PETALING JAYA: Adequate buffer zones and better catchment protection are needed to protect the viability of water catchment areas, especially surrounding dams.
International Islamic University Malaysia’s Faculty of Engineering Assoc Prof Dr Zaki Zainudin said many catchment areas were converted to plantations, leaving the top soil exposed.
“When it rains, the solids are transported downstream, resulting in teh tarik rivers,” he said.
Malaysian Nature Society (MNS) president Prof Dr Maketab Mohamed said water quality in rivers deteriorate during dry seasons as there is less water to dilute pollutants.
“The water quality can reach Class IV (irrigation water standard). Some intakes such as Bukit Tampoi (in Sungai Langat) had to be closed so many times due to high levels of ammoniacal nitrogen during the recent water crisis,” he said.
Selangor Youth and Sports, Infrastructure and Public Facilities Committee chairman Dr Ahmad Yunus Hairi said state water authorities have taken measures such as gazetting alternative water sources like former mining pools and lakes, as well as a 50m strip of land on both sides of the river in 2010 as “zones of protection” under Section 48 of the Selangor Water Management Authority Enactment 1999.
These protected zones cover 47,479.09ha of land surrounding 2,365.09ha of water body. For zones surrounding the state’s seven dams, there were an additional 50m of buffer to prevent activities that could harm or disturb the catchments.
In addition to this, there was a policy in place to ensure that developments surrounding river and ponds take into account their impact to the environment, he said.
“Existing ponds cannot be filled for development purposes but are maintained as storage for surface runoff,” he said, adding that new water resource protection regulations have also been passed.
Admitting that rapid development in river basins had reduced the amount of water infiltration or seepage into the ground (and onwards to rivers), he nonetheless said that the recent volume drop in the Batu, Klang Gates, Langat, Semenyih, Sungai Selangor, Sungai Tinggi and Tasik Subang dams was due to the hot and dry weather.