Heavy rain, snow melt, not water management to blame for last year's flooding, report says
Record-breaking wet weather and not poor water management was to blame for the flooding on Lake Ontario in 2017, according to a report released Thursday by a binational body responsible for managing water outflows on the lake.
The International Lake Ontario-St. Lawrence River Board (ILOSRB) concluded that natural weather factors came together last winter and through the spring to cause the worst flooding along the shores of Lake Ontario and along the St. Lawrence in a century.
The ILOSRB is responsible for regulating the outflow of water from Lake Ontario through an international dam located on the St. Lawrence River at Cornwall, Ont., and Massena, New York.
The board, which is composed of appointed scientists and water managers from both sides of the border, has faced criticism for not doing more to prevent flooding by opening the dam earlier.
"This was and extreme event — a perfect storm, if you will," said Tony David, program manager for water resources with the St. Regis Mohawk Tribe, a U.S. member of the ILOSRB board.
He says Lake Ontario experienced record high water levels due to record amounts of precipitation — the most since 1942. By the end of May, the lake level exceeded all previous measures since records began being kept in 1918.
But David says the tools at the board's disposal had an only limited effect.
"The board manages outflows. The board does not control Lake Ontario water levels," he said.
People on Toronto Island, meantime, agree it was most likely Mother Nature, not human error, that was responsible for much of the spring and summer flooding.
"Weather systems are hard to predict ," said Zorah Freeman-McIntyre of the Island Cafe on Ward's Island.
Last year flooding had a major impact on the family run business. While the cafe remained open, most the island's parkland was closed due to extensive damage and that meant fewer customers.
"There have been floods on the island every 20 years or so. It was sort of on time, but on a larger scale than we've experienced before," he said.
But on the U.S. side of the lake, many demanded the flood gates be opened, even though impacts downstream would be made even worse. Each centimetre of water level released from Lake Ontario raises the water level in the St. Lawrence River by 10 centimetres.
The report notes that the Ottawa and St. Lawrence Rivers were experiencing similar conditions downstream with record precipitation in April combined with snow melt.
By April 20, the Ottawa River reached a record peak and because it flows into the St. Lawrence River near Montreal, more water from Lake Ontario could have made the problems there even worse.
The higher flows caused by the release of more water would also have increased currents and posed a risk to commercial shipping, according to the report.
The board's report also suggested waterfront communities in upstate New York are still at risk from future floods and should come up with "coastal resiliance" plans.
"2017 will certainly be significant in our understanding ," said Arun Heer, co-chair of the Great Lakes-St. Lawrence River Adaptive Management (GLAM) Committee. "Extreme conditions also exist with low water levels,"
Canada and the United States created the International Joint Commission (IJC) in 1909, an independent agency to regulate shared water bodies and settle disputes.The IJC decides the water management policy for the ILOSRB.
In New York State local politicians have been lobbying U.S President Donald Trump to replace all the American appointees to the IJC with commissioners who may be more receptive to the concerns of waterfront communities.
