Comparison of two agricultural water pricing systems with reservation and consumption.

Summary In this paper, we compare the properties of two irrigation water pricing systems based on management systems employed by water management companies in France, the Compagnie d'Aménagement des Coteaux de Gascogne (CACG) on the one hand and the Compagnie (CAEDS) on the other. The modeling uses a coupling of an agronomic model of plant growth (STICS) with a model of optimization of farmers' behavior in an uncertain universe. On data from the Midi-Pyrénées region, we compare these pricing systems according to the criteria of water consumption, value of agricultural production, farmer's profit and manager's revenue. The study of the properties shows that the CAEDS pricing system is more adapted to cope with droughts and at the same time cover the manager's costs with higher revenues. The CACG pricing system has the advantage of allowing farmers to make a larger profit. But both can not only contribute to a better implementation of the European Water Framework Directive, but also open an interesting way to original pricing systems to facilitate the achievement of the objectives of the managers of irrigated areas.