Brown water in Tengah canal due to accumulated silt churned up by rain

The mud-brown water that had pooled in a temporary canal in Tengah Garden Avenue was caused by the accumulation of silt that had been churned up by the heavy rain during the recent monsoon surge, said PUB on March 31.

- Zachary Lim

The silt has since made its way to Jurong Canal and likely even Jurong Lake, which is one of the 17 reservoirs in Singapore.

The national water agency said it has asked the contractors who are responsible for the discharge of the untreated silt to rectify the situation.

Nature Society Singapore (NSS) brought this matter to light in a March 22 post on its Facebook page, which included pictures of the brown-tinted silty water pooled at various construction sites within the up-and-coming Tengah estate and in the temporary canal.

When discharged into public drains, silty water—created by rainwater mixed with exposed earth materials and soil—increases the risk of flash floods when it rains heavily, because it reduces the fluidity of the waterways, said PUB in response to queries from The Straits Times.

It is also a concern for nature advocates because it impacts the ecosystem.

"The discoloured water limits the ability of stream-associated fauna—like kingfisher birds and otters—to forage for food," said Mr Tony O'Dempsey, a council member of NSS.

Contractors are required to contain and treat silty water before it is discharged into public drains, in line with PUB's code of practice on surface water drainage.