Disaster Risk Management and Territorial Governance: Lessons from Xynthia Storm in France
Résumé
Xynthia was a violent windstorm which crossed Western Europe in 2010. Its transit caused the death of 59 people in Europe. France was the hardest country hit by Xynthia: 47 people were killed, most of them from drowning, and direct losses amounted to more than 2.5 billion Euros. Strong gusts and waves of several meters of height, associated to high coefficient tides, caused a phenomenon of storm surge in the Atlantic coastal area of France, particularly in the Vendée and Charente-Maritime departments. Sea walls, lacking of maintenance and originally built to defend agricultural land, were not able to protect houses. Around 10,000 people were forced to evacuate after the inundation of their properties. Essentially, a restrictive construction policy is supposed to be applied to these areas. In actual practice, mayors are sometimes not able to resist the pressure of property developers and, since 1999, about 100,000 houses have been built in flood prone areas all over France. During the storm, uncontrolled urbanization was involved in the increase of stakes, as demonstrated by the fact that all the 29 victims in the city of la Faute-sur-Mer were living in houses built after 1980. There is also a very clear link between the type of building and mortality due to marine submersion: three-quarters of the victims died in houses without a second floor, where water reached heights over the ceiling elevation. After Xynthia transit, the government decided to destroy 1510 houses in the affected areas (called black zones). Most of the occupants did not agree with this decision, demanding further investigation, and eventually the government had to gradually revoke the policy for the black zones. We affirm that an attentive governance should include a balanced approach to risk protection, combining the reduction of natural hazard with broader measures of land management, to contemporary diminish vulnerability (e.g. by changing housing standards and building physical protections) and exposure (e.g. by zoning policies). Risk management includes a multitude of actors (national government, local authorities, communities) having different spatial scale and roles, and the difficulties relate to agents myopia, moral hazard problems, and conflicting interests. Moreover real estate market does not appropriately consider risk. We conclude that this complexity has to be accurately considered, and actors must be aware of the long term impact of their decisions. This could permit to improve actual risk governance and contemporary maintain the local economic dynamism.