After ‘notable increases’ Ottawa River stabilizing

WEST CARLETON – Normally a spring pastime, Ottawa River shore communities have been watching water levels this fall as they rise as October comes to an end.

The Ottawa River has rose over a rainy end to October and shoreline homeowners aren’t the only ones to notice.

“Following notable increases in water levels over the last few days due to significant rainfall received in the northern part of the basin, water levels along the main stem of the Ottawa River are beginning to stabilize,” The Ottawa River Regulation Planning Board (ORRPB) released in a statement Wednesday (Oct. 27). “Flows and levels are expected to continue to remain above normal for this time of the year over the coming week.”

Current water levels at the Chats Falls Generating Station are at 74.22 metres as of today (Oct. 30) at 10 a.m. The daily outflow is at 1,954 cubic metres per second.

The water was at 74.18 m on Oct. 28 and 74.1 m on Oct. 20.

The historic high for this time of year was 75.19 m on Oct. 27, 1928. The historic low for today is 74.02 in 1995.

The next ORRPB is scheduled for Nov. 3.

The ORRPB says high water levels are common for this time of year.

“Because of reduced evapotranspiration and increased precipitation during the fall, water level increases are common on the Ottawa River,” the ORRPB said. “In the fall, the soil capacity to absorb precipitation is less than in summer.”

This is because the vegetation, which has become dormant with trees having shed their leaves, is not intercepting rainfall or taking up the water contained in the soil. Such reduced evapotranspiration rates lead to rapid increases in water runoff to the river and increases in water levels.

“Operationally, as reservoirs are already full at this time of the year, all excess precipitation results in increased river flows that must necessarily pass through the system as there is no available storage,” the ORRPB said. “It should be noted that elevated water levels during the fall do not affect the ability to drawdown reservoirs over the winter period. Also, they are not a predictor of high water levels in the spring.”