Les Bas-Champs de Cayeux (Somme, France) : vers une gestion intégrée ?

Abstract

Have the recent public policies for the management of coastal areas impulsed notable changes in projects ? The example studied here tends to prove that a concept (the GIZC), rather new in France, can have some influence on local management of coastal areas if respected in its principles. We shall study a new kind of management in the southern part of the Baie de Somme, on a coastal area where new initiatives have been taken consequently to the decisions taken in the CIADT (interministerial committees for the territorial sustainable management) in April 2001 and September 2004. There, indeed, the notions of sustainable development and of GIZC have been promoted, belatedly with reference to advice of the Bonnot report (1995), and show the necessity of a proper policy concerning coastal areas, as playing no poor part in the global environmental policy. The « Bas-Champs » of Cayeux is a space demarcated on its eastern boundary by an old cliff and protected from erosion by the waves on its western boundary by a shingle ridge eroded by the waves. The penetration by the tide into this former sea space has been stopped since the « grand barrement » in 1752 (old gravel workings inland ). The struggle against sea action has been lasting for three centuries, in order to protect the land and surrounding fields gained on the sea. These sea defences have been damaged in some places after high tides and strong storms blowing West. The most powerful storm happened in 1990 and led to the flooding of 35 square kilometres of productive farmlands. The cost of works to protect and reinforce the ridge amounts to over 30 M euros, plus 350,000 euros a year for maintenance… which means… ad vitam æternam ? These costs are higher than the economic value of the properties they protect. Thus, allowing the tide to penetrate again into this former sea space migth be a solution in agreement with the principles of the GIZC and the sustainable development.

Keywords

• management
• coastal area
• sustainable development
• GIZC
• dépoldérisation
• Bas-Champs