International Gauging Stations (IGS)
Since 1909, Canada and the United States have worked cooperatively in monitoring the amount of water in transboundary watersheds. Under the Boundary Waters Treaty (1909), monitoring stations required for determining the quantity of water crossing the Canada/USA border or water levels in a shared water body are identified as "international gauging stations". The Treaty also established the International Joint Commission (IJC) to help to identify and formalize international monitoring obligations.
Subsequently, two federal statutes (the International Boundary Waters Treaty Act (1911) and the International Rivers Improvement Act (1955)) and some 32 water treaties, conventions and agreements have been established, resulting in the significant increase in the number of hydrometric stations1 in these shared basins. The data from these stations are used to address a broad range of issues: apportionment of natural flow between the two countries, flood mitigation, hydroelectric development, fisheries, watershed management, ecosystem health and protection, etc. 1
In 1985, a comprehensive review 2 was completed that established which specific hydrometric stations in the transboundary watersheds are considered to be essential by both countries and have been given the official designation of an International Gauging Station (IGS). A station can only be designated an IGS by means of either of two formal processes according to the guide:
- Approval in support of IJC activities and,
- Bilateral diplomatic approval.
The review resulted in the designation of 79 stations discharge and water level stations in Canada and the US. These stations are a small sub-set of the actual number of hydrometric stations being operated in transboundary watersheds. There are many more stations that provide supportive data for apportionment calculations or monitor flows into the Great Lakes that although important, are not considered to be a specific obligation under this process. Since the list was established, 9 stations (8 discharge and 1 water level) on the Canadian side have been discontinued based upon mutual agreement of both countries. Also, no new designations were made during this period. These stations are operated in accordance with procedures and standards of the host country. In Canada, the national standards are those that are established and documented by the Water Survey of Canada, part of the Meteorological Service of Canada. The data and information from these stations are reviewed by and are freely exchanged between the two countries.
- Bruce, J. and B. Mitchell, 1995. Broadening Perspectives on Water Issues, Canadian Global Change Incidental Report Series No., IR95-1.
- Huberman, S., J.E. Slater and A. Condes, 1985. Procedural Guide for International Gauging Stations on Boundary Waters between Canada and the United States of America, WRB Report IWD-HQ-WRB-PG-85-1, Internal Environment Canada Report.
- A hydrometric station or gauging station is a location where systematic records of stage (water level) or stage and discharge (flow) are obtained.
- Date Modified: