SHORT OF WATER

Otago Daily Times, Issue 24828, 30 January 1942, Page 6

SHORT OF WATER

THE SYDNEY SUPPLY (Air Mail) SYDNEY, Jan. 14. Years of drought on Uie catchment area have brought Sydney's water supply to a dangerously low level. Restrictions imposing hardships on 1,525,450 people who rely on the system have been applied, but can only put off for a few months the evil day when the city will have no water unless heavy rains fall. From 10 to 100 inches of continuous rain would be needed to lill the four main water supply dams. Ihe biggest, Avon dam, holds 47,000,000,000 gallons. Present storage is less than 2,500,000,000 gallons. That amounts to about two months' supply for Sydney at the new restricted consumption rate of 50,000,000 gallons a day. The wall at Avon dam is 225 ft high. The greatest depth of water is 96ft. This is 40ft below the lowest main discharge valve, and the water has to be released through an emergency valve at the base of the wall. The same amount, of water was in the dam in May, 1924, while it was still being built. No water was released, and it took four years and a-half —until October, 1928—for the reservoir to fill. For the Avon dam to fill quickly it would need 100 inches of steady rain. Nepean dam. three miles across the ranges from Avon, was full (18,000,000,000 gallons) three years ago. It now holds less than 500,000,000 gallons, and no water has been discharged from it since December 15. The Nepean dam is fed "by quickrunning streams, and should fill after 10 inches of continuous rain on its catchment area. Experts estimated it would fill twice a year under normal conditions, but it has been full only twice in the last five years. Sydney's rainfall for 1941 was 26.74 inches, compared with the yearly average of 46.56 inches. Restrictions on consumers prohibit the use of water except between 6 a.m.10 a.m. and 4 p.m.-8 p.m. Domestic, hot-water systems and bath-heaters are not permitted. Plungs baths are limited to four inches. Watering of sports areas and private gardens is banned, and watering hours of commercial gardens and poultry farms reduced to one hour a day.

The Water Board is having difficulty in policing the regulations, and the daily consumption rate of 50,000,000 gallons set by the board has been repeatedly exceeded by up to 20.000,000 gallons. Fines amounting to £3OOO have been imposed on 1200 persons for infringement of the restrictions, and heavier penalties are to be pressed for. Schemes are being considered by the New South Wales Government and the Water Board to relieve the position, but there is need for haste. Total storage has dropped to nearly 300,000,000 gallons below the official "dangers" figure of 20,000,000,000 gallons.

The most favoured scheme is the construction of a pipeline from the Wyangla dam, on a different watershed 80 miles from Sydney, to the Wollondilly River, which could be diverted to the Warragamba River. The Wvangla scheme would ensure a steady flow of 90,000,000 gallons a day. It would probably take 12 months to build the pipeline.