Hipolimnion water quality and its relationship to internal P loading in an eutrophicated water body: San Roque Reservoir (Córdoba, Argentina) / La qualité de l'eau de l'hipolimnion et son rapport avec le chargement interne de P dans l'eutrophisation de la masse d'eau : Réservoir De San Roque (Córdoba, L'Argentine)

Abstract

San Roque Reservoir (Cordoba, Argentina) is the main resource for drinking water to the city of Cordoba and its surroundings with a total population of nearly 1.5 million inhabitants.Water-quality related problems have increased in the reservoir due to deforestation, urban run-off and particularly the discharge of untreated sewage. The reservoir is currently receiving large inflows of nutrients and the process of eutrophication started decades ago. As a consequence, regular and continuous algae blooms occurred since 1988. The reservoir presents summertime stratification regime, when thermocline is formed, and consequently the bottom layer becomes anoxic. Redox potential gets reductive and numerous compounds release from sediment such as phosphorus. This work presents the results of a comprehensive field study consisting of 12 campaigns during a chronological year (2000).Water at the hipolimnion and sediment samples were taken at three monitoring stations: the center of the reservoir, old wall and the wate...