48. Coastal erosion

Coastal erosion is the gradual wearing away of coastal landforms, such as beaches, cliffs, dunes, and shorelines, due to the action of waves, currents, tides, and weathering processes. Coastal erosion is a natural geomorphic process influenced by factors such as sea level rise, wave energy, sediment supply, coastal geology, and human activities. Here is how the risk of coastal erosion can affect properties and their sale, and how it can be assessed: 

Impact on properties and sale 

• Property damage: Coastal erosion poses risks to properties located in erosion-prone areas, such as coastal cliffs, bluffs, or shorelines, where the loss of land can threaten structures, infrastructure, and land values. Erosion-induced land loss can lead to property damage, structural instability, and reduced property values, impacting the saleability and marketability of affected properties. 
• Insurance considerations: Properties at risk of coastal erosion may face challenges obtaining insurance coverage or may incur higher premiums due to increased exposure to coastal hazards. Insurance providers assess the risk of erosion-related damage when underwriting policies, considering factors such as proximity to the coastline, erosion rates, and mitigation measures in place. 
• Legal disclosures: Sellers are typically required to disclose known risks of coastal erosion to prospective buyers, ensuring transparency and compliance with legal obligations. Failure to disclose material erosion risk information could lead to legal disputes, liabilities, or claims of misrepresentation. 

Assessment of coastal erosion risk

• Coastal hazard assessments: Coastal erosion risk assessments involve evaluating factors such as historical erosion rates, shoreline change, sediment dynamics, coastal geology, and sea level rise projections to identify erosion-prone areas and assess the magnitude and frequency of erosion hazards. 
• Remote sensing and GIS analysis: Remote sensing technologies, such as aerial photography, satellite imagery, LiDAR (Light Detection and Ranging), and GIS (Geographic Information Systems) analysis, can be used to map coastal landforms, monitor shoreline changes, and quantify erosion rates over time. 
• Site surveys and monitoring: Field surveys, beach profiling, and monitoring programs can provide detailed information on coastal morphology, sediment transport, wave climate, and erosion processes at specific locations, enabling accurate assessment of erosion risk and identification of vulnerable properties. 
• Coastal engineering studies: Coastal engineering studies may involve hydraulic modelling, wave run-up analysis, shoreline stabilisation techniques, and coastal management strategies to assess erosion risk, design coastal protection measures, and mitigate erosion impacts on properties and infrastructure. 
• Local authority guidance: Local planning authorities or coastal management agencies may provide guidance, regulations, or policies related to coastal erosion risk management, land use planning, setback requirements, and development restrictions in erosion-prone areas. 

Mitigation and adaptation measures

• Shoreline stabilisation: Implementing shoreline stabilisation measures, such as revetments, seawalls, groynes, or beach nourishment projects, can help reduce erosion rates, protect coastal properties, and enhance beach resilience to erosion hazards. 
• Managed retreat: In some cases, managed retreat strategies may be employed to relocate or adapt coastal development away from erosion-prone areas, minimizing exposure to erosion hazards and safeguarding long-term property interests. 
• Land use planning: Land use planning policies, zoning regulations, setback requirements, and development controls can guide responsible coastal development, avoiding construction in high-risk erosion areas and promoting sustainable land use practices to mitigate erosion impacts. 
• Public education and outreach: Increasing public awareness, education, and community engagement on coastal erosion risks, adaptation options, and resilient coastal development practices can empower stakeholders to make informed decisions and support effective coastal management initiatives.