CORNWALL – Water flowing out of the Moses-Saunders Hydropower Dam will slow down starting today (Tuesday) to help crews retrieve the work tugboat LCM 131.
The International St. Lawrence River Board of Control agreed to temporarily reduce the water flow during the daytime for 14 hours (6 a.m. to 8 p.m.) to improve conditions for salvage operations.
The flow will drop from 8,520 cubic meters a second (300,900 cubic feet per second) to 6,810 cubic meters a second (240,500 cubic feet per second).
Not only will it mean the water level will drop in the St. Lawrence River but people upstream by Lake St. Lawrence, west of Cornwall, may see the water rise a bit.
Officials are planning to lower the gates at the Iroquois dam to control the flow to make sure it doesn’t get above an alert level of 74 meters (242 feet).
During the nightly changeover of water flow at the Cornwall dam, officials said the levels could drop by 80 centimeters (31.5 inches) temporarily (west of the Moses Saunders Dam and east of the Iroquois Dam i.e. Lake St. Lawrence).
People boating on Lake St. Francis (near Bainsville) and Lake St. Louis (near Montreal) during the daytime are being advised to be careful with the low water levels.
The water draw-downs are expected to happen daily through Saturday. During the course of the week, this whole exercise will actually result in the water level on Lake Ontario rising by three centimeters (1.2 inches).
“This water will then be removed from Lake Ontario as quickly as possible following the removal of the remaining tug. The Board currently anticipates being able to complete this process within a period of between five to eight weeks,” said the IJC in a statement.
The work tugboat LCM 131, along with the Lac Manitoba, sank June 22 while trying to position a barge for work on decommissioning the north channel bridge.