Drawdown

Drawdown is when water levels are lowered in the Rideau Canal.

It's a complex process that takes into consideration storage capacity of the lakes on the system, timing of fishery spawning, requirements for flood mitigation, typical fall and winter precipitation levels, downstream typography including constrictions like narrow river beds or dams, and overall volumes and flow rates.

Drawdown forecast

From mid-October until mid-November, water levels in the Rideau Canal system, between Ottawa Locks and Detached Lock, will be decreased to winter levels by adjusting dams and spillways in the Rideau Watershed. The following drawdown timing has been provided for Rideau Canal sections in the Lower Rideau:

• Water levels will be decreased in the sections below Hog's Back, including Dow's Lake, beginning Tuesday, October 14th, 2025 and will remain at their lowest level until mid-November, after which the water level will then be raised approximately one metre between Hartwells and Ottawa lockstations to prepare for the Skateway.
• Water levels will be lowered between Hogs Back to Black Rapids beginning Tuesday, October 14th, 2025.
• Water levels will be lowered between Long Island to Black Rapids beginning Tuesday, October 14th, 2025.
• Water levels will be lowered between Burritts Rapids to Clowes beginning Wednesday, October 15th, 2025.
• Water levels will be lowered between Merrickville to Kilmarnock beginning Monday, October 27th, 2025.
• Water levels will be lowered between Clowes to Merrickville and Long Island to Burritts Rapids beginning Friday, October 31, 2025.

We would like to thank all visitors and look forward to welcoming you again in 2026.