UNSCHEDULED water disruptions in Penang will be a thing of the past if plans to expand and fully utilise Mengkuang Dam go smoothly.
According to Penang Water Supply Corporation (PBAPP), the dam in central Seberang Prai will be converted from a strategic drought reserve dam into one that is capable of daily drawdown.
The conversion is to mitigate the risks of a statewide unscheduled water supply disruption like in July this year when high turbidity of raw water from Sungai Muda threatened operations at the Sungai Dua water treatment plant (WTP).
PBAPP chief executive officer Datuk Seri Jaseni Maidinsa said at a press conference in Komtar that the project would ensure constant water supply to the state.
“It will allow raw water stored in the expanded Mengkuang Dam to be available for daily drawdowns and emergencies, especially during the dry season when the level of Sungai Muda is low or when the river water quality is compromised and cannot be treated.
“With this conversion, the expanded Mengkuang Dam will function like the Ayer Itam Dam and Teluk Bahang Dam on Penang island,” he said
On July 4, three people were killed and thousands more had to be evacuated in what was said to be the worst flood to hit Baling district in Kedah.
A continuous downpour caused Sungai Kupang to overflow into residential areas but villagers blamed a previous durian plantation project on Gunung Inas.
The resulting muddy waters flowed into Sungai Muda and forced PBAPP to stop drawing raw water from the river for treatment, causing hundreds of thousands of Penangites to be without tap water for days.
Crowds headed to shops and supermarkets in a mad scramble to buy bottled water for drinking and other needs.
On Sept 8, several areas in Penang were again hit by water supply disruptions due to muddy waters caused by another Baling flood.
Jaseni said PBAPP planned to unlock the full potential of the expanded Mengkuang Dam, which is Penang’s largest, to mitigate water supply risks and address growing water demand.
Achieving this requires four major projects.
The first one, said Jaseni, was the ongoing RM120mil Mengkuang Dam Expansion Project (MDEP) Phase 2B by the Federal Government.
Expected to be completed in March 2023, it involves the laying of a 1.6m diameter pipeline for 7km from Mak Sulong Pumping Station to Sungai Dua Canal.
The new pipeline will raise raw water drawdown capacity from 300 million litres per day (MLD) to 600 MLD.
The second project by the state government is the laying of additional raw water pipelines with a 400 MLD delivery to improve drawdown capacity to 1,000 MLD.
It costs about RM100mil and is expected to be completed in 2025.
“The third project is the RM80mil phase 2C of the MDEP which involves construction of the 440 MLD Lahar Yooi Pumping Station,” said Jaseni.
“It is meant to enable rapid refilling of the expanded Mengkuang Dam from a second raw water resource in Sungai Muda. This project will be implemented by the Federal Government.
“The fourth project is the construction of a new water treatment plant (WTP) near the Mengkuang Dam to provide an extra 114MLD.
“The state will allocate a total of RM180mil for the new WTP,” he added.
The Mengkuang Dam WTP will be operational by December 2025. It will free up and deliver additional treated water from Sungai Dua WTP to south Seberang Prai.
Jaseni said PBAPP was also planning to build another new 114 MLD WTP near Sungai Kerian (at the southern boundary of Penang and Perak) to address the water needs of the south Seberang Prai community.
The proposed Sungai Kerian WTP is scheduled for commissioning in December 2026.
The Mengkuang Dam was first opened in 1985. Its original maximum effective capacity was 22.3 billion litres of raw water.
Raw water is pumped from Sungai Kulim via the Mak Sulong pumping station during wet seasons for water supply drawdown during dry seasons.
The dam was closed from 2014 to 2020 to facilitate expansion under Phase 1 and Phase 2A of the Mengkuang Dam Expansion Project (MDEP). These two phases of the MDEP were undertaken and financed by the Federal Government.
On Jan 9, 2021, the Expanded Mengkuang Dam (EMD) was opened after its maximum effective capacity was increased to 86.4 billion litres.
The conversion of the EMD into a dam for daily use is part of PBAPP’s Raw Water Contingency Plan (RWCP) 2030 to ensure water supply security for the state until the year 2030.
Earlier, Jaseni told Buletin Mutiara that PBAPP was currently taking measures to ensure Ayer Itam Dam and Teluk Bahang Dam were operating at optimum levels.
He said this was crucial to sustain a stable water supply for the next dry season, which is expected from February to April next year.
“As of today, the effective capacity is 68.9% at Ayer Itam Dam and 39.2% at Teluk Bahang Dam.
“As for Mengkuang Dam in Bukit Mertajam, it still has the highest effective capacity of all the three dams. It recorded 85.3% as of Oct 7.
“We need to achieve a minimum effective capacity of 90% for Ayer Itam Dam and a minimum effective capacity of 60% for Teluk Bahang Dam by December this year.
“If we don’t, we may not have enough water for the upcoming dry season early next year,” said Jaseni.
He said PBAPP was currently doing dry weather controls to release as little water as possible to sustain the dam water levels, especially in the two dams on the island.
“We will also continue to do cloud seeding operations until December this year.
“Another proactive action we started in September is diverting excess raw water from Sungai Pinang, Balik Pulau and Batu Ferringhi water catchment areas to Teluk Bahang Dam.
“With all these steps, we hope to achieve the minimum required dam capacities by year end.
“We would also like to advise the public to use water sparingly,” he said.