I refer to the malaysiakini report RM100 mil to combat flash floods in KL.

Indeed, this is another RM100million added to the previous RM1.9 billion spent on the Smart tunnel that might go down the drain (or tunnel). Questions should be asked regarding on what input data basis was the Smart tunnel designed as well as its capability to disperse a huge volume of flood water. The government expert and the tunnel's consultant should have agreed on the results of the computer model of the Smart tunnel's capability to disperse water in the event of heavy water inflow.

There have been many instances of the phrase 'storm rainfall' and 'flash floods' being mentioned in the press since the recent flash floods. I wish to offer a clarification here. For the Klang Valley, the flood drainage system should be designed for the most extreme possible rainfall (here, it is always called the storm conditions or storm type of rainfall).

The drainage should not be designed just for average rainfall conditions. In the Klang Valley, the only possible source of storm-type of rainfall comes from severe thunderstorm clouds, not from typhoons. A thunderstorm cloud can cause flash floods in KL because the local drainage system cannot handle the intense rainfall (expressed in cm per 15 minute or at one-hour intervals).

On June 10, there was a line of very severe thunderstorm clouds that passed over KL and this line was detected as it moved towards KL (I downloaded a series of hourly cloud pictures from the Naval Reseach Lab in Monterrey, California that showed the trackable movement).

These thunderstorm clouds were 45,000 to 50,000 feet high, and from past experience, these 'storms' are very severe weather clouds with huge amounts of rainfall to dump. When this line of thunderstorm clouds came over KL, the rainfall that came down was such that our drainage could not handle the flow amount.

There was another flood in the previous week, but that line of thunderstorm clouds was comparatively less severe.

These are not freak thunderstorms. The same line of cloud pictures show that such type of severe thunderstorms occur neary every week over Malaysia. It is just a matter of where the rainfall will occur. The question again is whether the design consultant for the Smart tunnel has prudently reviewed all types of input data for the tunnel's design and its water discharge capability .