IJC says Lake Ontario reaching peak, outflows increased rapidly
Press Release, International Joint Commission
Lake Ontario water levels have started to stabilize due to decreased precipitation and increased Lake Ontario outflows, which have been increasing rapidly as Ottawa River flows have continued to drop from their record highs this spring.
Outflows reached 10,000 m3/s (353,100 cfs) on Wednesday, close to the highest on record, and further increases are expected.
Extraordinarily high outflows combined with forecasts of warmer, drier conditions later this week, make it likely that Lake Ontario is at or very near its peak level this year. Any additional rise is likely to be small, less than 3 cm (1 in.) depending on rainfall, and there is a good chance levels will remain stable or even start to decline slowly next week.
With levels above average their remains the possibility for locally higher levels, especially during periods of active weather, and the Board reminds everyone to refer to local forecasts for conditions and warnings specific to your area.
The Board continues to monitor the situation, makes use of every opportunity to increase outflows, and consider all possible measures to provide relief from the record-high water levels.
Extreme high levels are never normal, but they have occurred in the past and they will occur again in the future. The primary causes of high water levels are always the same – wet weather. Record precipitation caused the record high water levels in 2017, and it led to record inflows from Lake Erie and the Ottawa River system, resulting in new record highs this year.
Such conditions are uncontrolled and highly unpredictable, and this has always been the case. The new normal is that we must make the preparations for the next event a part of everyday practice and planning, even though it is becoming especially difficult to know how soon that next event will be.