Recent storms are improving the low water levels in the Great Lakes, at least a little.
Lakes Michigan and Huron hit record low levels this winter.
(See National Oceanic and Atmospheric Administration's Great Lakes Water Level Dashboard for a look at Great Lakes levels in historical context.)
Ships are carrying less cargo, and boaters have had trouble getting in and out of harbors. To help with the low lake levels, the state started emergency dredging projects for some harbors. And experts say the recent storms are also helping a little.
Keith Kompoltowicz is the Chief of Watershed Hydrology for the U.S. Army Corps of Engineers in Detroit.
It’s normal for the lakes to go up a little in the spring, but Kompoltowicz says we’ve had so much rain lately that the typical spring increases in Lakes Michigan and Huron are up by about two inches more than normal.
"There’s a huge contribution from those storms," said Kompoltowicz. "It’s looking like we came up from the first of the month through 22nd of the month. We’re up well over 5 or 6 inches, so far, from start of the month."
Two inches more on Lakes Michigan and Huron means the storms dropped 1.6 trillion gallons of water into the system.
But they’re called the GREAT Lakes, so even with all that water, Kompoltowicz says the lakes are likely to remain low.
“It’s still likely that Lakes Michigan-Huron are going to remain well below their long-term average heading into the rest of the spring and summer. Just one month of significant rainfall isn’t enough to bring the lakes back to average. You need consecutive months in consecutive seasons to get the lakes back to long term average and keep them there,” said Kompoltowicz.
Levels are coming up in the other Great Lakes as well (Erie, Ontario, and Superior), but they all remain below their levels from last year.
From the USACOE's Detroit District:
The water levels of Lakes Superior and Michigan-Huron are 4 and 10 inches, respectively, lower than their levels of a year ago. Lakes St. Clair, Erie, and Ontario are 5, 7, and 5 inches, respectively, lower than at this time last year. Over the next month, Lakes Superior and Michigan-Huron are both forecasted to rise 3 inches. The water level of Lake St. Clair is expected to remain near its current level while Lakes Erie and Ontario are projected to rise 2 and 4 inches, respectively, over the next thirty days. See our Daily Levels web page for more water level information.
Uncertain future for lake levels
When I asked Kompoltowicz about the impact global warming might be having on lake levels, he told me the USACOE doesn't make forecasts more than six months out.
On a press call, Drew Gronewold, a hydrologist with NOAA's Great Lakes Environmental Research Laboratory, said they have a hard time knowing what future lake levels will be.
Using available global warming models, the lakes could go up ... or down even more. Here's a look at their predictions:
Climate models predict warmer temperatures, which would lead to more evaporation and a loss of water in the Great Lakes. But the models also predict more precipitation in our warming climate, which could lead to lake level increases.
"The take-home message is our uncertainty in future water levels, which is rather considerable, is a direct reflection about our uncertainty in future climate," said Gronewold.