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