Great Lakes monitors slow the flow; will explain in virtual meetings this week
Those responsible for monitoring and managing water flow in the Great Lakes have deviated from their usual flow controls to address lower-than-average rainfall totals they say raise concerns for levels in Lake Ontario and the St. Lawrence River. This week, the body that watches those two waterways under the guidance of the International Joint Commission is hosting online meetings to explain current conditions and their decisions in response to them.
According to the Great Lakes Environmental Research Laboratory and the US Army Corps of Engineers, the most recent 12 months over Lake Ontario were the driest since 1966. With very low rainfall, Lake Ontario’s level rose less than an inch in May. On average, it rises by more than three and a half inches.
The International Joint Commission moved recently to reduce outflows at key points along the St. Lawrence River, in order to slow the overall flow of water out Lake Ontario, up the St. Lawrence and out to sea. The idea is to avoid losing too much water to outflow and driving levels too low.
“What they've done is they've cut flows by approximately 7,000 cubic feet per second, below what the planned flows would be over the last couple of weeks, and their plan is to continue that through June 19,” said Bryce Carmichael, the US Section Secretary for the International Lake Ontario - St. Lawrence River Board, which oversees that portion of the Great Lakes system. “Continue those low cuts, and that will help store a little bit of extra water on the lake.”
The board is hosting a pair of virtual meetings this week to explain current conditions in their portion of the Great Lakes system.
Two years ago, and two years before that, engineers were facing the opposite when lake levels resulted in flooding along the southern Lake Ontario shoreline. Governor Andrew Cuomo, while visiting one of the flood sites, had referred to an increase in weather extremes as "the new normal."
Carmichael says it's a delicate operation, working to keep lake waters at a level that doesn't compromise any of its stakeholders.
“Under the extreme high water, the board was required to consider providing all possible relief to shoreline property owners, and under the low conditions they are required to consider all possible relief to commercial navigation, municipal water intakes and in hydro power issues,” he said. “The focus is different, but the process is the same. They can't take on operations that would unduly harm some specific interests.”