FINAL REPORT - International Joint Commission

Other Plans
The Study Board considered a number of other plans that were evaluated using the Shared Vision Model,
but discarded because their results did not meet the Study Board’s primary guidelines of providing net
economic and environmental benefits, or because they produced results similar to those of another of the
candidate plans, but slightly inferior. One example is Plan C. Plan C was developed using the rule curve
approach described in the plan formulation section of the previous chapter. Plan C has a similar foundation
as the 1958-D plan, but adjusts and adds a number of limits to better satisfy the Study Board's guidelines.
While this plan had fairly good results, the Study Board did not feel it was distinct enough from Plan D + to
warrant going forward, and Plan D + provided better overall economic and environmental results.
FINAL REPORT
Candidate Regulation Plans
This Section explains the objectives and impacts of the regulation plans that the Study Board examined
and decided were the best plans to present to the International Joint Commission as options. Preliminary
versions of each of these plans were presented to the public during the summer of 2005, and each was
then modified based, in part, on the public input they received. The three candidate plans have all been
labeled with a “ + ” sign to indicate that these plans have been modified/improved since they were last
presented to the public.
The Study Board believes that each of these three “candidate plans” represents distinct, yet reasonable
efforts to improve on Plan 1958-D with Deviations in terms of providing more balanced economic and
environmental benefits. The candidate plans are the focus of the full evaluation, comparison and rankings.
Plan E is presented along with results of the candidate plans to provide reference for the unregulated
condition.
In what follows, three types of information are provided for each Plan:
• Plan Descriptions: The plan’s objectives and over-all approach are briefly explained. This material is
taken from the plan descriptions contained in Annex 3 to this report.
• Plan Evaluations: A brief description of the plan’s major impacts and benefits is presented. The
impacts of each of the plans are divided into the following categories: hydrologic, economic,
environmental and equity. A set of graphs and tables provides quantitative evidence of the plans’
impacts compared with those of Plan 1958-DD.
• Plan Comparisons: The candidate plans are assessed in relative terms against one another and in
relation to Plan 1958-DD. The key facts and important pros and cons of each of the plans are
highlighted and discussed.
Plan A + : Balanced Economics
Plan A + was developed based on the optimization/rule curve approach described in the plan formulation
section in the previous chapter of this report. It is termed the Balanced Economic Plan because it focused
on producing the best overall economic scores for each interest. Environmental targets were not included
in the optimization, but were evaluated and addressed with adjustments to the plan to cover environmental
shortcomings. This plan produced the highest overall economic scores of the three candidate plans, but
the lowest environmental scores.
Plan A + used an optimization model to generate a rule curve for each quarter month relating lake level to a
prescribed Lake Ontario outflow. The optimization model minimizes expected differences from targets for
the outflow and for Lake Ontario, Lac St. Louis, Montreal Harbour, and Sorel levels. Each of these targets
varies through the year and was derived from relevant performance indicators or other similar sources.
The optimization procedure minimizes the likely deviation from these desired targets given uncertain future
inflows. The model uses a probabilistic approach to account for the uncertainty of these future inflows.
Options for Managing Lake Ontario and St. Lawrence River Water Levels and Flows
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