Two years ago, a Dutch drainage engineer took a tour of the Fraser River floodplain.

As B.C. moves into the “I told you so” phase of recovery following significant flooding across the province, the man’s warning may be among the most direct of the many issued in recent years.

“He said dikes fail, and these ones will fail,” recalled Dave Zehnder, who owns a ranch in Invermere and heads up Farmland Advantage, a non-profit group that works with farmers to protect and restore natural land.

The engineer advised a complete rethink of the way B.C. manages its rivers, saying they need to be given space, with a dike system that “allows for the natural ebbs and flows” caused by rain and snowmelt.

It’s a view shared by a diverse group of experts from both the University of B.C. and Simon Fraser University, based on research and experience in flood-prone places like the Netherlands and New Orleans.

B.C. won’t be able to build its way out of the challenges posed by climate change, said Kees Lokman, a landscape architecture professor at UBC. “I don’t think it can be business as usual. Dikes and seawalls will help, but we also need to think holistically about these issues.”

That means identifying the factors that lead to higher water flows from upstream mountains, like deforestation or wildfires, and updating flood maps to better understand what could happen in extreme weather.

In the absence of trees — and billions of tree needles — to help trap water and provide structure to slopes and riverbanks, more water may be rushing downstream than in the past. Could some be trapped upstream in flood cells to limit flows during high water?

“Certain decisions will need to be made,” said Lokman. 

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