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Rideau Canal National Historic Site of Canada

Have you noticed foam on the Rideau Canal lately?

Foam on the Rideau Canal

The foam found along the Rideau Canal is the result of natural ecosystem processes and is harmless. 

Molecules that make up water bond together very strongly at the water’s surface. This is a physical property known as surface tension (it is what allows an insect to “walk on water”). When this surface tension decreases as a result of adding organic compounds (from decomposing algae and aquatic plants in the water), and the water is vigorously mixed from travelling over dams and spillways, bubbles are generated. The bubbles then collect and build up as foam.

Parks Canada is dedicated to ensuring that the Rideau Canal’s cultural and natural resources are respected and protected so that all Canadians can cherish and enjoy them for many generations to come.   For more information on the Rideau Canal’s ecosystem please call the Rideau Canal Headquarters at 613-283-5170.