In California and elsewhere, irrigation canals are crucial parts of irrigation systems to water crops, and while there are lots of options for liners, one stands out as better than all the others. You’ll want a liner material that is as leak proof as absolutely possible, especially in arid or drought-prone areas where water loss needs to be carefully regulated. Clay liners are an option, but with these, seepage can cause you to lose nearly half of the water flowing through the canals—plus they come with many maintenance concerns like water flow problems and weed growth. Similarly, concrete and asphalt, while they will prevent weed growth, still allow for excess water to be lost through seepage.
Flexible liners are better options, and there are lots of materials available, including RPE, PVC, EPDM, HDPE, and LDPE. HDPE tends to be stiff, which can cause problems with tearing when loose soils (which are common in California) start to shift. LDPE is another heavy option that can tear, and like HDPE, it is also difficult to install because of its weight and stiffness. EPDM doesn’t feature great chemical resistance, which can be problematic if it’s part of an irrigation system that handles runoff water for processing and containment. PVC has a short lifespan when exposed to UV rays, but it is a flexible, lightweight material that is easy to install. RPE is the liner material of choice because it combats all of the above issues. It features some of the best UV resistance available, it’s tear resistant, flexible and lightweight, and it can features a high chemical resistance that makes it ideal for handling runoff water.
