Nature's best defence

Photo: Bernadette Jarrard

Recent flooding in Kelowna.

By David Suzuki

Spring flooding in Canada this year upended lives, inundated city streets and swamped houses, prompting calls for sandbags, seawalls and dikes to save communities.

In the Okanagan, rapidly melting snowpack and swelling creeks caused lake levels to rise to record heights, prompting evacuations. Ontario and Quebec’s April rainfall was double the 30-year average, and parts of New Brunswick recorded more than 150 millimetres of rain during a nearly 36-hour, non-stop downpour. 

Floods have become one of the most visible signs of climate change in Canada.

Spring floods aren’t unusual, but the intensity and frequency of recent rains are breaking records. When temperatures rise, the atmosphere carries more moisture so when it rains, it dumps. 

With more than 80 significant floods in Canada since 2000, insurance costs are skyrocketing. The 2013 Alberta floods alone cost more than $6 billion. Canadians personally shoulder about $600 million each year in losses related to flooding.  

Deforestation, wetland destruction and artificial shoreline projects worsen the problem. Insurance agencies recognize that keeping ecosystems healthy prevents climate disasters and saves money. Lloyd’s of London encourages insurers to consider the value of natural coastal habitats when pricing flood risk. One study found ecosystems such as wetlands are more effective than seawalls in protecting against coastal storms. Insurers say conserving nature is about 30 times cheaper than building seawalls.

Urban concrete and asphalt surfaces prevent water from infiltrating into the ground and increase storm-water runoff. Rain gardens, bioswales and permeable pavements better manage flooding by reducing runoff and protecting flood plains and foreshore areas. 

Many local governments are trying to keep up by limiting development in flood zones, better managing flood plains and updating flood-management systems. Some, such as Gibsons, B.C., are using a new approach that considers nature as a vital part of the town’s infrastructure and puts “natural capital” assets on equal footing with built assets. 

The federal government has set aside $2 billion to help local governments defend against natural disasters like fire and flooding. It should allocate a significant portion to natural infrastructure solutions. 

It’s time we recognized the importance of intact nature and built green infrastructure as central to flood-prevention efforts. Nature can help us — if we let it. 

David Suzuki is a scientist, broadcaster, author and co-founder of the David Suzuki Foundation.