Bukit Timah diversion canal to be expanded

Feng Zengkun Straits Times 21 Sep 12;

EFFORTS to curb flash floods in upper Bukit Timah will be bolstered with the expansion of a canal in the area by 2016.

National water agency PUB said yesterday that it plans to widen and deepen the Bukit Timah first diversion canal which will allow the upper stretch of the catchment zone to take in 30 per cent more rainwater.

This should reduce the risk of flash floods in the area like those in recent years, said PUB's director of catchment and waterways Tan Nguan Sen in a briefing at the Environment Building in Newton.

The 3.2km diversion canal - completed in 1972 - runs from Bukit Timah Road near Sixth Avenue to Clementi Road.

Built to alleviate frequent floods in Bukit Timah in the 1960s, the $7 million diversion canal re-routes stormwater from the Bukit Timah Canal into Sungei Ulu Pandan near Clementi.

But more intense rainfall in recent years has sometimes overwhelmed the area's ability to cope with storms. In 2009 and 2010, heavy rain flooded the basements of buildings in the area.

The expansion project is part of PUB's five-year, $750 million plan to reduce flash floods across Singapore. Announced earlier this year, the plan includes enlarging five other major canals in neighbourhoods such as Geylang and Bedok.

Work to expand the Bukit Timah diversion canal will start next month and will be carried out in three phases.

The first phase will involve the expansion of an underground drain beneath Ulu Pandan Road. It will cost $33.7 million and be completed by 2015.

Contracts for the two other phases have not been awarded.

Mr Tan said measures will be taken to minimise disruption to the public, including setting up noise barriers and closed-circuit television cameras to track traffic conditions during construction.

Low-vibration machines will be used and nearby structures will be monitored.

While the anti-flooding initiative is welcomed, residents are also wary of the impact of the construction. For the first phase, roads will be diverted and two bus stops and an overhead bridge will be moved 80m farther away temporarily.

"Even without construction, there have been traffic jams on the road, especially when it rains," said student Chia Shuhui, 24, who lives in the Pine Grove condominium next to Ulu Pandan Road. "It will be annoying for a while but if it makes the area more flood-proof, then it will be worth it," she added.

PUB to enhance flood protection at Bukit Timah Canal
Olivia Siong Channel NewsAsia 20 Sep 12;

SINGAPORE: National water agency PUB has announced it will be enhancing flood protection for the upstream section of the Bukit Timah Canal.

To do that, the PUB plans to widen and deepen the Bukit Timah 1st Diversion Canal.

This will increase drainage capacity in the Upper Bukit Timah catchment by about 30 per cent.

It is hoped this will prevent a repeat of flashfloods in the area.

The expansion will be carried out in three phases.

Phase One - costing some S$33.7 million - will see a new box culvert or underground drain built across Ulu Pandan Road.

The second phase involves the expansion of 1.6 kilometres of existing drains between Maple Avenue and Holland Green.

This expansion is expected to commence in the second quarter of 2013 and is slated for completion by the last quarter of 2015.

Details for the third phase are still being worked out.

A wider and deeper canal will increase the capacity to hold more rainwater and therefore minimise the risk of flooding.

PUB's catchment & waterways director, Tan Nguan Sen, said: "It will definitely alleviate flooding in the flood-prone areas by increasing the capacity of the drainage system. The extent and the severity of the flood will be much reduced and of course if there is any flash floods that occur, it will minimise the impact."

During construction, six lanes of road leading towards Clementi and the city will be diverted. The road diversions will take place in the later stages of construction to minimise disruption to residents at Pine Grove condominium.

The two bus stops and overhead bridge outside Pine Grove condominium will also be temporarily relocated.

Many Pine Grove residents said they weren't aware of the construction work, which begins next month.

This is despite PUB saying it had briefed the condominium's Management Corporation Strata Title some months ago.

Chia Shu Hui, who has been a resident at Pine Grove condominium for 18 years, said: "It's going to be really annoying, frankly. I also think it's going to jam, really bad, because every time it rains, the road over there will jam. So it's going to be really annoying, inconvenient. But if it stops flooding further down or further up, it's going to be good in the long run. But in the short run, it's going to be inconvenient for everybody."

Another resident Lynn Liew said: "We haven't heard anything regarding the works but currently we have other entrances and exits, so it's not really much of a problem."

Retiree David Low, 65, said: "Yes it's a bit inconvenient, especially for those elderly people."

The entire upgrading project is expected to be completed by 2016.

- CNA/xq/ck