McLaren v Caldwell[1] was a landmark decision of the Judicial Committee of the Privy Council that upheld provincial jurisdiction in matters of a local or private nature, as well as over property and civil rights.

As a result of the Privy Council's ruling, the Legislative Assembly of Ontario passed the Rivers and Streams Act, 1884,[17] which the federal government decided not to disallow.

[18] In order to assert its own jurisdiction, the Parliament of Canada subsequently passed the Navigable Waters Protection Act.

[19] McLaren v Caldwell established the principle in Canadian law that waterways are open to all, and that while private interests can charge a reasonable amount for the use of any improvements they have made, they cannot refuse passage to anyone.

[20] The Judicial Committee of the Privy Council, in turn, increasingly ruled in favour of the provinces, with a broad interpretation of what constituted local matters.