SOURCES OF WATER SUPPLY TO SINGAPORE (Estimated maximum and safe capacity)

Mr A. P. Rajah asked the Prime Minister what is the estimated maximum and safe capacity, in millions of gallons per day, of the following sources of water supply to Singapore:-

(i) MacRitchie Reservoir;

(ii) Peirce and Seletar Reservoirs;

(iii) Gunong Pulai and Pontian; and

(iv) Tebrau River.

The Parliamentary Secretary to the Prime Minister (Mr Chan Sun Wing) (for the Prime Minister): Mr Speaker, for impounding reservoirs the maximum and safe daily capacity is the average quantity of water that can be drawn off daily. One must allow for the available storage capacity of the reservoirs, dry weather conditions, and the capacity of our treatment plants to supply good quality water. The maximum safe capacity of a reservoir is therefore its safe yield which takes into account these considerations.

The estimated safe yields of our reservoirs are as follows: MacRitchie 8 million gallons daily Peirce and Seletar 12 million gallons daily Gunong Pulai and Pontian 18 million gallons daily Tebrau River 30 million gallons daily during wet weather or 15 million gallons daily during dry weather

We therefore draw an estimated total of 38 million gallons daily from our reservoirs. But our estimated average daily consumption is 62.5 million gallons. The remaining 30 million gallons during good climatic conditions is drawn daily from the Tebrau River which goes direct to the consumer after treatment.