Garden Island is one of the geographical features in what is now the Adelaide metropolitan area that was formed as a consequence of sea level rise at the start of the Holocene. Sea level rise had three consequences. Firstly, watercourses existing at the time were forced to create new mouths in new coastline. Secondly, currents arising along the new coastline formed beaches, a coastal dune system and ultimately the spit known as the Lefevre Peninsula all by the process of longshore drift. Finally, watercourses such at the River Torrens and the Sturt River were forced to flow north to what is now the Port River estuary after being prevented from draining into Gulf St Vincent by the emerging coastal dune system with result of forming features such as Torrens Island and Garden Island.
Flora and fauna
Flora
The principal plant species is Avicennia marina which has colonized the coastline of Garden Island within the intertidal zone, particularly the island’s east end.
History
European use
Since 1836, the land tenure has mainly been that of crown land. A third of the island on its western side was dedicated to the South Australian Harbors Board and in 1962, the entire island was dedicated as a reserve under Harbors Board control. The first public road was opened for public use in 1968. The use of the island as a base for recreational boating and as a landfill site began in the 1970s.
Landfill site
Garden Island was the site of a landfill from about 1972 until 2000. This activity occupied of the island’s and “served the domestic waste disposal needs for almost half of Adelaide.” Landfill gas is managed by an extraction system commissioned in 2015. As of 2014, land filling is still permitted by planning statute on the island in sections 463 and 464 of the cadastral unit of the Hundred of Port Adelaide.
Multifunction Polis
Garden Island which is located within the Adelaide metropolitan area was proposed as one of the sites for the Multifunction Polis, which was a planned community with a projected population of 250,000 proposed in 1987 and which was abandoned in 1998. As of 2014, land including Garden Island which was intended to be the site of the multifunction polis was still zoned for that purpose.
Ship graveyard
In years between 1909 and 1945, the southern coast line of Garden Island was used as a ship graveyard for the disposal of about 25 vessels including Dorothy H. Sterling and Santiago. The ship graveyard is promoted by the Government of South Australia as a canoeing trail.
Recreational and tourism uses
Since the 1970s, Garden Island has been used as a venue for recreational boating activities associated with adjoining bodies of water such as the Barker Inlet and Port River.
