Lake Ontario Outflow Changes

Strong north-easterly winds have resulted in a significant water level decline on Lake St. Lawrence. Lake Ontario’s outflow will be temporarily decreased to raise Lake St. Lawrence’s water level and provide safer conditions for navigation. This temporary flow change is considered an operational adjustment to address unexpected changes in St. Lawrence River conditions and is consistent with the IJC’s Directive (https://ijc.org/en/loslrb/who/directives/deviations). Conditions continue to be monitored closely.

Once wind conditions improve and Lake St. Lawrence levels rebound, Lake Ontario’s outflow will again be set 200 m3/s (7,100 cfs) above the amount set by Plan 2014 to return Lake Ontario to the level it would be had outflow deviations not been required earlier this year. For more information: The International Lake Ontario – St. Lawrence River Board will Increase Outflows through the Moses-Saunders Dam from October 16 through mid-December

 

DATE HOUR/HEURE OUTFLOW/DÉBIT OUTFLOW/DÉBIT
(YYYY-MM-DD) (HHMM) (m3/s) (cfs)
2021-10-26 1201 7,850 277,200
2021-10-23 0001 8,170 288,500
2021-10-16 0001 8,120 286,800
2021-10-11 1301 7,920 279,700
2021-10-11 1201 7,890 278,600
2021-10-08 1201 7,320 258,500
2021-10-02 0001 7,920 279,700
2021-09-25 0001 7,890 278,600
2021-09-18 0001 7,910 279,300
2021-09-04 0001 7,940 280,400
2021-08-28 0001 8,020 283,200
2021-08-21 0001 8,000 282,500
2021-08-07 0001 8,030 283,600
2021-07-31 0001 8,100 286,000
2021-07-24 0001 8,140 287,500
2021-07-17 0001 7,960 281,100
2021-07-10 0001 7,620 269,100
2021-07-03 0001 7,600 268,400
2021-06-26 0001 7,550 266,600
2021-06-19 0001 7,560 267,000
2021-06-12 0001 7,600 268,400
2021-06-05 0001 7,620 269,100
2021-05-29 0001 7,840 276,900
2021-05-22 0001 7,970 281,500
2021-05-15 0001 8,090 285,700
2021-05-08 0001 8,070 285,000
2021-05-01 0001 7,920 279,700
2021-04-24 0001 7,410 261,700
2021-04-16 2101 7,350 259,600
2021-04-15 2101 7,820 276,200
2021-04-10 0001 7,420 262,000
2021-04-03 0001 7,980 281,800
2021-03-20 0001 7,380 260,600
2021-03-13 0001 8,000 282,500
2021-03-06 0001 8,080 285,300
2021-03-01 0001 8,140 287,500
2021-02-21 1501 8,600 303,700
2021-02-20 1201 8,400 296,600
2021-02-19 1201 8,000 282,500
2021-02-18 1801 7,600 268,400
2021-02-18 0701 7,400 261,300
2021-02-17 1101 7,000 247,200
2021-02-16 1401 6,600 233,100
2021-02-12 1401 7,000 247,200
2021-02-11 1601 7,400 261,300
2021-02-10 1901 8,300 293,100
2021-02-09 2001 8,500 300,200
2021-02-05 1801 8,800 310,800
2021-02-04 1201 8,200 289,600
2021-02-03 1401 7,700 271,900
2021-02-01 1501 7,100 250,700
2021-01-31 1801 6,900 243,700
2021-01-28 1601 7,200 254,300
2021-01-26 1001 7,700 271,900
2021-01-24 1701 7,200 254,300
2021-01-23 1701 8,400 296,600
2021-01-19 1501 9,200 324,900
2021-01-16 1701 9,400 332,000
2021-01-14 1201 9,200 324,900
2021-01-12 1201 9,500 335,500
2021-01-09 1501 9,400 332,000
2021-01-07 1301 9,300 328,400
2021-01-05 1001 9,200 324,900
2021-01-04 1701 9,400 332,000
2021-01-03 1301 9,500 335,500
2021-01-01 0801 9,400 332,000
2020-12-26 0001 8,090 285,700

 

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

Flow Changes - 2020

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