The National Water Research Institute has called for more states to go for aquifer storage and recovery or the ASR system and stop their reliance on rivers.
GEORGE TOWN: Water companies have to switch to groundwater and storm water sources to ensure pipes keep flowing at a time of water shortage caused by climate change and depleting river water levels, an expert has advised.
Md Nasir Md Noh said only 1.2% of the country’s groundwaters has been tapped into, with Kelantan drawing the most, while storm water storage, which taps surface run-off or floodwaters, was not too many.
Nasir, who is National Water Research Institute (Nahrim) director-general, said the country’s reliance on drawing water from rivers – such as Sungai Muda, Sungai Selangor and Sungai Johor – has left them under “severe stress”, causing them to dry up.
“It is not that we do not have water, we have plenty. They are through storm water, not rainfall, and also largely untapped groundwater.
Water exploitation index of major rivers in the state. Sungai Muda is at the highest stress due to the water demands from Kedah and Penang.
Nasir said the ASR system, largely used in the Americas and Europe, basically stores water underground during rainy periods and later reuses it during dry seasons.
He said this was the same approach under the TAPS system being proposed on the Kedah side of Sungai Muda, where storage tanks are built on its banks to store storm water which will be re-released into the river during dry periods.
Nasir said another method was the construction of underground dams, where groundwater could be extracted and kept.
A preliminary study by Nahrim showed at least a quarter of Kuala Lumpur’s water demands can be met through groundwater extraction in six zones in the federal territory.
He said Nahrim has identified two “perfect” locations for groundwater dams so far – one being the Sg Ulu Melaka basin in Langkawi, and the other, the Sg Melaka basin in Melaka.
Nasir said an early study showed that the Langkawi dam could provide water supply for at least 22 months, with 263 million litres a day (MLD) storage potential. The Melaka groundwater system could yield better results at 500 MLD, which could likely cut the need to buy water from Johor as presently practised.
He said the country only used 1.3% of groundwater as of 2019, with Kelantan, Pahang and Perlis being the only states to do so. A total of 202 MLD was drawn out that year from 21 intakes in the country, with the majority by Kelantan.
Nasir said presently, 81% of the country’s water supply came from 198 rivers, extracting a whopping 12,498 MLD as of 2019.
Flood storage ponds or storm water ponds could also yield a lot of water supply for KL in the long run, Nahrim study finds.
He said a preliminary study showed that Kuala Lumpur could benefit from storm water storage ponds and groundwater aquifers, with 491 MLD ready to be supplied from six zones in the federal territory.
He said this would easily meet half of the current demand of 1,008 MLD.
