Mr. Douglas Fairbairn (Senior Counsel, Crown-Indigenous Relations and Northern Affairs, Department of Indigenous Services) at the Indigenous and Northern Affairs Committee

To your question, no, we're not aware of any historic treaties that mention drinking water. There are modern treaties that do have elements of water included in them. This provision seems focused on treaty rights, which are fairly broad, so it might involve modern treaties as well. In those treaties, water is already covered due to negotiation between first nations and the government over the years.