FINAL REPORT - International Joint Commission

ANNEX 3
Operationalizing Plan D +
Implementation
The computer program for Plan D + can easily be converted from a quarter-monthly to a weekly operational
time step. Procedures for operational forecasts for Lake Erie inflow, Lake Ontario net basin supply, and
Ottawa River and tributary flows need to be determined and put in place. Because the plan is calibrated to
the statistical annual net total supply forecast and is a function of the past 48 quarter-months' supplies,
this forecast procedure can be carried forward into the operational plan. The operational plan would need
to be tested and coordinated between the U.S. and Canadian Regulation Representatives. A trial period
before transition to the new plan would be advisable.
Within-week flow adjustments
As in the case of all the candidate plans, this plan is dependent upon forecasts and minimum and
maximum flow limitations. It has been recognized by the Study Board that, in some circumstances,
adjustments will need to be made within the week due to the difficulty of accurately forecasting changing
ice conditions and Ottawa River and downstream tributary flows. These adjustments are to be made
consistent with the intent of the plan. For Plan D + , explicit relationships can be developed from the results
of the 50,000-year stochastic simulation to guide these within-week adjustments.
202 Options for Managing Lake Ontario and St. Lawrence River Water Levels and Flows