Irrigation and the agrarian development in Portugal: impact of dam construction in the Alentejo (1958-2022)

Abstract

Since the 17th century, irrigation has been seen as a solution for reverse depopulation in the Alentejo due to the increase in agricultural production and the consequent land reform. However, only from the mid-20th century onwards there was a growth of irrigated areas. After more than six decades, this article studies the impact of the construction of the Maranhão dam, Avis, Alentejo crossing the proposed objectives with the respective demographic, economic and social developments. From the analysis of different statistical series, it is concluded that most of the objectives were not achieved. Avis is today a depopulated territory, with low development rates and a latifundium property structure. Additionally, there has been a rapid expansion of intensive monocultures, endangering the environmental sustainability of the region. This reflection based on historical analysis is fundamental at a time when the construction of new dams is being announced.