Rideau Valley Conservation Authority issues Level 3 low water advisory for Rideau River watershed

A man cools sits in a picnic table in the waters of the Rideau River in Ottawa on Monday, June 23, 2025. THE CANADIAN PRESS/Adrian Wyld

The Rideau Valley Conservation Authority (RVCA) is issuing a “Level 3 – Severe” low water advisory for the Rideau River watershed.

Ongoing dry conditions with little rainfall and several days of hot weather this summer have led to water levels in eastern Ontario rivers, lakes, and streams being lower than usual.

The Rideau Valley Conservation Authority says Level 3 conditions are triggered when rainfall deficits fall below 40 per cent of the long-term average and/or when stream flows decline to severe low-water thresholds, defined as typically below the 10-year return period low flow.

“A Level 3 low water advisory is not a declaration of an emergency, but an indicator of significant dry conditions and impacts observed across the Rideau Valley watershed,” the conservation authority said in a news release Tuesday.

The notice covers an area ranging from Orléans through south Ottawa and toward the St. Lawrence, and also includes communities such as Smiths Falls, Perth, and Westport.

Residents are asked to check with their respective municipalities regarding water use notices, but anyone in the affected areas is strongly encouraged to reduce their overall water use and suspend non-essential water activities until natural supplies begin to recover.

“Residents served by the City of Ottawa’s central drinking water system are not subject to the same water supply pressures, as this system draws from the Ottawa River. However, conservation measures are still strongly encouraged to reduce overall demand and to support broader watershed resiliency,” the RVCA says.

People on private wells are encouraged to use water responsibly and those with permits to take water are asked to reduce withdrawals as much as possible.

Environment Canada has recorded just over 20 millimetres of rain in the Ottawa area since July 24. Open air fire bans are in effect across eastern Ontario because of the dry conditions.

Rideau Canal maintaining navigation

The RVCA says Parks Canada is actively monitoring water levels throughout the Rideau Canal system to ensure the canal remains navigable.

“The drawdown of reservoir lakes in the Tay River and Upper Rideau subwatersheds is being carried out at the minimal levels required to maintain navigation along the Rideau Canal,” the conservation authority says. “Currently, water levels in the reservoir lakes (Bob’s Lake and Wolfe Lake) and the navigation lakes (Upper Rideau Lake and Big Rideau Lake) are below normal and are expected to decline further. Levels on the Rideau Canal system are currently being maintained within navigable range.”

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