The Rideau River is a Canadian river which flows north from Upper Rideau Lake and empties into the Ottawa River at Rideau Falls in Ottawa, Ontario. Its length is 146 km. The river was given the French name "Rideau" (curtain) after the appearance of this waterfall.
The Rideau Canal, which allows travel from Ottawa to the city of Kingston, Ontario on Lake Ontario, was formed by joining the Rideau River with the Cataraqui River. The river diverges from the Canal at Hog's Back Falls in Ottawa.
In early spring, to reduce flooding on the lower section of the river, workers from the city of Ottawa use ice blasting to clear the ice which covers the river from Billings Bridge to Rideau Falls by cutting "keys" through the ice and using explosives to break off large sheets of ice.
Communities along the Rideau include: