New Tools; New Applications; New Challenges

Isotope hydrology has evolved into a multidisciplinary field. As new approaches are developed, new applications and tools are being added to the isotope toolbox. For example:

Among the key challenges in future isotope applications are:

Isotopes Reveal Leaks in a Dam

The El Colorado dam in Chile forms a reservoir with a volume of about 1.5 cubic kilometres. Major leakages beneath the wall developed and a grid of wells was drilled downstream from the dam to relieve the groundwater pressure.

A field survey revealed that reservoir water had a mean deuterium concentrarion of -950/00, which differs from local groundwater having a mean 2H = -70/00. Analysis of water samples from the boreholes showed that leakages were most pronounced near the flanks of the dam wall. Guided by this information, an area of major leakage on the reservoir floor was later confirmed, using the artificial radioactive tracer 131I. Mitigation measures to prevent the eventual collapse of the dam were then undertaken at this location.