628 PROCEEDINGS OF SECTION I. 



The Kapunda water is the least saline of all cur waters, and also 

 verj' soft, but holds such an enormous quantity of matter in sus- 

 pension that it is hardly, if at all, used for drinking purposes ; its 

 principal use being for locomotive engines, for which it is particu- 

 larly adapted, especially in connection with other waters of a hard 

 saline character. 



Among moderately hard waters the purest is that in the Blue 

 Lake at Mount Gambler used for supplying the towai. The source 

 of this w^ater is not accurately known, but its great organic purity 

 will be seen from the analysis in Table 1. The water in this lake 

 is subject to periodical disturbances, during which the water loses 

 its wonderfiil clearness, but the matter brought into suspension 

 quickly subsides, leaving the water almost purer than before. 

 Sufficient data has not been obtained to explain this phenomenon. 

 I am inclined to think it may be caused by the inrush of a volume 

 of gas near the bottom, which, stirring up the sediment, causes the 

 water to lose its transparency for a time. The Beetaloo water is 

 another example of a hard water, it being, for fresh waters, probably 

 the hardest utilised here for a large supply. The organic purity 

 of this water varies very greatly according to the season. Some- 

 times the Beetaloo water supply is purer than that of Hope Valley ; 

 at others the quantity of flood water taken in makes it much worse 

 for a long time. The analysis of Beetaloo flood Avater in Table 1 

 shows how bad this water may be during a very heavy flood. Un- 

 fortunately the uncertainty of the rainfall in this coiony makes it 

 necessary in some cases to let water into the reservoirs while the 

 streams are still turbid. Further on I have endeavored to point 

 out a means by which our flood waters could be utilised to a large 

 extent and a pure clear supply secured. A great many waters 

 which might otherwise be utilised are too saline. 



In Table 1 analyses of the Port Augusta, Gawler, and Bundaleer 

 Creek w^aters are given. The Port Augusta Avater approaches the 

 limit of salinity permissible, but is at the same time generally of 

 considerable organic piirity. The Gawler water is certainly more 

 saline than is desirable, but is apijarently used Avithout any ill 

 effects. The Avater from Bundaleer Creek is too saline for the 

 supply of a large town. In some cases Avhere the usual floAv is too 

 saline for a jiotable water the flood Avaters could be utilised, but 

 would require purification. 



The natural jiurification of the waters in this colony is very 

 quick under faAJ-orable circumstances, and the GaAvler supply 

 appears a good example of this quick purification. The nitrogen 

 as nitrates in this water renders it of a very^ suspicious character, 

 and the analyses are Avatched with some degree of anxiety. The 

 Magill water also contains so much nitrogen as nitrates as to cause 

 suspicion regarding previous contamination, although otherwise it 

 is a A^ery pure Avater. The nitrogen as nitrates in other Avaters 

 sometimes varies very much ; thus in the Avatcr from tlie Aveir at 

 the Torrens Gorge it rose from 0-026 in February, 1893, to 0-099 



