The isotopic content of the groundwaters of the Lower Andarax was used as the basis for differentiating two subterranean flow systems. The more superficial system is represented by less impoverished waters with temperatures of less than 24 °C. The deeper system corresponds to lighter waters and temperatures exceeding 24.5 °C. Using these data one can consider the hydraulic connection between the carbonate aquifer and the deep aquifer, and the possible recharge at depth between the carbonate and detritic aquifers in the Cádor area