LXXII. T. W. KEELE. 
SOME NOTES on THE STATE oF THE MELBOURNE 
WATER SUPPLY. 
By T. W. KEELE, m. Inst. 0.8. 
[Read before the Engineering Section of the Royal Society of N. S. Wales, 
July 15, 1908. | 
In view of the present very serious situation at Melbourne 
in regard to the water supply, it will doubtless be of some 
interest to members of the Engineering Section of the 
Royal Society to know from whence the water is derived 
and what is the reason for the present shortage. 
Melbourne is served by (1) The Yan Yean, (2) The 
Maroondah, two separate systems which deliver the water 
into a distributing Reservoir at Preston, which is about 7 
miles in a direct line from the G.P.O., and is at an eleva- 
tion of 328 feet above sea level. Its capacity is 16 mill- 
ion gallons or 2 millions less than our Centennial Park 
Reservoir. 
The Yan Yean System derives its supply from the drain- 
age of the coastal range of mountains, the summit of which 
at this part is 2,630 feet above sea level, and about 29 
miles in a direct line from the G.P.O. Here the River 
Plenty, Wallaby Creek, and Silver Oreek take their rise, 
the former flows to the South of the range, and the two 
latter to the north. Small weirs intercept the drainage 
from the Wallaby and Silver Creek catchments, whose 
combined watersheds amount to 11,500 acres or 18 square 
miles, and divert it into an aqueduct which conveys it to 
a low place on the crest of the main dividing range, where 
the elevation is 1694 feet above the sea. From this point 
the water drops a height of 633 feet in a length of 683 feet 
through a series of shoots and artificial falls lined with 
