FINAL REPORT - International Joint Commission

egulation plan ranged from mild support to strong opposition. After full consideration of issues raised
during the public meetings and comment period, the International Joint Commission determined that it did
not have sufficient information on the environmental impacts and that Plan 1998 would not constitute
sufficient improvement over the existing situation. The Commission decided not to adopt Plan 1998 for
the regulation of Lake Ontario outflows at the time.
FINAL REPORT
In brief, all the candidate plans the Study Board is advancing will outperform both Plan 1958-D and Plan
1998 in terms of net overall economic and environmental impacts. Plan 1998 is similar to Plan 1958-DD
in its results and provides little overall economic or environmental gain. Plan 1958-D produces large
economic losses in the coastal sector relative to 1958-DD. If lake levels were regulated using Plan 1958-D,
given the range of supplies considered, lake levels would rise higher, causing hundreds of millions of dollars
in flood damages, and during droughts, Montreal Harbour would first be a little higher, but eventually, as
Lake Ontario drained, would be much lower than it would be under Plan 1958-DD. When tested under the
wider range of the stochastic water supply conditions, both Plan 1958-D and Plan 1998 “fail” because
Lake Ontario rises so high (over 80 metres (265 ft)) and falls so low (below 60 metres (197 ft)) that the
mathematical relationships used in the model are no longer reliable estimates of conditions.
The economic and environmental performance of plans 1958-D and 1998 for the 101-year historical water
supply case are presented in Annex 3 – Plan Descriptions and Results.
Interest Specific Plans
Using the plan formulation methods identified in the previous chapter, as well as other regulation ideas,
plan formulation teams deliberately developed special interest plans for different stakeholder groups.
Although these plans did not meet the Study Board’s “no disproportionate loss” guideline, they were
helpful in defining the upper range of possible benefits for a stakeholder group and assisted the teams in
understanding the relationships between water levels and benefits.
A plan formulation approach that led to a plan called “OntRip3” sought to minimize flooding and erosion
damages for the people who lived on Lake Ontario shorelines based on the interest satisfaction method.
That effort helped explain why plan formulators were unable to create a balanced plan that performed
much better than 1958-DD for shoreline property interests. OntRip3 created $550,000 U.S. in average
annual benefits for Lake Ontario shoreline residents, with improvements in shore protection maintenance,
flood and erosion damages. But it also reduced boating benefits on Lake Ontario by over $4 million U.S. and
power benefits at the Moses-Saunders dam by over $5 million U.S. per year compared with Plan 1958-DD.
Subsequent experiments with even more unbalanced plans – including some, such as maintaining Lake
Ontario at a constant 74.80 meters (245.41 feet), which would be impossible to realize because of the
huge releases required – showed that OntRip3 did define the maximum improvement possible for shoreline
residents on Lake Ontario. The most expensive cost for coastal residents is maintenance of existing shore
protection. Although residents associate higher water levels with greater shoreline erosion and damage to
shore protection due to overtopping, lower levels cause more undercutting of the nearshore allowing
greater wave energy to attack the bluff and shore protection when water levels rise once again.
An attempt to maximize recreational boating benefits led to the development of a plan called RecBoat.
RecBoat created almost $4 million U.S. per year in recreational boating benefits, but created large losses at
the Hydro Quebec power generating plants. The strategy behind the development of RecBoat was to use
Lake Ontario as a reservoir, releasing just enough water to keep it in the best range for boaters while also
maintaining Lac St. Louis levels above 21 metres (68.9 feet) during the boating season. This strategy
often required substantial flow cutbacks after the boating season ended to preserve water for the following
year. Because of the lower flows, Plan RecBoat reduced Hydro Quebec power benefits by an average of
over $18 million U.S. per year and caused large flood damages in the lower St. Lawrence River as well as
significant damages in terms of commercial navigation.
Options for Managing Lake Ontario and St. Lawrence River Water Levels and Flows
33