The ecological situation of Osona’s rivers
The intense drought of 2021 has highlighted the worrying quality of some river courses in the Osona region. This observation comes from the report on the evaluation of the ecological state of the river courses, carried out by the Mediterranean River Studies Center (CERM) of the University of Vic-Universitat Central de Catalunya (UVic-UCC) and the Area Environmental of the Ter de Manlleu Museum. According to the report, overall water quality was affected, with most of the parameters studied worsening compared to previous years.
Impact of drought and the use of fertilizers
The reduction in flows due to the drought has contributed to the decrease in the biological quality of the water, affecting aquatic macroinvertebrates. In addition, the lower amount of water has limited the ability of rivers to dilute direct and diffuse pollutants, exacerbating the situation.
Variability of river quality
The study also highlights that the rivers that run through forest areas, such as the Ges, the Major stream and the Ter river, show positive qualities, while those that pass through agricultural, industrial and urban land, such as the Rimentol stream, the Gurri river and Meder river, have qualities between mediocre and bad.
Recommendations for improving the situation
Núria Sellarès, CERM researcher, points out the need to reduce the use of water in domestic, industrial and agricultural areas, including hydroelectric jumps, as a measure to address this problem.
Sampling of river sections
Thirteen river sections were analyzed during 2021, including the Ter river in the municipal terms of Manlleu, the Masies de Voltregà and Torelló, the Rimentol stream, the Meder and Gurri rivers in the municipal terms of Vic and Gurb, the Major stream in Viladrau , and the river Ges in Sant Pere de Torelló.
