ABSTRACT: The ever increasing demand for water resources and its temporal and spatial unavailability in terms of required quantity and quality necessiate its efficent use ormanagement to provide economic, environmental and social benefits. However, the success of water resources management is achieved only by accurately determining the whole relationships among processes effecting the hydrologie system. In this stage, the definition of the system- as a basin within its natural boundaries and determination of its available yield will enable a rational and effective water resources management The so called classical safeyield approach should not be used to determine the available groundwater potential Instead, the sustainability approach, which meets the long-term water demands without creating undesirable effects on the system at the end of active water usage period, must be used,. In the last stage of the water resources management, the sustainable yield should be shared among various users with a water allocation policy by considering the use priorities to provide maximum- benefits for the basin. The effective and efficient water resources management for a basin is only realized by this water allocation policy. This study also presents the water resources management studies in Turkey, the administrative and legal conditions and th.e general recommendations for a basin-wide water resources management