The First Water Supply
The site of Sydney was chosen by Governor Phillip in 1788, because of all the bays of Port Jackson where ship could anchor Sydney Cove had the best fresh water supply. This was provided by a fine run of fresh water stealing silently through a thick wood, later to become known as The Tank Stream.

Image of the Tank Stream (The Sydney Morning Herald 2 October 1954)
The stream which flowed into the cove, had its rise in marshy ground between Park and Market Streets, fed by springs in the sandstone ridges of Hyde Park. It then took shape as a stream in the angle of Sydney Arcade near King Street and then flowed northwards between George and Pitt Streets until it reached Hunter Street, from which point Hamilton Street covers the course of the stream to Bridge Street where it met high water.
Nearly two years after the landing, the dry summer led Phillip to conserve the dwindling water in the stream, and he directed the stone-mason’s gang to cut tanks in the rock on its banks.
The first of these tanks was completed in May 1792, and it held nearly 8,000 gallons of water: the other two tanks were cut on the opposite banks of the stream. These three tanks comprised the first water supply for Sydney, and consequently the first in Australia.
The exact location of the tanks was at the intersection of Little George Street and Hamilton Street. These tanks, from which the Tank Stream takes its name, provided Sydney with part of its water supply for nearly 40 years; but all over old Sydney excavations reveal wells sunk by private property owners to supplement the public supply.
The old Tank Stream is now a drainage tunnel under the streets and buildings of the city; the old Post Office tower was right on top of it.
Today Sydney draws its water from dams with huge storage capacities.
The Sydney Morning Herald (NSW: 1842-1954), Saturday 2 October 1954, page 3
The Tank Stream is commemorated in a sculpture by Stephen Walker (1981)
The sculpture is located in Circular Quay Sydney NSW