Watering crops in an arid environment may feel unmanageable. One effective and cost-effective solution is flood irrigation, a method which uses water in ditches or canals alongside each field. Irrigation dams allow you to contain and direct the water where you want it to go.
There are two ways to use irrigation dam material. One is to simple line a ditch or canal with the material, preventing the water from soaking into the ground. The other use is to block the water from flowing past a certain point, causing the water to spill over the edge and thus irrigate the field.
Typically, a loop (or sleeve) is sewn along one edge of the dam. This loop allows the use of a 2x4 or a pipe to secure the top of the dam at the surface of the ditch. The rest of the dam will drape down and block the water. Often this will be aided by shoveling dirt onto the portion of the dam at the bottom of the ditch/canal.
Irrigation dams are sold in pre-cut segments as well as rolls of material that can be cut to whatever length is needed. They are generally available made from polyethylene or from neoprene.