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Milk River

Originating in the foothills of western Montana and flowing northeast into Alberta near Del Bonita, the Milk River flows due east for about 170 km across southern Alberta before re-entering eastern Montana. Sharing of its waters is governed by Article VI of the Boundary Waters Treaty (1909), and the 1921 Order of the International Joint Commission. These agreements entitle Canada (Alberta) ito receive the following quantities of the natural flow of the St. Mary River at its crossing of the International Boundary:

Non-irrigation season (November 1 to March 31)
50 per cent of the natural flow.

Irrigation season (April 1 to October 31)
For natural flow rate up to 18.86 m³/s (666 cubic feet per second (cfs))
25 per cent of the natural flow
For natural flow rates in excess of 18.86 m³/s (666 cfs)
A prior allocation of 4.71 m³/s (166.5 cfs) plus 50 per cent of the natural flow above 18.86 m³/s (666 cfs)

The annual natural flow of the Milk River during the irrigation season and the annual entitlements for Canada (Alberta) and the U.S. can be seen by clicking the link below.


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Updated: Mar 6, 2015