We were under threat of another water rationing in Febuary after little rain fell during the first two months of the year (2002). Fortunately the precious rain came in March and April bringing relief to worried water consumers in the Klang Valley.

The fear of encountering another water shortage in the near future was dispelled when water demand and production figures for Selangor were released by the State Authority. (See 'Enough water supply to meet demand until 2007", NST 3rd April, 2002.)

The projections on supply capacities made by the State Authority are quite different from those given in a study by a reputable water consultant on "water Demand Projection" completed in 2001. The supply capacity figures, in million litres per day (mld) from both sources are shown in the Table below:

* Figures from the State Authority
# Figures intrapolated from "water demand projection, 2001"

Examining the two sets of supply figures, the consultants' figures seem more realistic. Take the current year's production, Klang Valley had just narrowly escaped a water rationing and therefore the demand and supply should be of the same order. The higher supply figure given by the State Authority for the year 2002 seems to be based on the maximum capacities of existing water treatment plants, without taking into consideration the available safe yields of raw water sources that set the limit of treatment plant production capacities. Overdrawing from Sg. Langat and Sg. Semenyih dams to satisfy demands are good examples of overestimating supply capacity.

The new Sg. Selangor dam and the Sg. Selangor Phase 3, Stage 1 (SSP3/1) treatment plant are expected to be completed by the middle of next year. Upon their completion, they are not expected to produce any significant amount of treated water. Firstly, the new dam needs to be charged before it can function as a regulating dam and this is expected to happen only during the last quarter of 2003 i.e. the monsoon season. Secondly, the new treatment plant of 400mld capacity would not be allowed to draw water from Sg. Selangor during the drier months because the natural flow in the river is needed to feed existing treatment plants of Sg. Selangor Phase 1 and Phase 2 (SSP1 & 2).

Therefore, the consumers in the Klang Valley would need to brace themselves for an expected water shortage next year.

When SSP3/1 water treatment plant together with the Sg. Selangor dam are up and running in 2004 there shall no water shortage in that year. However, while waiting for Sg. Selangor Phase 3, Stage 2 (SSP3/2) treatment plant to complete, 2005 would be a vulnerable year. This is because at the beginning of that year, production would just balance demand and some water shortage can be expected during the first half of that year. Year 2006 would see no water shortage as all treatment plants constructed under SSP1, 2 & 3 are running at full capacities.

The crunch will come in year 2007 when additional water production will depend entirely on the timely completion of the tunnel in the mammoth Pahang-Selangor raw water transfer scheme. From the report "Why water shortages occur" (Focus, NST 7th April), it appears that this important project is already more than one year behind schedule and there is still no indication when physical work will start. Under this scenario, the consumers in the Klang Valley can expect to face serious water shortages from year 2007 and beyond until the completion of this critical inter-state raw water transfer scheme.

The above analysis shows that, in the near future, the water supply situation in the Klang Valley looks rather bleak. It is hoped that water authorities will take timely course correction measures to avoid water shortages.