Lake Ontario Outflow Changes

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.

The water level of Lake Ontario remains below the applicable low Criterion H14 threshold. The Board reached consensus to implement a deviation strategy as authorized by the IJC’s Directive. For the coming week, the average Lake Ontario outflow is expected to be 7,560 m³/s (267,000 cfs), which is 200 m³/s (7,060 cfs) less than the amount prescribed by the Rule Curve of the regulation plan. The Board will continue to monitor conditions and the effects of the deviation strategy closely while simultaneously tracking weather forecasts and drought conditions.

 

DATE HOUR/HEURE OUTFLOW/DÉBIT OUTFLOW/DÉBIT
(YYYY-MM-DD) (HHMM) (m3/s) (cfs)
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