The Hydrogeology Group of the National university of Mar del Plata, Argentina, has about 30 years of existence, but since 2008 its activities were strongly improved by the donation from IAEA of a laser spectroscopy Los Gatos research DLT-100. The Group, without any previous experience in Mass Spectrometry (MS) analysis, has produced 3000 results of stable isotope in water, which leads to an important academic production. The capabilities of the group for analyzing and understanding the hydrological cycle in the Pampa Argentina environment was increased producing a revolution in the conceptualizing of the systems in the Pampa plain.