Derwent River, Tasmania
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The Derwent is a river in Tasmania, Australia.
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While obviously named after one of the English River Derwents, the name - which apparently means "valley thick with oaks" - is especially appropriate. When first explored by Europeans, the lower parts of the picturesque valley were clad in thick she-oak forests, remnants of which remain in a few places.
The river is 180 km long with flows ranging from 50 to 300 tonnes per second, its large estuary forms the Port of the City of Hobart - often claimed to be the deepest sheltered harbour in the Southern Hemisphere; some past guests of the port include the USS Enterprise and USS Missouri. The largest vessel to ever travel the Derwent is the 113,000 tonne, 61 metre high, ocean liner 'Diamond Princess', which made its first visit in January 2006. At points in its lower reaches the river is nearly three kilometres wide, and as such is the widest river in Tasmania. This is a great contrast to the upper reaches of the Derwent, near the town of Derwent Bridge, where, in summer, the river often slows to a trickle and can be easily crossed with one step.
Until the construction of several hydroelectric dams between 1934 and 1968, it was prone to frequent flooding. The State of Tasmania is now almost entirely powered by hydroelectricity. Two lakes have been formed by damming the River for hydroelectric purposes: Lake Repulse and Cluny. A substantial part of the dam construction work was performed by Polish and British migrants after World War II.
Several bridges connect the western shore (the more heavily populated side of the river) to the eastern shore of Hobart - in the greater Hobart area, these include the five lane Tasman Bridge, near the CBD, just north of the port; the four lane Bowen Bridge; and the two lane Bridgewater Bridge and Causeway. Until 1964 the Derwent was crossed by the unique Hobart Bridge, a floating concrete structure just upstream from where the Tasman Bridge now stands.