Risk of damaging flooding along Lake Ontario has been downgraded to 'low' International Joint Commission says high outflows continue Reyes, Anthony and last updated 2021-03-03 08:31:43-05 BUFFALO, N.Y. (WKBW) â The risk of flooding on Lake Ontario and the upper St. Lawrence River has declined from 'moderate' in December 2020 to 'low.' According to a new report the International Joint Commission's International Lake Ontario-St. Lawrence River Board released Monday, that risk dropped had to just 8%. Risk analysis in December found that the chances water levels would exceed the threshold at which damage would occur in shoreline communities was at 28%.