70 Proceedings of the Royal Society of Victoria. 



the water with the action of the waves upon the banks. From 

 the Yan Yean Reservoir to the pipe head dam at Morang the 

 water is conveyed in an open aqueduct, 7 miles long, and 

 capable of delivering 33 million gallons a day. From this point 

 the water is conveyed by pipes to the local distributing and 

 storage reservoirs. The chief of these is at Pteston, 7 niile& 

 from Morang. 



The Maroondah system is supplied by the Watts River and its 

 tributaries at a point 45 miles to the N.K of Melbourne, and 

 3 miles beyond Healesville Railway Station. An aqueduct^ 

 41 miles long, capable (as at present completed) of delivering 

 25 million gallons a day, conveys the water to Preston Reservoir. 

 As will be seen from the results of our examinations, the bacterial 

 content of this water is practically identical with that from the 

 Yan Yean catchment, but it reaches the consumer direct, while 

 that from the Yan Yean system has the advantage of sedimenta- 

 tion during its storage in the large reservoir. 



All the aqueducts ai-e built of stone set in cement, or of 

 concrete, and elaborate precautions are taken to prevent the 

 washing away of the banks or the entry of storm water into the 

 channels. The catchment areas are uninhabited except by the 

 caretakers, all the settlers having been bought out prior to 1887. 

 There is very little animal life of any kind in the forests, and 

 steps ai'e taken to restrict the ingress of tourists. No public road 

 enters the Yan Yean catchment, but the Maroondah catchment 

 is traversed for 6 miles by the road from Healesville to 

 Marysville. At the point where this road crosses the Watt& 

 River the village of Fernshaw formerly stood, but all the houses- 

 have been removed, and the gardens and orchards allowed to 

 return to a state of nature. The neighbourhood of this bridge is 

 the only place where contamination of the water is likely to 

 occur, and, as a matter of fact, the water below the bridge nearly 

 always shows a few more organisms per cubic centimetre than, 

 that taken from the river above the former site of the houses. 

 Whether this is to be accounted for by the drainage from the 

 road or from the old cultivated grounds is a point on which I am 

 not at present prepared to express an opinion. The whole of both 

 catchments is covered with dense forest and undergrowth, and 

 the annual rainfall varies at different points from 40 to- 

 60 inches. 



