Certain prefabricated materials used as linings in small irrigation ditches to control seepage and vegetation have shown considerable promise. Nevertheless, their use is limited—to some extent—by relatively high initial cost and questionable longevity under the variety of field conditions which exist on irrigated farms. However, increased production and availability of some of the new materials—such as plastics—are lowering costs to a point where replacement may be economical on a 1-3 year basis.

Donald Fox, Farm Advisor, Yuba County, Jack A. Corry, Senior Engineering Aid, University of California, Davis, and William Wu, formerly Senior Engineering Aid, assisted in the studies reported here.