Water in Celtic Countries: Quantity, Quality and Climate Variability (Proceedings of the Fourth InterCeltic Colloquium on Hydrology and Management of Water Resources, Guimarães, Portugal, July 2005). IAHS Publ. 310, 2007, 139-147.

---

Eutrophication in the River Vouga basin—impacts on the quality of water for public supply

J. FIGUEIREDO DA SILVA¹ & FAUSTO OLIVEIRA²

1 Departamento de Ambiente, Universidade de Aveiro, 3810-193 Aveiro, Portugal

jfs@ua.pt

2 Águas do Vouga,3850 Albergaria a Velha, Portugal

Abstract The aim of this paper is to make a characterization of water quality problems in the River Vouga, regarding its use for public water supply. The River Vouga basin is located in a mountainous area, draining to the coastal lagoon of the Ria de Aveiro. Other medium size rivers also contribute to the pollution load entering the estuarine system of the Ria de Aveiro. Two major impacts of the pollution in the River Vouga basin were identified. One is the eutrophication process of the lower reach of the river, including the Ria de Aveiro; the other is the occasional deterioration in the quality of the water from the medium reach of the River Vouga. The causes of this deterioration are related to the enrichment of the river water with organic material. To improve the river water quality, both urban wastewater and agriculture related sources must be controlled.

Key words filtration; nutrients; suspended solids; water quality; water treatment

---