Evaluating the Sustainability of Agricultural Water Pricing Policies using Composite Indicator: A Case Study of Qazvin Province of Iran

One of the most difficult duties for public decision-makers is to select a practical and legal instrument to receive water tariffs in the agricultural water pricing policies. This study aimed at analyzing the potential consequences of different instruments for irrigation water pricing (area, volumetric and two-part tariff) and their effects on the sustainability of irrigated lands with respect to economic, social and environmental impacts. For this purpose, farmers’ behavior in response to pricing instruments was simulated through positive mathematical programming and the composite indicators were calculated for sustainability measurement of different instruments in these irrigation water pricing policies using Analytic Hierarchical Process (AHP). The required data were collected in two-stage cluster sampling by 120 questionnaires completed from farmers under the irrigation network of Qazvin Plain in Iran as well as opinions and experiences of experts and documentary data. The results showed that the implementation of the studied irrigation water pricing policy instruments had negative impacts on economic sustainability indicator (i.e. profitability) and social sustainability indicator (i.e. employment) and a positive impact only on environmental sustainability indicators; and water consumption increased in area pricing and decreased in volumetric and two-part tariff pricing. In addition, the overall sustainability index in two-part tariff was higher than other water pricing instruments. Therefore, a two-part tariff pricing policy and adoption of alternative policies to achieve complete sustainability and compensate for the negative effects of this pricing policy were recommended.