Wivenhoe Dam
Wivenhoe Dam is a dam built across the Brisbane River that creates the artificial Lake Wivenhoe. The dam is located about 80 kilometres by road from the centre of Brisbane, Queensland, Australia.
The dam holds a volume of water two and a half times the water in Sydney Harbour. The primary purpose of the dam is to provide a water storage for south-eastern Queensland as well as extra storage for mitigation of periodic flooding of the Brisbane River. The lake also forms part of the water storages for the Wivenhoe Power Station. The dam was designed as a multifunctional facility and built in the late 1970s - early 1980s by a consortium of construction companies including Thiess.
- Its primary function is to provide a safe water supply to the people of Brisbane and adjacent regions.
- It is also the lower storage in a pumped-storage, hydro-electric generating facility, the Wivenhoe Power Station.
- Additionally to that, during a flood the dam is designed to hold back 1.45 million megalitres of additional water for flood mitigation.
Lake Wivenhoe is also a camping and outdoor recreation destination. The managed camping facilities at Captain Logan Camp include hot showers, barbecues and toilets, and are adjacent to playgrounds, kiosk, boat hire and boat ramps at Logan Inlet.
Key facts
Wivenhoe Dam consists of an earth and rock embankment 2.3 kilometres long and 50 metres high. It has a concrete spillway section on which five steel crest gates are installed. The gates, at 12 metres wide and 16.6 metres high, are amongst the largest of their type in the world.
The dam has a total storage capacity of 2.61 km³, of which 1.16 km³ is used for urban water storage. 200 properties were acquired to provide the 337.50 square kilometres of land required for the dam. The catchment area is 5,554 square kilometres.
The dam holds twice as much water as Sydney Harbour and is about seven times bigger than Hinze Dam at the Gold Coast. Wivenhoe Dam does contribute to the Gold Coast's water supply.
As of 2007, the reservoir has diminished in the midst of Queensland's severe drought, and the original path of the Brisbane River has become increasingly visible. Pockets of isolated water have begun to form and an island has revealed itself towards the lake's centre.
Statistics
- Catchment area: 5 554 km²
- Average annual rainfall: 940 mm
- Capacity – water supply: 1 165 000 ML
- Capacity – flood storage: 1 450 000 ML
- Submerged area at full supply level: 109.4 km²
- Stream Bed Level at Structure (AHD): 23 m
- Full Supply Level (AHD): 67 m
- Spillway Level (AHD): 57 m
- Embankment or Crest Level (AHD): 79 m
- Type of Structure: Embankment (4 000 000 m³) and Concrete (140 000 m³)
- Year of Completion: 1985
- Length of Wall: 2 300 m
- Shoreline: 462 km
- Spillway Gates: 5 x 12.0 m x 16.6 m
- Regulator Valves: 2 x 1.5 m diameter
- Average Evaporation (mm/year): 1 872
- Hydro Electric Station/dam structure: 4.5 megawatts
- Design: Queensland Water Resources Commission
Bauwesen
Wivenhoe was initially investigated for a dam site in the 1890s and again in 1933[1]. Further investigations into a dam began in the mid 1960s. In November 1971, Government approval was given to proceed with construction. Acquisition of lands of the submerged portion of the dam began in March 1973. In 1976 the Government gave approval to proceed with construction of the pumped storage hydro-electric scheme. Total cost for the hydro-electric project was $450 million.
See also
References
- ^ Queensland Environmental Protection Agency, Heritage Trails of the Great South East, State of Queensland, 2000 ISBN 0-7345-1008-X