There's no mystery. The water is being stolen, or the water never existed anyway. Water allocations are based on a single year which had high rainfall. Models

There's no mystery. The water is being stolen, or the water never existed anyway. Water allocations are based on a single year which had high rainfall. Models attempting to predict rainfall are problematic, and models attempting to predict available water following measured rainfall are confounded by over-extraction (ie: water theft). Water theft is being made increasingly easier by reducing the funding available for policing the regulations. If you want a summary of the political situation around water rights in Australia just search for "Angus Taylor water rights" or "Barnaby Joyce water rights". Our government is openly corrupt and they make no attempt to conceal it.