The Minister for Home Affairs asks to be advised as to the constitutional position of the Commonwealth with respect to the resolutions (with the papers) regarding the distribution of the waters of the Murray River and its tributaries to the use of the States of New South Wales, Victoria and South Australia, agreed to by the Premiers of the said States at a conference held in Sydney on 16 April 1906.

The main points of the proposed agreement are:

1. a limitation of diversions by the upper States (N.S.W. and Victoria);
2. a proposal to initiate and complete a canalization and locking scheme;
3. the appointment of an administrative Commission.

With respect to (1), the proposals appear to be in the nature of a mutual renunciation of rights by the two upper States. The Commonwealth is not in any way concerned-except so far as the agreement might be construed as founding a claim of right for diversions of water up to the maximum limit.

With respect to (2) and (3), and also as regards any such possible construction of (1), the Commonwealth is concerned as regards the possible effect upon the rivers as highways of interstate navigation. With regard to such navigation, the Commonwealth has paramount power of legislation, subject only to the limitation imposed by section 100 of the Constitution that it cannot abridge the right of a State, or of the residents therein, to the reasonable use of the waters for conservation or irrigation.

In the absence of Federal legislation, there appears to be nothing in the agreement itself which necessarily conflicts with the constitutional rights of the Commonwealth; though any action under the agreement which obstructed interstate navigation might be a breach of the provisions of section 92 of the Constitution requiring trade, commerce and intercourse among the States to be absolutely free.

In view of the importance of the scheme, I would suggest that this matter be brought under the formal notice of the Prime Minister for his consideration whether or not he would communicate on the subject with the States concerned. He might think it advisable, while congratulating them on the proposed utilization of the river waters, to remind them that the supreme oversight of navigation has been imposed upon the Commonwealth. The Federal Parliament and Government are therefore directly concerned in the matter, and with a view of a thorough understanding of what is intended to be done, and of avoiding so far as possible any difficulties in the future, the States might be invited, before committing themselves to any definite engineering works, to supply the Federal Government with complete plans and information.

[Vol. 5, p. 407]

*See also Opinion No. 327.