440 



THE IRBIGATION AGE. 



15 feet, and the average height of the stream during the 

 time that water would be pumped for irrigation, is 5 

 feet. Calculations, therefore, were made on this basis, and 

 the speed of the pumps determined in accordance, giving 

 an average lift of about 20 feet at the river station. At 

 the other stations the regularity of the land gave a lift 

 of about 13 feet in all cases. 



"The problem of conveying the water from one sta- 

 tion to the next and of distributing to the laterals was 



to the reservoir. The boards are usually kept in the waste 

 ditch, and so would divert any water running over a spill- 

 way into the next regular reservoir below, thus losing only 

 one lift. If, however, it was desired to pump down a 

 reservoir, the boards being placed in the entrance would 

 pass the water down the line to the river and finally 

 reach it. 



"At each station there is a provision made through a 

 "tee" in the delivery pipes, by which any reservoir can 



Showing Canal Emptying into Reservoir, Patterson Ranch, California. 



given careful study, and, after a comparison of pipes, 

 flumes and ditches, it was decided to adopt the latter; 

 these being designed with a uniform slope of .0002 and 

 lined with 3 inches of concrete and protected with one- 

 quarter inch of plaster finish. 



"The slope of the ground was such that the maximum 

 height of embankment was about 8 feet. The distributing 

 laterals were taken off at a point where the flow line in the 

 canal was 18 inches above the ground level. The canal 

 was then continued into cut, and ended in a reservoir 

 calculated to have approximately one hour's supply for 

 the pumns drawing from it. These reservoirs were lined 

 with 5 inches of concrete, with ^4-inch plaster finish. In 



be pumped down, or water allowed to escape from the 

 canal ahead, and pass into the waste ditch. 



"The discharge of the water from the pumps into the 

 canals has been carefully designed, the arrangement and 

 dimensions of the passages being such as to give a uni- 

 form decrease in the velocity from that of the pump to that 

 of the canal. The end of each canal, where it discharges 

 into the reservoir, is widened and provided with a weir. 

 Below the weir is a basin that acts as a water cushion. 

 With the proper electrical instruments, the plant can be 

 kept under constant test conditions. 



"The distributing laterals (ten in number, one for each 

 side of each canal level) are provided with a specially 





Showing Transforming Station of Power Line, Which Furnishes Electric Power for Patterson Irrigation System, Situated at Reser- 

 voir No. 1. 



the canals and reservoirs an asphalt expansion joint was 

 put every 12 feet. 



"In each of the canals an emergency spillway was 

 built, consisting of a weir with its crest 12 inches above 

 the normal flow line of the canal. These spiliivays dis- 

 charge into a waste ditch running parallel to the main 

 canal. At each reservoir there is an opening from the 

 waste ditch to the reservoir so arranged that flash boirds 

 can be placed either in the waste ditch or in the entrance 



designed regulating and measuring device. It consists 

 of a S^-inch balanced valve used in connection with a 

 discharging weir. On account of the necessity of con- 

 serving head, this weir was made 16 feet in length and set 

 diagonally across the lateral. The cases of the balanced 

 valves are made of concrete, with the valve seats and other 

 metal parts cast in. A tube with an opening that can be 

 adjusted to any height above the weir connects with a 

 scale pan that controls the position of the valve discs 





