100 



DAMS AND HEADWORKS 



LONGITUDINAL SECTION 



Bent Eted rails laid in cement, 

 h tic rods, l"diam. 



Intake 



ELEVATION OF INTAKE 



/.. .1 



Ledge 



Upe *| 



FIG. 50. Fishway. 



or they may leap over the cross-partitions, according to their 

 habit. 



4. INTAKES 



Intakes of many kinds are employed, and their design and 

 location is to a great extent governed by local conditions. 



Trash Racks. An essential feature common to all types and 

 which has a bearing on the economic use of water, is the trash 

 rack and its design. These racks should be so constructed as 

 to give sufficient area for passing the desired quantity of water 

 without excessive loss in head. This is especially important in 

 low-head developments, where large quantities of water are 

 utilized. Considerable loss of efficiency may result from restricted 



