North Saanich braces for higher tides

Municipality starting the discussion on the impact of climate on its coastline.

North Saanich Mayor Alice Finall (foreground

North Saanich is jumping into the topic of rising sea levels with both feet — and are already facing a bit of a chill from some residents.

On Nov. 17, the District led a workshop on the potential impact of climate change on sea levels — and the subsequent effect on the 45 kilometers of coastline around the District.

Leading the discussion was University of British Columbia doctorate candidate Tugce Conger from the school’s Institute of Resources, Environment and Sustainability. Using a study of the possible impact of ocean level rise on North Saanich by SNC Lavalin, Conger outlined worst-case flooding scenarios in the event of a half-metre or one metre rise in sea levels around the Saanich Peninsula. Using that data, she was able to show 3D models of what could occur, should predictions around climate change occur.

In both cases, the predicted ocean level rise would see flooding of waterfront — or waterfront-adjacent — properties in the event of storm surges and wave effects during high tides.

Immediately, some residents at the workshop expressed fear over the impact of such predictions on their property values.

One participant said the information shown was ‘scary’ — reflecting a loss of land in the event of sea level rise.

Others expressed concern that the data used for Conger’s own study included land significantly higher than sea level and was flawed, therefore skewing any other study based on it.

Mayor Alice Finall said the SNC Lavalin data on which the workshop was based, is a draft report that does not carry with it an intent to focus impacts on any particular properties. It’s goal, she explained, is to assess the overall impact of sea level rise on the District of North Saanich.

“This is the first time a study like this has been done,” added Conger. “It’s a way to start a discussion and an entry point into planning for the future in North Saanich.”

Councillor Geoff Orr agreed, asking the group at the workshop not to “go too deep” into the details at this point.

“This is big picture,” he said, “the beginning of planning work.”

Both Orr and Finall said these are the early steps of planning for the impact of climate change. The plan is to come with an early framework, from which the District can create new planning documents to govern how North Saanich might address flooding on existing properties, future ones and even what to do after an extreme weather event.

Finall said there are around 800 properties in the District that are considered waterfront — and not all of them will be affected in the same way. Planning for all of them is the type of detail work that could take a long time and a lot of input, Orr added.

Conger said her work is based on both optimistic and pessimistic predictions on climate change’s impact on ocean levels. She noted that current science shows the optimistic predictions have already been surpassed. However, she said there is still a large amount of scientific uncertainty on what the actual sea level rise will be — making it very difficult to plan for.

Conger outlined possible adaptation strategies that North Saanich could consider: protection, accommodation, avoidance and managing the retreat of high water events.

She said the main method cities typically use is protection — building sea walls, dykes or building up vegetation to protect human-made buildings.

“This can lead to a false sense of security and allow people to keep building in these areas,” she said.

From that strategy, Conger said the options become more long-term and in some cases, a lot more expensive. Accommodating sea level change, she said, includes retrofitting buildings and homes to allow for their survival during floods. It also includes making regulation changes to increase setbacks from the shorelines or putting development restrictions in place for areas that are sensitive to flooding.

That flows into the avoidance strategy — or having planning tolls in place to prevent human activity in flood-prone areas.

Managed retreat strategies, Conger said, is the most long-term and most expensive. It involves the planned relocation of existing housing and infrastructure. And that, she continued, has large political and economic concerns.

North Saanich plans to post Conger’s presentation — and workshop results — to its web site (northsaanich.ca), alongside the SNC Lavalin report and the District’s work to date on the subject.