New report from CGLR and Mowat identifies uncertainty about future water levels, gaps in data affect climate adaptation decisions

Effectively adapting to changes in Lake Michigan-Huron water levels requires more research, balancing competing interests and a stronger adaptive management approach, says a new report from the Council of the Great Lakes Region (CGLR) and the Mowat Centre.

“Water levels in the Great Lakes are in a constant state of flux and there is a lot of uncertainty about future trends,” said Mark Fisher, President and CEO of the Council of the Great Lakes Region, a bi-national organization working to find new ways of accelerating economic growth in the region safely and sustainably. “So if we want to make the best decisions about adaptive measures and how they will affect local communities, we need to strengthen the data we have available.”

The first decade of the 21st Century saw some of the lowest water levels on record across the Great Lakes, especially in Lake Huron and Georgian Bay. Concern over low water levels prompted calls for interventions to mitigate these fluctuations or even manage water levels across the Great Lakes through a series of new strategically placed dams. A 2014 report from CGLR and Mowat calculated that if extremely low water levels persisted until 2050, the adverse effects on the Great Lakes economy could reach $18.82 billion.

“Water levels have actually risen in recent years, underscoring the unpredictable nature of the Great Lakes water system in rapidly changing conditions,” explained Fisher. “Our new report’s findings highlight the fact that gaps in currently available data may limit our public decision-making on how to respond to this reality.”

The report set out to assess the costs and benefits of the three commonly proposed responses to fluctuations in Great Lakes water levels: building dams or other water-controlling structures to restore historic water levels in Lake Michigan-Huron and especially Georgian Bay, creating a system of water-controlling structures to manage water levels throughout the Great Lakes system and adaptive management, which entails finding new and better ways of adapting to changes in water levels informed by bi-national monitoring, modelling and assessment of hydrological trends and impacts.

But researchers soon found that available data did not allow for a credible quantitative analysis of all three approaches and their economic impact across the region. A credible economic analysis could only be carried out on restoration through previously-studied water-controlling solutions, some of which date back to early and mid-20th Century and only in the context of Lake Michigan-Huron. Updating older data and using conservative economic assumptions, the report found that restoring historic water levels in Lake Michigan-Huron using such engineering solutions, after factoring in the cost of these solutions, could yield a benefit of up to $250 million by 2064.

The report concludes that it is imperative to significantly improve and update the data available to officials deciding on responses to climate change. It recommends that governments support and strengthen the adaptive management system proposed in recent years by the International Joint Commission, the bi-national body charged with helping resolve disputes over the management of water bodies shared between Canada and the United States.

“Great Lakes decision-makers must navigate a politically complex environment in which some interests benefit while others perceive to be on the losing side,” said Fisher. “Stronger data is essential for decision-makers to get the balance right.”

Maritime Editorial