In a historic ruling that began to shape the solution to a conflict that has been going on for more than 70 years, the Supreme Court of Argentina ordered in 2017 that the province of Mendoza, together with the province of La Pampa, should allocate the water flow of the Atuel River within 30 days in order to enable restoration of the ecosystem that was affected in the northwest of La Pampa by the Los Nihuiles dams. In the ruling, the Argentine high court ordered that the two provinces, together with the national government, submit a work plan for allocation of the waters of the Atuel River. This Comment examines the ruling and offers a reflection on the importance of a paradigm shift in the management of shared water resources.