A MORE comprehensive and data-driven approach to flood mitigation planning in Selangor must be adopted to ensure it is more accurate and resilient, says Association of Water and Energy Research Malaysia (Awer) president S. Piarapakaran.
He said data analyses must serve as the primary basis for evaluating the effectiveness of drainage systems and flood mitigation projects, including the identification of both predictable and unpredictable rainfall patterns.
Without accurate comprehensive data, he said drainage system designs could not be adapted to current environmental changes, leading to recurring flood risks despite the implementation of various projects.
“The main weakness identified is a mitigation approach that does not consider the entire water flow system from upstream to downstream, resulting in solutions in one area potentially increasing risks in another.
“Projects focusing only on a single location may appear successful locally, but they effectively shift the problem to downstream areas,” he told Bernama.
Piarapakaran, who is also Centre for Water and Energy Sustainability (CWES) chief executive officer, said the situation was becoming more critical as rapid development increased the number of paved and impermeable surfaces, leading to higher surface run-off that exceeded the capacity of existing drainage systems.
He said that several areas in Selangor identified as flood hotspots, including in Shah Alam, Klang and Petaling Jaya, were older settlements now surrounded by new developments and situated in naturally high-risk zones such as floodplains, wetlands and river estuaries.
Piarapakaran noted that old drainage systems that were not upgraded in tandem with land-use changes also contributed to the inability to cope with increased water flow, particularly when upstream projects channelled water directly into main rivers.
In this regard, he proposed immediate measures including ensuring drainage systems were not clogged, maintaining retention ponds regularly and implementing real-time flood warning systems to reduce the impact on residents.
In the long term, Piarapakaran suggested a redevelopment plan based on river basin data, including stricter controls on development in sensitive areas and better coordination between Sleangor and Kuala Lumpur in water flow management.
He suggested adopting the approach used in the Netherlands, which emphasised slowing water flow and giving the river room, though he noted this must be adapted to local geography and climate.
At the same time, pollution in Sungai Klang directly affected flash flood risks and reduced the potential for clean water sources in surrounding areas, he said.
River restoration efforts through a “pollution reversal” approach could be implemented but this would require significant changes to infrastructure, policy and enforcement, he added.
In April, the Sultan of Selangor Sultan Sharafuddin Idris Shah, had again advised the state government to give full priority to addressing flood problems through meticulous planning and more effective immediate action.
He urged the state to seek the views and expertise of international experts, particularly from the Netherlands, to draft the best approach in overcoming the protracted flood issue.
Following this, state infrastructure and agriculture committee chairman Datuk Izham Hashim said the flood issue in Selangor was expected to be resolved within the next four years through the Selangor Flood Mitigation Project.
Izham added that several river deepening works were underway but comprehensive solutions for flooding would require time to be completed.
