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: