Every spring, melting snow and heavy rainfall brings a higher risk of flooding and riverbank erosion to parts of Canada. Bank erosion is responsible for a significant portion of annual flood damage in Canada, with estimates suggesting the costs could grow as high as $13.6 billion annually by the end of the century.

In British Columbia, erosion is primarily managed by “hardening” riverbanks with large rocks called riprap. These rocks are so prevalent along B.C. rivers that you might think they are part of the natural environment, but they are not.

Hardened riverbanks offer temporary protection from river movement, but riprap can lead to degraded rivers. Erosion is a natural process that helps maintain healthy and diverse river habitat. However, as societies expand, there is more demand to control river movement and prevent erosion.

Through my work as a river scientist and flood risk researcher in New Zealand and Canada, I have witnessed the sometimes devastating impacts of river erosion and have also seen just how lifeless rivers can become when overly restricted.

Of course we need to protect people, property and infrastructure from riverbank erosion. But current erosion management is hurting B.C. rivers.

Riprap is essential for stabilizing riverbanks when infrastructure and property are at immediate risk. The rocks are often laid down as “temporary” erosion prevention before or during floods.

The problem is, if you harden one area with riprap, that bank transfers the erosion-hungry current elsewhere,

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