Nutrients enrichment in aquatic ecosystems is given by multiple natural and human factors. Their accumulation in water bodies can lead to undesired consequences on the water quality. Considering that information of nutrients in tropical aquatic ecosystems, specifically in Colombia, is limited, it is important to carry out research projects aiming at conservation and proper management of water resources. In this context, a study of the spatial and temporal changes in nutrient loadings into the Amani reservoir (Magdalena River mid-basin, Colombia) was carried out considering inter-basins water transfers from Guarino river to La Miel river. In order to compare the trophic status in the reservoir before and after transfer operations have started, simple eutrophication models were implemented.