Failure of the Van Yean Reservoir. 



155 



land. This is well exemplified in Melbourne, where we have 

 many showers of rain which do not extend ten miles out of town. 



I have allowed four inches for dew over the whole basin of 

 the Plenty, an amount of water which would give eight feet 

 eight inches in the reservoir; although it is very probable, in 

 this dry climate; that there may not be two inches; and I 

 have allowed two inches for the reservoir, without any scien- 

 tific data to show that dew would be deposited at all; and, 

 from an estimate which I have made of the whole watershed 

 of the Plenty, based on scientific data, it appears that I have 

 given the reservoir the advantage of nearly the whole amount. 



And, what is of greater importance than all else, I have 

 deducted nothing from the supply of ordinary seasons on ac- 

 count of droughts, of which we have had ample and painful 

 experience in other parts of Austraha; and a gentleman, who 

 has recently returned from Adelaide, has told me that they 

 have scarcely had any rain there for the last eighteen months. 



I must not omit to mention here, that it is intended to have 

 two intermediate reservoirs betwixt Melbourne and Yan 

 Yean,— the one at Pentridge, the other near the Plough Inn. 

 Yoiu' Committee requested information respecting their extent 

 of surface, with a view to determine the amount of loss from 

 evaporation, but they were refused all information on the 

 subject. I have, therefore, been unable in my estimate to 

 make the necessary deduction for their evaporation. 



I shall only further add, in support of my statement that 

 ample justice has been done to all the sources of supply, that 

 while I place implicit confidence in Mr. Hodgldnson's opinion 

 respe®ting the retentive nature of the bottom of the reservoir, 

 there are not wanting others, who have had great experience in 

 this colony, who think that the chances are very great indeed 

 that in some parts of the vast extent of the reservoir, the 

 water will find its way through the fissures of the clay slate 

 to a lower level I need not say there is no remedy in such 

 a case. £2,000,000 would not suflace to puddle a surface of 

 7,000,000 square yards. 



^VTien this scheme was first proposed, I felt astonished to 

 think that the Plenty could supply so much water as was 

 alleged. T imagined, however, that the deficiency might 

 probably be made up by the winter rains over an extensive 

 district. And although t considered this a very objectionable 

 source, I entertained the hope, that with a depth of 25 feet, 

 and a current established through the reservoir by means of 

 the river, and with a perfect system of filtration, the Avater 



