Are Lake Levels on the Rise?
Charles Shabica, Ph.D., P.G.: Spring 2014
One day in April 2014, Lake Michigan water level was up 2 ½ feet as compared to last year. According to observations documented by NOAA, Lake Michigan’s water level reached 579.2′ (IGLD 1985) at Calumet Harbor on April 14, 2014. That’s 2 ½ feet above the average lake level from April 2013. It was a temporary spike. Hourly and daily fluctuations in water levels are normal, but this high water level hasn’t been recorded in years. The monthly average lake level of Lake Michigan is higher but only by a foot as compared to last spring.
Many of our Lake Michigan clients have reported significant narrowing in their beaches this spring. There are two reasons why beach widths typically narrow – a reduction in sand supply, or an increase in lake level. This year, an 11-foot loss in beach width may simply be the result of a 1 foot rise in lake level. Over the last decade, Great Lakes levels have been lower than average, leaving wide beaches in many locations. The record low level was set in January 2013 after 10 years of warm weather, high evaporation rates and low levels of precipitation. The record high level in Lake Michigan occurred in 1986. It appears that the lakes may be on their way up.
Over this past winter, most of the Great Lakes region saw higher than normal snowfall causing a rise in lake levels. And for the first time in decades, ice-cover on the Great Lakes reached 93% or more (excepting Lake Ontario at 43%). This means colder lake water for the summer and fall seasons of 2014 and less evaporation off the lake surfaces resulting in higher lake levels.
Great Lakes water level predictions are based on computer models including the Advanced Hydrologic Prediction System model run by NOAA’s Great Lakes Environmental Research Laboratory (GLERL). According to NOAA, the “forecast generated by NOAA-GLERL’s AHPS on February 10, 2014 indicates that the water levels of Lake Michigan and Huron will be significantly higher this summer than during the summer of 2013. Lake Superior may be slightly higher than last year, and Lake Erie water levels will be similar to 2013” (http://www.glerl.noaa.gov/pubs/brochures/lakelevels/lakelevels.pdf).
For more information on daily Lake Michigan water levels, visit the NOAA website.