If you live in the Southern Georgian Bay area you have undoubtedly noticed the water level is lower this fall than it has been in recent years. The question you may be asking yourself, is this just a seasonal shift or are there are other factors influencing this change?
Of the five Great lakes, Lakes Michigan and Huron which includes Georgian Bay is 132,600 square kilometers. They are at the same level and as such any deviation in the water level is equal across all three. These three bodies of water are also unique in that there are the only lakes of the five for which there is no control of their outflowing water. Water flows down the St Clair River at the southern most tip of Lake Huron whereas Lake Superior, Erie and Ontario have locks which are part of the St Lawrence Seaway System for the most part keeping their respective water levels in check.
As I write this post I have just returned from my family cottage on Manitoulin Island. My mother was born and raised on Manitoulin and I have spent every summer on the island since I was an infant. We have owned our family cottage there since 1973, it is located just off Lake Huron at South Baymouth. During my fifty-one years of ownership and even prior to that as a kid, I have seen the lakes go through many cycles where the water level has both risen and fallen, at times quite dramatically. Growing up I was told there is a 7 or 9 year cycle and even today, some people claim there is a regular cycle of ups/downs and “not to worry.”
The chart below shows a history of the water levels in the Great Lakes from 1918 to 2024. As you will note Lakes Michigan and Huron which includes Georgian Bay are on the same graph as their water or level of elevation above sea level are the same. On this chart, the red line measures the “Long Term Annual Average” water level while the blue line shows the “Monthly Mean Level.”
Around 1926 Lake Superior had a significant drop in its water level as did Lakes Michigan, Huron and St Clair. The water level in Lakes Erie and Ontario also declined around that time frame but not to the same degree. During the following ninety-eight years, Lake Superior had many ups and downs in its water level but when you look at the graph for Lakes Michigan and Huron the changes to the water level in those lakes is much more pronounced. Around 1964/1965, the water level in these lakes reached a record low only to then rebound during a 22 year period reflecting annual increases in the water level up to 1987. During the 3 years from 1987 to 1990, the water level did decline slightly coming back to a high point in 1989 before falling below the Annual Average from 1999 to 2015 (16 years). From 2015 to 2020 the water level in Lake Michigan and Huron (including Georgian Bay) rose significantly once again reaching a near record high in 2020. Since that time the water has been in a declining cycle. Clearly, this 106 year old chart shows many ups and downs and there is no 7 year, 9 year or any other “repetitive” cycle that some claim or believe exists.
As shown above, in the late 1980’s, the water in these three bodies of water was at or near a record high level before going through over 25 years of decline to a record low in 2012/2013. It was during this cycle that “Stop The Drop” signs began appearing around the Southern Georgian Bay area with many waterfront property owners and community groups raising an alarm. In the spring of 2013, the start of the ferry service to Manitoulin was delayed until modifications were made to the docks at both Tobermory and South Baymouth in order to allow the Chi Cheemaun ferry to dock and unload vehicles. The photo below is my cottage shoreline in the summer of 2013.
Summer 2012
In 2019 and 2020 the water level in Lakes Michigan and Huron increased quickly and rather unexpectedly rising to a near record high. The shoreline at my cottage was no longer walkable as shown in the photos below, the water was up into the trees. Many including myself were surprised by the sudden rise while at the same time asking, how long with this last? These pictures show a sharp contrast to 2013. Fortunately I have a lengthy light weight aluminum that is easy to put in and take out both spring and fall allowing us to adjust its placement depending on the water level. Other waterfront property owners around the Georgian Bay area are no so lucky especially if their cottage is boat access only and their dockage is fixed.
Summer 2020
Summer 2020
Since 2020 the water level has consistently declined and at a rapid rate. Today, approximately one metre of water has disappeared from the aforementioned lakes covering 132,000 square kilometers. The photos below show where the water level is as of this post. The brown rock in the photo above is today, high and dry, well away from the water’s edge.
November 2024
November 2024
November 2024
The big question where has all the water gone and what is the cause? Let’s explore what’s behind the drop in water levels and what it might mean for our environment and communities both now and in the future.
- Natural Weather Patterns
- Temperature Changes: In the warmer months, higher temperatures lead to increased evaporation from the lake surfaces. When temperatures stay elevated for longer periods, as they have recently, more water evaporates, causing levels to drop.
- Precipitation Variability: Rainfall is a critical source of water for the Great Lakes. When rainfall is low, less water flows into the lakes. Recent periods of dry weather and less-than-average rainfall have reduced the amount of water feeding into Lakes Michigan, Huron, and Georgian Bay.
- Increased Evaporation Rates
- Warmer Water and Air: Higher air temperatures warm the lake surfaces, especially in the summer and fall. Warmer water evaporates faster than cooler water, and with climate patterns bringing warmer seasons, the rate of evaporation has increased. This water loss is a significant contributor to the current drop in lake levels.
- Ice Cover Changes: Ice cover on the Great Lakes acts like a natural barrier, slowing down evaporation in the winter months. However, warmer winters have led to less ice coverage in recent years. Without this protective layer, the lakes lose more water to evaporation, even during colder months.
- Climate Change Impact
- Altered Weather Patterns: Climate change is causing more frequent and extreme weather patterns, including both periods of heavy precipitation and drought. While heavy rain can temporarily raise lake levels, extended droughts can have a lasting negative effect, depleting levels over time.
- Longer Warm Seasons: With warmer temperatures extending further into fall, lakes remain in the “evaporation zone” longer than they used to. This extended period of warm water increases water loss across Lakes Michigan, Huron, and Georgian Bay.
- Changes in Lake Outflows
- St. Clair River Flow: Lake Huron drains into the St. Clair River, which eventually flows into Lake Erie. Factors such as dredging or changes in flow rates through the St. Clair River can affect water levels in Lakes Michigan, Huron, and Georgian Bay. If outflow increases, water levels can drop more rapidly.
- Human Influence: Some human activities, like dredging for navigation or controlling water levels for hydroelectric power, can impact the flow and retention of water in these lakes. While these activities are often managed with environmental considerations in mind, they can still play a role in water level changes.
Summary
Clearly there are a number of factors affecting the levels of these lakes. From my perspective and I suspect others, the changes we are currently seeing are more frequent and pronounced. It has been a number of years since we last saw winter ice coverage on Georgian Bay and last winter brought us very little in the way of natural snowfall. Many times while out skiing we were able to look at a wide expanse of open water with little to no ice anywhere in sight. Last winter there was for the first time ever, virtually no ice on South Bay, a body of water 18 miles long where my Manitoulin Island cottage is located and most of the Great Lakes remained ice free all winter. While this past summer was not unusually hot, it was in many areas very dry with no significant rainfall to offset the evaporation rate mentioned above.
Many years ago it was brought to my attention by an environmental engineer that the earth has a fixed amount of water, it just gets moved around driven by weather and more so today due to climate change. In part 2 of this post I will cover what this apparent shift is going to have on our use and enjoyment of the lakes and in particular the impact it may have on real estate values for those like me that own waterfront properties in the affected areas.
The author is a Broker, Market Value Appraiser-Residential with Sotheby’s International Realty Canada and a Past President (2008) of the Lakeland’s Association of REALTORS®.