Great Lakes Water Levels – Some River Levels

Bill's Blog

The top pic. is the Muskegon MI Channel Friday AM (9/24/21). You can see the Lake Express Ferry heading west toward Milwaukee. After 4 straight mostly cloudy days, it was nice to see some sunshine today in W. Michigan. The high temperatures of 60° on Wed. and 57° on Thu. in G.R. were the coolest days we’ve had since last May.

The water levels of the Great Lakes are at or below the levels of one year ago. Lakes Superior, Michigan and Huron are significantly lower than last September.

Graph of the Water Level of Lake Superior

The water level of Lake Superior was unchanged over the last 10 minutes, BUT…the level is 10″ lower than one year ago. Lake Superior is now 1″ LOWER than the September average level an 13″ lower than it was in Sept. 2019. A drop of 10″ represents a loss of 5.5 TRILLION gallons of water. The main cause of this has been below average precipitation. Marquette MI has had 19.85″ of precipitation this year…that’s 6.47″ below average. Duluth MN has had 19.15″ of precipitation this year and that’s 5.03″ below average.

Because the water level of Lake Superior is below average now, the average flow of water down the St. Marys River into Lake Huron-Michigan is also below average. The flow on the St. Marys River is dependent on the wind speed and direction. As I type this, the flow on the St. Marys River at S. Ste. Marie is 48,300 cubic feet per second, The average flow for today is 87,600 cfs. That seems like a big difference. The wind as I type this at S. Ste. Marie is southeast at 13 mph. Since the St. Marys River flows northwest to southeast…a southeast wind pushes on the water and slows the flow down the river. A northwest wind would speed up the flow of water down the river.

Graph of the Water Level of Lake Michigan-Huron

The water level of Lake Michigan-Huron (one lake for lake level purposes connected at the Straits of Mackinac) is down 2″ in the last month and down 14″ year-to-year. The lakes are still 16″ above the September average level, but we are 17″ below the record level set in the fall of 1986.

Graph of the Water Level of Lake Erie

The water level of Lake Erie is down 3″ in the last month and down 3″ year-to-year. The lake is still 20″ above the average September level, but it’s 7″ below the record high September level set in 2019.

Graph of the Water Level of Lake Ontario

The water level of Lake Ontario is also down 3″ in the last month. The level is unchanged from one year ago and is just 1″ higher than the September average. Lake Ontario is now 25″ lower than the record high September level set in 1947,

Graph of the Water Level of Lake St. Clair

The water level of Lake St. Clair 3″ higher than it was one month ago. The lake is down 2″ from one year ago and is still 25″ above the September average. It’s 5″ lower than the highest September level.

The flow on many Great Lakes rivers rose significantly this week due to moderate to heavy rainfall. Isolated weekly totals of 6″ were reported in SE Michigan. Grand Rapids had 1.64″ of rain from Monday – Thursday.

The Grand River at Grand Rapids has a flow of 2,850 cfs (as I type this), compared to an average flow of 1,650 cfs. The Kalamazoo River at Kalamazoo has a flow of 1,470 cfs, compared to an average flow of 531 cfs. The St. Joseph River at Niles has a flow of 3,140 cfs – average is 1,980 cfs and the Muskegon River at Croton has a flow of 1,680 cfs, compared to an average flow of 1,160 cfs. So, there is more water going down the Muskegon River at Croton right now than the average amount of water that goes down the Grand River in late September.

The Saginaw has at Bay City has a flow of 2,210 cfs, compared to an average flow of 911 cfs. The Fox River at Oshkosh WI has a flow of 3,070 cfs compared to an average flow of 2,880 cfs.

GREAT LAKES NEWS:

Copyright 2021 Nexstar Media Inc. All rights reserved. This material may not be published, broadcast, rewritten, or redistributed.

Weather Tools