GEORGE TOWN: A university environment specialist has dismissed the Penang government’s claim that extensive development in the state was not the cause of flash floods that happened three times in a week here.
On the contrary, said Professor Chan Ngai Weng from Universiti Sains Malaysia’s (USM) School of Humanities, it was rapid development and unscrupulous hillslope cutting that contributed to environmental degradation.
Chan, who specialises in environment hazard management, told the New Sunday Times that development in Penang was moving at a swift rate and flood mitigation measures were not prioritised.
“It is unwise to dismiss rapid development and hillslope cutting as the cause of flash floods.
“In fact, changing land use from green areas to urban built-up areas reduces permeable surfaces,” he said, taking the DAP-led state government and even the previous administration in Penang to task for “not doing enough”.
“Cutting hillslopes weakens soil structure and leads to erosion, forcing sediments to flow into rivers.
“These are certainly part of the reasons behind the slew of floods statewide.”
River encroachment also posed another problem, he said.
“Development happens very close to rivers, leaving river water no room to manoeuvre,” he said.
Chan said low-lying areas close to rivers were also undergoing rapid development, causing high rates of surface run-off that was not being absorbed into the ground.
Urban drainage was also poorly planned, he said, with much irrigation still depending on the open monsoon drain system, although the Irrigation and Drainage Department had adopted the environmentally-friendly urban drainage model called the urban storm water management (MSMA).
Chan added that contractors did not follow the MSMA drainage system because it was costly.
He also blamed litterbugs and poor enforcement by the authorities, which had caused clogged drains and rivers.
Citing an example, Chan said the USM engineering campus was built on a MSMA drainage system and rainwater was allowed to seep into the ground and flow into the river.
“Of course, climate change has also contributed to an increase in rainfall, but we cannot solely blame nature. When it rains, it only floods in urban and suburban areas, and not forested areas.”