SMART Tunnel Passes Test

The Star, September 6th, 2007

KUALA LUMPUR: The Smart Tunnel closure on Monday was justified because it was the first time the system was put to the test and proved effective in diverting floodwater, Smart project director John Abraham said.

“An alert from the Drainage and Irrigation Department’s Stormwater Control Centre (SCC) was received when rainwater reached critical levels at the monitoring station at 8pm.

“As a result of the closure, the tunnel managed to divert about 500,000 cubic meters of rainwater into the Taman Desa holding pond, keeping the water at a safe level of 28m at the monitoring stations,” he said during a press briefing at the Smart Motorway Control Centre in Jalan Davis, off Jalan Tun Razak, here yesterday.

The briefing was called in response to public queries on the necessity of the tunnel closure that resulted in hundreds of motorists being caught in a massive traffic jam.

He said although the rainwater diversion involved only the lower deck of the tunnel, the upper deck or the motorway tunnel was also closed for the safety of highway users.

The tunnel was closed at 9pm on Monday and re-opened at 5am the following day.

Abraham said the closure also gave the authorities the chance to put the system to a real test rather than basing its effectiveness on a wet-test. It also allowed the system to be fine-tuned.

“An important implication of the tunnel closure is that the system was able to divert rainwater away from the confluence of Sg Klang and Sg Ampang, to avert flash floods in the city.

“The level of water at the Tun Perak measuring station remained at 28m throughout the downpour, meaning that the tunnel helped to keep the water lower there,” said Abraham, adding that the river would overflow if the water level reached 29.5m.

He also said the system was able to give an accurate prediction of rising water levels at the rivers 30 minutes prior to it happening, while water levels at the 28 catchments areas were updated every five minutes.

The information was then relayed to the SCC before any closure instructions were given.