Pi PIC Line Structures 



151 



ascending grade, and if the ordinary gate pit had been built its 

 height would have been 21 feet. The covered compartment is 

 reinforced with steel and corrugated iron. When the gate is closed 

 or partly closed, water can be taken from any or all risers on the 

 nursery line. At other times the gate is kept open. 



; I 2-11' 1 '■ '■ 



u* 



r-4- f-U- —^^-6^ 1- /-«■-!- 



' —4- ^4- ^• 



^ecT/orf 



sSltCT/O/f 



Fig. 34. — A divlsioh and 

 measuring pit where main 

 supply of water is divided 

 into two equal heads. 



Many unusual cases arise and require special treatment, particu- 

 larly on rolling and hilly topography. Many of our Southwestern 

 valleys, however, are almost plane surfaces and only standard struc- 

 tures are needed. 



