St. Mary and Milk Rivers Study Gets Moving

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Kevin Bunch
Diana Moczula
May 18, 2022
milk river montana

Since the IJC appointed six members of the International St. Mary and Milk Rivers Study in November 2021, the board has been hard at work getting the study up and running. The board has been busy developing its workplan while setting up advisory and technical groups.

For centuries, the St. Mary and Milk rivers watershed has sustained the people, environment and animals that live there. The rivers originate in Montana, and flow north across Amskapi Piikani (Blackfeet) territory into Alberta. The Milk River crosses back into Montana about 40 kilometers (25 miles) west of the Alberta-Saskatchewan provincial border. The eastern tributaries of the Milk River also drain the extreme southwestern corner of Saskatchewan.

The rivers are linked through the St. Mary Canal, also located within Amskapi Piikani territory. The St. Mary River flows consistently through the year, while the Milk River is naturally reliant on precipitation for water flows during the summer months. The canal allows water from the St. Mary to enter the Milk River, providing additional water for irrigation, municipal and environmental needs.

Both rivers are vital sources of water for irrigators and communities located in Canada and the United States. The waters are apportioned between the two nations according to formulas laid out in the 1909 Boundary Waters Treaty and a 1921 IJC Order.

As one might expect, conditions in the basin have changed over the past 100 years. Much of the infrastructure built in the early 1900s to store and move water is showing its age. The impacts of climate change are becoming evident, from precipitation changes to a shift in the growing season. There is also an increasing demand for water driven by a century of development in the basin. The Accredited Officers –two individuals appointed by the governments who measure and document the apportionment –  recognized the impact of these changing conditions and recommended that the IJC study ways to improve this situation.

In June 2021, the Canadian and US governments gave their support to the IJC’s plan to launch a study on the St. Mary and Milk rivers. This study will explore options to improve access to the shared waters and consider structural and nonstructural solutions over the course of its four-year length. Climate change and other apportionment challenges that have emerged over the past century will be part of the study’s consideration. The study board’s recommendations will be presented to the IJC once it has completed its work. From there, the IJC will finalize recommendations and send those with the study findings to the governments for final disposition.

The study board was appointed by IJC Commissioners and is composed of six highly experienced water professionals, three from Canada and three from the United States. The six were chosen for their expertise and ability to provide unbiased, scientific advice for the basin, informed by backgrounds in water policy, hydrology, academia, research and irrigation management.

The study board is co-chaired by the two Accredited Officers of the St. Mary and Milk Rivers, John Kilpatrick and Dr. Alain Pietroniro, both with knowledge of water measurement and apportionment within the basin. Sue Lowry and Mark Anderson come to the board from the United States, while Dr. Dena McMartin and Laurie Tollefson join from Canada. Malcolm Conly and Joanna Thamke, field representatives to the Accredited Officers of the St. Mary and Milk Rivers, serve as alternate co-chairs.

“The co-chairs are extremely excited about the prospects for this study and the excellence of our study board members,” said Pietroniro. “We are truly pleased to have eminent scholars and practitioners assist with implementing this very important IJC study and look forward to working closely with them over the coming years.”

The study board will be supported by several committees and advisory groups. At a minimum, these will include a Government Forum, Public Advisory Group, Indigenous Advisory Group, Independent Review Group, Options Formulation and Evaluation Group and various Technical Working Groups. Two special liaisons to the study board, John Tubbs and Dr. Frederick Wrona, also have been appointed to facilitate the work of the Government Forum.

The study board aims to involve the public and Indigenous Peoples to the fullest extent possible, while working toward solutions that are mutually beneficial to Canada and the United States. The study board is committed to active and ongoing outreach and communication. A special effort will be made to invite and incorporate Indigenous knowledge and expertise.

Although the study board is developing its work plan, it is clear that extensive hydrological modelling will be required, as well as various historical, ecological and socio-economic analyses. The modelling will focus on changes in administrative procedures and infrastructure, while also analyzing potential options under various climate conditions. The historical analysis will largely look at water availability, apportionment and irrigation within the watershed, while also examining responses and mitigation measures adopted by water users during periods of drought or limited water availability. The socio-economic analysis will evaluate the sociological effects and quantify the costs and benefits of various options being examined to improve access to apportioned water.

The board acknowledges that a significant amount of work has been accomplished by the Montana-Alberta Joint Initiative. The initiative was established to recommend options to the governments of Montana and Alberta to better access the shared waters of the St. Mary and Milk rivers. The study board will consider this work and build upon it.

The study board is currently developing a draft workplan, which will lay out the study’s structure and the process it will use to achieve its goals. Once completed, the draft will be shared with the public for feedback.

The IJC has a long history of working on apportionment in the region. In the late 1800s, irrigation began in the Milk River basin in Montana and subsequently in the St. Mary basin in Alberta. With pressure from governments and settlers to increase farming and manufacturing in the area, tension rose and disputes over the waters shared between Canada and the United States persisted. The disputes led to an increased desire to share a reliable supply of water, and was a catalyst for signing the Boundary Waters Treaty that established the IJC.

More information about the study can be found on the Study Board’s website at

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Kevin Bunch

Kevin Bunch is a writer-communications specialist at the IJC’s US Section office in Washington, D.C.

Diana Moczula

Diana Moczula is a junior policy analyst at the IJC’s Canadian Section office in Ottawa, Ontario.