Appalled by water authority's ignorance on Sg. Selangor Dam

I wish to refer to the letter, "Sg Selangor Dam behaving normally" (The Star, Dec 2) by En. Nik Mohd Nasim Nik Ismail, the Deputy Director (Technical) of Selangor Water Monitoring Department.

His letter, in response to my letter "Where has the water gone" (The Star, Oct 12) seems to confuse matters rather than clarify them.

It is true that there are five treatment plants abstracting water from Sg Selangor as stated by Nik Mohd Kasim. But the gist of my letter is on Sg Selangor Dam, which is merely an add-on dam to provide raw water for two new water treatment plants i.e. SSP 3 and Rasa.
  The other system consists of Sg Tinggi Dan, which provides raw water for the SSP 1 & 2 treatments plants. It was in operation many years before Sg Selangor Dam came online.
  The total water abstracted by all the treatment plants from Sg Selangor may amount to 600 mcm between Jan 1 and Sept 15. But my figure of 92 mcm is the amount needed to be released by the Sg Selangor Dam for abstraction by SSP 3 and Rasa treatment plants which were operating at less than half of their designed capacities.

If, according to Nik Mohd Nasim, 205 mcm of water was released from Sg Selangor Dam from Jan 1 and Sept 15 (50% in excess), it can only be concluded that there was a wasteful release of water from the dam.

The rainfall station at Kuala Kubu Baru (KKB) is nearest to the dam where rainfall records can be made available to the public by Kajicuaca Malaysia. Comparing the two sets of rainfall records, the catchment area of the dam seemed to receive about 10% less rainfall compared to rainfall recorded at KKB during the periods from Jan 1 to Sept 15 for years 2004 & 2005.
  But with nearly 1,300mm of rainfall in eight-and-a-half months, one cannot simply conclude that it was the dry spell that caused the dam to deplete to a level of 40%. Does Nik Mohd Nasim realize that Malaysian water supplies, with or without dams, were designed for a 1 in 30-year drought (now 1 in 50)? Has he worked out the return-period of the drought for Sg Selangor Dam during this period in question?
  It is a gross error to state that Sg Selangor Dam was built to serve "the three largest treatment plants in the country - SSP 1, 2 and 3"!

In my letter of 12 Oct I have not questioned the design integrity and safety of the dam. However, to operate the whole of Sg Selangor river basin efficiently, an integrated management and operational system needs to be in place using the latest electronic measurement tools and technology with advanced telemetry system of monitoring. Is such a system now in operation? If not, it is another classic case of "a first world facility operated with a third world mentality".

I am disappointed at the glaring misinterpretation of my letter, which was published more than one and a half months ago. Furthermore, I am even more disappointed at all the misleading information on Sg Selangor Dam presented by Nik Mohd Nasim. By doing it, he has not only done a great disservice to himself but also to his department.


1. An edited version of the above was published in The Star on 06/12/05.
2. The totally uncalled-for letter "The Sg Selangor Dam behaving normally" is attached.

Friday December 2, 2005
Sg Selangor Dam behaving normally

WE WOULD like to thank A.S. Toh for his letter, "Where has the water gone", (The Star, Oct 12).

However, the letter contained inaccuracies that resulted in the writer making the wrong conclusions:

THERE are five treatment plants, not two, abstracting water from Sungai Selangor: Rasa (with a capacity of 250 million litres per day or mld), Rantau Panjang (27mld), Bukit Badong (800mld), SSP1 (950mld) and SSP2 (950mld).
  In total, the water abstracted between Jan 1 and Sept 15 would have been about 600 million cubic metres (mcm) and not 92mcm as quoted by Toh.
  An average of 2,300mld of treatment water is produced by these plants.

DURING that period the Sungai Selangor Dam released 205mcm. The balance abstracted by the treatment plants would have come from the base flow and Sungai Tinggi Dam.

RAINFALL computations using the station at Kuala Kubu Baru would have not been representative as it is located downstream of the Sungai Selangor Dam, whereas the catchment area is upstream of the dam.
  The actual rainfall measured in the catchment area over the past four years is given below:
  January 2002-September 2002 - 1,748.22mm in total rainfall,
  January 2003-September 2003 - 2,087.11mm,
  January 2004-September 2004 - 1,295.71mm, and
  January 2005-September 2005 - 1,297.03mm.

As can be seen, the rainfall for the first nine months of this year is not significantly different from the corresponding period last year.

The Sungai Selangor Dam was completed in 2003 and reached full supply level (235mcm) in April last year.

It has been depleted to a level of 40% because of the dry spell and because it services the three largest treatment plants in the country - SSP1, 2, and 3.

The dam is designed according to international standards and vetted by foreign experts. Toh can rest assured that instruments monitoring the integrity and safety of the dam show that the dam is behaving normally.

Deputy Director (Technical),
Selangor Water Monitoring Department 2007