KL SMART Tunnel is about 9.7 km long and has internal diameter of 11.83 m. The SMART integrates both storm water management and a motorway in the same tunnel.
The Storm water Management Component comprises of the diversion structure, a holding basin, a bypass tunnel, a storage reservoir and the twin box culvert and an outlet structure. The total storage capacity for SMART system is 3 million m3. The existing ponds at Kg. Berembang and Taman Desa utilized as holding basin and storage reservoir.
The motorway consist of a 3 km double deck structure within bypass tunnel with ingress and egress connection links at both ends of the structure. The ingress and egress connection to the motorway Tunnel Linking KL - Seremban Highway to Jalan Sultan Ismail and Jalan Tun Razak.
The motorway consist of four ventilation and emergency escape shafts at about 1 km intervals and cross passages at 250 m intervals along the motorway tunnel.
A flood detection system and control and surveillance team will be incorporate in the overall SMART system to effectively integrate and manage both storm water and traffic.
The operation of the SMART system works on three principal mode operation based on the relationship between flood discharge at the Sg. Klang / Sg. Ampang confluence and the operations status of the motorway. The river water stages and river discharge will be monitored via hydrological stations along the rivers.
The flood discharge will only be diverted into the bypass tunnel when it exceeds 70 cumecs. For flood discharge between 70 to 150 cumecs, the motorway will still be open to traffic. The motorway will only be closed when the flood discharge exceeds 150 cumecs for the full storm water operation of the SMART, which is expected once or twice a year.
The reinstatement from storm water to motorway operation will be initiated when the flood discharge recedes to 70 cumecs. The reinstatement process will take about 4 days and this involves cleaning up and reinstalling all portable equipment to full operation mode.
Take a look in this video from Discovery Channel
