This publication presents the results of a Coordinated Research Project (CRP) undertaken by the IAEA to make an assessment of the potential use of isotopes to better understand and predict hydrodynamic changes induced by exploitation of groundwater resources. It provides a synthesis of a series of hydrochemical, isotope and geohydrological data sets which will be used for quantitative assessment of the long term dynamic response of the groundwater system. The results show that both stable and radioactive isotopes are excellent tools for characterizing and understanding aquifer systems that are undergoing long term exploitation. Specific outcomes include establishment of methodologies for monitoring and predicting changes in water quality and quantity that will lead to improved water resources management. The publication will be a valuable source of information for isotope hydrologists involved in isotope field applications, and a useful guide for groundwater managers involved in groundwater resources programmes.