Environment and Water Ministry secretary-general Datuk Seri Dr. Zaini Ujang has revealed that the SMART Tunnel has set a new record when the stormwater drainage tunnel was activated for 22 hours to divert rising waters of Klang River.
Completed in 2007, SMART is a 9.7km underground tunnel that works as a stormwater tunnel and a motorway tunnel that links Jalan Sungai Besi to the centre of Kuala Lumpur.
A total of 5 million cubic metres of water was diverted from Sungai Klang and Sungai Ampang to the Taman Desa Reservoir since it was activated at 1.32pm on Saturday until noon on Sunday. According to SMART Tunnel’s statement, this exceeded SMART’s capacity of 3 million cubic metres of water. SMART Tunnel was fully closed to traffic on Saturday, 18th December at 6.47pm.
Further, Dr Zaini Ujang shared since 2017, there were a total of eight diversions and the water diversion operations took about 3 hours. For this diversion, it was carried out for about 22 hours due to the very high rain intensity in Kuala Lumpur, Putrajaya and Selangor. The recent heavy downpour was described as a one-in-100-year weather event as the heavy downpours that lasted for over 24 hours were equal to the average rainfall for a month.
Besides, Dr Zaini added that if the 5 million cubic metres of water had not been drained, the flood situation would have been more severe in the Klang Valley especially in the heart of Kuala Lumpur including Masjid Jamek. Besides SMART, the Department of Irrigation and Drainage (DID) has also activated pump houses at maximum capacity.
He added that the process of pumping water out downstream of the river has not been able to be carried out as the river water level is still high at the downstream area of the SMART system.
SMART tunnel has a total of 4 modes of operations. During normal, moderate, or major storms, the tunnel can be used to carry traffic on a double-decker layout.
However, during a prolonged major storm and after 1-2 hours of Mode 3 being activated, the road tunnel will be closed and it can be fully utilised for flood water diversion after evacuation is completed.
SMART Tunnel Mode 4 was activated last year in September and it diverted 3 million cubic metres of water from the Klang River. It was reported that if the SMART tunnel wasn’t activated, an area of 1km radius around Masjid Jamek would have been flooded.