The Wivenhoe Dam is a rock and earth-fill embankment dam with a concrete spillway across the Brisbane River in South East Queensland, Australia. The dam wall is located about by road from the centre of Brisbane. The primary purpose of the dam is the supply of potable water for the Brisbane and Ipswich regions. The dam also provides for flood mitigation control, hydroelectricity, and recreation. The impounded reservoir is called Lake Wivenhoe and the dam, the lake and a narrow strip of surrounding land forms a locality also called Lake Wivenhoe. Wivenhoe Dam was planned in the early 1970s. The 1974 Brisbane flood highlighted the need for flood protection for South East Queensland. The lake also forms part of the water storages for the Wivenhoe Power Station. Location and features The earth and rock dam structure is high and long. The dam wall holds back the reservoir when at full capacity. From a catchment area of that includes much of the southwestern slopes of the D'Aguilar National Park, the dam creates Lake Wivenhoe, with a surface area of , a maximum shoreline of , and an average annual evaporation level of . The gated spillway, with five steel crest gates that are wide and high, has a discharge capacity of . The dam also has an auxiliary spillway to stop over-topping. The dam is managed by SEQ Water since July 2008 when most dam assets were transferred to the statutory authority, as part of a water security project in the South East Queensland region, known as the South East Queensland Water Grid. Construction Wivenhoe was initially investigated for a dam site in the 1890s and again in 1933. 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 A$450 million. In March 1977, the first construction contract was awarded. The dam was designed by the Queensland Water Resources Commission. In June 1983, the partially completed dam mitigated a potentially severe flood that may have caused damage equal to the 1893 Brisbane flood. Construction work, carried out by Thiess Brothers, was complete by 1985. To provide the of land required for the dam,