Largest tributaries
The River Derwent, also known as timtumili minanya in palawa kani, is a significant river and tidal estuary in Tasmania, Australia. It begins its journey as a freshwater river in the Central Highlands at Lake St Clair, descending over 700 metres across a distance of more than 200 kilometres. At the settlement of New Norfolk in the Derwent Valley its waters become brackish, flowing through Hobart, the capital city of Tasmania, its seawater estuary eventually empties into Storm Bay and the Tasman Sea.
Formed by the confluence of the Narcissus and Cuvier rivers within Lake St Clair, the Derwent flows generally southeast over a distance of 187 kilometres to New Norfolk and the estuary portion extends a further 52 kilometres out to the Tasman Sea. Flows average in range from 50 to 140 cubic metres per second and the mean annual flow is 90 cubic metres per second.
