Murray-Darling irrigators
Dead fish in the Darling River system (Image: (Supplied/Kate McBride)

South Australia's Murray-Darling Basin Royal Commission has once again shone a light on one of the biggest rorts in Commonwealth history: the waste of billions of dollars in handouts to irrigators, agricultural groups and farmers under the guise of grants for infrastructure efficiency.

Around $4 billion of taxpayer funding has been poured into concessional loans and grants for water infrastructure projects from the Commonwealth alone in recent years, including $1.6 billion on a grants program designed to fund infrastructure upgrades to return "water savings" to the Murray-Darling system. In his notorious 2015 agriculture White Paper, Barnaby Joyce boasted: