Arnold v Minister Administering the Water Management Act 2000

The High Court of Australia considered an appeal by the appellants, who held bore licences under the *Water Act 1912* (NSW). These licences were replaced by aquifer access licences under the *Water Management Act 2000* (NSW) pursuant to a funding agreement between the Commonwealth and New South Wales. The replacement was effectuated by the Minister Administering the *Water Management Act 2000* (NSW) making a Water Sharing Plan for the Lower Murray Groundwater Source. The appellants contended that the Commonwealth legislation or the funding agreement contravened section 100 of the Constitution, and that their bore licences entitled them to use "the waters of rivers".

The legal issues before the Court included whether the Commonwealth legislation or the funding agreement contravened section 100 of the Constitution, which limits Commonwealth legislative power concerning the use of waters of rivers for conservation or irrigation. The Court was also required to determine whether the replacement of the appellants' bore licences constituted an acquisition of property otherwise than on just terms, contrary to section 51(xxxi) of the Constitution. Additionally, the Court considered whether the Minister took irrelevant considerations into account when making the Water Sharing Plan under section 50 of the *Water Management Act 2000* (NSW).

The Court held that the waters in question were underground water, not "the waters of rivers" as contemplated by section 100 of the Constitution. Consequently, the arguments concerning the operation of section 100, and the potential invalidity of the Commonwealth legislation or funding agreement on that basis, did not need to be examined. The Court also found that there was no acquisition of property, thus rendering the challenge under section 51(xxxi) of the Constitution unfounded. Regarding the administrative law ground, the Court determined that the existence of the funding agreement was not an irrelevant consideration for the Minister when making the Water Sharing Plan, as the plan was intended for the sustainable management of water sources and the funding was provided to effect this plan.

The appeal was dismissed. Special leave to appeal was granted on the section 100 ground, and leave was granted to the Commonwealth to file notices of contention. The appellants were ordered to pay the Commonwealth's costs, while the State of New South Wales and the Minister sought no order as to costs.