Managing Natural Assets to Increase Coastal Resilience
Guidance Document for Municipalities
As more research is directed toward the concept of natural infrastructure, it is becoming clear that coastal ecosystems can provide substantial protection from flooding and erosion, often at less cost and with greater long-term resilience compared to traditional grey infrastructure (Arkema et al. 2017). These ecosystems also provide a number of other services or “co-benefits” such as carbon storage, water quality regulation, nutrient cycling, unique recreation opportunities and habitat. Many of these benefits can complement hard/grey infrastructure investments like seawalls or breakwaters by supplementing the focal services they provide, protecting them from damage or replacing them entirely. Failing to include the value provided by coastal natural assets in policy and management decisions has contributed to a global disappearance of these ecosystems and an associated loss of ecosystem services (Barbier 2007). If the economic benefits of these assets were better understood, it would facilitate their inclusion in municipal asset management and, by recognizing their true worth to society, contribute to protection of coastal ecosystems. Rising sea levels threaten coastal zones through a range of coastal hazards, including (i) the permanent submergence of land by higher mean sea levels or mean high tides; (ii) more frequent or intense coastal flooding; (iii) enhanced coastal erosion; (iv) loss and change of coastal ecosystems; (v) salinization of soils, ground and surface water; and (vi) impeded drainage. Over the next century, without adaptation, the vast majority of low-lying coasts and communities face substantial risk from these coastal hazards (Oppenheimer et al 2019).