Thursday, January 16, 2014

Babagon Dam siren: Stop spreading rumours and fears

With the social media tools in our hand there are two things that are certain: Good and bad.

In this particular example, I opine that it has done more harm than good because the good intention to inform the public of potential danger from heavy rain and flood was defeated by the spread of fears and rumours among the population around the dam and along the river.

Noisy are you! One of the sirens was erected on the compound of SK Babagon, Penampang

I was lucky enough to have attended one of the many awareness programs conducted by the water concessionaire and there is nothing like what was circulated through the social media. Rumours has it that whenever the siren goes off, the authority is releasing water from the dam.

Nonsense! I understand how the logic of the siren works.

What Ir. Teo Chee Kong explained in the Daily Express, is exactly how it works. The siren goes off when the water at the dam reaches certain level, and that is the time when the water would start to overflow naturally through the spillway and subsequently channeled to the river.

Explanation by water engineer, Ir. Teo. Daily Express, January 16, 2014

It is not a 'release of water'. It is a normal overflow. Think of it as you filling a bucket from your tap. When the bucket is full and you don't stop the cock, you get a spill.

The siren is meant to warn people along the river not to do any activity, because the dam is full and water is about to overflow from the spillway.

Explanation by Kota Kinabalu water concessionaire. The Borneo Post, January 16, 2014

If you like mathematics and logic, this is for you:
  • The dam level is maintained at 130.5 m (from sea level) before it starts to overflow.
  • Level is measured by several ultrasonic level sensors and transducer. 'Several', so that level measured agree to each others. (Statistics say that the more samples you take the lesser mistake you do). More expensive to maintain but this is for safety; why would you want to compromise.
  • When the the level rises by, say 5cm, the sensor tells the logic controller (PLC) to let in electrical current to the motor and subsequently sounds the siren.
  • This happens in a matter of micro-seconds.

If you are interested, google and find out how transducers, ultrasonic level sensors, and PLC work.

TheGreenMechanics: The next time you want to spread news on social network, please check your facts with the authority concerned. You are not helping by fear mongering.

Be vigilant and have a safe week, when it is raining.

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