It was named by Colonel William Light in 1836 in honour of Sir Robert Torrens, the chairman of the South Australian Colonisation Commission. It rises some 55km east-northeast of Adelaide in the Mount Pleasant district of the eastern Mt Lofty Ranges and only 20km from the eastern scarp of the upland. Draining an area of about 500km2 the Torrens flows westwards across the ranges, cutting a deep gorge before emerging on to the Adelaide Plains at Athelstone. For the next 7–8km the river runs through a series of basins and shallow defiles, with steep south-facing bluffs. Then, from Hillcrest to Adelaide, the river runs in a deep channel cut into old valley floors or terraces, so that Walkerville Terrace, for example, runs along a physical feature of the same name, while Mann Terrace is located on the slope linking two such old valley floors.
More information: http://adelaidia.sa.gov.au/places/river-torrens