Phase 2 Work & Updates

Picture of Moses-Saunders dam

Phase 2 of the Expedited Review is broadly examining Plan 2014’s performance, especially its response to extreme high and low water levels and to variability brought on by the changing climate. It includes reviewing the rules within the regulation plan that govern outflows as well as the trigger levels that authorize the International Lake Ontario-St. Lawrence River Board to consider deviations from those rules.  

The goal of the review is to find ways that could moderate extreme water levels and reduce impacts on the various uses and interests throughout the Lake Ontario and the St. Lawrence River system. The review could identify possible minor or major revisions to Plan 2014 rules and deviation authorities as recommended improvements by the International Lake Ontario-St. Lawrence River Board for consideration by the IJC and governments.  

Phase 2 features multiple technical working groups developing and testing alternative regulation plans. To learn more about the GLAM’s work and its working groups you can read their 2023 Annual Work Plan.

Graphic of GLAM committee org chart


  • Hydroclimate Team: Understand and model the full range of hydroclimate conditions  

  • Plan Simulation and Formulation Team: Calculate water levels and flows 

  • Integrated Socio-Economic and Ecosystem Team: Develop and use predictive models to assess outcomes supported by the Ecosystem Team, the Commercial Navigation Team, the Shoreline Impacts Team and the Hydropower Team who are developing and validating indicators for use in the model 

  • Plan Evaluation and Ranking Team, including the Board Room Team and the Decision Support Team: Evaluate plan performance and support the IJC and boards in making decision based on the available information

  • Integrated Social, Economic and Environmental (ISEE) system model  

A major tool being developed for Phase 2 is the Integrated Social, Economic and Environmental (ISEE) system model. This integrated modelling platform, or a software tool, used to simulate and compare alternative water regulation plans for Lake Ontario. It is designed to estimate how different outflows and water levels that would result from alternative regulation plans would impact shoreline properties and infrastructure, shipping, ecosystems, hydropower production, and recreation within Lake Ontario and along the St. Lawrence River.  

To effectively compare alternative regulation plans, performance indicator response throughout the system must be simulated under a wide range of plausible conditions.    

Performance indicators quantify water level and flow impacts on uses in the system, such as: municipal water supplies, beach closures, additional safety precautions and mitigation measures needed to maintain commercial navigation, damages to riparian structures, reduction in hydroelectric generation, crop loss, habitat loss and riparian ecosystem degradation. Performance Indicators measure the potential effects of differing water levels and flows on something of value to interests within the basin that are representative of broader impacts.  

Fact Sheets on Phase 2