Sungai Perak blue water caused by rain, minerals and changes in water flow, state assembly told

IPOH, September 8 — The blue hue of Sungai Perak was attributed to a combination of factors, according to a report presented to the Perak State Legislative Assembly. Perak Science, Environment and Green Technology Exco Teh Kok Lim revealed that heavy rain, mineral particles, and altered water flow played a role in the color change.

Teh explained that the phenomenon was the result of increased runoff from torrential rains, which carried more mineral particles into the river system, particularly from open areas. He emphasized that a specific concentration of minerals and suitable water flow conditions were necessary for the color change to occur simultaneously.

Sungai Rui, a narrower river with a faster current, slowed down when it merged with the wider Sungai Perak, allowing fine mineral particles to remain suspended and accumulate, which further contributed to the bluish appearance when interacting with light. In terms of water quality, Sungai Perak was classified as Class II under the National Water Quality Index, allowing for recreational activities, fisheries, and as a source for conventional water treatment.

The Perak government, through the Department of Environment, continuously monitors and enforces water quality regulations. Teh mentioned the implementation of a Total Maximum Daily Load (TMDL) study to identify pollution sources and the establishment of a state-level task force to address pollution, among other proposed measures.