He said the lower height of the barrage was causing a wastage of raw water.

“Ours is already 2 metres, theirs is less than 1.55 metres, which causes water to flow out,” he said while on a visit to Langkawi. “And their barrage is 50-years old and not maintained,” the state government’s information secretariat quoted him as saying.

A sudden drop in the level of the Muda river on Saturday has disrupted operations at water treatment plants, causing water shortages which have affected more than 400,000 consumers in Penang, and more than 200,000 in Kedah.

Yesterday, Sanusi said a sensor failure at a barrage on the Muda river had caused a floodgate to open, letting river water flow out to sea and dropping the river level to below 1m instead of the normal 2m.

The Penang water company said the main treatment plant at Sungai Dua was unable to draw river water for treatment because of the lower river level. Two treatment plants in Kedah were also affected but have resumed full operations, producing treated water at 40% capacity.

The Kedah water supply company Sada said a multi-stage pump had been installed to draw river water to the treatment plant intake, allowing the plant to increase its treatment capacity without waiting for the river level to return to normal levels.

The treatment plants at Sungai Petani and Pinang Tunggal had to stop operations temporarily after the river level dropped on Saturday. Sada said it was actively stabilising the operations at the plants.