CLAYTON — The hope to further lower Lake Ontario and the St. Lawrence River water levels prompted Save the River to once again call for intermittent shipping, so more water could be released from the lake.
John M. Peach, executive director of the nonprofit, on Tuesday wrote in a letter to various officials that he wants the International Lake Ontario-St. Lawrence River Board to be able to release more water through the Robert Moses-Robert H. Saunders Power Dam in Massena and Cornwall, Ontario to lower lake levels more. In order to raise outflows, which could create unsafe conditions for shipping, Mr. Peach urged the St. Lawrence Seaway Development and Management corporations, entities that operate the Seaway on the U.S. and Canadian sides, respectively, to implement temporary, routine shutdowns of shipping.
Water levels of the Great Lakes remain above average, and Mr. Peach said if they stay high, he fears riparians and shoreline business owners could face another year of widespread flooding like this year and in 2017.
The director of Save the River referenced ending the shipping season early on Dec. 1 so the river board could release more water, but because of the possible “scheduling and logistics challenges” and supply disruptions for shipping, he said intermittent shutdowns, which he referred to as patterning, would be the best compromise and solution.
“They could do this three days on and three days off,” Mr. Peach said. “This is a pretty extreme situation we’re in.”
Outflows have been at sustained record levels for almost the entire summer in an attempt to mitigate record-high water levels, but have been decreasing since Aug. 20 to provide safer conditions for commercial shipping freighters, help reduce cross-currents and erosion. As Lake Ontario’s level drops, St. Lawrence River velocities increase as the same volume of water passes through a lower and narrower river making it necessary to reduce outflows in order to manage the dangerous currents.
The river board typically lowers outflows gradually through the fall and into winter so the water can form a stable ice cover during the winter and prevent ice jams. Outflows then increase once more.
Lake levels were 246.24 feet Tuesday, about half a foot above the historic average for this time. Outflows were 9,090 cubic meters per second Tuesday, above record and historical average outflows for this time.
Frank L. Bevacqua, U.S. information officer for the river board’s parent agency, the International Joint Commission, said while exploring options to raise outflows above regulatory constraints, the board had not considered intermittent shipping for temporary hikes. Patterning, he said, would not lower lake levels more than keeping a sustained outflow pattern.
Mr. Peach previously contended that authorities implemented patterning in 1993, but Mr. Bevacqua said it failed to yield favorable results.
“It was an experiment,” Mr. Bevacqua said.
Excessive precipitation across the Great Lakes Basin and high outflow from Lake Erie, which also experienced record-breaking water levels, were key factors in Lake Ontario and the upper St. Lawrence River experiencing unprecedented water levels this year.
The effects were compounded by a heavy snow pack along the Ottawa River basin melting a little later than usual and major rains throughout the basin in late April and into May, which led to record flows from the river into the lower St. Lawrence River. This excess water caused Lake St. Louis, located where the Ottawa and St. Lawrence rivers meet, to exceed flood stage, flooding large areas near Montreal and elsewhere in Quebec. In order to mitigate the effects of this flooding, the river board reduced outflows, backing water up on Lake Ontario.