162 Failure of the Yan Yean Reservoir. 
from the Yarra, as impracticable and absurd, Mr. Jackson 
considers that the Merri Creek swamp, were it not for its 
distance, would be a very eligible site for a store reservoir for 
the City; and says, that it receives the drainage of about 
thirty square miles. 
He says, also, “the necessity of constructing a store reser- 
voir would not be manifest to a casual observer, but, as it 
would appear from the evidence of those settlers who have been 
established on the banks of the River Plenty for the longest 
period of time, that at a ford known as the Bridge Inn Ford, 
the Plenty has been known, on several occasions, to cease to 
flow, the necessity becomes more obvious.” 
He further says, “I found that the Yan Yean reservoir 
would receive the drainage of eighteen square miles. (Mr. 
Hodgkinson’s measurement is four and half square miles) an 
area which, in my belief, is sufficient in itself to afford an ample 
supply of water for the City, without looking to any other 
source; but, as droughts of two or three years’ standing have 
been known to occur, I consider it advisable to lead in the 
Plenty River.” 
He further adds, “that the reservoir can be made to receive, 
in addition to the Plenty River, the drainage of upwards of 
120 square miles of surface.” The Survey maps give sixty 
square miles as the area of the Plenty basin. 
It needs no additional arguments, as it appears to me, to 
show the great advantages which a Yarra gravitation scheme 
would possess over a gravitation scheme having the eastern arm 
of the Plenty as its only souzce of supply; but if these are 
wanted, they will be found in the fact that if we are to be 
satisfied with the supply of our present wants only, at the 
enormous cost of 369,900/., and if we are to depend upon the 
eastern arm of the Plenty for this supply on the constant ser- 
vice principle, we have no guarantee whatever that our wants 
will really be supplied after all, or that the supply will be equal 
to the actual demand. At forty gallons per head per day, the 
eastern arm is no doubt fitted to supply 100,000 inhabitants, 
if we are prepared to chance the droughts; but it has been 
practically found that there is no way of limiting each indivi- 
dual to his forty gallons, if the distribution is on the constant 
service principle. And the Comissioners of Sewerage and 
Water Supply, backed by the opinion of the Select Committee, 
have, very properly, from the first, determined to supply the 
City on this principle, and it would be a sad retrogression in 
sanitary economy to revert to the antiquated method of inter- 
