Lake Ontario Outflow Changes

The International Lake Ontario – St. Lawrence River Board, under authority granted to it by the International Joint Commission, will continue to deviate from Plan 2014 and will look for any and all opportunities to remove additional water from Lake Ontario prior to the spring of 2020. The Board will continue to set outflows as high as possible based on changing conditions throughout the basin. See latest News Releases for more.

Outflows from Lake Ontario are established by the International Lake Ontario - St. Lawrence River Board in accordance with the current regulation plan and the International Joint Commission's Orders of Approval. The table below displays the outflow changes that have occurred this year. All flows are reported in cubic metres and cubic feet per second.

Latest conditions and operational requirements: 

A partial ice cover remains in the Beauharnois Canal. The high Lake Ontario outflows along with ice accumulating downstream of Lake St. Louis causes water levels on Lake St. Louis to rise. The Lake Ontario outflow has been adjusted in recent days to ensure Lake St. Louis remains below flood levels. Mild temperatures are expected to return and this may allow outflows to be increased again soon. Outflows continue to be maintained as high as possible and will continue to be adjusted as necessary, according to conditions in the St. Lawrence River.

DATE HOUR/ FROM/DE    TO/À   
(YYYY-MM-DD) HEURE (m3/s) (ft3/s) (m3/s) (ft3/s)
2020-02-20 1601 9,400 332,000 9,000 317,800
2020-02-19 1301 9,700 342,600 9,400 332,000
2020-02-18 0901 10,100 356,700 9,700 342,600
2020-02-16 1301 9,700 342,600 10,100 356,700
2020-02-15 1701 9,400 332,000 9,700 342,600
2020-02-15 1001 8,700 307,200 9,400 332,000
2020-02-14 1501 8,400 296,600 8,700 307,200
2020-02-13 1901 9,500 335,500 8,400 296,600
2020-02-12 1201 9,300 328,400 9,500 335,500
2020-02-11 1501 8,800 310,800 9,300 328,400
2020-02-10 1601 8,200 289,600 8,800 310,800
2020-02-09 1601 7,600 268,400 8,200 289,600
2020-02-09 1001 7,300 257,800 7,600 268,400
2020-02-08 1901 7,500 264,900 7,300 257,800
2020-02-08 1001 8,200 289,600 7,500 264,900
2020-02-07 1801 9,200 324,900 8,200 289,600
2020-02-07 1501 10,200 360,200 9,200 324,900
2020-02-02 1201 10,000 353,100 10,200 360,200
2020-02-01 1201 9,600 339,000 10,000 353,100
2020-01-31 1201 9,000 317,800 9,600 339,000
2020-01-29 1701 8,700 307,200 9,000 317,800
2020-01-23 1601 8,300 293,100 8,700 307,200
2020-01-22 1601 7,700 271,900 8,300 293,100
2020-01-21 1301 7,200 254,300 7,700 271,900
2020-01-20 1601 7,000 247,200 7,200 254,300
2020-01-19 1801 7,500 264,900 7,000 247,200
2020-01-18 1901 8,200 289,600 7,500 264,900
2020-01-17 1801 9,000 317,800 8,200 289,600
2020-01-17 1001 8,800 310,800 9,000 317,800
2020-01-16 1301 9,450 333,700 8,800 310,800
2020-01-15 1801 9,250 326,700 9,450 333,700
2020-01-15 0001 9,000 317,800 9,250 326,700
2020-01-14 1201 8,750 309,000 9,000 317,800
2020-01-12 1501 9,000 317,800 8,750 309,000
2020-01-12 1001 9,400 332,000 9,000 317,800
2020-01-12 0001 9,900 349,600 9,400 332,000
2020-01-11 1601 10,400 367,300 9,900 349,600
2020-01-10 1701 10,200 360,200 10,400 367,300
2020-01-10 0001 10,400 367,300 10,200 360,200
2020-01-09 1601 10,600 374,300 10,400 367,300
2020-01-07 1101 10,400 367,300 10,600 374,300
2020-01-05 1201 10,300 363,700 10,400 367,300
2020-01-04 1901 10,500 370,800 10,300 363,700
2020-01-03 1601 10,700 377,900 10,500 370,800
2020-01-02 1201 10,500 370,800 10,700 377,900
2020-01-01 2001 10,300 363,700 10,500 370,800
2020-01-01 1001 10,000 353,100 10,300 363,700
2019-12-31 0801 9,200 324,900 10,000 353,100

 

To view outflow change records from previous years, please use the links below:

Flow Changes - 2019

Flow Changes - 2018

Flow Changes - 2017

Flow Changes - 2016

Flow Changes - 2015

Flow Changes - 2014

Flow Changes - 2013

Flow Changes - 2012

Flow Changes - 2011