FINAL REPORT - International Joint Commission

Ice formation
Ice cover stability is necessary to enable the flows prescribed by the plan to be released throughout the
winter. An ice jam will inhibit these releases causing a drawdown in head that could impact municipal
water supplies in the vicinity of the Moses-Saunders Dam. The inability to pass the required outflows will
cause levels on Lake Ontario to rise prior to the spring melt, adding to high level concerns. In addition,
when ice jams release, damage to shorelines and flooding downstream will occur. An unstable cover or ice
jam will force power generation to be reduced because flows will be inhibited and the operating head will
be reduced. Therefore, managing flows in order to allow formation of a stable ice cover each winter is
very important and it is particularly important to the hydropower entities.
ANNEX 2
Plan 1958-D (as originally formulated without deviations) simply assumes that ice forms throughout
January and therefore reduces flows throughout January. In reality, the timing and duration of ice formation
varies, and actual operations under 1958-D with deviations address ice formation as it actually occurs.
Because this is so important, all new candidate regulation plans include the same ice management rules to
reduce flow when and while ice is actually forming. In practice, ice management operations under any of
the new candidate plans would continue as they have been conducted under 1958-D with deviations.
Therefore, all the candidate plans meet this need equally well and no performance indicator is tracked.
Baseline Economics – Hydropower
The hydropower performance indicators are used to rank plans. They reflect the societal value of marginal
differences in electricity production among the candidate regulation plans. The Board asked our economic
experts to develop some measure of the scale of that change in relation to the overall scale of the economic
activity for the Board's use in determining if a loss in one sector's benefits was disproportionate. For
hydropower, the experts suggested that the scale of the overall activity is the net economic value to society
of all the electricity produced at each of the generating stations (i.e., the economic surplus). Using information
provided by the three power companies, and assistance from the Economics Advisory Committee, a
producer surplus was derived from the total baseline market value of electricity produced.
The derived numbers should be taken as planning level estimates only and they are merely meant to
provide some context for the net benefits results shown in the main body of this report. The actual value
of electricity produced and the resultant producer surplus may be different in any given year, depending on
market conditions and other factors (see footnote on page E1).
The economic baseline for hydropower under Plan 1958-DD was calculated as the economic surplus
measured as net operating revenues minus the economic cost of capital, before deduction of taxes,
transfer payments, and special pricing. The numbers derived were similar to those produced in other
studies, such as the Federal Energy Regulatory Commission (FERC) relicensing analysis for the
St. Lawrence-FDR generating station (Moses). Table E-1 below shows the derived baselines.
Table E-1: Estimated Hydropower
Economic Baselines
($US million)
HYDROPOWER $350
NYPA-OPG $250
Hydro Québec $100
Options for Managing Lake Ontario and St. Lawrence River Water Levels and Flows
109