The Great Lakes and Lake St. Clair have broken 100-year old water level records and forecasters expect the trend to continue.
The U.S. Army Corps of Engineers Detroit District says three months of abnormally wet spring weather kept stream flows into the Great Lakes well above average and water levels continued to rise in June – reaching some of the highest levels in recorded history. The recorded levels are monthly mean levels and the record highs are relative to a 100-year period from 1918 to 2018. The Corps says new record high monthly mean water levels were set on Lake Superior, Lake Erie, Lake Ontario and Lake St. Clair in June. Lake St. Clair is part of the waterway linking Lakes Huron and Erie. Previous records for Lakes Superior, St. Clair and Erie were all set in 1986, while the previous Lake Ontario record was set in 2017. Technical Lead for Great Lakes Hydrology Lauren Fry says those lakes all broke previous records by three to four inches, while Lake Michigan-Huron was less than one inch from its June record. She says there was a very wet spring and in June, there was above average precipitation across the Great Lakes basin – which was the third consecutive month of above average precipitation. The persistently wet weather also allowed stream flows into the Great Lakes to remain well above average for this time of year.
The higher water levels mean the Great Lakes region will continue to see the threat of coastal flooding and shoreline erosion, especially during storm events. Localized water levels are often impacted by winds and can be significantly higher during storms. With the action of waves happening at higher levels, Fry tells WHMI it is more likely to be impacting infrastructure and there is more lakeshore flooding but especially when there is a meteorological condition setting up water level differences. Fry says water levels can be very different from one end of a lake to the other, for example if there is a westerly wind pushing water to the east. She says while those meteorological conditions happen all the time, the impacts are really becoming more important at these higher water levels. She says flooding and shoreline erosion result, especially during weather events that cause wind and wave action. The high water levels have resulted in flooding along many waterfront communities in different areas of the state. Recently sandbags were placed along the Detroit River and near canals as water has been flowing over aging seawalls – flooding basements, homes and streets.
Fry says predictions are showing that above average water levels on all of the lakes will continue and additional record high water levels are possible on all of the Great Lakes and Lake St. Clair this summer. More information on the levels can be found through the provided link. (JM)