122 . Failure of the Yan Yean Reservoir. 
ing serious or irreparable injury upon the inhabitants of the 
district through which the Plenty takes its course. One 
witness, who was examined before the Select Committee, 
gravely proposed that a-half-inch pipe from the reservoir 
should be given to the inhabitants on the banks, in lieu of 
the river itself; but to be serious, I am most decidedly of 
opinion that it would inflict irreparable injury upon the 
inhabitants of the Plenty district to abstract more than two- 
thirds of their river from them. Even with this loss they 
will suffer enough in the permanent closing of all the mills ; 
and I have no hesitation in saying that the good sense of the 
ublic of Melbourne would neither expect nor demand more. 
If the Yan Yean scheme cannot afford to do this it had better 
be abandoned at once. Nor do I think that the public interests 
would suffer much thereby. 
In ordinary seasons, as already shown, the discharge of the 
Plenty above Yan Yean, is 2700 gallons per minute in 
December, and deducting one-third there will remain 1800 gal- 
lons, or an equivalent to 2 feet 5 inches; this, added to 2300 
allons, which is the amount at present lost in the swamps, 
but which I take for granted will be saved, gives 4100 gallons 
per minute as the average amount of water available from the 
river for the supply of the reservoir, and this will give a 
depth of 5 feet 6 inches. 
It is more difficult to calculate the amount that might be ~ 
obtained from the river in time of floods, from the uncertainty 
of their occurrence, volume, and duration. Had the reservoir 
been in close proximity to the river, with a sufficient fall, a 
large amount of flood water might easily have been secured ; 
but in order to obtain 25 feet of depth for the reservoir, it 
is necessary to bring in the river from a higher level by means 
of an aqueduct of about 2 miles in length, which winds round 
the base of the range which separates the river from the 
reservoir, aud which will enter the latter by a tunnel which 
is being cut through this dividing range. Unless, therefore, 
a very strong embankment be constructed for the purpose of 
damming the flood water, which would be a very difficult and 
expensive operation, owing to the level character of the right 
or opposite bank, it is difficult to see how the floods can be 
taken advantage of to any great extent. On such occasions 
the water is widely extended over a large surface, and will 
naturally prefer the lower level of the river to the higher 
level of the canal or aqueduct. 
Assuming, however, that the aqueduct can be filled from 
