Commonwealth v Tasmania  HCA 21
Remedies, Constitutional Law, The external affairs power
Facts; The Hydroelectric Commission of Tasmania wanted to build a dam on the Gordon River downstream of its junction with the Franklin River, the construction of the Dam was authorised by Tasmanian Legislation i.e. The Gordon River Hydroelectric Development Act (1982) and was intended to create job opportunities on the west coast which inccidentally had the highest rate of unemployment in Tasmania and produce low cost electricity. The Commonwealth took action to stop construction of the Dam on the basis of its significant impact on remote wilderness areas and sacred Aboriginal sites. To further complicate matters the Tasmanian Government nominated the Franklin River and Franklin National Park for World Heritage Listing which was accepted by UNESCO in 1982. The Commonwealth passed regulations making it unlawful to construct the Dam in a World Heritage area without the consent of the relevant Commonwealth Minister. The issue sparked the largest and most historic conversation battle in Australia. In 1981 a referendum was held in Tasmania in an attempt to resolve the issue. However the option of 'No Dams' was not provided on the ballot paper, which resulted in 33% of the electorate casting informal votes by writing it on their ballot papers.
Law; The remedy provided was a declaration that s 91H of the World Heritage Properties Conservation Act 1983 (Cth) was valid and that as a consequence it was unlawful to discuss a Dam without the consent of the relevant Cwth Minister. It's important to be careful with Constitutional remedies since the Courts are not to make policy decisions that is the role of the executive branch, not the judicial branch.
Holding; Against that highly political background Tasmania asked the High Court to consider whether the Cwth World Heritage Legislation was consistent with the Constitution. The decision in this case was a 4:3 majority. The majority found that the Cwth legislation was in the legislative power of the Cwth under s 51 (29) i.e. the external affairs power because the laws implemented national treaty obligations under the world heritage convention. Therefore under s 109 of the Constitution, the Cwth overrode the State legislation and thus the building of the Dam was not lawful.