36 On the Supply of Water 



necessary for me to make any observations, as a fatal objec- 

 tion occurs at tbe very outset of its consideration, namely, 

 in the quality of tbe water it is proposed to afford. — ( Vide 

 Dr. Macadam's analyses and Report.) 



Subsequently, and very lately, another proposition has 

 been mooted, namely, an extension of the Yan Yean to 

 Geelong. It requires but the enumeration of a very few 

 counter-reasons to set aside so futile a scheme. 



To those not quite conversant with the Yan Yean scheme, 

 I may briefly say that it is the name of the reservoir which 

 is intended to supply Melbourne with Avater. It is an exten- 

 sive natural basin, comparatively shallow, covering about 

 1300 acres, into which the waters of the River Plenty are 

 directed, and is situated five hundred and ninety-five feet 

 above the level of Hobson's Bay. 



The water, if brought in an unbroken line to the city, 

 (assuming the pipes to stand the pressure, which they will 

 not do unless by the intervention of self-acting " pressure 

 reducing valves,) would command the highest houses. It is, 

 however, imperative on that Commission to filter their 

 water from its vegetable and other impurities ; and it is 

 their intention to construct such filters adjacentto the line 

 of mains at Darebin Creek, about midway, say three 

 hundred feet, above datum ; therefore the pressure, in 

 relation to the height of the highest houses in Melbourne or 

 elsewhere, must be reckoned only from the altitude of the 

 service reservoir supplied from the filter-beds. 



The length of pipe main conveying the water to Melbourne 

 is about twenty miles ; and the idea is to continue a sub-main 

 (branching to Williamstown) along the Geelong and Mel- 

 bourne Company's Railway to Geelong, the distance being an 

 additional fifty miles, to be fed by the re-erection of the old 

 Collingwood cast-iron tank, at North Melbourne, from whence 

 Williamstown and Geelong would be permitted to get a 

 night supply, thereby re-introducing and perpetuating (on the 

 supposition of there being water to spare) the exploded inter- 

 mitting system. 



Besides, in alluding to it at all, which of necessity I am 

 called on to do, as the only work of the kind as yet approaching 

 completion in the colony, there are certain geographical and 

 physical considerations which I should notice, were it not that 

 by so doing, I would run this paper to a greater length than 

 I had contemplated. Seeing, however, that attempts have 

 been made to foist this water on the district to which I have 



