Commonwealth v Tasmania (popularly known as the Tasmanian Dam Case) was a significant Australian court case, decided in the High Court of Australia on 1 July 1983. The case was a landmark decision in Australian constitutional law, and was a significant moment in the history of conservation in Australia. The case centred on the proposed construction of a hydro-electric dam on the Gordon River in Tasmania, which was supported by the Tasmanian government, but opposed by the Australian federal government and environmental groups. Background to the case In 1978, the Hydro-Electric Commission, then a body owned by the Tasmanian government, proposed the construction of a hydro-electric dam on the Gordon River, below its confluence with the Franklin River, in Tasmania's rugged south-west region. The dam would have flooded the Franklin River. In June 1981 the Labor state government created the Wild Rivers National Park in an attempt to protect the river. The boundaries would have allowed the construction of another dam lower on the Gordon River, below its confluence with the Olga River. In May 1982, a Liberal state government was elected which supported the dam. The federal Liberal government at the time, led by Malcolm Fraser, made offers of compensation to Tasmania, however, they were not successful in stopping the dam's construction. In November 1982, UNESCO declared the Franklin area a World Heritage Site after a nomination by the Labor government, forwarded by the Commonwealth, was accepted by the World Heritage Committee. During the 1983 federal election, the Labor party under Bob Hawke had promised to intervene and prevent the construction of the dam. After winning the election, the Labor government passed the World Heritage Properties Conservation Act, 1983 (Cth), which, in conjunction with the National Parks and Wildlife Conservation Act 1975 enabled them to prohibit clearing, excavation and other activities within the Tasmanian Wilderness World Heritage area. The Tasmanian government challenged these actions, arguing that the Australian Constitution gave no authority to the federal government to make such regulations. In May and June 1983, both governments put their case to the High Court of Australia. Case The case revolved around several major constitutional issues, the most important being the constitutional validity of the World Heritage Properties Conservation Act 1983 (or World Heritage Act). The division of powers between the Australian federal government and the individual state governments are defined mainly by section 51 of the Australian constitution. The