At 11 km, it is the longest stormwater tunnel in South East Asia and has helped to mitigate flooding problems in the city centre.

The major components of the SMART Project comprise:

• A stormwater bypass tunnel with a capacity of one million cubic metres
• A 600,000 m3 holding basin and diversion structures
• A storage reservoir
• Gated in-take and outfall structures
• An operation control centre complete with administrative, stormwater management and traffic management facilities
• A 3-kilometre double-deck motorway within the bypass tunnel equipped with a ventilation system and emergency escape provisions.

The project mitigated flooding problems in Kuala Lumpur’s city centre and helped to ease traffic congestion in southern Kuala Lumpur, near the Sungai Besi Airfield.