Failure of the Van Yean Reservoir. 



147 





rt. 



Tit 



in. 







o 

 o 



Deduct one-half for district - 



- 12 



4 



jOdidiicti lor reservoir 



1 o 





Eain in reservoir - - 



2 



7 



42 4 per cent, of rain over drainage 







area of ditto 



2 



4 



Total in reservoir - - - 



- 17 



3 



Deduct evaporation - 



9 



0 



Total for the use of the city 



8 



3 



This amount will exactly supply, at thirty gallons per 

 head, 333,000; at 100 gallons per head, 100,000. 



NoAV, let us contrast twenty-three feet six inches, with two 

 feet two and two-third inches, the discharge for eight months 

 accordir.g to the measurement of the Committee. Thus they 

 make the Plenty for the eight winter months contain ten 

 times the volume of water that it does in January, or, accord- 

 ing to Mr. Blackburn's measurement^ in December. 



It will perhaps he said that this actually takes place in 

 the Merri Creek ; but such reasoning, if it proves anything, 

 proves too much. This creek is not a river, and only runs 

 after wet weather, and does not always run in winter ; or the 

 stream is so small that it can scarcely be said to run in very 

 dry winters. After a heavy fall of rain, the creek is flooded 

 for two or three days, but if the flood water were divided 

 over 365 days, it would be a miserably small amount. 



If any argument could be extracted from this, it would 

 prove that, because the Merri Creek is at one season many 

 million times larger than it is at another, therefore the Plenty 

 may be so also, which is absurd ; besides, this sort of reason- 

 ing has its inconveniences as well as its advantages. If we 

 take the highest flood in the Plenty, and reduce it by a few 

 million times, it would cease running altogether like the 

 Merri Creek, and the City would stand a poor chance of a 

 permanent supply of water from this source. 



Perhaps it may be thought that the Yarra is an analagous 

 case, and if it can be shown that it contains ten times the 

 volume of water during the eight winter months that it does 

 in December, so may the Plenty. The Yarra differs in many 

 essential points from the Plenty, and chiefly in this important 

 particular, that it takes its rise in very high mountains 



