Evaluation of the Condition of Affluent of Aburra-Medellin River through Indices

This article evaluates and analyzes water quality of 21 streams tributaries of Medellin-Aburrá river, with the information obtained since 2004 in the project entitled “Network for Monitoring Water Resource at Aburrá Medellin River Basin, RedRío” executed between environmental authority “Area Metropolitana del Valle de Aburrá” and Universidad de Antioquia. This evaluation was performed through several water quality indices and allowed identifying the water bodies requiring immediate recovery actions. Among the indices considered, the ICACOSU (qualitative index) formulated by IDEAM in 2009, was evaluated; this index is a tool used by the Ministry of Environment and Sustainable Development to evaluate water resources in the entire country; it was then found that it is the least drastic tool. However, all indices showed a number of critical streams, but always including the following tributaries: La García and La Hueso. This latter stream is of special importance since different actions of the Wastewater Discharge Sanitation and Handling Plan have already been implemented. Finally, it should be noted that the application of each index will depend on the objective pursued in the study, and that the quantitative index obtained from the information measured in the basin streams is a good tool to make specific decisions on these water streams, since the biological component is involved and water bodies of the region with minor intervention are taken as a reference.