Résumé
Because of an important increase of irrigated area since the 70s, Charente river basin face important imbalance between the available water resources that is very sensible to climatic variability and uses. Favoured by the 1992 French water act, rending the metering progressively obligatory and that recommend dialogue among water actors, a volumetric management mechanism has progressively been implemented, especially in the upstream Charente river basin since the Mas Chaban dam creation that allow to resupply the river. This article presents the volumetric based management instruments implemented in this basin, discusses its effectiveness and propose an alternative management system based on an optional water pricing and on a new water consumption declaration system. We then highlight that this demand management instrument, for a comparable effectiveness, is less costly than the regulatory measures already adopted by river basin authorities and the farmers preferred measure that consist in creating new resources.