Malaysia: Dams full but dry weather threatens

RAZAK AHMAD The Star 22 May 17;

PETALING JAYA: The Klang Valley’s eight dams are all nearly full thanks to the recent wet weather, but a severe dry spell in the coming months could drain them and cause water supply disruptions.

Data from the Selangor Water Management Authority website (iwrims.luas.gov.my) showed that the water level in Sungai Selangor dam, which supplies 70% of the treated water in the Klang Valley, was at 100% last Friday.

Two other dams – Semenyih and Langat – were also at 100% capacity, while four others were at more than 98%.

A dry spell typically happens in the Klang Valley from July to August due to a reduction in rainfall in the west coast of the peninsula, so the high water levels at the dams should ensure adequate supply of raw water in the months ahead.

However, Association of Water and Energy Research Malaysia president S. Piarapakaran said the high water levels are no cause for cheer.

He said unpredictable weather patterns due to climate change means there is a possibility that the coming dry spell could be more severe than expected.

“Two of the three treatment plants drawing water from Sungai Selangor are already overloaded by 10% and 20% respectively.

“A severe dry season could bring down the water levels at the dam much faster than expected,” he said, adding that this could raise the risk of supply disruption.

Pollution in rivers supplying water to treatment plants will also take longer to clean up when water levels at the rivers are low in the event of a severe dry spell.

“The authorities must be on guard and not be complacent due to the high water levels at our dams now.

“They must anticipate unforeseen circumstances to reduce possible risks,” said Piarapakaran.

To reduce the danger of lengthy disruptions to treatment plants due to pollution, he suggested that counter-measures be taken.

These include pre-treatment of raw water upstream before the water is drawn by the treatment plants.

This is done using several methods including placing mechanised devices that stir the water upstream to add oxygen to the water and reduce ammonia pollution.

The Langat 2 water treatment plant is being built to increase the raw water supply for Klang Valley but Piarapakaran said this is only expected to be ready at the end of 2019.

The unpredictable weather also poses a challenge to the Fire and Rescue Department, which is preparing for an outbreak of forest and peat fires during the dry season.

“There is no longer any clear or specific trend when it comes to the severity of the dry season,” said its director-general Datuk Wan Mohd Nor Ibrahim.

He said that in general, Peninsular Malaysia gets two dry spell episodes, the first from February to March followed by a second one which starts in June or July.