Rising seas and shifting sands: Combining natural and grey infrastructure to protect Canada's Eastern and Western coastal communities

This report describes how Canada can scale-up the use of nature-based solutions, in tandem with grey infrastructure, to protect communities along the East and West coastlines. Importantly, action must consider natural processes along the coast to a greater extent than has occurred to date. Reduction of flooding and erosion at one site, if not carefully designed, can cause instability further along the coast and degradation of coastal ecosystems on which communities depend.

Canada does not yet have a strategic planning framework or standard classification of approaches for coastal risk management. Coastal risk management responses identified by the Intergovernmental Panel on Climate Change (IPCC) include Protection, Accommodation, Retreat and Avoidance, as well as non-intervention.2 A suite of options should be appraised to select appropriate approaches along Canada’s East and West coasts.

Coastal protection measures can be divided into two key categories:

• Grey Infrastructure: hard, engineered coastal protection measures, and;
• Nature-Based Solutions: measures that depend on, or mimic, natural systems to manage flood and erosion risk, that may be a) predominantly sediment-based, such as adding sediment to beaches through beach nourishment, or b) predominantly vegetation-based, such as saltmarsh restoration.