In the present study, the evaluation of groundwater is carried out with isotopic studies of δ13C. Isotopic fractionation studies (δ13C) allowed for the identification of trends in dissolved inorganic carbon (DIC) behavior in groundwater from the northern area of the Valle Medio del Magdalena basin, confirming that different sources contributing to DIC can be distinguished. By complementing the analysis with 14C values, the evolution of DIC in open systems versus closed systems was discriminated. However, due to the heterogeneity of the area, it is important to conduct local characterizations, considering the water mixtures that occur due to the complexity of both the surface and underground aquifer systems. While highlighting the main sources of DIC, it is important to note that they are not the only one present. The results indicate that to the north of the study area the DIC evolution is influenced mainly by inorganic interaction, while to the south fractionation is more related to organic interactions are observed.