Coastal erosion is a perpetual and serious concern for Pacific island countries. Coastal erosion may include various consequences from natural disasters, such as high water levels, sediment impacts on coral reefs, coastal sand extraction on beaches and rivers, and sediment traps. The effects of climate change, such as the rise in sea level, degradation of coral reefs, and increased frequency and intensity of storms, also increase the risk of erosion. Erosion and accretion are natural processes that can potentially affect high-value assets, placing road, maritime, and aviation infrastructure at risk with significant potential cost implications. Erosion is of particular concern to the transport sector which, through its infrastructure, provides a critical lifeline for these geographically dispersed nations. While a range of measures may be applied to mitigate erosion hazards, including a departure from perilous locations or the relocation of assets, such options often are not viable when the availability of land is limited or the infrastructure in place is expensive to relocate. In such cases, land and assets must be protected. This technical guidelines report has been developed following scaled laboratory tests of selected designs, conducted by the University of New South Wales Water Research Laboratory. The designs, identified during the initial research phase of the project, aim to add to the existing knowledge by developing innovative solutions for coastal protection to maximise the use of local materials and labour, while minimising the requirements for imported materials and equipment.
This technical guidelines report provides an overview of the design process that includes a description on how to identify a soil erosion issue, determine the most appropriate mitigation solution, and assess design conditions. It also outlines the required steps for ensuring a robust engineering design, assessing environmental effects, obtaining the necessary construction documentation, and monitoring throughout the process. In addition to the technical design of selected coastal protection options, the report covers concept-level design guidelines for selected conditions, general specifications, design drawings, proposed construction methodology, and information on maintenance requirements. It aims to assist government public works departments, coastal managers, consultants, non-government organisations and contractors, among others. This document neither includes detailed designs for complex or high-priority structures, nor does it intend to replace codes, standards, or guidance manuals that are in existence. A full understanding of the local setting is critical to the development of any design solution.