Integrated flood plan needed

Still flooded: Water was still ankle-deep at Taman Langat Murni, Banting, Selangor, yesterday afternoon. — SAMUEL ONG/The Star

THE recent major floods in the Klang Valley have raised questions about disaster preparedness and flood management. Malaysia needs a comprehensive integrated flood management (IFM) plan to address the challenges of mitigating and preventing floods in the long-term.

IFM is necessary to integrate land and water management with river basin management, and to integrate structural flood control measures (eg, flood walls and bunds) and non-structural measures (eg, land use zoning for flood detention storage). IFM would inform a national policy to manage, mitigate and prevent floods within a sustainable and economical framework. There is also a need to understand that it is not feasible to stop all land socioeconomic development in flood plains; at the same time, designing an absolutely flood-free system is also not economical feasible.

An IFM must include both structural and non-structural measures. Structural flood control measures use engineering to alleviate flooding, such as by improving rivers and designing drainage systems to cater for surface runoff; constructing dams, flood attenuation ponds, and flood bypasses; diverting rivers; constructing levees and embankments; and using pumping systems.

The non-structural approach, which must complement the engineering approach, requires commitment from the government and policymakers to implement development planning; land use zoning and planning; flood plain management; installing flood forecasting and warning systems; flood mapping; and creating education and awareness programmes.

In terms of guidelines and design standards, the Department of Drainage and Irrigation has implemented the Urban Stormwater Management Manual (Masma) since 2001, under which drainage system design has paradigm shifts to control at-source measures. The Masma manual emphasises a control at source strategy, ie, the rainfall peak runoff in any developed area should be contained within that development compound and once the flood recedes the extra runoff accumulated should be released in a downstream section without affecting the livelihoods of the downstream community.

A comprehensive national flood masterplan strategy with IFM is required to balance socioeconomic development and flood and river basin management strategies. The implementation of an IFM requires legislative and policy commitment as well as appropriate funding to develop sustainable flood alleviation strategies.

WONG CHEE FUI

Engineer and technologist

Specialist at Universiti Tunku Abdul Rahman