Assessment of the effectiveness of optional water pricing for irrigation in Charente river basin (France)

In period of low water level, some river basins face an imbalance between the available water resource and the uses. Favored by the 1992 French water act, rending the metering progressively obligatory and that recommend dialogue among water actors, a volumetric management (VM) mechanism has progressively been implemented. This is the case since 2000 in the Upstream Charente river basin that face an important imbalance added to high sensitivity of the resource to the climatic conditions. This article presents the VM instruments implemented in this basin, discusses their effectiveness and propose an alternative management system based on an optional water pricing and on a new water consumption declaration system improving control and allowing potential sanctions. It is then shown that this demand management system allow a 10% resource saving, reduce inequities among farmers and is most cost effective than supply creation options or regulatory ones.