Jonathan Migneault | CBC News | Posted: May 15, 2025 9:00 AM | Last Updated: 2 hours ago
Less rainfall than normal in the fall a key factor for lower water levels
Image | Lake Superior
Caption: Water levels at Lake Superior are 18 centimetres below the long-term average. (Nicky Shaw/CBC)
All of the Great Lakes, except for Lake Erie, are below their average water levels for this time of year due to a relatively dry fall, according to measurements from Environment and Climate Change Canada.
Water levels for Lake Superior and Lake Ontario are at their lowest since 2013, and Lake Michigan and Lake Huron are at their lowest level since 2014, according to a
new reportfrom Environment Canada.
Frank Senglenieks, a water resources engineer with Environment Canada who co-authored the report, said water levels for each of the great lakes can fluctuate by as much as two metres from one season to the next.
He said water levels for the Great Lakes have been higher than average for the last 10 years, so the change this year could come as a shock to people who have property near the lakes or use them recreationally.
"That rock that you haven't had to think about for 10 years, well, now it's actually going to be a little bit closer to the surface," he said.
Senglenieks said fluctuations in water levels for the Great Lakes are part of a natural cycle, but those are expected to increase because of climate change.
"What we see in our climate change research for water levels is more extreme, so even higher highs, but even lower lows," he said.
"So even where I said the range was about two metres for each lake. So, you know, add 30 or 40 centimetres on either side of that."
He added that it would take higher than average rainfall this summer for most of the Great Lakes to return to average water levels.
Image | Tropical Weather hurricane fiona satellite
Caption: The National Oceanic and Atmospheric Administration in the United States, which is responsible for weather forecasting and tracking atmospheric and oceanic conditions, has has significant cuts under U.S. President Donald Trump. (NOAA/AP)
CBC News contacted the National Oceanic and Atmospheric Administration (NOAA)— the federal agency in the United States responsible for weather forecasting and tracking atmospheric and oceanic conditions, including the health of the Great Lakes— for its data on water levels.
A spokesperson responded that NOAA was undergoing restructuring and did not have anyone available to provide comment.
The agency has faced significant cuts under U.S. President Donald Trump. By March, roughly 1,300 NOAA staff members had resigned or had been laid off.
Seglenieks said the changes are concerning from the Canadian side of the lakes.
"We've got a great relationship with our U.S. counterparts for sure," he said.
"They are going through some things, obviously funding and different other issues."
Seglenieks said that so far, however, Environment Canada has continued to receive water level data from American counterparts.
"We have some contingency plans in case that data source stops or is interrupted," he said.
