Lake Erie and Lake Superior broke records for average water levels in May, as did Lake St. Clair on Detroit’s eastern edge, according to the U.S. Army Corps of Engineers. In May, Lake Erie also reached its highest level on record for any month.
Record- or near-record-high water levels are forecast to continue in the summer before making the usual downturn into fall.
Damage to lakeshore property was reported again this week along Lake Ontario in Upstate New York in the town of Henderson.
“There’s houses surrounded by water, water going into houses and lake water in the roads,” Eric Anderson, an operations coordinator for the Henderson Fire District, told the Watertown Daily Times. “Carp are feeding in people’s front lawns.”
This kind of flooding has occurred along the shores of the Great Lakes for months, in some places repeatedly, and intensifies during high-wind events and storms.
Major winter snowfalls and excessive rainfall are primary drivers for high water this year.
Normal water levels in the Great Lakes are largely modulated by precipitation, natural springs and rivers. Great Lakes water levels typically rise during the spring into summer, but this year it has been extreme.
Year-to-date precipitation in much of the Great Lakes region is running 150- to 200-plus percent of normal. Only the Lake Ontario region has seen somewhat lesser amounts, though it has still endured flooding. Winter saw record snowfall. Last year was also fairly wet.
Although rainfall surpluses have continued to be significant in recent months, the past few weeks have seen a drier pattern take hold. But this drier spell may not last, and only persistent dryness would meaningfully reduce the risk of future flooding.
The outlook from the U.S. Army Corps of Engineers indicates monthly mean water levels for June are likely to meet or surpass record highs for that month.
Water levels are forecast to continue rising through June on Lake Superior and through the heart of summer. For Superior, levels are anticipated to stay near or above previous monthly records every month through September.
Lakes Michigan and Huron also are likely to see additional rises of several inches through June. Elsewhere, lake levels are anticipated to fall but remain near or above record levels for that time of year.
Although water levels in the Great Lakes are in constant flux, the recent observed shifts have been particularly extreme.
“Over the past two decades, water levels on the Great Lakes have gone through an unprecedented period of persistent below-average conditions, a record-setting rate of water level rise and, now, a series of record-setting high levels,” said Drew Gronewold, a hydrologist at the University of Michigan.
While experts work to better understand the effects of climate change on Great Lakes water levels, they are seeing increased evidence of a new normal, characterized by rapid shifts between extreme high and low levels. To see this in action, we need look no further than the flooding of today, compared with the record lows six years ago.
“We are undoubtedly observing the effects of a warming climate in the Great Lakes,” wrote Richard Rood, a University of Michigan climate scientist. “We are at the beginning of what’s going to be a number of decades where the climate is going to be changing very fast. During that time, we will have many unexpected weather events, and we need to learn from these events to better prepare for the future.”