Commonwealth v Western Australia

The Commonwealth of Australia brought proceedings against the State of Western Australia and others concerning the application of Western Australian mining legislation to land owned or leased by the Commonwealth. The High Court of Australia was required to determine whether the *Mining Act 1978* (WA) applied to such land, and whether certain Commonwealth legislation, specifically the *Lands Acquisition Act 1989* (Cth) and regulations made under the *Defence Act 1903* (Cth), was inconsistent with the Western Australian Act. The case also involved a question regarding the constitutional validity of the Defence Force Regulations under section 51(xxxi) of the Constitution, concerning the acquisition of property.

The central legal issues before the High Court were the construction of reservations for mining and minerals in Crown grants and leases, and the effect of Commonwealth legislation on the application of state mining laws to Commonwealth land. Specifically, the Court had to consider whether section 64 of the *Judiciary Act 1903* (Cth) rendered the *Mining Act 1978* (WA) applicable to Commonwealth land, and whether the *Lands Acquisition Act 1989* (Cth) or the Defence Force Regulations were inconsistent with the *Mining Act 1978* (WA) under section 109 of the Constitution. The Court also examined whether the Defence Force Regulations constituted an acquisition of property for the purposes of section 51(xxxi) of the Constitution.

The High Court allowed the demurrer by the State of Western Australia in part, specifically concerning a perimeter area, but overruled it in relation to freehold and leasehold lands owned or leased by the Commonwealth. The Court also allowed the Commonwealth's demurrer to the State's counterclaim. The reasoning focused on the construction of the *Mining Act 1978* (WA) and its interaction with Commonwealth legislation. The Court determined that the *Mining Act 1978* (WA) did not apply to the freehold and leasehold lands held by the Commonwealth. Furthermore, the Court found that the provisions of the Defence Force Regulations did not effect an acquisition of property.

Consequently, the High Court ordered that the demurrer by the State of Western Australia to the Commonwealth's Amended Statement of Claim be allowed in part and otherwise overruled. The demurrer by the Commonwealth to the State of Western Australia's Counterclaim was allowed. The matter was stood over to be listed before a single Justice for further or consequential orders, with costs of each demurrer reserved for consideration by that Justice.