Conflicting objectives in groundwater management

This paper studies the conflict between economic and environmental sustainability objectives faced by a water agency when she allocates water quotas to farmers. This conflict consists in a water allocation problem between the amount of water claimed by farmers to irrigate their crops and the water flows needed for the conservation and the preservation of the ecosystems. This conflict in objectives is analysed in a dynamic hydro-economic model in discrete-time using the viability approach. The viability kernel that defines the states of the resource yielding intertemporal feasible paths able to satisfy the set of constraints over time is analytically identified. The associated set of viable quota policies and the trade-off between food production and ecosystem conservation objectives are characterized. The theoretical results of the paper are illustrated with numerical simulations based on the Western La Mancha aquifer in Spain.