The legal framework on coastal erosion and integrated coastal zone management

The impacts of erosion can be summarized in the following way:

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loss of habitat/ beach and landscape quality; degradation or loss of coral reefs due to deposition of silt and increased water turbidity; loss of buildings, infrastructure facilities, such as roads and power lines; increased sea water turbidity and decreased water quality; reduction of the tolerance of the coastal environment to face natural hazards such as severe wave surges and Tsunamis or cause flooding in the lowland areas; decrease of sand volume to compensate the natural littoral processes; reduction of the scenic beauty of the beach; collapse of the tourism in the affected area; loss of boat anchorage sites; increased wave energy on beaches endangering swimmers and passers-by; reduction of primary production and fish productivity; considerable annual expenditure for damage mitigation, control and disaster relief.

2.4. HARD AND SOFT COASTAL PROTECTION ENGINEERING

Coastal erosion problems have led to major efforts to manage them and to restore coastal capacity to accommodate short-and long-term changes induced by human activities, extreme events and sea level rise. The erosion problem becomes worse whenever the countermeasures (i.e. hard or soft structural options) are inappropriate, improperly designed, built, or maintained and if their effects on adjacent shores are not carefully evaluated. Most times erosion is addressed locally or at regional boundaries, instead of at littoral cell’s real boundaries that reflect natural processes. This anomaly is mostly attributable to insufficient knowledge of coastal processes and the protective function of coastal systems. Hard structures for coastal protection have very high economic and social costs; there are strong negative public reactions to rock emplacements along the coast. This has led to uncertainty among managers and local government authorities on how to treat shoreline erosion. It has become an issue for serious debate for politicians, coastal managers, land and property owners, lawyers, bankers, insurers and fisherfolk, especially in areas of intensive use and rapidly rising coastal land value. Many of these stakeholders are resorting to planned retreat where houses or hotels are simply removed and the coast is left to erode. Beach nourishment – reshaping can be an expensive solution, unnecessary and sometimes impossible, especially in highly modified environments, however it is often applied in the recent days as the only viable solution. Increased interest in soft structures for coastal protection and a combination of hard and soft structures is dominating nowadays and is in harmony with advanced knowledge on coastal processes and natural protective functions. There is evidence that coastal vegetation and forests provide some coastal protection and that the clearing of coastal forests and trees has increased the vulnerability of coasts to erosion. Some of the most effective soft coastal engineering measures that have proved to be really powerful are sand dune management and stabilization, artificial reefs to behave as detached breakwaters, geotubes for beach stabilization or for making shallow submerged breakwaters and finally bypassing, a regulation to maintain sediment budget close to ports and river mouths, unfortunately rarely honored.

Figure 2: Examples of soft coastal engineereing practices. From top left to lower left: artificial reefs, dune management using temporary constructions, dune stabilization through planting and geotubes as submerged breakwaters. Source: The Web

2.5. WHAT IS REALLY THE STATE OF THE WORLD’S BEACHES

For many years, the accepted idea was that 70% of our beaches were eroding. There is a recent research showing that the sandy coastline does not actually erode that dramatically1). Indeed, there are more beaches that grow than beaches that shrink. The main reason is that we are able to maintain our coasts well (as in the Netherlands) or even to expand them (as in Dubai and Singapore). A source of sand (sometimes forgotten) is the discharges from the mining industry. It has now been quite convincingly proven that 24% of the world’s sandy beaches are eroding at rates exceeding 0.5 m/yr, while 28% are accreting and 48% are stable.