Lake Ontario Releases Water to St Lawrence River for First Time in 13 Years

In a significant move, water from Lake Ontario has been released into the St. Lawrence River for the first time in 13 years. This event occurred on a Friday and will persist for a period of 36 hours, ending at 7:01 PM on Saturday. The increase in outflow will reach 500 cubic meters per second during this time.

Reasons for the Release of Water

This temporary measure aims to address the severe drought affecting the St. Lawrence River and parts of Quebec. While this action will not fully resolve the water shortages, it will aid boaters in safely removing their vessels from the riverbed before freezing temperatures arrive.

Richard Arsenault, a hydrology expert from the HC3 laboratory at the École de technologie supérieure (ETS), explained that normally, ample water flows naturally into the river. However, this season, the Ottawa River and other natural water sources are notably low. Therefore, the only viable option is to open the gates of Lake Ontario to ensure adequate water supply.

Strict Regulations Governing Water Management

The decision to increase the outflow from Lake Ontario came from the International Joint Commission (IJC), responsible for managing shared water resources between the United States and Canada, particularly regarding the Great Lakes. According to Michel Baraër, a colleague of Arsenault, the IJC operates under stringent conditions that limit water deviations to minor adjustments. This action can only occur when specific drought thresholds are met.

Impact on Lake Ontario and the St. Lawrence River

It is estimated that the water level of Lake Ontario will decrease by approximately 0.34 cm due to this temporary release. Despite this loss, the effect on the lake’s overall level will be minimal. As Arsenault notes, “It’s like draining a large swimming pool with a hole made by a small straw,” emphasizing the vastness of the lake.

• The release is limited and sporadic, minimizing long-term effects.
• Once the water is released, it does not return, raising concerns about cautious water management.
• The increase in St. Lawrence River water levels will last for only two to three days.

While the outflow will primarily help boaters, it may also influence groundwater levels, commercial shipping, and local biodiversity. However, these impacts are expected to be limited due to the temporary nature of the release. Overall, stakeholders are awaiting rainfall to bring relief to the affected watercourses in Quebec.