How to build resilience when coastal communities are at risk

From beaches, open spaces to working ports, coastal areas are commonly viewed as a community’s most highly valued natural attributes, however, they are also exposed naturally occurring hazards. Disturbances such as rising sea levels, storm surges and shoreline erosion are now commonplace. At stake are places and spaces, human lives, natural heritage and local livelihoods.
Prioritising coastal resilience strengthens a community’s ability to withstand and rapidly bounce back from climate-induced hazardous events. It’s more than just understanding flood hazards. It’s using a multi-disciplinary approach to gathering data of wave and tidal dynamics, analysing storm events and sea level rise projections to identify management actions and inform adaption projects.

Proactively identifying, planning and implementing coastal adaptation strategies serves to protect the community and environment while informing a blueprint for infrastructure investment, reduce uncertainty around development and point to long-term economic sustainability.

Risks are not uniform across locations, and there is no one-size-fits-all approach. Vulnerabilities differ from one community to another since they have varying topography, infrastructure, available resources, shoreline conditions and tolerance to flooding. Local coastal resilience plans, and adaptation strategies must be tailored according to these specific contexts. These variations require solutions adapted to each community’s unique needs, values and priorities, while aligning goals and guiding principles of a broader coastal resilience strategy.

Physical, social and economic disparities greatly influence the capacity to prepare for, respond to and recover from hazards. For example, communities in low-lying areas must prepare for the impacts of flooding – whether raising or flood-proofing infrastructure and buildings or raising flood protection structures or consider realignments and relocation of vulnerable assets. While communities atop bluffs face threats of cliff erosion and its impacts on their roads, homes and utilities. In addition, low-income and minority communities are often the hardest hit due to insufficient resources to rebuild.

In today’s context, communities that view the reality of rising sea levels and changing weather patterns as both a challenge and an opportunity are achieving multiple wins. For instance, a project primarily intended for flood reduction can incorporate other benefits, such as enhanced coastal access or habitat improvement or carbon capture, among others. State and federal grant programs and resource and permitting agencies are also more likely to provide support for multi-benefit solutions than a project that addresses a single problem.

GHD’s work for Humboldt County in California involved detailed flood studies, the outcome of which was a design utilising an abandoned railroad prism to create a living levee and pedestrian trail. This living levee is currently in plan and the under-construction pedestrian trail will help to restore historical marsh habitat, reduce wave erosion and flooding, as well as enhance recreational opportunities and safety along a highway.

Insights gained from the undertaking of Coastal Hazard Risk Management and Adaptation Plan (CHRMAP) and Coastal Hazard Adaptation Strategy (CHAS) projects for local governments in Western Australia and Queensland serve as invaluable guides for global practices. An approach that prioritises community engagement, coastal engineering and land use planning has proven effective in creating adaptation pathways with clear actions to mitigate both immediate coastal inundation and erosion risks, as well as long-term strategies for addressing increasing risks over time. GHD has applied this process to similar projects outside of Western Australia, demonstrating its broad applicability and effectiveness. With the likelihood of coastal erosion and storm surges rising, a completed CHRMAP offers a blueprint for future planning across dynamic coastlines.

Nature offers prime examples of defending ecosystems against sea level rise and severe storms. Wetlands like salt marshes serve as front-line defenders against the worst coastal threats by dissipating wave energy and reducing storm surge impacts.

Adopting nature-based solutions requires a deep understanding of how strategies can effectively work with, not against, natural processes. Hybrid approaches integrate engineered infrastructure with natural or restored ecosystems to optimise benefits. An example is combining sea walls or revetment with restored mangrove belts to serve as physical barriers and provide water filtration benefits via the mangroves.

For the Humboldt Bay Natural Shoreline Infrastructure project, we were working closely with diverse stakeholders to propose a nature-based design solution. This initiative helps restore salt marsh, capture carbon and reduce flood to over 6,500 feet of California State Highway 101, which is a vulnerable transportation corridor located along Humboldt Bay.

Additionally, GHD provided advice to the New South Wales Environmental Protection Agency on the principles of living coastal defense structures. We also supported a port authority in executing a sand bypassing project that utilises natural wind, wave and current forces to redistribute placed sand. We also collaborated with the Sydney Institute of Marine Science (SIMS) by leveraging engineering capabilities to develop eco-friendly tiles aimed at enhancing biodiversity on conventional coastal defense structures.

Once you have an innovative project proposal — one that includes a product of assessments and close collaboration with local councils and key stakeholders — aligning funding sources from grant and loan programs is key. Ensure that your project is competitive for grant funding and is permittable and constructible. Identify the right funding agency based on the project type and elements proposed. External consultants or partners can provide guidance in maximising a proposal’s funding potential and navigating these complex permitting processes.

Strategic external partnerships have helped municipalities unlock funding and secure permits to get their projects off the ground and actualise their coastal resiliency goals. We delivered a Sea Level Rise Vulnerability & Capital Improvement Adaptation Plan for the City of Eureka. This plan determined the inundation pathways, extent and duration of flooding to inform future improvements of the city’s critical infrastructure. Through a holistic approach, it included near-term and long-term adaptation strategies that demonstrated the project’s viability and sustainability to permitting and resource agencies.

At the core of coastal resilience is equipping communities with sustainable infrastructure that mitigates damage and enables rapid recovery. These are the key considerations:

• Understand and identify the community’s unique needs and characteristics – Assessments help provide a clear picture of a community’s vulnerabilities, risk profiles, adaptation capabilities and infrastructure needs, which can inform targeted interventions.
• Integrate nature-based or hybrid solutions – Nature-based solutions contribute to holistic adaptation strategies that maintain our natural ecosystems while protecting communities and economies.
• Design and build for evolving conditions – Build robust and dynamic infrastructure that accounts for uncertainties, the probability of future conditions due to climate change and the potential modifications as better technologies become available.

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