River Derwent (Tasmania)

River Derwent
Sunrise over the River Derwent
Location of the river mouth in Tasmania
Native name	timtumili minanya (Mouheneenner language)
Location
Country	Australia
State	Tasmania
Cities	Derwent Bridge, New Norfolk, Hobart
Physical characteristics
Source	Lake St Clair
• location	Central Highlands
Source confluence	Narcissus River Cuvier River
• location	Cradle Mountain-Lake St Clair National Park
• coordinates	42°7′12″S 146°12′37″E / 42.12000°S 146.21028°E / -42.12000; 146.21028
• elevation	738 m (2,421 ft)
Mouth	Storm Bay
• location	Hobart
• coordinates	43°3′3″S 147°22′38″E / 43.05083°S 147.37722°E / -43.05083; 147.37722
• elevation	0 m (0 ft)
Length	239 km (149 mi)
Basin size	9,832 km2 (3,796 sq mi)
Discharge
• location	Storm Bay
• average	90 m3/s (3,200 cu ft/s)
• minimum	50 m3/s (1,800 cu ft/s)
• maximum	140 m3/s (4,900 cu ft/s)
Basin features
Tributaries
• left	Nive River, Dee River, River Ouse, Clyde River, Jordan River
• right	Repulse River, Tyenna River, Styx River, Plenty River, Lachlan River
Natural lakes	Saint Clair Lagoon; Lake St Clair
[1][2]

v t e River Derwent summary route map
Legend
Lake St Clair St Clair Lagoon Derwent Bridge / Lyell Highway Lake King William Clark Dam Unnamed Road Wayatinah Road Wayatinah Lagoon Wayatinah Dam Wayatinah Road Lake Catagunya Catagunya Dam Catagunya Road Lake Repulse Repulse Dam Lake Repulse Road Cluny Lagoon Cluny Dam Meadowbank Lake Ellendale Road Meadowbank Lake Meadowbank Dam Gordon River Bridge New Norfolk / New Norfolk Bridge Bridgewater Bridge Bowen Bridge Tasman Bridge Storm Bay Tasman Sea

The River Derwent, also known as timtumili minanya in palawa kani,^[3] 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 (2,300 ft) across a distance of more than 200 kilometres (120 mi). 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.

Historically, the banks of the Derwent were covered by forests and frequented by Aboriginal Tasmanians. With the arrival of European settlers, the area saw agricultural development and the construction of dams for hydro-electricity generation during the 20th century.

Today, the Derwent's catchment area is characterised by agriculture, forestry, and hydropower generation. It serves as a vital source of water for irrigation and urban supply, notably providing a significant portion of Hobart's water needs.^[4] The river is also crucial for recreation, supporting activities such as boating, fishing, and leisure along its banks. Additionally, it facilitates marine transportation and various industrial activities, playing a central role in Tasmania's economy and lifestyle.^[2]