Driving consensus on what to do about water levels in Georgian Bay.
In October 2020, Georgian Bay Forever (GBF) and the Georgian Bay Association (GBA) held the 2020 Water Levels Symposium featuring scientific and policy experts.
The purpose was to get to a consensus on what is driving extreme water levels and its volatility, and identify some gaps that need to be filled to help mitigate those extremes.
The on-line event was attended by a total of 460 participants. Morning speakers were qualified scientists, engineers and academics. Afternoon speakers were those who can comment on the current system of human interferences (control boards etc.) in the Great Lakes system, the decision making process and how it could be better coordinated to achieve some mitigation of extreme high and low water levels.

Key Takeaways
Expect higher highs, lower lows and wilder weather.
Water levels are dictated primarily by changing weather patterns over the years with precipitation and evaporation being the most significant factors. There is considerable uncertainty about future water levels as no predictions are accurate beyond approximately 6 months.
Future extreme highs and lows may exceed past extreme levels and may occur more often. Given these uncertainties and the potential for high energy storms, it is wise to plan for wilder weather, higher highs, and lower lows.
It is essential that the Environment and Climate Change Canada (ECCC) research study on water levels be released.
Currently under technical review, this study indicates that it is expected that extreme high water levels could be as much 3 feet higher than the last extreme high by the year 2100, gradually increasing over the next 80 years, highlighting the need to take action immediately. This new study uses the Large Lake Statistical Water Balance Model (LLSWBM) which reconciles the differences between the components method and the residuals method historically used to calculate Net Basin Supply (NBS). There is no conflict between the components and residuals methodologies, because they are used for different purposes.
The solution to extreme water levels does not lie with improved management of the current system.
Current management of the Great Lakes system is not deficient, including Plan 2012. Outflows from Lake Superior into Lake Michigan-Huron have not exceeded Plan 2012 limits. The solution to extreme water levels does not lie with improved management of the current system and the current tools in place for mitigation are limited. Major investment is required to improve mitigation of extreme high/low water levels.
There is an opportunity to improve mitigation of extreme high/low water levels by improved coordination of flow rates/adjustments among the control structures in the upper Great Lakes. While there is coordination among St. Marys River Control Works; Niagara River; and Moses-Saunders Power Dam and Plan 2012 Balancing Factor Long Sault Dam, these three boards do not coordinate to any great extent with the other control structures on the Great Lakes.
The International Joint Commission (IJC) has no power itself to implement any action. Plan 2012 is currently under review and GBF and GBA plan to ensure that M-H interests are properly addressed within the new plan. We will also request that the plan includes coordination with the Long Lac/Ogoki and Chicago diversions, plus regular review of the flow rate down the St. Clair River.
There have been various suggestions on adding control structures over the years, including from the IJC. However, the decision to build rests with the Canadian and US federal governments and any agreement to do so is likely to be a long term process requiring a strong consensus amongst all stakeholders to encourage action.
Action should be taken on specific improvements to the quality and content of water levels data and modelling.
In 2013, the International Joint Commission (IJC) 2013 made the recommendation to put in place a Great Lakes Water Levels Advisory Board.
This recommendation has not been acted on. A key and important role for a Great Lakes Advisory Board would be to integrate and fortify gaps in data through monitoring, measuring and modelling water levels in the Great Lakes to better inform government and citizens of changing conditions due to climate change. GBF is advocating to revisit the formation of a Great Lakes Water Levels Advisory body.
What is GBF and GBA doing to advance the objectives out of the water levels symposium?
Informing Municipal Governments
The executive directors of the GBA and GBF have been presenting the findings from the October 2020 symposium to various councils. As of May 18 2021, they have presented to the townships of Tiny, Georgian Bay, The Archipelago, and Killarney. If you think your Georgian Bay Township would like a presentation on the water levels findings, please email info@gbf.org with the name of the municipality and we will look into it. Key points from the presentation include:It is expected that extreme high water levels could be as much 3 feet higher than the last extreme high by the year 2100, gradually increasing over the next 80 years. (Source: ECCC report in technical review.)
Conversely extreme low water levels are only expected to be lower by around 4 inches.
Therefore:
- Wave action, run-up, pluvial and fluvial flooding must be considered.
- Given the uncertainty for planning purposes, consider raising the high water mark accordingly to 178.4 meters (585 feet) above sea level, or plan to increase it in increments.
- When making investment decisions on docks, coastal roads/infrastructure, boat launches etc. plan for this expanded range of water levels.
- Primary issue will be ensuring environmental protection at residences – setbacks only effective if high water level is correct.
- The highest impact will be on: septic systems, docks, boat houses and low elevation shoreline structures, start planning and educating your residents accordingly.