5 million tonne or more stockpile

Previously I had asked if anyone could throw light on why CDU would be stockpiling more than 5 million tonne of ore on commencement of the commissioning of the process plant when the plan is to process 3 million tonnes a year for 10 years.

I think I may have the answer. CDU has ample underground water to sustain the processing of that 5 million tonne of ore.