was in effect a department of the Tasmanian government, and not a trading corporation. However, as the HEC was engaged in the widespread production and sale of electricity, and had a degree of independence from the government, it was held to be a trading corporation. Acquisition of property on just terms Section 51(xxxi) of the Australian Constitution provides that the federal government has the power to appropriate property "on just terms" for any other purpose it has powers to make laws about (see Section 51 of the Constitution of Australia: for example, acquiring land to build a military base). The crucial phrase in this section is "on just terms". Tasmania argued that the federal government has deprived it of property unjustly bypassing the World Heritage Act. Justice Brennan said however that Tasmania had no proprietary rights over the site for the proposed dam (that is, it was not private land), and therefore it had not been deprived of any property. Decision A four to three majority of the seven members of the High Court held that the federal government had legitimately prevented construction of the dam, and that the World Heritage Act was authorised under the "external affairs" power. Although other parts of the Act were invalid, the provision banning the construction of dams was valid. Consequences The case ended the HEC's plans to construct more hydro-electric dams in Tasmania. The legal debate over the extent of the "external affairs" power continued for a decade in a series of cases in the High Court in which the wide view of the external affairs power prevailed. It is now firmly established that under section 51(xxix) of the Australian Constitution the Australian Government has the power to enact legislation that is reasonably capable of being considered appropriate and adapted to fulfill Australia's international legal obligations. Due to the large number of international obligations that Australia has accepted under international treaties, the external affairs power in section 51(xxix) gives the Australian Government a very wide constitutional power to make laws on many subjects, including protecting the environment. Large parts of Australia's main national environmental law, the Environment Protection and Biodiversity Conservation Act 1999 (Cth), depend for their constitutional validity on the decision in the Tasmanian Dam Case regarding the external affairs power. These include the protection of World Heritage properties, Ramsar wetlands, threatened species and threatened ecological communities, and migratory species. Definition of