Etude globale pour une stratégie de réduction des risques dus aux crues du Rhône

Global study for a strategy of risk reduction due to Rhone river floods

¹ Institution interdépartementale des bassins Rhône Saône
² Compagnie nationale du Rhône
³ Agence de l'Eau, Rhône Méditerranée Corse
⁴ DIREN Rhône Alpes, Délégation de bassin Rhône Méditerranée Corse

Abstract

The river is characterised by complex hydrological and hydraulic regimes. It is fed by a large number of tributaries with strong flood flows, draining a valley dominated by mountainous massifs and varying climatic conditions. As for the Rhone Valley, it is highly urbanised with large concentrations of industry. In addition, the operation of the river has been modified considerably by developments constructed for hydropower, agricultural and navigation requirements. Nonetheless, the diversity of the environments through which it flows still makes the Rhone a rich fund of habitats and species of flora and fauna, remarkable both in France and Europe. Lastly, whether superficial or underground (alluvial water), the waters of the Rhone constitute a key factor for the valley's development. Given the extent of these challenges, the Catchment Area Committee adopted a "Rhone action plan" in 1992, after carrying out a major study programme. This aimed at restoring the quality of the components making up the hydrosystem (water quality, by-passed sections and environments associated with the river, migration plans, etc.). In order to take new knowledge into account, the Rhone-Mediterranean-Corsica SDAGE, adopted in 1996 by the Catchment Area Committee, programmes the updating of this action plan. Following the heavy flooding of 1993 and 1994, which caused major damage along the Rhone, the Ministry of the Environment decided to make an overall study of the operation of the river under flood conditions, taking into account all the developments constructed over the last fifty years. The objective announced was to carry a wide-ranging study covering the entire catchment area, in order to modify current land use practices in flood plains and reinforce the protection of urban areas against floods. The promoter plans to carry out wide-ranging consultation with neighbouring populations, etc., in order to define a strategy to reduce the risks of floods along the Rhone.