Floods on the River Barwon. 97 



Note A (see Appendix). 



The elevation of the Barwon railway bridge (C.S. No. 4) shows 

 about 23 per cent, of each span obstructed by piles and struts, which, 

 besides contracting the waterway, reduce the co-efficient of discharge 

 very materially. The area of the waterway, taken on the skew (at 

 right-angles to the probable direction of the stream in flood), is some- 

 what less ; but a larger co- efficient of discharge than in the other case, 

 •with a certain velocity of approach for the current, may be adopted. 

 Considered in any way, however, the conditions of the case are very 

 unsatisfactory, and the calculation of discharge correspondingly com- 

 plicated. 



Note B (see Diagram). 



References to the Paragraphs illustrated by the various Lines of the 



Diagram. 



Par. 

 Black shaded line — Mid-stream section of flood of 1880 - 7 



Black unshaded lines — Levels against banks in 1880 - - 11 & 13 



Bed shaded line — Calculated levels of flood similar to that of 

 1880, with all obstructions removed ; or, as the river 

 was in 1852 ------ 18 



Bed dotted line — Calculated levels of flood similar to that of 

 1880, with railway embankment only removed ; or, as 

 the river was between 1852 and 1875 18 



Blue shaded line — Probable levels of flood of 1852 20 



Blue dotted line — Probable levels of a flood similar to that of 

 1852, with existing obstructions in the river (N.B. 

 The sudden rise between C.S. Nos. 1 and 2, which 

 occurred in the flood of 1880, has not been allowed for 

 in this case) - - - - - 21 



i2 



