FINAL REPORT - International Joint Commission

The Study Board considered the impacts of alternative regulation plans assuming current economic and
environmental conditions. The evaluations were done using a wider range of water supplies to the basin
than have been experienced in the 20th century. Water supplies that might occur sometime in the future
because of climate change were used to make sure the plans would work under those conditions. Expert
opinion on economic and environmental trends was used qualitatively to show which areas of the regulation
plan might need to be changed in the coming decades.
FINAL REPORT
Study Scope
During the Levels Reference Study, and since its completion in 1993, a number of interests or user groups
were identified as being directly affected by fluctuations in water levels and flows in the Lake Ontario-
St. Lawrence River system, in addition to those directly specified in the Orders of Approval.
The work undertaken in this Study was specified in great detail in a Plan of Study, developed in 1999, and
reaffirmed by the IJC Directive (2000). It developed an assessment framework that examined how water
level fluctuations affect all the specified interests, expressed in physical, economic and ecological
dimensions. This assessment consisted of a review of the data, findings and reports of the 1993 Levels
Reference Study, followed by field investigations, new data collection, more detailed topographic and
bathymetric data, original scientific investigations, and public interviews, surveys and questionnaires.
Where practical, studies or data already completed for other agencies or other purposes were relied on to
minimize duplication of cost and effort. Emphasis was placed on identifying the analytical and technical
foundations for evaluating the respective demands of the environmental, recreational boating and shoreline
property interests on the management of the Lake Ontario-St. Lawrence River system, as reflected in the
Scope of Work Document (1999) (the Executive Summary of the Document is included in Annex 1 of this
report, published separately). A comprehensive analytical approach was initiated, in conjunction with a
robust public involvement process, referred to as “Shared Vision Planning.”
Regulation of the outflows of Lake Ontario affects water level conditions on Lake Ontario and the St. Lawrence
River as far downstream as Lac St. Pierre near Trois-Rivières, Quebec. It should be noted that water level
fluctuations downstream of Cornwall, Ontario, to Massena, New York, are also affected by actions taken at
the other control works, as well as by natural factors. The levels and flows of the St. Lawrence River in the
vicinity of Montreal can also be significantly affected by discharges from the Ottawa River, particularly
during spring runoff into the Ottawa River basin, referred to as its freshet. The Ottawa River Regulation
Planning Board coordinates the Ottawa River discharges. These discharges can at times be as significant
as the outflows from Lake Ontario. The outflow regulation of the Ottawa River is not under the jurisdiction
of the IJC and is not part of the scope of this Study. Prior studies have concluded that no feasible location
or conditions for additional structures on the Ottawa River have been found that would provide sufficient
additional controls over water levels and flows in the lower St. Lawrence River.
Study Organization
The Study organization is shown in Figure 4. As mentioned previously, the Study was created by the
International Joint Commission in response to a reference from the governments of the United States and
Canada. The Commission responds directly to the public. The Study Board consists of fourteen members,
with both countries equally represented; members are selected for their expertise rather than affiliation
with any interest or agency. There are two general managers, who facilitate Study Board activities and
handle finances in each country. There are nine technical work groups (TWG). Six consider the impact of
water levels on specific interests, namely, wetlands and environmental, recreational boating and tourism,
coastal processes, commercial navigation, municipal, industrial and domestic water uses, and hydroelectric
power generation. The Hydrologic and Hydraulic Modeling Group provides historical and hypothetical
Options for Managing Lake Ontario and St. Lawrence River Water Levels and Flows
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