DETROITDISTRICT

U.S. ARMY CORPS OF ENGINEERS

CELRE‐CHW

477 MICHIGAN AVENUE

DETROIT, MICHIGAN 48226

MARCH 2024 GREAT LAKES WATER LEVEL SUMMARY

LAKE SUPERIOR

Lake Superior declined slightly from February to March. The March monthly mean level of 601.08 feet was an inch below

its March long-term average (LTA) level, 9 inches below its 2023 March level, and 16 inches below the lake’s record high 

March level. The current 6-month water level bulletin projects Lake Superior’s seasonal rise to begin over the next month 

and continue into the summer. From April to September, water levels are predicted to be 5 to 13 inches below last year’s 

levels and 14 to 17 inches below record high levels. Water levels are projected to be 1 to 2 inches below LTA levels during 

those months.

LAKE MICHIGAN‐HURON

Lake Michigan-Huron maintained its February water level within an inch, ending March with a mean level of 578.71 feet.

This level was 2 inches above its LTA March level, 2 inches below the March 2023 level, and 33 inches below its March

record high level. Water supplies* were below average likely due to above average evaporation and near average 

precipitation. Lake Michigan-Huron is projected to start its seasonal rise in the coming month, likely reaching its peak in 

July. Water levels are projected to be 4 to 7 inches below last year’s levels and 33 to 35 inches below record high levels over 

the next 6 months. Also, water levels are forecast to be near LTA levels from April to September. 

LAKE ST. CLAIR

Lake St. Clair’s water level stayed relatively steady, ending March with a mean level of 574.80 feet. The March level was

10 inches above its LTA March level, 4 inches below last year’s level, and 25 inches below its record-high March level set 

in 2020. The 6-month water level forecast projects that Lake St. Clair will start its seasonal rise in the coming month and 

reach its peak this summer. Over the next 6 months, the lake is projected to be 3 to 6 inches above LTA levels and 27 to 

29 inches below record high levels. Levels are forecast to be 6 to 10 inches lower than 2023 levels over the same period.

LAKE ERIE

Lake Erie maintained its February water level within an inch, ending March with a mean level of 572.24 feet. This level was

12 inches above the LTA March level, 5 inches below its March 2023 level, and 21 inches below the record high March

level set in 2020. Lake Erie received substantially below average water supplies* in March likely due to below average 

precipitation and runoff. The current 6-month forecast indicates Lake Erie will continue a modest seasonal rise followed 

by a decline throughout the summer months. The lake’s water levels during this period are projected to be 4 to 11 inches 

below last year’s levels. Over the forecast horizon, water levels are projected to be 3 to 9 inches above LTA levels and 22

to 26 inches below record high levels.

LAKE ONTARIO

Lake Ontario continued its seasonal rise and increased 1 inch to a mean monthly level of 245.18 feet. The March level was 

2 inches above the March LTA level, 6 inches below last year’s level, and 25 inches below its record high level for March.

Lake Ontario also experienced considerably below average water supplies*, likely due to below average precipitation. The

latest 6-month forecast shows that Lake Ontario will continue its seasonal rise until early summer, likely reaching its peak 

in June. The lake’s levels are predicted to be 7 to 13 inches below last year’s levels from April to September. The 6-month 

forecast also predicts water levels to be between 2 to 5 inches below LTA levels over this period. These water levels are 

projected to be 28 to 38 inches below record high levels over the next 6 months.

* ”Water supplies” refers to the combined quantity of precipitation plus runoff minus evaporation. Also known as the net 

basin supply.