydrodynamic modelling of Marina Catchment to measure surface run-off
- By Jan 2013: New guidelines on surface run-off for new developments and flood protection for buildings
- By Feb 2013: Sewer and NEWater pipelines in Stamford Canal removed and diverted to increase capacity of canal
- By Dec 2013: Pilot of flood forecasting system. Review and publication of Drainage Master Plan
- By Dec 2017: Expansion of capacity of major canals
