2 BULLETIN" 906, U. S. DEPARTMENT OF AGRICULTURE. 



An experience covering a period of over a quarter of a century 

 on the Pacific Coast, and more especially in California, has demon- 

 strated that large quantities of water can be saved by the substitu- 

 tion of pipe for earthen ditches. The results of a large number 

 of measurements made by the irrigation division of this bureau 

 show that the transmission losses in earthen channels vary from 10 

 to 60 per cent, and average fully 35 per cent of the quantity of water 

 admitted through the intake. When pipes are substituted for earthen 

 channels, the loss of water in conveyance is usually negligible. 



The use of pipe for the carriage of water and of pipe systems for 

 its distribution to farmers, not only prevents loss of water but affords 

 better facilities for its control, distribution, and delivery. Irrigating 

 land by means of open channels in earth is a laborious and unpleas- 

 ant task, wasteful of water, time, and effort. On the contrary it can 

 be rendered comparatively easy and pleasant if the proper equipment 

 is provided in the way of pipe, pipe systems with proper gates, turn- 

 outs, and other fixtures. The interest on the cost of such betterments 

 for highly profitable crops is more than likely to be amply com- 

 pensated for by the water and labor saved and a more uniform 

 moistening of the soil. 



The purpose of this bulletin is to present to the irrigation farmers 

 and orchardists of the West information concerning pipe and pipe 

 systems and more especially the use of concrete pipe in irrigation, 

 with such practical suggestions regarding making and laying as may 

 enable those engaged in this work to avoid mistakes and attain satis- 

 factory results. 



THE USE OF PIPE IN IRRIGATION. 



Before proceeding to a discussion of concrete pipe as used in irriga- 

 tion systems, brief references are made herewith to other kinds of 

 piping used for the same purpose. These other kinds include metal 

 pipe, wood pipe, and vitrified clay pipe. These, with concrete pipe, 

 differ in strength, durability, cost, and general fitness for any par- 

 ticular location and use, and in planning an irrigation system where 

 pipes are to be used in quantity, care should be exercised to select the 

 kind of piping that will best meet the requirements of each individual 

 case. It happens quite frequently that the same kind of piping can 

 not be advantageously used to convey water to all parts of an irriga- 

 tion enterprise. 



Metal pipes, and especially riveted steel pipes, possess strength in 

 a high degree and on this account should be used for high pressures 

 and where excessive fluctuations in pressure occur due to water- 

 hammer and other causes. On the other hand riveted steel pipe of 

 the quality now manufactured is not durable when exposed to un- 



