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bulk of water that must be stored in the sands, else the draught of many 

 large bores would have distorted the tongues of good water still leading direct 

 from intake to outlet. 



It will be noted that, with one exception, neither the isopotentials nor the 

 chemical data so far indicate any definite intake between Marree and the eastern 

 border. At Cat Spring, to the north of the Flinders Range, the water is of the 

 sulphated artesian type, and can only come from a local intake, which, however, 

 may extend for some distance towards Marree. Yerilla and Lake Crossing 

 Bores, which are not deep enough to get the main or carbonated supply, must derive 

 their sulphated water from a western intake into some bed above the main water- 

 bearing horizon, and this water must come from the slopes of the Flinders Range. 



Montecollina, which just touched the water-bearing bed, has worse water 

 than should be normal for the locality, though it has improved since first struck. 

 This improvement is a feature of several bores, and the writer suggests that 

 as the water just below the shale is probably more stagnant than in the main 

 sand body it has retained more salts, and that this more saline water is gradually 

 replaced by better water flowing from below towards the bore. 



Other bores again, though apparently deep enough (e.g., Gypsum), show 

 water so bad for their locality as to suggest contamination by the low-grade 

 ground water which may have corroded the casing or got down past it. 



The plans all go to show the significance of the mound springs in con- 

 sidering the artesian suppfies. 



The flow of these springs, numerous though they are, cannot be compared 

 with the flow from the thousands of bores now sunk in the basin in Queens- 

 land, New South Wales, and South Australia, and as there is no evidence that 

 the springs were much stronger immediately before the inception of boring, it 

 follows that the annual intake, at that time, approximately balanced the escape 

 through the mound springs and beneath the Gulf of Carpentaria, and that the 

 draught of the bores is on accumulated water stored in the more elevated portion 

 of the main water-bearing bed, and which high-level water increased the potential 

 throughout the basin. With the lowering of potential that is now going on, 

 more and more of the bores throughout the basin will only yield by pumping 

 what water is actually required, and the escape from the mound springs and 

 into the Gulf of Carpentaria will also fall off from the same cause, so that 

 ultimately there will come a new state of balance, in which the influx of water 

 will meet the demands of pumped bores, of the diminished spring and bore 

 flows, and of the leakage into the Gulf. What amount of water actually enters 

 the intake is impossible of computation. Prior to the inception of boring, when 

 the potential was probably not less than 10 per cent, or more than 20 per cent, 

 greater than it is to-day, there would be a correspondingly greater escape by the 

 natural vents of an additional quantity that nevertheless could easily escape 

 observation. The present draught has diminished this escape and is still lowering 

 the potential. When the new state of balance arrives the lowered potential will 

 have further decreased the escape by natural vents, and it is only reasonable 

 to suppose that the additional absorption capacity of the drained intake beds 

 will permit of an annual accession greater than existed before boring began. 

 The annual available supply in the future may thus be confidently counted upon 

 as being considerably greater than the escape from the outlets of the basin just 

 prior to the sinking of the first bore. 



Unfortunately there is no way of controlling the flow of these outlets. 



South Australia, having the lowest elevation, will be the least and last 

 affected, but meanwhile rigid control to prevent waste of water from the bores 

 will help to defer the loss of the accumulated stores of water, and delay that 

 extension of widespread, expensive, and deep pumping which will follow when 

 the residents of the basin are dependent on the average annual income of water. 



