394 PROCEEDINGS OF SECTION E. 



Billabong, a most valuable natural distributary channel which in 

 1870 carried the waters of the Lachlan to within about thirty 

 miles of the Darling. 



Other prominent cases of rivers passing through similar stages 

 are furnished by the Namoi and Gwydir, whose condition corres- 

 ponds with that of the Darling, the Narran, which occasionally 

 flows into the lake of the same name, the Bogan, Castlereagh, 

 Bokhara, Culgoa, and Warrego, which reach the Darling only 

 during floods, and the Paroo which is known to have flowed into 

 the Darling only once since the settlement of that part of the 

 colony — namely, in January, 1885. 



The characteristics which distinguish our westei^n rivers, with the 

 exception of the Murray, being the natural outcome of the phy- 

 sical and climatic conditions existing throughout the country west 

 of the Dividing Range, are also found illustrated on a smaller 

 scale by numberless creeks. It will be sufficient here to mention 

 three instances which have frequently come under my observa- 

 tion. The first is Puletop, or Burke's Creek, which rises in the 

 range constituting the watershed between the Murrumbidgee 

 River and the Billabong Creek, and which after flowing about 

 fifty miles, disappears entirely at the edge of the Bullenbong 

 Plain. Burke's Creek when in flood attains the proportions of a 

 riA-er. Before it reaches that part of its course where its channel 

 fails to carry the flood waters, its width is from eighty to one 

 hundred and twenty feet and its depth from twenty to twenty- 

 five feet. When in flood this creek carries a large quantity of 

 silt which is used partly in raising its bed and banks, and partly 

 in raising the level of the Bullenbong Plain. The waters of the 

 creek after spreading over this plain, which is remarkably uniform, 

 and about seven miles in length by five in breadth, collect again 

 in a creek of greatly diminished section, and flow into the Bullen- 

 bong Creek. 



The other two creeks to which I wish to refer are Brookong 

 Creek and Boree Creek, both of which look unimportant either on 

 a map or on the ground, though much interest attaches to them 

 on account of the part they have played in the formation of the 

 great fertile Brookong Plain. Both of these creeks have their 

 sources in the ridges which run like long projecting I'oots from the 

 Galore — the Brookong Creek in the ridges which run southward, 

 and the Boree Creek in those extending to the north-west. In 

 both cases the courses of the creeks across the plain have been 

 obliterated. The process by which the plain was raised to its 

 present level, and the creek beds silted up is still in progress. 

 The tendency of the ends of the creeks to recede still further 

 towards the ridges is apparent to any observer, and though the 

 lowering of the average sources of the creeks cannot be observed 

 it can no less correctly be inferred. As in cases of other creeks 

 and rivers under similar conditions, both Boree and Brookong 



