Georgian Bay water levels near record high
May 27, 2019 by Ian Adams Wasaga Sun
Drop by drop, Lake Huron’s water level might be closing in on a record high.
Seven years ago, water levels were at their lowest, following a sustained 15-year period during which lakes Huron and Michigan remained below chart datum of 176.5 metres.
Concerns were raised about the impact on marinas and wetland areas; for instance, the Collingwood Yacht Club moved its docks into the harbour area when its basin became too shallow for the keels on some members’ boats.
“The extreme highs and the extreme lows hurt a lot of things and a lot of people,” said Joe Hayward, a Craigleith resident ( and an advocate for seeing better controls of water levels in Lakes Huron and Michigan, pictured above) who is a member of the Georgian Bay Great Lakes Foundation and has been active in campaigning for awareness about falling water levels.
For instance, he noted, the low water levels had a negative effect on fish spawning habitat. On the other hand, high water levels can have an impact on waterfront property — something he experienced personally in 1986 when he had to take steps to keep waves from lapping up against his home.
In mid-2013, Huron experienced an abrupt swing the other way, and has had a positive inflow (a combination of precipitation and runoff) versus outflow (a combination of precipitation and flow through the St. Clair River) for four of the last six years.
In mid-May, the level was, on average, 20 centimetres higher than it was the previous May.
Hayward is not convinced the trend is reversed, however, or that the lake will reach its 1986 high — ever.
“It is a cycle … since the turn of the century. The problem is the slope of the cycle continues to go down, and the best research says it’s still doing that,” he said, joking that in recent months friends have congratulated him for “saving Georgian Bay.”
Keith Kompoltowicz, chief of watershed hydrology for the U.S. Army Corps of Engineers, Detroit District, said he doesn’t anticipate the middle lakes to reach record highs — although the corps does forecast records for Superior, Erie and St. Clair.
However, he noted, the water in Huron and Michigan will be at the highest level experienced since the record high in 1986.
The corps will produce its next forecast at the end of May, and Kompoltowicz anticipated water levels will be approximately 15 centimetres below record highs.
“As we go through the rest of the summer, there is a chance the upper end of our forecast range might approach record highs with very wet conditions, but right now it doesn’t look like the levels will reach a record,” he said.
The forecasts are based on modelling of the inflow and outflow into the lakes; evaporation, however, is difficult to measure and predict..
“It’s not like rainfall where you see it happening; evaporation is one of the things we’re trying to better understand,” Kompoltowicz said. “You have to do some calculations and measurements and make some assumptions to get what we think is the best estimate.”
Brent Lansing, a physical scientist with the National Oceanic and Atmospheric Administration’s Great Lakes Environmental Research Laboratory (GLERL), said research from the University of Wisconsin found less cloud cover, allowing sunlight and the resultant heat to get into the lakes, during the period of low water levels.
“One of the things I emphasize about evaporation, it’s caused by getting heat into the surface you’re evaporating from,” he said. “People make the mistake, thinking about heating up the air, but it’s more about important to heat up the actual water.”
The experts say there’s not enough information to determine if this is a natural cycle.
“If people say there’s a strict timing to the cycle, I would say no,” Lansing said. “We don’t have a good theoretical understanding of why there may be something like that.”
“It’s not enough data to say there are 30-year cycles, or 10-year cycles. It’s just not a long enough period of record,” Kompoltowicz added. “We’ve certainly experienced over the past decade both ends — very low and very high — and that’s a result of shifting weather patterns over the Great Lakes.”
Hayward said the governments on both sides of the border have an opportunity to act and prevent extreme highs and lows in the middle Great Lakes. The International Joint Commission has only two points of control for lake levels — at the St. Mary’s River, where water from Superior enters Huron-Michigan, and where Ontario empties into the St. Lawrence River.
Hayward said controls in the St. Clair River — for which there have been plans since the late 1960s — should be implemented. Groups concerned with water levels in Huron and Michigan often point to dredging that took place in the St. Clair prior to the 1960s, to assist in navigation, as the reason for lower levels.
“The solution is there and ready to go; the IJC and government are well aware of it,” he said. “You’re protecting yourself to a degree — it’s not perfect, but you’re protecting from extremely high waters, or going too low.”
by Ian Adams
Ian Adams is a reporter for Simcoe.com, covering community news and events throughout south Georgian Bay, and municipal councils in Collingwood and Wasaga Beach.