The Environment Report
2:52 pm
Thu February 27, 2014

What all the snow and ice will mean for Great Lakes water levels

It might seem a little counterintuitive, but right now, a bunch of scientists are thinking about how high the water at Great Lakes beaches will be this summer.

Early last year, the Lake Michigan-Lake Huron system hit record low water levels.

It made life tougher for the shipping industry, and it’s hard on people who run Great Lakes ports.

Russell Dzuba is the harbor master in Leland.

“For us, it’s shallow. When we went to dredge this year we had to go a foot deeper and the world was a foot shorter, if you will,” he says.

When we finally have a spring thaw...

All the snow we’ve gotten this winter has a lot of people hoping lake levels will rise when that snow melts.

To find out if that’ll happen, I met up with Drew Gronewold. He’s a hydrologist at NOAA’s Great Lakes Environmental Research Laboratory.

“So, what we’re observing right now is that while there’s a lot of snow, there’s not really an anomalous amount of snow relative to the historical record. For example, it’s not the most snow we’ve ever had,” he says.

But he says they can estimate how much water is captured in the snow that’s on the ground right now. He says around Lake Michigan and Lake Huron there’s roughly 3 to 5 inches of water in the snow that will eventually melt and run into the lakes.

So, what does that mean for lake levels? Gronewold says they’re expecting an average or maybe slightly above average rise in water levels this spring.

"Some of the models suggest that a rise of 20 inches isn't out of the question. The models also suggest, though, that a rise of 6 inches might not be out of the question, due to all the combinations of environmental factors that we simply can't predict, including temperature and precipitation, three, four months from now."

Gronewold says they work in partnership with the U.S. Army Corps of Engineers. The Army Corps puts out an official water level forecast.

Ice, ice, baby

So what about all the ice on the Great Lakes? As Mark Brush explained in a post yesterday, it's been a frosty year for the Lakes: ice cover reached a maximum of 88% this year.

Drew Gronewold says that ice helps keep the lakes cool, and that'll cut down on evaporation later in the year.

"When we have a lot of ice, like we do right now, it's going to take a lot of solar energy to melt that ice and to begin warming the water up again. And as a result, it's very likely that water temperatures next fall are going to be cooler than they have been in the past several years. And if we have cooler water next fall, that'll mean less evaporation again, and water levels will not decline as much as they typically have been in the fall. That's one of the more profound effects of ice cover right now, is that it'll really help the lakes maintain a temperature throughout the season."

It'll also make for some chilly summer swimming. Wetsuits, anyone?

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