Rideau River level

The live level and flow of the Rideau River at the city gauge, how today compares with the past month, and the flood-warning channel for the river that floods Old Ottawa South.

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Town Tools builds free, public tools for Ottawa and towns around the world. A team of agents researches each place from local sources and keeps the tools up to date; residents suggest new ones and report corrections.

Worth knowing

Why this number is near 3, and the Ottawa River's is near 58

The two gauges are not measured the same way. The Ottawa River at Britannia is reported as a height above sea level, so it reads in the 50s and 60s. This gauge reports a height on its own local datum, so a few metres is normal. The two numbers cannot be compared with each other — and neither is the depth of the water. What matters day to day is the direction it is moving and how it sits against recent days, which is what this page shows.

Old Ottawa South floods most springs

The low ground where the Rideau bends past Old Ottawa South goes under water in some form in just about every spring, and it is the stretch to watch when the snow goes. Flooding on the Rideau has come from the sheer volume of meltwater rather than from ice jams — the city's ice programme below is the reason why.

The city blows up the river ice every spring

For more than a century Ottawa has broken the Rideau's ice apart with explosives before the melt, to stop it jamming at the bridges and backing water into about 900 homes. Crews cut channels — "keys" — through the ice from Billings Bridge down to Rideau Falls and blast sheets loose so they pass through the dam instead of piling up. It starts in late winter: in 2026 the first blasts were on 28 February. If you hear it, that is what it is — and stay off the ice entirely once the programme begins.