International Lake Ontario-St. Lawrence River Board

Water levels on Lake Ontario have begun to decline more rapidly in recent days due to a combination of continued record-high outflows, declining inflows from Lake Erie and generally drier weather across the basin. 

Water levels are declining throughout the system as warmer, drier weather and record Lake Ontario outflows of 10,400 m³/s (367,270 cubic feet per second) continue. 

Water levels are expected to decline throughout the system this week as drier conditions are forecast and record Lake Ontario outflows of 10,400 m³/s (367,270 cubic feet per second) continue.  At its meeting on June 28^th, the Board reached consensus to maintain the current o

The Board is doing everything possible to provide all possible relief to Lake Ontario and upper St. Lawrence River residents, while considering impacts throughout the system.

Lake Ontario water levels have reached 75.85 m (248.85 ft) and will likely reach or exceed the 2017 record high of 75.88 m (248.95 ft) with the next few days.  Forecasts show that Lake Ontario levels are expected to crest within the next one to three weeks, mostly likely within a few centimeters