FINAL REPORT - International Joint Commission

ANNEX 2
At the request of the Study Board, the Environmental Technical Work Group also provided error bounds
around these ratios so the Study Board could clearly determine which plans were having a significant impact
on a specific performance indicator. The Work Group identified a 10% error bound around performance
indicators, with the exception of the fish indicators, which were assigned an error bound of 5%. The lower
St. Lawrence River performance indicators were assigned a 10% error bound. For consistency, the Study
Board used a standard 10% error bound on all environmental performance indicators.
The Environmental Technical Work Group further assisted the Study Board by identifying a sub-group of
13 priority performance indicators which they felt should be given greater weight in the decision process
because, collectively, they provide a coherent and consistent account of the impacts of a regulation plan.
The priority performance indicators are listed below.
Lake Ontario and upper St. Lawrence River
Meadow Marsh
Black tern reproductive index
Virginia rail reproductive index
Muskrat house density
Northern pike YOY
Large-mouth bass YOY
High Veg 24C fish guild
Lower St. Lawrence River
Golden shiner suitable feeding habitat area
Virginia rail reproductive index
Migratory wildfowl productivity
Northern pike reproductive area
Bridle shiner reproductive habitat surface area
Muskrat surviving houses
A further sub-group of key performance indicators was defined for the purposes of the National Academy
of Science/Royal Society of Canada independent peer review. With the exception of the wetland marsh
indicator, each of the remaining performance indicators in the list is a species at risk. These indicators
were chosen for review because they appeared to represent the greatest potential for conflict with
indicators from other technical work groups, in terms of development of a regulation plan. The indicators
chosen for the external peer review included:
• Wetland meadow marsh area (Lake Ontario)
• Least bittern (Lake Ontario) and least bittern (lower river, Lac St. Louis to Trois-Rivières)
reproductive index
• King rail (Lake Ontario) preferred breeding habitat coverage
• Yellow rail (Lake Ontario) preferred breeding habitat coverage
• Black tern (Lake Ontario) reproductive index
• Spiny softshell turtle (Lac St. Louis to Trois-Rivières) reproductive habitat surface area
• Bridle shiner (Lac St. Pierre) reproductive habitat surface area
• Eastern sand darter (Lac St. Louis to Trois-Rivières) reproductive habitat surface area
Finally, the Environmental Technical Work Group was asked by the Study Board to provide an overall
environmental index. While the Work Group cautioned the Study Board against using such an index for
plan ranking since too much underlying information is lost, an overall environmental index was developed
by Limno-Tech. This index did prove helpful to the Study Board when used in concert with the 32 key
performance indicators because it gave a relative score among plans that was not always obvious when all
32 performance indicators were considered.
The overall environmental index was developed based on a weighting scheme that assigns weighting
factors to 1) individual performance indicators, 2) performance indicator groups within the three regions
(Lake Ontario, the upper St. Lawrence River and the lower St. Lawrence River, and 3) the three regions.
Based on these weighting factors, the performance indicator ratios (relative to 1958-DD) are collapsed into
group weighted average ratios, region weighted average ratios, and finally an overall index. The complete
weighting scheme is provided in Table A-3.
24 Options for Managing Lake Ontario and St. Lawrence River Water Levels and Flows