Background

SMART is an acronym for Stormwater Management and Road Tunnel. It is an innovative project of the Government of Malaysia to solve flooding problem in the City Centre of Kuala Lumpur at Klang River and around the vicinity of Masjid Jamek, Jalan Tun Perak caused by Klang River overflowing its banks. The project also serve to ease the traffic congestion problem between Kuala Lumpur City Centre and Southern gateway at Sungai Besi. The Unique feature of SMART is the 3 km double-deck motorway within the 9.7 km tunnel which starts near the Kampung Pandan roundabout in the city centre and ends at Kuala Lumpur-Seremban Highway next to TUDM Airfield at Sungai Besi.

A sophisticated and modern flood Detection System (FDS) provides real time flood forecasting information. This enables the efficient and safe management at the operation of the tunnel. For the safety of motorists, the motorway traffic is unidirectional and safety features such as ventilation shafts, cross passages, vms, fire extinguisher and air ventilators have been incorporated in the design in compliance with international and Malaysian Standards. This project has been a great challenge for the local engineers involved in the management and construction of the SMART Project as it runs below congested roads, near sensitive structures and through varied geological ground conditions.

Objectives of SMART

Primary objective of SMART: To alleviate flooding problem at the Kuala Lumpur city centre due to stormwater from the Klang-Ampang catchment.

Added benefit of SMART: To ease traffic congestion at the southern main gateway (TUDM at Sungai Besi) to the city centre.

SMART Operation

The tunnel begins at Kg. Berembang where the Diversion Weir at the confluence of Sg. Klang/ Sg. Ampang and Offtake Structure divert flood water to the Holding Pond. The water then flows through the Intake Bell Mouth structure into the Tunnel and discharge at the Attenuation Pond at Taman Desa flood water is stored in this pond before releasing to Sg. Kerayong through the Twin Box Culvert.

Operational Modes of The Smart Tunnel.

Mode 1

• When weather is fair with little or no rain falling and traffic is allowed in the tunnel.

Mode 2:

• activated when moderate rain falls and the flow rate recorded at the confluence of upper Sungai Klang/Sungai Ampang ('L4' flow station) is 70-150 m3/s.
• excess flood water will be diverted to SMART holding pond and only the lower drain of tunnel will be used to convey flood flow to the Desa attenuation pond. 50 m3/s will be discharged to City Centre.
• road traffic tunnel will remain opened to road users.

Mode 3:

• activated when major storm event occurs and flood model forecasts a flow rate of 150 m3/s or more at L4. Only 10 m3/s will be discharged to city centre.
• traffic will be evacuated from the road tunnel.
• if heavy rain storm stops early or due to some specific circumstances, then the traffic tunnel will not be flooded.

• road tunnel will be re-opened to traffic within 2-8 hours after closure.

Mode 4

• activated if heavy rain storm prolongs, usually will be confirmed 1-2 hour after Mode 3 is declared.
• road tunnel will be used for passage of flood flow after traffic evacuation completed.
• road tunnel will be re-opened to traffic within 4 days of closure.