The Tank Stream is a heritage-listed former fresh water tributary of Sydney Cove and now tunnel and watercourse located in the Sydney central business district, in the City of Sydney local government area of New South Wales, Australia. The Tank Stream was the fresh water supply for the fledgling colony of New South Wales in the late 18th century. Today it is little more than a storm water drain. It originated from a swamp to the west of present-day Hyde Park and at high tide entered Sydney Cove at what is now the intersection of Bridge and Pitt Streets in the Sydney central business district. The catchment was , corresponding roughly the size of the Sydney central business district. It was added to the New South Wales State Heritage Register on 2 April 1999. History The history of Tank Stream incorporates aboriginal use of the land; the history of European settlement; the natural forming stream as a water supply; and its later use for waste disposal and as a part of the stormwater system. The Gadigal (or Cadigal) people were the Aboriginal group most commonly accepted to have lived around the Sydney Cove area prior to European arrival. The catchment area around Tank Stream provided "a range of environments- marine, estuarine, rock platform, creek, open forest, wetland" all located within a short distance and able to provide a range of food and material. Excavations around Tank Stream have uncovered aboriginal flake stone artifacts made from water-worn pebbles. The stream is thought to have given the Aboriginal people fresh water, fish and other resources. Although it was unable to consistently provide water in dry weather, the stream also played a role in dividing the settlement, with the eastern side being held for government and administrative functions and convicts living on the western side. The area was chosen by the commander of the First Fleet, Captain Arthur Phillip, R.N., in 1788 as the location for the New South Wales colony for similar reasons. The colony had originally been planned for Botany Bay, on the recommendation of Sir Joseph Banks who had visited the area with Captain James Cook 17 years earlier, but when no fresh water was found there, Phillip sought a better site, and found it in the previously unvisited Port Jackson. Sydney Cove was chosen for settlement as it "was at the head of the cove, near the run of