http://www.straitstimes.com/premium/...atten-20120919
Wells to help halt damage in Watten
They will pump back water which has seeped away due to digging works
Published on Sep 19, 2012
By Maria Almenoar Transport Correspondent
TWENTY-EIGHT "recharge wells" will be built to prevent further damage to houses in Watten Estate.
These wells will pump water back into the underlying soil which is likely to have seeped away due to adjacent excavation works for the Downtown Line.
Some 34 families, who live off Dunearn Road, have complained about cracks in walls both inside and outside their homes discovered since last month.
Other problems: Doors that don't shut, tilted tiles, and sunken drain covers.
The Land Transport Authority (LTA) said that the damage was likely to be due to water seeping out of the underlying soil. The ground then adjusts and causes cracks in buildings.
The first seven or eight wells, built along Bougainvillea Park in front of Watten Estate, will be ready by the end of this week. The rest will be ready within a month.
In the meantime, excavation work for the Tan Kah Kee station, at areas closest to the estate, has been stopped.
It will resume only when water has been pumped back into the area and the ground has been stabilised, LTA said.
It added that this will not delay construction of this part of the Downtown Line, which is due to open in 2015.
LTA deputy chief executive for infrastructure and development, Mr Chua Chong Kheng, said the agency did not think Watten Estate would be affected by the construction works. Preliminary studies of the area had highlighted Hwa Chong Institution as the only building likely to be affected.
He said: "We were extra cautious with buildings that fell within this zone... There have been no problems so far.
"Watten Estate, however, fell just outside this zone."
About 200 instruments to measure the ground's movement and other parameters have now been installed in Watten Estate.
LTA officers are checking these instruments every day, said Mr Chua.
He said that all houses with cracks have been checked by an independent engineer and certified to be safe, and added that these cracks did not affect any structural components of the houses.
LTA said that it has informed Watten Estate residents that it will pay for repairs for any damage caused by its works.
Some of the repair work is already under way - such as in areas where fallen tiles may cause residents to slip and fall.
Retiree Kwok Kee Kuan, 77, whose main gate was affected by the underground works, said that LTA has raised the ground near his home so the gate now works fine.
"I'm satisfied with the explanations from the LTA officers. They came around to speak to the residents personally," he said.
This is not the first time construction work for a rail project has affected neighbouring buildings.
A similar problem was encountered during the building of the North-East Line near Outram Park station, when cracks were found at the nearby buildings and recharge wells had to be built.
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