“Strategic retreat” in BC’s sea level rise toolkit

BC’s Ministry of the Environment released a report on sea level rise adaptation over the weekend. It is inevitable that Metro Vancouver municipalities will come to restrict new development and abandon at-risk areas to protect homes, infrastructure and agricultural land from the higher, warmer sea.

Compared to other provinces, BC:

has the lowest proportion of its land area at risk but the majority of [Canadian] dwellings at risk, due to the high housing density in the Lower Mainland, much of which is low lying. The Lower Mainland, consisting of Metro Vancouver and the lower Fraser River Valley, is very vulnerable to sea level rise because of a 127 kilometre system of dikes, which were not built with sea-level level rise factored into the design. This area also has very expensive real estate subject to flood risks.

The report looks at two responses for our coastal areas: climate-related development planning and strategic retreat.

The first means no new construction would be permitted in high risk areas. The latter strategy means a gradual abandonment of these areas. Citing the now-shuttered National Round Table on the Environment and the Economy, the study notes strategic retreat produces significant benefits over development planning. In some areas, dikes would need to be 6–8 metres high to protect dwellings, much taller than current structures.

Full report PDF is here.