WHEN THE FLOODS CAME
Unusual ice conditions, wet spring, yo-yo winter blamed for deluge of 2017
Study says 2017’s record-breaking water levels in Lake Ontario were bound to occur, no matter which control system was in place,
It didn’t matter which operating plan was used to control the deluge of 2017 — likely the “most extraordinary to ever occur” in Lake Ontario and the St. Lawrence River — flooding was bound to occur, according to a recently released report. “The total amount of water entering the system was overwhelming, setting records both at Lake Ontario and in the St. Lawrence River, causing a record rise in water levels,” says the report, produced by the International Lake Ontario St. Lawrence River Board, which is appointed by the In- ternational Joint Commission. The flooding, triggered by a yoyo winter, “unprecedented ice conditions” and a wet spring, caused “severe damage and distress,” it says, noting that from January to the end of May, Lake Ontario rose about 1.4 metres. “We had a flooded Lake Ontario flowing into a flooded St. Lawrence River. That’s what it boils down to, and that went on for weeks,” said Rob Caldwell, secretary of the board. The event broke multiple records and the board took exceptional measures. The board controls outflows from Lake Ontario with the Moses-Saunders Dam, which stretches between Cornwall and Massena, N.Y., Caldwell said. Ancillary to it is the Long Sault Dam. Water levels were so high that the board discharged more wa- ter from the dam than it otherwise would. In late May, it increased outflows above levels set out in the regulation plan, in order to lower water levels in the lake and provide relief. The discharge from the dam was eventually reduced in early August. The board implemented a new regulation in January 2017 called Plan 2014. Caldwell said “major deviations” cannot be undertaken until extreme levels are reached. Frank Sciremammano, a former member of the board, said he agrees with the report, noting the flooding “would have occurred anyway.” But he has a bone to pick with Plan 2014 because all damages were lumped on Lake Ontario, particularly the south shore, he said. “It’s inconsistent with protection against extremes.”