Many rivers and some of the largest lakes in the world lie along, or flow across, the border between the United States and Canada. The International Joint Commission assists governments in finding solutions to problems in these waters.

The 1909 Boundary Waters Treaty established the Commission, which has six members. Three are appointed by the President of the United States, with the advice and approval of the Senate, and three are appointed by the Governor in Council of Canada, on the advice of the Prime Minister. The Commissioners must follow the Treaty as they try to prevent or resolve disputes. They must act impartially, in reviewing problems and deciding on issues, rather than representing the views of their respective governments.

The Commission has set up more that 20 boards, made up of experts from the United States and Canada, to help it carry out its responsibilities.