WATER COXSERVATJON, ETC. 247 



tlie former always, and the latter genonilly, 1ias a good supply during 

 the greater part of smmner. These two river« are the most valiialjlT- 

 in the Colony as a source of water for irrigation ]>urp()ses, and astheii- 

 courses, after leaving the mountains, pass tlirough iunnense alluvinl 

 plains of great fertility, the utilisation of their waters in irrigation 

 canals is a question to be dealt with in the near future. Schemes for 

 this object have, in fact, already been prepared. 'J'he rivers north of 

 the Murrumbidgee, which flow westward from the Dividing K;ingo, 

 are more uncertain in their supplies. The land along the courses of 

 these rivers is of a very fertile description, and has been proved to be 

 well adapted for irrigation. 



The outline of the country east of the Dividing Kange differs widely 

 from that of the country extending westward. In the case of the latter 

 there are broad expanses of tableland, the mountains decline gradually 

 till they finally disappear beneath the great st-a of alluvium, and the 

 plains which thus extend from the slopes of the hills, though to all 

 appearance perfectly level, have a fall varying generally from 3 feet 

 down to 1 foot per mile. On the other hand, between the summit of 

 the Dividing Range and the coast the mountains generally fall rapidly, 

 and, beginning abruptly from their base, the alluvial fiats, including 

 extensive areas of swamps, and of land subject to inundation, extend 

 seaward. 



For the consideration in outline of questions relating to water con- 

 servation, irrigation, and drainage, and, in fact, for the elucidation of 

 important points in connection with settlement on the land, it is most 

 convenient to regard the Colony as consisting of four gi-eat natural 

 divisions. These are, first, the coast district ; second, the Dividing 

 Range and the high tableland ; third, the western slojies of tlie 

 Dividing Range ; and, fourth, the great plains of the interior. 



The Coastal Didrirt. 



Taking the coastal disti-ict as a whole, it may be broadly stated that 

 as the eastern slope of the Dividing Range is steep, the fall of the 

 rivers rapid, and the alluvial flats difiicnlt to irrigate satisfactorily, 

 the conditions, as a rule, are not favourable for any large schemes for 

 vv^ater conservation and irrigation. Besides, the average rainfall is so 

 nearly sufficient for ordinary farm crops that irrigation would not, as a 

 general rule, be rumunerative even under favourable conditions as 

 regards the nature of the land, and the facilities for obtaining water. 

 It is otherwise in the case of crops like fruit and vegetables, which 

 require more care, and the value of which per acre is comparatively 

 high. For such crops, irrigation, if conducted under fairly favourable 

 circumstances, and in a business-like manner, is highly remunerative. 

 In the best instances of this in the coastal district the land irrigated 

 consists of rich and deep river deposits underlaid by boulders ami drift 

 and the water is raised by steam power to a height of thirty to fifty 

 feet. The soil is suflTiciently porous to allow of gradual ])ercolation 

 down to the drift and boulders, which provide excellent subsod dram- 

 age. Under such circumstances, experienced fruit-growers have found 

 tiiat an initial outlay of £20 per acre on pumping plant and fittings is 

 more than justified by the results. 



