Economic valuation of water and «willingness to pay» analysis with repect to tropical fruit production in southeastern Spain

[ENG] This paper reports a survey of how 64 tropical fruit growers from the Granada coast of Spain use and value their water resources. This area produces crops of high added value. The agricultural demand for water is ever increasing and is much greater than the actual supply. This problem is worsened by the infiltration of seawater into the aquifers that provide most of the irrigation water for the area. Moreover, the population increases five-fold in the summer due to tourism, further aggravating the problem of water scarcity. Technical innovations, especially the reuse of urban wastewater, and economic solutions, namely increasing the price of water, have been proposed under the European Union Water Framework Directive. The main questions in the survey are described and the responses analysed. The productive, technological and resource management characteristics that determine the growers’ expressed willingness to pay for the water they use, as well as their attitude towards the use of alternative sources (such as residual water) are examined. Finally, the marginal product value of irrigation water in the area is calculated. [This paper reports a survey of how 64 tropical fruit growers from the Granada coast of Spain use and value their water resources. This area produces crops of high added value. The agricultural demand for water is ever increasing and is much greater than the actual supply. This problem is worsened by the infiltration of seawater into the aquifers that provide most of the irrigation water for the area. Moreover, the population increases five-fold in the summer due to tourism, further aggravating the problem of water scarcity. Technical innovations, especially the reuse of urban wastewater, and economic solutions, namely increasing the price of water, have been proposed under the European Union Water Framework Directive. The main questions in the survey are described and the responses analysed. The productive, technological and resource management characteristics that determine the growers’ expressed willingness to pay for the water they use, as well as their attitude towards the use of alternative sources (such as residual water) are examined. Finally, the marginal product value of irrigation water in the area is calculated. [ESP] El presente artículo expone algunos resultados de una encuesta realizada a 64 explotaciones de fruticultura tropical de la costa tropical de Granada sobre el uso y valoración de los recursos hídricos de que disponen. Se trata de una zona de cultivos con un gran valor añadido, en la que la demanda agrícola de agua es creciente y muy superior a la oferta. Esta situación se ve agravada por problemas de intrusión marina en el acuífero del que se surte principalmente la zona, con la consiguiente degradación de la calidad en el agua de riego. Además, la población se quintuplica en verano por el turismo, lo que agudiza el problema. Se han planteado tanto soluciones técnicas (especialmente el uso de aguas residuales depuradas de origen urbano), como soluciones de naturaleza económica (básicamente incrementos del precio del agua), de acuerdo con lo establecido en la Directiva Marco de la Unión Europea. En primer lugar se presenta un análisis descriptivo de las respuestas más importantes de los agricultores a la encuesta. A continuación se estudia qué características productivas, tecnológicas y de gestión de recursos en las explotaciones determinan una mayor disposición expresada por los agricultores a pagar por el agua actualmente utilizada, así como su actitud ante el uso de fuentes alternativas tales como las aguas residuales. Finalmente se calcula el valor del producto marginal del agua de riego.This work was performed as part of INIA Project SC99-06