Great Lakes - St. Lawrence River Adapative Management Committee

Economic impact assessment of halting Commercial Navigation on the St. Lawrence Seaway because of dangerous velocities/cross currents

In recent years, Lake Ontario and the St. Lawrence River has experienced record-high water levels. The IJC and its Boards seek to provide additional relief to homeowners, businesses, and recreational water users along the shorelines of the Lake Ontario - St. Lawrence River system.  As a result, the International Lake Ontario-St. Lawrence River (ILOSLR) Board has considered temporarily increasing releases from Lake Ontario beyond the maximum flow safe for navigation in the upper St. Lawrence River while under the authority to deviate from the water level and flow regulation plan agreed to by Canada and the US (“Plan 2014”). In order to improve the robustness of future decisions regarding the outflows from Lake Ontario, it is useful for the ILOSLR Board to have quantified estimates of the economic impact of passing higher flows, which may result in temporary interruption of commercial navigation on the St. Lawrence Seaway.

 

Engaging South Shore Lake Ontario Municipalities in Documenting High Water Impacts to support GLAMs Expedited Plan 2014 Review

The Commission’s Order of Approval for the regulation of outflows from the St. Lawrence Power Project requires the Commission to conduct a review of the results of regulation under the Order within 15 years after the date of the Order and report to Canada and the United States its findings. Due to public pressure from high water levels in 2017 and 2019, the Commission is expediting the regulation review. The overall goals of this project are to develop and implement an engagement process with local shoreline municipalities to gather local information on high water impacts and obtain information about the impacts of high water flows on shoreline municipalities.

 

Assessment of critical ice conditions for Lake St. Lawrence during low water period associated with winter operations

This project will investigate the potential for increased outflows on the St. Lawrence River once a stable ice cover has formed, which typically allows outflows to be substantially increased. This is of particular interest during high water conditions on Lake Ontario when outflows are maximized to reduce Lake Ontario water levels. Changing flow rates too quickly can cause the stable ice cover to fracture, leading to ice jams, which would require flow reductions. This project will analyze historical ice conditions on Lake St. Lawrence related to dam forebay operations in winter, specifically to define the rate and maximum extent of water level draw down over the ice-cover period to maintain a stable ice cover and reduce the risk of fracturing. The analysis will look at how ice conditions have been impacted by the rate and magnitude of water level changes on Lake St. Lawrence and will include an assessment of the uncertainty in the findings and implications for further data collection.

 

Assessment of critical low water thresholds for Lake St. Lawrence during winter operations and periods of ice cover

This project will investigate potential opportunities to gather new insight into known operational constraints with the objective of identifying ways to release a small amount of additional water by increasing outflows during winter ice operations under high water conditions in the basin. The winter operation low water threshold addresses critical water intake elevations of municipal and industrial water intakes in the Lake St. Lawrence area, and the goal of maintaining a stable ice cover on Lake St. Lawrence to prevent fractured ice cover and ice jamming. Changes to a number of municipal and industrial water intakes over the years will require gathering of updated engineering information on critical winter operational needs of municipal and industrial water intake on Lake St. Lawrence, including minimum operational elevations, and assessment of potential shore well users in the system to identify the potential number of impacted properties under a range of water level conditions.

 

Review of potential ecological impacts from winter drawdown scenarios in Lake St. Lawrence

Unusually large precipitation in the spring of 2017 and 2019 have led to record or near-record water levels in the Great Lakes basin which are projected to continue into 2020.  To help lower water levels in Lake Ontario and the upper St. Lawrence River in advance of the spring of 2020, the IJC, through its ILOSLRB, is considering increasing outflows at the Moses-Saunders Power Dam during the winter season of 2019-2020 above those currently defined in Plan 2014.  A consequence of this increased discharge could be unprecedented low winter water levels in the Lake St. Lawrence forebay just upstream of the Moses-Saunders Dam.  

To understand the potential ecological consequences of greater winter outflows, this project will undertake a review of the current literature related to winter drawdown effects on lake and river ecosystems associated with hydroelectric dam operations.  In addition, using existing bathymetry and high resolution imagery generated from Unmanned Aerial Vehicle (UAV) surveys, the project will conduct a sensitivity-based analysis of winter drawn down scenarios on Lake St. Lawrence by simulating water levels in a Geographic Information System (GIS).

 

Shore Protection Structure Condition Assessment following 2017 High Water Levels on Lake Ontario

High water levels throughout the Lake Ontario-St. Lawrence River system in 2017 impacted several residential shoreline communities, stakeholders, and businesses.  Media outlets reported property owners experienced flooding, erosion and damage to their shore protection structures due to water level and wave conditions.  This project will re-visit the properties that were surveyed by Quinte and Lower Trent Conservation Authorities (2009-2012), New York State Department of Environmental Conservation (2011) or United States Army Core of Engineers (2015) as part of the model validation efforts following the 2006 International Lake Ontario - St. Lawrence River Study to assess the condition, design characteristics, and expected performance of shore protection structures were consistent with inputs to the FEPS model. This effort shall concentrate on the Lake Ontario shoreline, and not include any structures on the St. Lawrence River.  Future efforts shall consider impacts to shore protection structures in other parts of the system.  The information will be summarized and analyzed to support the GLAM Committee’s annual reporting to the Lake Ontario-St. Lawrence River Board, and to support performance indicator review and model validation efforts.

 

2019 Monitoring of Lake Ontario coastal wetland habitat in support of adaptive management

This project will result in detailed vegetation community data referenced to elevation and seasonal water levels in 16 Lake Ontario coastal wetlands. These data can be used for adaptive management monitoring and integrated into wetland vegetation community modelling (i.e., refine Integrated Ecosystem Response Model inputs and validate outputs) in Lake Ontario following implementation of Plan 2014. This is a continuation of ongoing GLAM efforts to collect data to support model validation.