252 



FARM DEVELOPMENT 



purpose ; and for great care in building the ditches, dams 

 and gates. 



Conveying water from source to farms. Choosing 

 the point at which the main canal will receive the 

 water from the stream, lake, reservoir or pump; 

 deciding upon the course of the canal, and plan- 

 ning the head gate and the construction of the canal, 

 with any necessary flumes, tunnels and drops, often 

 form a complex problem. In large and complicated 



_^^ _ _^ t projects only 

 trained engineers 

 experienced in 

 this class of 

 work can assem- 

 ble the neces- 

 sary facts upon 

 which to base 

 judgments and 

 can devise plans 

 which will serve 

 in carrying the 

 water effectively 



Figure 148. Division box, showing how part or all the 

 water can be turned from a ditch into laterals. (After U. S. 

 Farmers' Bulletin, 263.) 





in soils and farm 

 management are needed to form difficult judgments as 

 to the value of lands which it is proposed to supply with 

 water at large expense, that enterprises be not under- 

 taken which will not prove to be profitable. 



In Figure 146 are shown two lines of survey made in the 

 selection of a ditch line from the highest part of the 

 Farm A to some point on the stream D, E. D is found 

 to be the practical place for the head gate. The trial 

 line, D, F, A, following a gentle grade about the bases 

 of the hills, makes too long a line and some rocky ex- 

 cavating is necessary. By placing a drop at M to drop 



