Canada-US agreement on Souris River basin water levels

Official title: Agreement between Canada and the United States for Water Supply and Flood Control in the Souris River Basin

Subject category:
Type of agreement / instrument:
Canada - United States
Legally-binding treaty
  • Signed and effective October 26, 1989.
  • Apportionment provisions amended in 1995 due to a dispute over interpretation of the original apportionment provisions of the Agreement.
  • December 2000 Amendment to the Agreement Between Canada and the United States for the Water Supply ad Flood Control of the Souris River Basin.
Lead & partner departments:
Global Affairs Canada
Environment and Climate Change Canada
For further information:
Web links:
ECCC Inquiry Centre
Compendium edition:
February 2022
Reference #:

Plain language summary

This legally binding treaty between Canada and the United States concerns two dams in the Souris River basin in Saskatchewan. Its main goal is to maintain Canada’s water supply, as well as ensure proper flood control is maintained from the US’ perspective. This agreement, led by Global Affairs Canada, allows for the monitoring of water and ensures its quality. Environment and Climate Change Canada (ECCC) provides this data to the Board responsible for implementing the agreement. Further, ECCC works closely with the province of Saskatchewan, as well as Manitoba, on this agreement.


The agreement provides for the construction, maintenance, and operation of the Rafferty and Grant Devine (formerly Alameda) dams and other works by Canada in the Souris River basin in Saskatchewan for the purposes of water supply in Canada and flood control in the United States.

The agreement also established the Water Quality Monitoring Group, which administers a joint water quality program.

Key elements

Apportionment provisions are administered by the International Joint Commission (IJC) through the International Souris River Board.

In 2000, diplomatic notes were exchanged between Canada and the United States that established an amendment to the 1989 agreement that moved the duties of the Water Quality Monitoring Group to the IJC.

In 2006, the IJC’s International Souris River Board was reconstituted with a new order with responsibilities for the water quality program under the agreement.

The new board had six members from Canada (Environment and Climate Change Canada and the provinces of Saskatchewan and Manitoba), and six US members. In 2015/16, the membership was expanded to include 6 additional public members (three from Canada and three from the US). Currently, the board has 8 Canadian Members and 8 American Members, a Canadian and American Co-Chair and a Canadian and American Secretary. The IJC is conducting a governance review that may change the board structure in the future.

Expected results

The Agreement is intended to provide a combination of water supply for Canada, and flood control for the United States, and provides for the administration of a joint water quality program.

Canada’s involvement

Under the terms of the Agreement, all operational responsibilities related to construction, maintenance, and operation of the dams were delegated to the province of Saskatchewan.

Global Affairs Canada (GAC) is the lead. Environment and Climate Change Canada supports the International Souris River Board, and provides staff to sit on the board and sub-committees.

In its support role to the board, Environment and Climate Change Canada:

  • provides water quantity and quality monitoring of the Souris River in the Saskatchewan and Manitoba portions of the basin as well as at the boundary crossings;
  • provides hydrometeorological information for use in apportionment calculations; and
  • calculates the apportionment of the water.

Results / progress


Environment and Climate Change Canada provides annual water quantity and quality monitoring data to the IJC board and calculates annual natural flows in Saskatchewan to allow determination of the apportionment of the river. Environment and Climate Change Canada actively participates in the Hydrology Committee and is responsible for documenting apportionment procedures.

Environment and Climate Change Canada also sends staff to attend and participate in IJC board meetings.


The International Souris River Board produces an annual report to the IJC summarizing how apportionment was met and discussing water quality monitoring results in consideration of water quality objectives at the border.

When significant floods occur, the US Army Corps of Engineers produces a report on the operations that transpired and documents that its operations were in accordance with the agreed operating plan under the agreement.


Following severe flooding in 2011, the IJC established the International Souris River Study Boardfor the implementation of a Study Plan to review the water supply and operating plan contained in the Agreement. Recommendations from the Study were submitted by the IJC to the governments in 2022.

Report a problem or mistake on this page
Please select all that apply:

Thank you for your help!

You will not receive a reply. For enquiries, contact us.

Date modified: