Kuala Lampur, April 21 -- Around a million people in Johor may be affected by water disruptions as three dams in the state supplying raw water to treatment plants have fallen below their critical marks.

The Sunday Star reported the National Water Services Commission (SPAN) as saying the Lebam, Upper Layang, and Pulai 2 dams are now at 15.9, 21.8, and 36.1 per cent, respectively.

The decline is due to the prolonged heatwave in some parts of the country despite occasional thunderstorms elsewhere.

Lebam dam provides water to treatment plants that supply around 100,000 people living in Bandar Penawar, Kota Tinggi, Pengarang, Tanjung Balau, and Teluk Ramunia.

The Upper Layang dam supplies water to the Sultan Iskandar treatment plant that s...