Irrigation and Inter-Colonial Co-operation. 361 



The advantages of such works are that they will utilise small 

 catchments and small natural physical features, and that they will 

 provide for the irrigation of small isolated areas, which could not 

 otherwise be supplied with water. They can be made cheaply by 

 means of local labour, and, as they will not require high-class 

 engineering, they can be carried out by farmers, with, if necessary, 

 a little professional advice and some assistance from the State by 

 means of loans. They are eminently suited for private effort, and 

 they can best be constructed by individual farmers, who are the 

 best judges of local conditions and requirements. Their construc- 

 tion will develop enterprise, and their maintenance and utilisation will 

 encourage independence, as they will be under the sole control of 

 their owners. By th-eir means farmers will be enabled to grow 

 high-priced crops, to practise intense cultivation, and, generally, to 

 develop their farms. 



The disadvantages of such works are that their cost per unit 

 of supply will usually be excessive, their supply may fail in bad 

 years, and, even in good years, will in many cases prove insufficient 

 to last until the end of the dry season, when it is most useful for 

 starting crops. 



It would be impossible for the State to undertake such works 

 with economy in construction or maintenance, or to administer and 

 collect revenue from them. All that it can do is to assist farmers 

 by loans and by professional advice, and thus to lead to the estab- 

 lishment of numerous works all over the country, so as sensibly to 

 increase its productive powers. 



9. Medium-Sized Works. 



These will generally consist of medium-sized storage reservoirs 

 and furrows led from the smaller rivers ; of works, for the drainage 

 of vleis and swamps, and the reclamation of fertile bottom lands ; 

 for the opening up of the sources of springs and the improve- 

 ment of the channels of the smaller rivers ; and for the linking up 

 of numerous furrows where they exist, so as to utilise the available 

 supply more economically. Such works will improve the agricultural 

 conditions of a district. 



The advantages and disadvantages of these works will be similar 

 to those described for small works, but generally their material 

 advantages will be greater, and their disadvantages will be less, than 

 those of that class. They will have the further advantage of 

 inducing co-operation without much surrender of individuality, seeing 

 that the schemes will be managed by the popular vote of those 

 benefited by them. 



As far as investigation has gone in the Transvaal, there are not 

 many suitable sites for medium-sized reservoirs. This is due to the 

 fact that on the high and middle veld the slopes of the smaller 

 rivers and of the country through which they run are very steep, 

 being on the highly elevated crest of the sub-continent, and also to 

 the valleys being restricted in width, and having few cross ridges 

 suitable for the location of dams and waste weirs. 



