The Sydney Tank Stream is still an active stormwater drain. Photo: Steven SiewertIt quietly winds its way through Sydney’s heart – underneath offices and crowds, landmarks and traffic – to emerge just handful of times a year as one of the most sought-after tickets in town.
The Tank Stream was opened up to a lucky few on Sunday – more than 226 years after Captain Arthur Phillip identified it as the lifeblood of the future colony, which, in turn, soon contaminated the fresh water source and eventually drove it underground.
About 160 people from among the thousands who typically try for a spot on a Tank Stream tour were granted access to a small section of the tunnel near Hunter Street, where the pick marks left by convicts during a 1791 drought can still be seen hewn into Sydney’s bedrock.
“It’s one of the least accessible tourist spots in Sydney,” said Sydney Water’s archaeologist Yvonne Kaiser-Glass, who led the tours organised for Sydney Open through what now largely functions as a stormwater channel.
“If, when you leave this space and you can get that image in your mind as to how it would have looked 200 years ago, then I’ll feel: job done.”
Swamp land near Hyde Park originally fed the stream, which coursed down a 30-metre drop towards Circular Quay. The swamp was drained in 1850.
But the water trail that shaped Sydney still flows through the tunnel, even though successive development has often similarly cut off – or at least diverted – some of the stream’s other sources.
“That lines up perfectly with Spring Street,” Ms Kaiser-Glass of water seeping into the tunnel through its sandstone wall.
“And Spring Street was called that because it had such active flows around it.”
Alongside convict maker’s marks, there are also more recent signs of the life that endures in the darkness: paw prints of rodents have been preserved in what was once wet cement.
Ms Kaiser-Glass said many of the cockroaches, which also share the tunnel with “albino grasshoppers”, appeared to have been cleaned out by Saturday’s downpour – along with the typical high-water mark of polystyrene.
“The most ironic thing you’ll see after heavy rain is the little soy fish,” she said. “So fish have come back into the Tank Stream, just not in the way we wanted.”
It was hoped that more tours, or in future even a webcam, could help teach Sydneysiders about the water cycle, she said.
The Tank Stream was one of about 50 venues and spaces usually off-limits to the public made accessible for the Sydney Living Museums’ Sydney Open.
Airdrie Martin travelled from the Blue Mountains to take part in the underground tour after a spare ticket became available on Saturday.
“I think it’s just amazing, the history of it,” she said. “And the fact that it’s still flowing and doing its job.
“I hope it serves Sydney forever.”