Kelly M. Cobourn

Conjunctive Water Management in Hydraulically Connected Regions in the Western United States

Abstract Conjunctive management often includes policies for conjunctive administration, which seek to reconcile separate property rights systems for surface water and groundwater in regions where the two resources are hydraulically connected. Hydraulic connectivity between surface and groundwater implies that the extraction of water from one source influences the availability of water for extraction from the other source. This chapter develops a hydroeconomic model that integrates dynamic surface water–groundwater relationships with a model of irrigator decision-making to evaluate conjunctive administration policies. We show that the economic efficiency of alternative policies depends on the interaction of three factors that vary across space: the hydrologic dependencies between surface water and groundwater, the pattern of initial water rights ownership, and the productivity of water by farms.