Observed Conditions & Regulated Outflows in 2017


This report by the International Lake Ontario - St. Lawrence River Board (the Board) describes the causes of the record high water levels in 2017 on Lake Ontario and the St. Lawrence River, as well as the regulation of outflows by the Board during this event. The Board is appointed by the International Joint Commission (IJC), an organization created as part of the 1909 Boundary Waters Treaty between the United States and Canada to regulate shared water uses and resolve transboundary water conflicts. The Board is responsible for regulating the outflow from Lake Ontario through an international dam located on the St. Lawrence River at Cornwall, Ontario and Massena, New York, according to orders issued by the IJC. Water levels on Lake Ontario and the St. Lawrence River are thereby influenced, though not completely controlled, by these actions. The IJC has also appointed members to the Great Lakes - St. Lawrence River Adaptive Management (GLAM) Committee, which is responsible for an on-going evaluation of the regulation of outflows from Lake Ontario and Lake Superior as a body of the three Great Lakes Boards. The GLAM Committee will produce a report later this year that will provide a detailed synthesis of the hydroclimatic conditions and their effects on the high water levels in 2017, and document the related effects of high water levels on the various stakeholders and interests throughout the Great Lakes– St. Lawrence River system.

International Lake Ontario-St. Lawrence River Board