DRAINAGE 145 



most profitable cropping, and in other States north and 

 south there are larger or smaller areas of flat lands 

 which need draining. 



Side flooding. Along rivers and streams there are 

 areas which are subject to flooding by the streams rising 

 and flowing out over the banks. There are other areas 

 where there are no well-defined streams which receive 

 the flood water from the surrounding lands, and are thus 

 made too wet from the lack of suitable channels in which 

 the water can run off. In sections where the drouth is 

 excessive, as in the semi-arid regions of the west, lands 

 which receive flood water have a great advantage, since 

 they are thus naturally irrigated, and in that dry climate 

 the water does not usually stand on them so long as to 

 kill out the plants. But in regions of considerable rain- 

 fall, it is generally desirable to prevent water from 

 higher lands flowing over the fields used for cultivated 

 crops, depending only upon the rain which falls directly 

 upon each acre. The Nile valley in Egypt is an excellent 

 example of the lands naturally irrigated and also fer- 

 tilized by annual deposits of mud. 



Localities especially needing drainage. Some districts 

 need drainage only on small areas, each drain confined 

 to one, or, at most, a few neighboring farms. In other 

 cases the drainage becomes a large problem concerning 

 one or more countries. Thus, in the valley of the Red 

 River of the North, there is a flat area 75 miles by 300 

 or more, covering several counties in Minnesota and 

 North Dakota, and a large area in Manitoba which need 

 draining of flood water. Here are many conditions 

 which require co-operation of neighboring farmers of 

 an entire township, or several townships, and, in some 

 cases, two or more counties. The problem in that 

 region has been such a large one that the State of Min- 

 nesota has appropriated hundreds of thousands of dollars 

 to aid in constructing very large main drains into which 



