130 WATEB SUPPLY TO SYDNEY P.Y GRAVITATION. 



brackish waters from behind, to create a fine fresh- water lako 

 extending to Liverpool, a distance of more than 20 miles. 



Before passing on from this subject, I desire to be clearly 

 understood that the above remarks should in no way be considered 

 as an advocacy of the so-called " George's River scheme," as in the 

 least against my gravitation plan ; because by my method, 

 certainty of pure supplies in abundance from high elevations and 

 with valuable pressure would be the consequence, as against the 

 risk of obtaining adequate supply of pure waters under what could 

 only be at best a pumping scheme from George's River. 



I regretted that there were no members present at our last 

 meeting who represent our present water supply system, and 

 who persistently advocate an extension of the Lachlan and 

 Botany swamps sources of supply. As none of these gentlemen 

 were present at the meeting, and as I observed that they tacitly 

 ignored my gravitation scheme, I hope I may be permitted to 

 make some allusion to their amended and proposed method of 

 extending the supply of water for the city. 



Feeling strongly upon this point of our present supply, I 

 should, perhaps, under this opportunity, be wrong in withholding 

 my own expressions on this subject for what they may be worth, 

 and I trust therefore that I may not be considered to be out of 

 order in making the following remarks on the Botany water supply. 



Much has lately been said as to the mistaken advocacy of 

 reserving thousands of acres around the present nucleus of a 

 large city, and which is unanswerable ; but too little has, I 

 think, been said of the risk of the supply waters failing under 

 severe seasons. I believe that most men of long experience here 

 think that all the exising dams and proposed extension would 

 avail nothing if we were to have even only one such drought of 

 which we have seen many in years long past ; neither is it 

 thought that the supposed artesian pressure of water at Botany 

 would exist when once the upper sources of water of the super- 

 incumbent sand drift were exhausted. 



Next to the imminent risk of total exhaustion of water 

 comes the other serious objection to an undue prolongation of 

 the Botany supply. This lies in the growing sources of pollu- 

 tion to such waters. This evil is annually becoming greater and 

 greater, and dangerously worse and worse, because no amount of 

 filtration is a guarantee against the pernicious solutions of 

 nitrates, sulphates, and chlorides, which emanate from the disso- 

 lution of animal and vegetable, and even from mineral matters 

 from the neighbourhood of dense populations. In our case here 

 this great evil has been proved by Professor Liversidge, having 

 detected the presence of nitrates and nitrites in the Crown-street 

 reservoir waters which are pumped up entirely from Botany. 



