LXXIV. T. W. KEELE, 
demand for water requiring an additional supply resulted 
in the selection of the Maroondah or Watts’ system being 
brought into operation in the year 1891. 
Maroondah System.—The water from this system is 
obtained from the tributaries of the Yarra arising from the 
flanks of Mount Juliet, Mount Monda and Mount Riddell, 
whose altitudes are 3,651, 2,974, and ' feet respectively. 
The completed Maroondah scheme includes a storage reser- 
voir with a dam 105 feet high, calculated to store 2,000 
million gallons. This dam has not yet been constructed, 
as up to the present the natural flow of the creeks with 
the storage in the Yan Yean reservoirs have proved quite 
capable of providing all the water at present required for 
Melbourne, equal to about 44 million gallons per day sum- 
mer service. The watershed of the Maroondah system 
embraces an area of 35,500 acres or 55°46 square miles. 
A temporary weir has been constructed of Portland 
cement concrete across the Watts’ River, from which the 
water is led in an aqueduct 41 miles long to the Preston 
Reservoir. On this length there are 253 miles of open 
contour channels, 12 tunnels aggregating 65 miles, three 
of which are about one mile long, and 14 inverted syphons 
totalling 9} miles. The open conduit is lined with cement 
concrete or brickwork in cement, the cross section being 
a quadrant of 3 feet 10 inches radius, with 1 to 1 slopes, 
and a fall of 1 foot per mile. The channel as now com- 
pleted, is capable of delivering 25 million gallons per day, 
while the tunnels are of this capacity lined where necessary 
with brickwork or cement concrete. 
The valleys are crossed by wrought iron syphons 50 to 
53 inches diameter, with falls of 73 or 4 feet per mile 
respectively. These syphon pipes are + inch or # inch 
wrought iron plate, in some places carrying a pressure of 
100 ibs. per square inch. With the exception of the Plenty 
’ This height cannot be supplied. 
