Dams, distribution systems are vital
I WISH to refer to the report, "Dams not the answer" (The Star, May 16), and the letter, "Proper water rationing is better way" (The Star, May 22) by Datuk Kam U Tee of Penang.

Kam, in his clarification, contended that though "dams are not the only answer" the authorities should focus more on keeping the existing distribution network in good order.

For me, I am no less an advocate of having an efficient distribution network and of imposing restrictions on water usage than the writer, but I will go on to stress that both dams and distribution systems are equally important to ensure adequate supply of potable water in future.

It cannot be denied that it would be economically not viable to build dams to cater for a drought with a returning period of one in 100 years. Dams were designed previously to cater for a drought of one in 30 years, but these days the design has been upgraded to one in 50 years because of some bad experiences of drought in recent years.

As a whole, Malaysia with a high annual rainfall has ample water resources for water supply. But on a regional basis water resources are becoming limited because of uneven rainfall distribution and other factors related to increased development resulting in higher water usage and higher level of pollution.

Some states like Perlis, Penang, Negri Sembilan, Malacca, and now Selangor are experiencing water deficits, especially during dry weather. As such, additional dam storage and interstate water transfers have now become necessary for these water deficit states.

With increasing water demands, building of dams would be necessary, as the more readily available water resources have already been developed. It would be ideal if an economic balance between the building of new dams and treatment works and efficient distribution management could be achieved.

On one side of the equation, suitable sources must be developed to augment supply, including building of dams if necessary, while on the other side efforts must be taken simultaneously to reduce leakage in the distribution systems to an economically achievable level.

A national study carried out in 1988 showed that an efficient distribution network, like the one in Penang, had losses of only 12% of production due to leakage, compared with 35% in Selangor.

If leakage losses in Selangor can be reduced to 12% of production and assuming an annual demand growth rate of 7.5%, capital expenditure on building new treatment works and dams can only be deferred by about three years.

However, it may take five years or more to achieve this level of saving in leakage from 35% to 12%. Therefore, building of new capital works has to go on to cater for new and additional water demands. As for Penang, it would not be economically viable for the authority to try to reduce leakage to lower than 10% of production as the law of diminishing returns would then apply.

For example, if a distribution network has losses of 30%, the first 10% reduction in leakage may be cheap to achieve, but the last 10% would be prohibitively expensive.

Therefore to cater for new and additional demands, like in Penang, it is simply not enough to focus only on maintaining the distribution network in good order without having to construct new works, including dams if required.

Also in the writer's clarification, he was of the view that "the drought event that we have experienced was said to be the worst in the last 150 years". If he is referring to the recent "drought", I wonder which authority had made the above statement.

As far as I am aware, the only statement on this subject was attributed to the Meteorological Services Department which stated that from rainfall records there was more than average rainfall in the Klang Valley during the first three months of this year (The Star, May 1).

Though it was also stated that the northern states in the peninsula generally received less rain during these three months compared with the past average rainfall, the recent El Nino phenomenon did not hit the region as badly as in 1982.

Therefore, it is not possible that the recent "drought' had a severity of one in 150 years. I hope the figure of 150 was due to a misprint.

nakedeyeview.com.my 2007