Water is a renewable, but often limited resource that is frequently wasted or polluted. Isotope hydrology is a nuclear technique that help countries to better manage water resources by providing information about water origin, age, quality and movement in underground aquifers. Isotopes of water are variants of its chemical elements. By studying isotopes of water, hydrologists gain scientific knowledge that helps to inform countries how to protect and preserve their water supplies. From Vienna, Austria Alexandra-Anna Panic has this report.?