Document Type

Full Issue

Publication Date



The most important prerequisite of linings for controlling seepage losses from irrigation canals is their watertightness. In addition to being watertight, a lining must be relatively durable if it is to be economical. Rigid materials provide satisfactory linings for canals with well-drained and stable subgrades. Under other conditions, where expansive soils are encountered and ground water is a problem, a rigid lining such as concrete is not durable. Considering the many factors that govern the utility and durability of linings, the ideal lining would consist of a material with some flexibility, a material resistant to erosion and mechanical damage, and one with a smooth surface. The search for a material of this type led to a consideration of asphalt and rubber-coated materials. Natural rubber, while watertight, deteriorates rapidly. Some of the synthetic rubbers such as butyl, on the contrary, show high resistance to deterioration from weathering and biological activity.



To view the content in your browser, please download Adobe Reader or, alternately,
you may Download the file to your hard drive.

NOTE: The latest versions of Adobe Reader do not support viewing PDF files within Firefox on Mac OS and if you are using a modern (Intel) Mac, there is no official plugin for viewing PDF files within the browser window.