CLEVELAND - Over the past dozen or so years, there has been a lot of buzz in the media about the Great Lakes water levels. Scientists have made repeated claims that the Great Lakes are drying up due to global warming/climate change/climate disruption.
Back in 2003, the Union of Concerned Scientists published a "fact sheet" stating just that. "Lake levels are expected to decline in Lake Erie as more moisture evaporates due to warmer temperatures and less ice cover," says the report. "Rainfall cannot compensate for the drying effects of a warmer climate, especially in the summer."
According to the report, climate change is warming the Great Lakes, including Lake Erie. This warming will cause increased evaporation and lower water levels. Reduced summer water levels are likely to diminish the recharge of groundwater, cause small streams to dry up, and reduce the area of wetlands, resulting in poorer water quality and less habitat for wildlife. Development and climate change will degrade the flood-absorbing capacities of wetlands and floodplains, resulting in increased erosion, flooding, and runoff polluted with nutrients, pesticides, and other toxins.
Wow. That sounds serious!
Lets examine the data. According to the April Great Lakes water level report from the Army Corps of Engineers, Lake Erie's water level is ABOVE the long term April average.
Yes, I said water levels are above normal.
Lake Erie's long term (1901-2010) April average water level is 174.22 meters. As of April 1, 2012, Lake Erie's water level was 174.36. The graph included with this story shows water levels for our shallowest great lake over the past 100 Aprils. Notice the ebb and flow of water levels by decade. Also notice the lowest lake level was back in 1934! We are nowhere near record low water levels.
In fact, none of the Great Lakes have been setting low water level records. The lowest recorded level for Lake Superior for April was in 1926 and for Lake Michigan and Huron (which geologists consider to be one lake) the April low was in 1964. The lowest April mark for Lake St. Clair was in 1926 and the lowest April level for Lake Ontario was in 1935.
Here are this month's Great Lakes water level gage readings compared to the long term (1918 to 2011) April averages (in meters).
Lake Superior's long term average — 183.26, April 1 — 182.98
Lake Michigan/Huron's long term average — 176.39, April 1 — 176.04
Lake St. Clair's long term average — 175.04, April 1 — 175.02
Lake Erie's long term average — 174. 22, April 1 — 174.36