Geylang river turning green? Here's what it most likely is

Stomper Jackye was concerned when he saw that the Geylang River had "turned green" at the stretch near Lorong 40 Geylang when he passed by it on July 29 and 30.

"I don't know what happened to the river," he said Stomp.

"It was totally green!"

Jackye told Stomp that he believes that the river was polluted.

However, the green hue of the river is most likely because of an algal overgrowth.

In 2017, the Singapore River had a similar greenish tint on the water's surface caused by an algal bloom.

In a report by The Straits Times (ST), the Public Utilities Board (PUB) said that the greener-than-usual waters were caused by algae - microscopic organisms naturally present in reservoirs and waterways.

PUB added that algae in waters here are removed effectively during the water treatment process for drinking water.

Environmental experts told ST that rain followed by strong sun, usually experienced after monsoon season, creates a conducive environment for algal blooms.

Algal blooms usually last up to a week and disappear once the nutrients within the water body have been used up.

Most algae are not toxic, but an algal bloom can kill fishes by starving them of oxygen and clogging up their gills.