Reassessment of the Reliable Yield for Reservoir Systems in Selangor and Wilayah Persekutuan Kuala Lumpur

By Dr Heng Hock Hwee


The purpose of this paper is to review and update the current water resources availability in the State of Selangor and Wilayah Persekutuan Kuala Lumpur in terms of their reliable reservoir yields. There are five (5) existing reservoirs in the State of Selangor that were built from the late 1950ís to the mid 1990ís, i.e. Batu, Klang Gates, Langat, Semenyih, and Tinggi and one under construction; Sungai Selangor.

The reliable yield is estimated based on acceptable methodologies such as Drought Sequence Approach (DSA) and long-term historical simulation technique.  DSA has been widely used in Malaysia since it was first introduced in the 1960ís. This technique is particularly useful and especially suitable when the hydrometric data and information is lacking during the earlier years of Malaysia water resources planning.  However, in light of availability of the long-term hydrological information of 50 or more years, a review and reassessment using other prevailing and acceptable techniques should be carried out, such as long-term historical simulation techniques for comparison and validation.

This paper also includes a post-audit study of the reservoirs and intakes with recent hydrological information during the 1997-1998 drought events in the state of Selangor and Wilayah Persekutuan Kuala Lumpur.