Sponge City concept undermined by unchecked development in Klang Valley

The concept of a 'Sponge City,' designed to mitigate flood risks by allowing rainwater to be absorbed into the ground, is proving ineffective in Malaysia's Klang Valley due to unchecked development. Experts warn that the initiative is becoming futile as urban expansion continues to reduce green spaces and water catchment areas.

Professor Dr. Aweng Eh Rak from Universiti Malaysia Kelantan's Faculty of Earth Sciences explained that while the amount of rainfall remains constant, a city's ability to absorb water is diminishing. "If development continues to reduce green areas, this concept will not achieve its goals," he stated. As non-permeable surfaces like buildings and roads increase, the land's capacity to absorb water decreases. Initially designed for existing permeable areas, the concept falters when these areas are converted for development, leading to increased surface runoff that overwhelms the original design.

This concern is amplified by reports that flood retention ponds in Kuala Lumpur have shrunk to about 30% of their original capacity. Gabungan Selamatkan Kuala Lumpur (SKL) chairman Datuk M. Ali noted that much of this land has been allocated to developers. While Minister in the Prime Minister's Department (Federal Territories) Hannah Yeoh announced the gazetting of additional green spaces, aiming for a more sustainable and resilient Kuala Lumpur, critics argue that proactive measures are lagging.

Aweng emphasized the urgent need for the government to designate flood catchment and water absorption zones as non-developable areas. He also called for clear limits on the extent of permissible development. Without such controls, the natural capacity of these areas to absorb and retain rainwater will continue to decline, significantly increasing the risk of recurrent flooding.