PETALING JAYA - Selangor needs a continuous spate of daily heavy rain over the next few weeks if water rationing here is to end.
This is unlikely, said Association of Water and Energy Research (AWER) president S. Piarapakaran, adding that the recent rainfall was not enough to replenish the drying dams in the state.
"The rainfall pattern is not as heavy as it used to be. There might be an increase in this short period of time, but it's just a small increase.
"If we have continous heavy rain over the next two weeks, we would not be going into the next stage of water rationing," he told The Star.
Piarapakaran said rain in Selangor was at a "medium" level, adding that high-intensity rain would result in flash floods.
It was previously reported that water rationing here will end when capacity levels at the Sungai Selangor dam reach 55 per cent.
However, Malaysian Meteorological Department central forecasting office director Muhammad Helmi Abdullah said heavy rainfall was likely in some parts of Malaysia over the next few months.
"It can be heavy at times, but not all places will receive the same kind of weather," he said.
Muhammad said rain would continue to fall from May to September, though at a lesser portion - about 100mm to 150mm each month.
He also expected water in dams in the state not to dry up as quickly as in February and March, adding that higher humidity due to recent rain decreased local evaporation rates.
A state-wide forecast said isolated afternoon thunderstorms were expected throughout this week, with isolated rain continuing at night until Thursday.
When asked if the Government could set up infrastructure to divert stormwater from rained-on areas to those served by water catchment areas, Piarapakaran said this was very expensive to do.
"If we want to go into stormwater management, we need to redesign our entire drain management system. There are all sorts of chemicals in them, and we need to ensure the water is clean," he said.
He said he was not confident that water authorities here were up to par in taking action against river polluters, adding that Malaysia had to decrease its non-revenue water and increase its dam capacity first.
Dam readings by LUAS, the Selangor Water Management Authority, were shown to have increased slightly over the past few days.
As of Monday morning, these were: 78.27 per cent (Batu), 53.96 per cent (Klang Gates), 49.35 per cent (Langat), 71.22 per cent (Semenyih), 37.31 per cent (Sg Selangor), 61.46 per cent (Sg Tinggi) and 87.24 per cent (Tasik Subang).
Some 6.7 million people in Selangor face water rationing.