Impacts of the application of a water charging policy in irrigated fields in Portugal: the lezíria do Tejo case

Abstract

The full application of the Water Framework, working out the problem of the sustainable use of water (namely by charging the water in such a way that fully reflects its real costs), will have an impact in all water dependent economic activities, particularly in agriculture. This study evaluates the socioeconomic and environmental impacts of the introduction of a water charging policy in the irrigated fields of Lezíria do Tejo. For that purpose, a mathematical programming model was developed (the MALTe – Modelling Agriculture in Lezíria do Tejo), calibrated by using the positive mathematical programming method (PMP). The analyses of the optimal solutions indicated that a reallocation of land to the different crops will occur, as well as a decrease of the total irrigation area. However, as long as caution and good sense are used on defining the water economic and financial regime, it is possible to overcome the drama of water scarcity without compromising the future of agriculture in that region.