Groundwater resources are considered as the key to all human activities and their survival adaptation, particularly in arid regions. Decision makers have special ambitious goal of optimal groundwater resources using with limited undesirable impacts both presently and in the future. Hence, groundwater development projects depend mainly on the ability to manage the resources and to protect their quality and quantity and utilize them efficiently. In this context, different approaches have been discussed in this chapter. Results shows that the developed indices for water resources sustainability are among the simplest used approaches that are based on a wide scale of hydrogeological and social indicators. On the other hand, numerical models can be used, as a powerful tool in the management plans and prediction of groundwater behaviour. In this chapter, retrieved approaches from different regions have been discussed based on the understanding of recharge, storage, and discharge mechanisms as being important for strategic freshwater resource. This chapter highlights the importance of understanding groundwater renewal, quality, and transport by way of numerous approaches, of which isotope hydrogeology is one of the potential approaches. Therefore, more emphasises on application of isotope hydrology approach and its conjugation with other approaches will help in providing a rapid and accurate understanding of the groundwater systems and characterizing its regime. In addition to that, it would also help in estimation of an accepted logistic framework that might help in controlling and even evaluating the significance of predicted climatic and anthropogenic impacts on groundwater resources.