Coastal stabilization practice in France

Abstract

The expansion of coastal urban fronts, leisure ports and tourism in the course of the twentieth century has been the main driver of large-scale modification of the coastal zone in France. The development pressures generated by mass tourism and the economic boom of the 1960s have had their strongest effects in the Mediterranean, but pressures have also been important on the coast of Normandy and Picardy. In the Mediterranean, where large-scale planned development involving joint state and private capital ventures was implemented, this situation has, in many cases, exacerbated coastal instability, while endangering coastal ecosystems, and the growth of urban fronts has commonly led to a drastic reduction in beach width and to dune degradation. Coastal sediment budgets have also been seriously affected by updrift stabilization of cliffs and beaches, especially in Normandy and Picardy. In France, some of the causes of, and the responses to, shoreline destabilization have been essentially a matter of ‘hard’ engineering, for both historical and cultural reasons, although the situation has been changing over the past decade. A brief overview of shoreline stabilization procedures and structures highlights the overwhelming predominance of seawalls and groynes. Recent practices have tended to move closer to beach nourishment, which is gaining ground in France. Four case studies briefly highlight the benefits and disbenefits of shoreline stabilization in France. These are: (1) a sandy city-front beach protected by breakwaters on the macrotidal southern North Sea coast downdrift of the large industrial port of Dunkirk, (2) the regularly renourished and heavily groyned gravel barrier of Cayeux in Picardy, the largest coastal gravel barrier in France, (3) a strongly eroding sector of the Rhône delta shoreline where various combinations of coastal stabilization projects have succeeded each other for over a century and a half, and (4) the regularly renourished gravel beach of Nice, on the French Riviera. These examples show that the emphasis on coastal stabilization at whatever cost that has underpinned coastal management practice needs to be reconsidered, as stabilization will become costlier in the future, as pressures from coastal development increase, as sea level rises and as sediment stocks diminish. Openings in this regard are coming from larger environmental awareness, the recognition of the failure or poor performance of many coastal stabilization projects, and the diversification of the actors involved in coastal management and planning. These developments are progressively generating a new logic of wider concert, on the basis of a more prospective, upfront and long-term approach to coastal management, instead of the logic of a ‘stabilization-only’ and a commonly one-shot immediate response to storm erosion problems that had tended to prevail in the past.