238 FARM DEVELOPMENT 



farms in semi-arid regions, and will give some food 

 for man and beast, even in the exceptional years of 

 least rainfall, and will help make the farm pay in all 

 years. 



In regions like Minnesota, on the other hand, the many 

 streams, the thousands of lakes, the large quantities of 

 available well water, the less amounts of water required 

 for irrigation where the rainfall is nearly sufficient, and 

 the possibility of storing surface water in large artificial 

 reservoirs, will make it comparatively easy to irrigate 

 large areas of land. Good lands have been so cheap that 

 farmers and gardeners have only begun to appreciate 

 the fact that at no distant date the higher price of lands, 

 together with the cheapened machinery and possibly 

 cheaper labor, will make irrigation profitable in many 

 places where the rainfall has been heretofore wholly 

 depended upon. 



Sources of water. The bulk of irrigation is now done 

 where the water is obtained from mountain streams or 

 rivers so situated that the water may be led out, by means 

 of canals and ditches, to lands which are nearly level, in 

 the valley lower down the stream. These ditches are 

 usually laid out with a very gentle slope, through the low 

 lands or around the borders of the hills. Branches from 

 the main canal are led off to the various tracts of land to 

 be irrigated, where the ditches are further branched and 

 the water carried to the farms and fields. In many 

 cases, lakes and reservoirs are employed in which to store 

 up flood water for use during the dry season when the 

 water in the streams is low. In other cases, the storage 

 capacity of lakes has been very greatly increased by 

 means of dams across their outlets. 



Storage reservoirs are being made in many places by 

 building dams across valleys, thus conserving large 

 quantities of water which can be led out and spread 

 over the fields in times of drought. As a rule, these 



