Criel sur Mer is a small town in Normandy in the region of Northern France, known for its stunning coastline of steep chalk cliffs. Erosion of the cliffs in Criel sur Mer is occurring rapidly as a result of climate change but also due to man-made construction works further up the coast. In Criel sur Mer a short piece of land on the coast that is eroding rapidly and several homes built near the sea are threatened by the predicted collapse of the cliff. In particular, a street of homes were faced with immediate danger from erosion. Between 1995 and 2003, the local administration organized the abandonment and demolishment of 14 homes due to imminent risk from natural disaster under the Barnier Law. The adoptive policy was to do nothing against cliff erosion and to demolish and relocate those in immediate threat and compensate them fairly for their lost property.

General description

Coastal erosion is a common challenge along many stretches of the coast in Normandy. The cliffs are extremely steep and the rock material is chalk which is soft and easily erodible. The verticality of the cliffs mean that erosion is especially intense at the base of the cliff leading to significant fractures and collapse of cliff and loss of pebble beaches that would otherwise help mitigate erosion from the sea. Moreover, in Criel sur Mer considerable engineering works carried out along the coast have exacerbated erosion. Specifically, the construction of the ports Le Havre, Fécamp, Saint-Valery-en-Caux, Dieppe, and Le Tréport as well as structures for water and nuclear stations in Paluel and Penly; and the creation of coastal defence structures (sea fronts, groynes etc) at the mouths of all the valleys. These manmade constructions have created disturbances to the transport of sediment (mainly course pebbles) to the shore and resulted in a faster rate of erosion due to lack of protection. Pebbles have also been extracted for gravel purposes. Loss of pebbles leads to a retraction of the beach which protect the mouths of the rivers and the cliffs.

One of the immediate challenges for the community of Criel sur Mer was the actual loss of cliffs where houses existed.Responding to this emergency, the local administration considered both hard and soft measures with for instance the consideration of the implementation of defence works at the base of the cliff. The high cost of defence measures and the low cost of the real estate threatened by erosion led the local administration to evacuate the families faced and to implement a coastal setback plan whereby any new developments must take place 100 m from the cliff top.

The innovative aspect of this relocation measure was the fact that the compensation rate to those individuals that lost their property was calculated against the real market value. It is common that properties known to be at imminent risk lose real market value quickly, however, in the case of Criel sur Mer the French Government ensured that those families losing property were provided for financially based on the ‘riskless’ market value of the homes.

Key lessons learnt

The lesson of the Criel sur Mer illustrates is the inevitability of managed retreat in the face of climate change and the fact that multiple variables affect the situation and decision taken. For example, the cause of erosion was not only climate change but also a result of manmade constructions and attempts to mitigate against erosion. Moreover, the possibility of implementing a hard defense was considered but was economically disadvantageous. Thus, the Criel sur Mer provides an example of an extreme case of communities being threatened by climate change and provides an example of how governments and administration can more fairly compensate them economically.

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