LAKE-MICHIGAN RECORD LEVELS OF 1838 - A PRESENT PERSPECTIVE

Record high lake levels for this century, set for all lakes but Ontario in 1985 and 1986, caused extensive economic losses and were a major concern of riparian interests. An analysis of early Lake Michigan-Huron water levels recorded at Milwaukee, Wisconsin, beginning in 1819 revealed an extremely high lake level regime peaking in 1838. To provide a valid comparison with recent data, the 19th century data were first adjusted to the International Great Lakes Datum of 1955 and corrected for differential isostatic rebound between Milwaukee and the outlet water level gage for Lake Michigan-Huron at Harbor Beach, Michigan. A comparison of the 1838 lake levels with the recent records indicates the former to be approximately 50 cm higher than the record set in 1986. A future recurrence of the climatic conditions causing the 1838 high lake levels would have a severe outcome for riparian interests throughout the Great Lakes region. © 1990, International Association for Great Lakes Research. All rights reserved.