GATE STRUCTURES FOR IRRIGATION CANALS. 
47 
height the permanent gate should reach, and it can be designed 
accordingly. If concrete is used in the beginning, then it is difficult 
4o add to the height without great expense and a patched appear- 
ance, and if the structure is already too high, then the extra material 
is wasted. 
Most checks are for the sole purpose of controlling the level of 
the water above the structure, and the question of tightness does not 
enter into their design. However, if for any reason it is desired that 
all the water be stopped at a check and delivered to a side gate, then 
the shutters must be made tight by closer joints, tar or other roofing 
paper, or in some such manner. 
Dimension Table. 
H T B F L W 
Ins. Ins. Ins. 
30 
Notes; In case ofdrop 
grade- or where the 
banks need protection add the 
small abutment walls "A, A". 
For single opening structure, omit 
centre pier. 
Fig. 13.- — Concrete check, lateral headgate or delivery gate, Sacramento Valley Irrigation 
Co., California. 
CHECK GATES, SACRAMENTO VALLEY IRRIGATION CO., CALIFORNIA. 
The Sacramento Valley Irrigation Co. has adopted a set of stand- 
ard plans which may be used in many other parts of the West. The 
check-gate structure shown in figure 13 can be used also as a lateral 
headgate or a delivery gate. In fact this is done by the simple L 
construction which is so well adapted to a combination of check 
and delivery. The general construction of this gate is adapted 
either to flashboards or a stem gate. The latter is used most com- 
monly by this company. As shown on the detail view in Plate I, £ 
this stem permits of holes through it far below the top of the shutter 
without causing leakage through the latter, and it is not necessary 
