268 



Charles Fenner : 



"vvay of really deciding a " trunk stream " would be to follow up the 

 river from the mouth, and at each junction to select the stronger 

 of the joining streams. 



Speaking now of the Werribee as it is mapped and accepted, we 

 shall consider its relations to the main tributaries. The Werribee 

 flows south-easterly, receiving all its main tributaries from the 

 north, with the single exception of the Parwan Creek (Plate XTIA., 

 For the purpose of a clear understanding, these tributaries may be 

 set out as under : — 



r Pyi<< 



Nortbevn 



Tributaries 



Werribee 



Southern 



C 



L 



Tributaries ^ 



Myrniong 

 Korkuperrimul 



Lerderderg 



Pyrete 

 Djerriwarrh 

 Tooliim Toolei 



Parwan 



Korjaniumnip 

 Korweinguboora 

 Dale's . . . Back 

 Korobeit 



f Goodman's 



I Clearwater 



<. Sargonne 



I Allen's 



L Split Tree, etc. 



Boggy 

 Condon's 



Yaloak 



The general directions of these tributaries are clearly set out on 

 Plate XII A., and need no further description. Tlie interesting point 

 of relationship is to be seen in their relative grades. Only the 

 chief tributaries are plotted in Plate XII B., since the addition of 

 lesser ones Avould only add further complexity, without giving any 

 additional information. It is at once apparent that the grades of 

 the Werribee system, and their relationships depart very much from 

 the ** characteristic section" drawn in Fig. 23. 



As already stated, the Lerderderg grade-line lies everywhere 

 lower than the Werribee, except that for the last three miles before 

 they junction, the grades are practically the same. This is in the 

 Bacchus Marsh flats. The reason for the Lerderderg's lower levels 

 are the greater age and the greater volume of that stream; it has 

 been practically uninfluenced by the newer volcanic flows, and is 

 for the greater part in the most elevated and most difficultly 

 eroded block of land in the area. 



^^hile the Parwan is seen to grade into the Werribee in quite a 

 normal way at the junction, its line crosses that of the latter 

 about three and three-quarter miles up stream, and thence lies at 

 a much lower level (500 feet lower in places), except where its 



