International river water flow pact will be reviewed for modernization
By MEDICINE HAT NEWS on November 23, 2021.
https://www.medicinehatnews.com@MedicineHatNews A 100-year-old agreement between Canada and the U.S. on water flows in the St. Mary’s and Milk rivers will be reviewed to improve water security and reflect the effects of climate change, the International Joint Commission announced Tuesday. The rivers, which emanate in Montana before entering Alberta, are distinct but are joined by the St. Mary’s canal that apportions water evenly between the two countries for irrigation, municipal use and natural flow. That is the result of international pact signed in 1909 and 1921. Now, a study expected to last four years will include extensive stakeholder feedback and options for non-structural changes to increase “resiliency,” including balancing periods and deficit trading between the two river basins. Those could “improve each nation’s ability to receive their apportionments of water,” said Rob Sisson, a member of the four-person commission that is jointly appointed by the two countries. “Changing climate conditions increases the timelines and importance of this work … (and could establish) more efficient water apportionment in the future,” said commissioner Pierre Beland. The Milk River re-enters Montana to eventually join the Missouri River system, while the St. Mary’s feeds major southern Alberta irrigation districts that extend eastward to near Medicine Hat. In the spring of 2020, a canal failure in the U.S. led to a drastically reduced amount of water flowing into the Milk River system. Levels in that river are more dependent on snow melt and weather and are therefore more prone to drought conditions. The recently passed U.S. federal infrastructure bill includes US$100 million to modernize the St. Mary’s head works as part of an allotment for the state. 11-10
