Can KL be flood-free?

Heavy rain in several areas in the Klang Valley has caused flooding, including on the New Klang Valley Expressway on the road from the Shah Alam toll heading towards Bukit Jelutong. Many road users are stranded, and authorities have deployed to the scene to manage the traffic situation at around 530 pm on Nov 2. — EZARD FAROUQ/The Star

I concur with all the proposals in the article “Flood mitigation systems in KL need an overhaul”, published in The Star on November 9, 2026, written by Tan Sri Lee Lam Thye, Chairman of the Alliance for A Safe Community. DBKL’s most urgent task is to quickly review the Kuala Lumpur Urban Drainage Master Plan in the context of the Klang River Basin.

Despite several mitigation efforts, cities worldwide still experience flooding. Almost all cities and towns in Malaysia face the same problem, and flooding seems endless. While the issue may have been resolved in some flood-prone areas, new areas downstream continue to appear on the hot spot list. Today, flood mitigation and urban drainage works cost enormous sums, and the available budget is always a constraint. The cost depends on the adopted rainstorm design, or the Average Recurrence Interval (ARI); the higher the ARI, the higher the cost.

Malaysia, like most developing countries, limits stormwater design based on affordability. According to the Urban Stormwater Management Manual for Malaysia, the standard adopted ARI for major flood mitigation projects and urban drainage design is 100 years, while minor drainage systems are designed for 2 to 10 years. As such, it is extremely difficult, if not impossible, to be flood-free. Even in developed countries such as the Netherlands, where the designed rainstorm is based on the 1,000-year ARI, some very low-lying areas are still susceptible to flooding; hence, the concept of living with floods has been accepted there.

That brings me to the point that, under our current national standard, we can only reduce the impact of flooding. In any flood mitigation or urban drainage project, the approach must follow the principles of Integrated Flood Management (IFM), shifting the focus from eliminating floods completely to managing flood risks across the entire watershed. Rather than relying solely on isolated engineering projects, IRBM treats the river basin as a single ecological and hydrological unit.

Flood risk is closely tied to land use. As such, flood interventions must consider the natural link between upstream and downstream areas. Actions in the upper catchment, such as deforestation, increase runoff and flood severity downstream, so planning must span administrative borders to cover the full hydrological catchment.

Effective flood protection combines structural and non-structural measures and balances physical infrastructure with land- and water-use policies and flood-preparedness tools. Structural measures include dams, levees, detention ponds, and diversion tunnels, while non-structural measures include floodplain zoning, early warning systems, hazard mapping, and ecosystem restoration.

The Risk Management Approach is also needed because absolute protection is impossible. Therefore, it is necessary to evaluate and manage residual risk. Strategies must be tailored to different flood probabilities and combine prevention, preparedness, emergency response, and post-flood recovery.

The Klang River Basin crosses multiple jurisdictions and affects diverse communities. Strong coordination among federal, state, and local agencies, alongside active participation from local residents, industries, NGOs, and environmental groups, is needed to prevent conflicting policies and ensure equitable protection.

While urgently addressing the hot spots within Kuala Lumpur, it may be time to adopt a mindset of “living with floods”. IFM recognises that floods are a natural part of the hydrological cycle and cannot be prevented entirely.

Instead of fighting nature at all costs, the government should aim to prevent loss of life and minimise economic damage while preserving the ecological benefits of natural floodplains and wetlands. We must urgently explore this as we review the Kuala Lumpur Urban Drainage Master Plan.

DATUK LIM CHOW HOCK

Malaysian Capacity Development Network for Sustainable Water Management

(MyCDNet)

National Network Manager