South Portugal Reservoirs – Status and major concerns

Abstract

In southern Portugal, the dry summers together with low precipitations and high temperatures highlight the importance of reservoirs, built mainly for water storage and to smoothing the interannual precipitation variability, in one of the driest regions in the country. According to the Water Framework Directive nº2000/60/CE, all states members are responsible for the classification of superficial water bodies using a system based on both ecological and chemical status. The Water Framework Directive set the aim of achieving the “Good” status for surface and groundwater by 2015. There are two reservoirs typologies in the south of Portugal, the main course and the south typologies. Data from the current River Basin Management Plans were used to identify the quality status of 28 reservoirs, 26 from south typology and 2 main course typology. General physical and chemical elements (total phosphorus, dissolved oxygen, oxygen saturation rate, nitrates, pH), biological elements (chlorophyll a), specific pollutants and priority substances were used to classify the reservoirs status in “Good” and “Less than Good” quality classes. Results showed that 20 reservoirs were rated as “Good” and only 8 reservoirs were below the “Good” status.