The Ottawa River Regulating Committee issued a statement on Apr. 2 advising the public that the 2026 spring freshet has begun, and that river levels will be rising over the coming weeks, though they are currently in line with average historic levels.
“Recent rain and mild temperatures have increased snowmelt especially in the southern and central parts of the basin. With additional rainfall events forecast over the coming days, spring runoff is expected to continue increasing,” the statement noted.
“It is too early to predict the magnitude and timing of the freshet peak in the main stem of the Ottawa River. The Regulating Committee will be closely monitoring the effects of precipitation and temperature increases throughout the spring freshet period as they may cause levels and flows to change rapidly.”
Daytime temperatures and rain over last week have initiated the rising river levels, though the statement notes that evening temperatures at or below freezing have slowed this increase. It said the rain and warmer weather over the weekend and into the week of Apr. 6 would cause the levels to rise more rapidly.
“The freshet magnitude will largely depend on weather conditions including the timing and amount of precipitation over the coming weeks,” the statement reads. “Weather conditions that trigger rapid snowmelt or heavy rainfall can only be known a few days in advance.”
The committee notes that reservoirs upstream have been drawn down in anticipation of the spring melt, with the goal of regulating the flow downstream.
“During the freshet period, the principal reservoirs in the northern part of the basin will store a large portion of runoff from this portion of the basin, thereby reducing flows in downstream areas,” the statement notes. “However, dams located in the central and southern parts of the basin are essentially ‘run of the river’ facilities with no significant storage capacity. These facilities are not able to reduce flows and the levels associated with increased spring runoff.”
Residents can check the home page of ottawariver.ca for regular updates on river levels.
