A visit to the Tank Stream
The Tank Stream, another of Sydney’s hidden secrets, has played a role in every part of our urban water cycle, from a drinking water source to a sewer and now, part of our stormwater system.
It was one of the most important factors that determined the location of Australia’s first colony on the shores of Port Jackson. It served as the first and main source of fresh water for the settlement for 40 years and was likely to have been of cultural significance to the Gadigal people, the traditional owners of the Sydney Cove area.
Tours are held twice a year by the Heritage Museum and Sydney Water, starting in Australia Square, extending 60 metres across Hunter Street with the other end under the Cenotaph in Martin Place. The Stream is three metres across at its widest points and two metres tall at highest. About 3,300 people apply each year at odds of 20–1 to be selected. Some have applied as many as nine times. My first visit was called off and rescheduled after heavy rain made the tunnel area dangerous and unsafe because of the water flow. Organisers said a close check is always kept on the weather as the stream can fill quickly to the ceiling during heavy rain.
On the second visit, the small group of visitors met at Australia Square, were taken to an underground room to put on gumboots, a helmet, harness and a light and listen to a short talk on the Tank Stream. The visitor’s room was built in 1988 for the Bicentennial celebrations and it was opened in 2002 for the public.
After completion of the talk, the group descended ten steep steps down into the tunnel. However, before this was possible, air had to be pumped into the tunnel at Martin Place to get rid of the stale and humid air and ensure the quality was breathable.
We splashed through water which was still flowing freely along the stream floor, bending most of the way, head bumping into the ceiling frequently. On this short journey, there was only one area where we could stand upright. Standard maintenance is carried out every week to ensure workings are safe and no worker goes into the tunnel alone; there is always a second or backup man because the stream depth can change quickly.
Phil Bennet from Sydney Water and John Breen from the Sydney Water Heritage Committee and a delegate to the National Trust kept the group informed as we walked.
‘Some smaller tunnels can link with the Tank Stream such as the Bondi sewer and the Stream empties into Sydney Harbour but now carries very little pollution. It’s mostly rain water,’ said Bennett.
‘There are marks believed to have been made by the builders which are visible on many parts of the walls. There are manholes in the ceiling under Hunter Street and you can hear traffic rumbling across.
‘The river is a valley going from Macquarie Street to George Street to the Queen Victoria Building, fills and empties quickly down to Circular Quay. It is a catchment area which is now two thirds of its original size. Some building basements still fill with water during rain.’
This Stream only flowed strongly after rain and dried up quickly leading to major water supply problems for the new colony. They dug tanks into the rock to store water and from 1791 the watercourse became known as the Tank Stream. One tank was over 4.5 metres deep in the centre and able to contain about 36,000 litres. The tanks were located somewhere between Bond and Hunter Streets.
Originally, the idea of a tunnel came from England where London had sewer problems and it took eight years of planning before work started on the tunnel. London quickly followed when it realised the idea was successful.
Sandstone is the main structure of the Tank Stream but some areas are brick. The Stream has been in constant use since 1788 and is still needed to take the runoff stormwater otherwise there would be blockages in the city streets.
The original stream was about 1.5 km long and flowed north from a perched swamp on the western side of today’s Hyde Park between Market and Park Streets. The swamp was fed by spring water seeping through the underlying sandstone.
In 1830, Busby’s Bore was built to meet immediate requirements for water supply. A trestle pipeline was extended to a point at the corner of present-day Park and Elizabeth Streets for water carts and other containers to be filled with water for dis - tri bution. The Bore went in many directions but Busby wouldn’t go down and sent inspectors instead as it was not always sandstone but sometimes quicksand.
The Stream was also fed by two or three small springs for which Spring Street is named. Bridge Street got its name from the original wooden footbridge that crossed over the Tank Stream. The Stream also served as a social divide between the governors and officials on its eastern bank and the convicts and soldiers housed on its western side.
Governor Phillip declared Australia’s first formal environment law on either side of the stream to protect the colony’s water supply by limiting land use on the stream banks. In olden days, washing in or polluting the Tank Stream was a punishable offence by which offenders could lose their home, be flogged or jailed. Now it is a fine which could be as high as $1 million.
On the footpaths of the city there are glass and metal installations to mark the old watercourse of the Stream. The City of Sydney commissioned a sculpture by Lynne Roberts-Goodwin for its Sculpture Walk in 2000. It has an inscription which reads:
Into the head of the cove, on which our establishment is fixed, runs a small stream of fresh water which serves to divide the adjacent country to a little distance in the direction of north and south.
Captain Watkin Tench 1788
Aboriginal people used the Tank Stream as a source of water, food and raw materials for stone tools. In the 1990s, 54 aboriginal artefacts and other items were found in Angel Place showing the stream had been used for at least 5,000 years before the First Fleet arrived. The white people managed to kill it off in 40 years.
Article extracted from Freemason magazine, September 2014, pages 14 and 15.