DETROIT- Great Lake water levels in 2021 are tracking below last year’s levels, though Lakes Superior, Michigan, Huron, St. Clair and Erie remain well above long-term average levels, according to U.S. Army Corps of Engineers officials who track and forecast Great Lakes water levels.
Lake Ontario recently fell slightly below long-term average levels. The February 2021 monthly mean water levels ranged from 7 to 23 inches below levels from this time last year.
Since November 2020, the Great Lakes basin experienced four consecutive months of below average precipitation. This combined with a cold air outbreak during February led to increased evaporation across the lakes and caused a St. Clair River ice jam to develop. When ice jams occur, water levels downstream of the restriction decline, while water levels upstream of the restriction rise.