106 



THE IRRIGATION AGE. 



Lining of 'Ditches and 



Reservoirs to Prevent 



Seepage Losses 



By PROF. B. A. ETCHEVERRY 



Berkeley, Cal. 



Examination of Lined Ditches in Southern Cal- 

 ifornia. About 1880 all surface waters in southern 

 California were being diverted and used. The heavy 

 profits derived from irrigation and the rapidly increas- 

 ing price of orange land since then caused a great de- 

 mand for additional water. The development of the 

 country depended on water, which was, and is even 

 more so at present, the most important question for that 

 locality. All available water supply must be developed 

 and all waste prevented. This meant the rapid devel- 

 opment of underground waters by wells and tunnels and 

 the storage of flood waters, and explains the large num- 

 ber of wells yielding probably a good deal more water 

 than the flow of surface water in midsummer. 



water to distribute is not large, and have to a great ex- 

 tent replaced the smaller open ditch. 



While for these parts of southern California there 

 is no doubt but what the use of cement in some form 

 will always be the most generally used material for 

 canal lining, it is expensive and its use is only justi- 

 fiable where the value of water is very high, or where ex- 

 cessive seepage must be stopped. 



For districts where water is plentiful the seepage 

 loss may not be of so much consideration, or at least not 

 so great but that a concrete lining would be prohibitive. 

 The canals or even the laterals of these districts carry 

 several times more water than the largest canals of 

 southern California. The lining, if concrete were used, 

 would have to be stronger and the cost large. 



Other considerations besides seepage must, however, 

 be studied before one can decide whether it would be 

 beneficial to line the water channels, and other linings 

 should also be investigated. 



A good lining should fulfill the following require- 

 ments: (1) It should stop seepage. (2) It should 

 prevent gophers and squirrels from burrowing through 

 the banks. (3) It should prevent vegetation. (4) It 

 should prevent scouring. (5) It should not be easily 

 damaged by the tramping of cattle and by the action of 

 the weather. 



Fig. 1. New Bear River Valley Company's Canal; Lined with Cobbles Set in Lime Mortar and Painted with Cement. 



It was here naturally that the loss of water due to 

 seepage was first felt. Every drop of water saved meant 

 increased prosperity. The value of water increased 

 rapidly after 1880. Water valued at $30 per miner's 

 inch in 1880 had a value of $300 in January, 1883, and 

 $720 in 1888. This naturally meant better use of water 

 and a higher duty of water. The duty of water in- 

 creased to one miner's inch for four or five acres, and 

 has still increased until at present this duty for some 

 of the best citrus lands is one miner's inch for ten acres. 



Most of the improvements for economy of water 

 and for the decreased loss in transportation were started 

 after 1880. 



Canals were first paved to prevent seepage and ero- 

 sion; and to permit the use of an economical section. 

 This paving was then improved upon by paving and ce- 

 menting. Plastering with cement mortar and the use 

 of concrete for lining came into use soon after. 



At about the same time the use of steel or cement 

 pipes was introduced. They have since become much 

 in favor in southern California, when the volume of 



No doubt concrete will answer for all these require- 

 ments, but cheaper linings in, many cases will be more 

 economical. It was mainly to inquire into this that 

 these investigations were undertaken, in May, June, 

 July, and August, 1906. 



These investigations include first a journey around 

 some of the irrigation districts of California to learn 

 the different types and methods of lining canals in use, 

 their cost and detail of construction. 



CANAL LININGS IN CALIFORNIA. 



Naturally the best types of canal linings are in 

 southern California, very little having been done in 

 other parts of the state. 



A study of the various types shows that they can 

 be classified as follows: 



(a) River boulders set in lime mortar and pointed 

 with cement mortar. 



(6) River boulders or cobbles placed behind a 

 wooden form and cemented together with cement mor- 

 tar rammed between the cobbles. 



(c) Cement concrete from 3 to 6 inches thick. 



