HISTORY OP CIVIL KNGINEERING IN NEW SOUTH WALES. 621 



HYDRAULIC ENGINEERING. 



SYDNEY WATER SUPPLY. 



The early settlers in Sydney depended for their water supply 

 upon tanks excavated along the line of a creek known as the Tank 

 Stream, which formed the dividing line between East and West 

 Sydney, and followed a line parallel to, and close to George-street, 

 widening out where Macquarie-place now stands. As the popu- 

 lation increased — especially along the banks of the stream — the 

 supply became polluted and insufficient for the rising city. The 

 next attempt to obtain a supply of water for the city was due to 

 Mr. Busby, who drove a tunnel from the Lachlan Swamp (under 

 the ridge dividing the drainage of Port Jackson from that of 

 Botany) to Hyde Park, which tunnel, known as the Busby bore, 

 supplied the lower parts of Woolloomooloo and Darling Harbour 

 by gravitation. A further examination of the site of the swamp 

 led to what is known as the Botany scheme, which up to last year 

 supplied Sydney with water. The Botany scheme consisted of a 

 catchment area of barely seven square miles in extent, composed 

 entirely of sand, which retained the water falling upon it, like a 

 sponge. A small portion of the drainage area supplied the ujjper 

 part of the Lachlan Swamp, and was distributed in the manner 

 already referred to ; the remainder of the drainage collected into 

 a stream known as the Lachlan or Botany Stream, which was 

 intercepted before falling into Botany Bay in the tirst instance 

 by means of a puddle dam built across the stream, and after- 

 wards by means of sand dams built along its course with timber 

 bye-washes, the objects being to hold back the water and keep 

 the sand thoroughly saturated. Three pumping engines of the 

 overhead beam construction were erected in 1858 to pump the 

 water from the Botany dams to a brick service reservoir built in 

 Crown-street, along a line of pipes six miles long. From the 

 Crown-street reservoir the water was pumped to similar reservoirs 

 at Paddington and Waverley for the supply of the higher parts of 

 the city. The maximum quantity supplied by pumping from 

 Botany was probably about six and a-half million gallons per day, 

 which was supplemented by about three hundred thousand gallons 

 from the Busby bore. The Botany scheme has supplied Sydney 

 up to the end of last year, and has never been exhausted, althougli 

 the city has frequently been put on a limited allowance. During 

 the year 1885, a pair of horizontal compound pumping engines 

 designed by Mr. Norman Selfe, M. Inst. C.E., were put down to 

 assist the old beam engines when necessaiy, but they have not often 

 been required. 



The necessity of securing an adequate supply of water for 

 Sydney and suburbs, caused the Government on September 24, 



