PENANG will carry out a study on the use of underground detention tanks to mitigate flash floods.

State flood mitigation exco Zairil Khir Johari (PH-Tanjung Bungah) told the state legislative assembly that the method is employed in the flood-mitigation project at Chulalongkorn University Centenary Park in Bangkok.

“It is an interesting flood-mitigation project. It also has aesthetic value as a public park.

“I visited Bangkok recently, and was briefed on the flood-mitigation projects there, including the one that uses underground detention tanks,” he said in his winding-up speech this afternoon.

Lee Khai Loon (PH-Machang Bubuk) earlier proposed that Penang look at how Bangkok tackles floods via the CU Centenary Park.

The park is a 4.5ha plot converted into a water-detention area with underground tanks that can store 3,785 cubic metres of rainwater, or 1.5 times the content of an Olympic swimming pool.

“The tanks store as much rainwater as possible. A pump slowly channels the water into a river. The idea is not new, and has been implemented in many countries,” said Zairil.

“But the issue is cost. To build the underground tanks is expensive. Bangkok authorities told me that the construction of the park cost more than RM300 million.”

Nevertheless, he said, Penang should take note of the project and study its viability as a requirement for future developments.

The CU Centenary Park, the only public park in Bangkok designed with water management in mind, was a pilot scheme to provide a natural solution to flooding in the Thai capital, reported the Bangkok Post last year.

On the delay in the Mengkuang Dam expansion project, Zairil said the state government does not accept defective projects.

He said the handover of the expanded dam in Bukit Mertajam to state authorities has been delayed due to a RM60 million pump house not working.

“Mengkuang Dam itself is not a catchment area, so water from Sg Kulim and Sg Muda has to be pumped in to fill the dam. There is also sedimentation in the pump itself.

“It is not our problem whether the design is defective. The state does not accept a defective product.”

The dam expansion, which started in August 2011, was a federal project under the previous Barisan Nasional government. It was scheduled for completion in July 2016.

Zairil said the structural defect at the Mak Sulong pump house’s draw-off tower has yet to be addressed, but the new Pakatan Harapan federal government has agreed to fix the problem.

He said it will take a while before the dam can be operational, as the facility must undergo further tests.

“To test the dam, we must fill it up. So, we have to get the pump fixed first. The contractor will need about two months to fix it.” – August 9, 2018.