According to the U.S. Army Corps of Engineers, as of Tuesday, water levels in Lake Michigan and Lake Huron have reached their lowest levels since record-keeping began, nearly 100 years ago.
Concerns had already been raised since the end of last summer, due to a combination of last year's warm, dry La Nina winter, followed by low rainfall amounts coming into the Great Lakes region due to the drought in the United States, and a late start to the snowy weather this winter. These natural effects are possibly enhanced by climate change, as greenhouse gas emissions continue to turn the global temperature up, however there is a more direct man-made reason that contributes to the low water levels.
“Plunging water levels are beyond anyone’s control, but the dredging crisis is man-made,” said James Weakley, according to the Toronto Star. Weakley is president of the Lake Carriers’ Association, in Cleveland, Ohio.
The entire Great Lakes Basin is well above sea level, so water from the lakes naturally flows down and to the east, out into the Atlantic Ocean. The rivers between the lakes —such as the St. Clair River — have acted as a natural limiting factor to how much water can drain out of the lakes for years. However, dredging projects have opened up these rivers to more than just larger shipping traffic. Studies have shown that water levels in Lake Michigan and Lake Huron have dropped by up to 45 cm just from the dredging of the St. Clair River alone.
Currently, Lake Michigan and Lake Huron measure nearly 74 cm below their long-term average for the month of February. That's the lowest level in those lakes since 1918, when record-keeping started, and nearly half of that was lost just in the past year. Levels in Lake Superior, Lake Erie and Lake Ontario are also below the long-term February average (~28 cm, ~15 cm and ~15 cm, respectively).
“We’re in an extreme situation,” said Keith Kompoltowicz, watershed hydrology chief for the Detroit district office of the U.S. Army Corps of Engineers, according to the Toronto Star.
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Plans had been drafted by the corps to reduce the drainage as early as 1972, however lake levels had been going through a natural high point up until the late 1990s, so little action was taken.
Reports released by the International Joint Commission (IJC) — a U.S.-Canada agency that was appointed to deal with the various issues regarding the shared waterways along the U.S.-Canada border — in 2009 and 2012 did not offer support for plans to control the amount of water flowing through the St. Clair River. Scientists and engineers with the IJC are currently reviewing public comments from last year's report, and should be issuing a statement sometime in the next month.
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