Most of the world's freshwater resources in the liquid state (i.e. not in glaciers and polar caps) are underground. As the population grows and demand for water rises, reliance on groundwater increases. In many cases the groundwater underlies boundaries, or is part of a hydraulic system that crosses boundaries. In such cases there is always the danger that the 'prisoner's dilemma' will run its course and all parties will compete over who will pump the most water, ultimately destroying the storage potential to the detriment of future generations of all parties reliant on the groundwater. This...