Those licences that were handed out in the 50's were dormant...

Those licences that were handed out in the 50's were dormant till a crop that showed decent return presented itself Cotton . I live on the Namoi but the licence I owned was a bore licence for 300megs , that bore is 5klms from the river but the aquifer it draws from is an extension of the gravel beds of the river . Imagine the river plain being like a layer cake of soil with gravel seams running through it & the water that flows down thriver seeps out into those seams in fact when I was standing next to the drill rig as they pulled up samples of gravel there were small shells in them .During the 80's as cotton increased growers were buying farms with attached licences , moving the license further down stream & selling the farm  as at that time the licence was not able to be moved any other way. (that has changed) as these licences became operational the river flow became less reliable over a decade or so this affected the amount of water recharging the aquifers so they began to fall. By that time river licences were tradable & were worth  quite a lot . Aquifer licences however were still attached to the land & unsaleable unless with the land so their value was hard to pin down . Confronted with this aquifer falling state govt made the decision to cut aquifer licences , in my case from 300 megs to 81megs , they paid me $22000 (taxable) for that 219 megs which on recent market is now worth over $ 1million . So even though the river activity caused the problem it was the aquifer irrigators who bore the cost because to cut river licences would have cost them much much more in compensation.To this day cotton is about the only crop worth growing under irrigation nothing else comes close. I have never grown it for the record & sold the irrigation farm 9 yrs ago as th slow allocation was unviable. 

ps back in the early 80's if we had asked for more allocation they would have gladly given us more but at 300 megs it was fine , odd how much things have changed.