This article studies the recognition of Rio Atrato as a subject of rights through Judgment T-622-16 of the Constitutional Court, in a case without precedent in Colombian Law. To contextualize this jurisprudential milestone, the authors argue that the current regulations failed to protect the biodiversity and related rights of the inhabitants of the areas near the Atrato River. The methodology involved an analysis of the jurisprudential line of the judgments that preceded the case analyzed, as well as the study of theoretical postulates and current environmental regulations from an analytical-deductive approach. As results, the authors present the first jurisprudential line of the Rio Atrato judgment, supported by their own reflections that demonstrate the birth of a new stage of environmental law in Colombia.