By Wendy Leger and Arun Heer, Great Lakes-St. Lawrence Adaptive Management Committee
The complex task of managing water levels and flows in the Great Lakes- St. Lawrence River system has received considerable attention recently following two notable regulatory changes and a series of unprecedented hydrologic events. Together, this presents a significant challenge and an important opportunity for the Great Lakes-St. Lawrence River Adaptive Management (GLAM) Committee.
In January 2015, the International Joint Commission (IJC) implemented regulation Plan 2012, a new set of rules governing the amount of water to release from Lake Superior through the St. Marys River.
More recently, with the concurrence of the U.S and Canadian governments, the IJC implemented Plan 2014 in January 2017 for the regulation of outflows from Lake Ontario through the St. Lawrence River.
Both regulation plans were implemented following years of studies that looked at the impacts of past, present and potential future weather and climate conditions on water levels and outflow regulation, and how these factors affect socio-economic and environmental outcomes throughout the Great Lakes system.
For the various interests and stakeholders that rely on this important resource, as well as the governments, IJC and its management boards, there is a shared desire to know if the expected outcomes of these new regulation plans are being realized under recently observed hydrologic conditions and whether the plans will continue to function as expected and as conditions within the basin change.
To that end, the IJC and governments made a bold commitment to adaptive management with the establishment of a binational, 16-member, GLAM Committee in January 2015. The committee reports to the IJC’s three Great Lakes water level boards and is directed by the IJC to provide an ongoing assessment of regulation plans and examine how these plans perform under a range of actual and potential future hydrologic conditions.
The committee’s primary responsibility is to assess how well currently available scientific data, information, models and tools reflect real world conditions so that improvements and updates can be made as our understanding of the system evolves.
The GLAM Committee will use information provided by government agencies, academic researchers and key stakeholders. It will coordinate the modeling and analysis necessary to assist IJC boards with evaluating the effectiveness of existing regulation plans in managing water levels and flows over the long term and under a range of continually changing conditions.
While the committee is still in its infancy, the importance of the adaptive management process has been quickly demonstrated through a series of extraordinary events within the Great Lakes basin during the past few years. More than a decade of below-average water levels in the upper Great Lakes culminated in record-low levels on Lake Michigan-Huron in January 2013. This prolonged dry period was followed by much wetter conditions. Over the following 24 months, Lake Superior and Lake Michigan-Huron experienced some of the most rapid rates of water level rise on the Great Lakes in recorded history. More recently, extraordinary climatic conditions including significant rainfall across the Lake Ontario, the Ottawa River and the St. Lawrence River basins resulted in record high water levels in 2017 (See “Extreme Conditions and Challenges During High Water Levels on Lake Ontario and the St. Lawrence River”).
These events have had widespread and highly varied impacts. Concerns from stakeholders related to the impacts of low-water on navigation, recreational boating, and coastal wetlands shifted to concerns related to shoreline erosion, minor flooding and modified aquatic habitat conditions in the St. Marys River as upper Great Lakes water levels and outflows increased. On Lake Ontario and the St. Lawrence River, severe flooding and coastal damages have occurred following the exceptional weather conditions this year.
The GLAM Committee is reaching out to multiple agencies and partners to identify data and tools available to analyze and document outcomes from these events throughout the Great Lakes- St. Lawrence River system and sectors covering coastal interests, recreational boating and tourism, commercial navigation, hydropower generation, municipal and industrial water uses as well as ecosystem indicators including wetland habitat response.
During the past year, the committee supported the development of an integrated ecological response model of the St. Marys Rapids to help better understand and predict the effects of changing flows and water levels on fish and other aquatic habitat conditions within this critical area of the upper Great Lakes system. The model will support the evaluation of improved and more efficient gate operations of the dam situated above the rapids.
For Lake Ontario and the St. Lawrence River, this year the committee is focused on documenting, to the extent possible, the overall hydrological and climatic conditions across the basin, as well as the impacts across all sectors. This includes using surveys and shoreline imagery to look at flooding and erosion as well as damages to shore protection and shoreline infrastructure experienced along the Lake Ontario shoreline and St. Lawrence River from Kingston downstream past Montreal.
The committee also is trying to better understand the impacts to recreational boaters and cruise ships that have had to deal with inaccessible docks and boat ramps, closure of marinas and other businesses and reduced tourism revenue. At the same time, the commercial navigation industry has employed mitigation measures to ensure continued safe navigation during a period of record high outflows and increased velocities in the St. Lawrence River, the costs of which the GLAM Committee will investigate. The committee also plans to conduct field surveys of wetland plant response during this high water level year.
A few years provides only a small sample of what future water supply conditions might be like and how various interests are affected, and as a result are insufficient to fully assess the performance of a regulation plan. Nonetheless, the information gathered by the GLAM committee and through other agencies and stakeholders will be used to help inform the IJC, its boards and governments on the overall long-term performance of Plan 2012 and Plan 2014and will more immediately serve to validate and improve the models and tools used to assess regulation plan outcomes, with the aim at improving performance as more is learned and as conditions change.
This is the essence of a collaborative adaptive management process: continued monitoring and assessment to test assumptions, improve methods and determine if regulation plans are meeting expectations and will continue to do so under changing conditions.
Wendy Leger is Canadian co-chair of the GLAM Committee.
Arun Heer is US co-chair of the GLAM Committee.