Farming with irrigation dams is quite common in arid environments. This method involves running water through ditches alongside your fields. The dams allow you to direct the water where it's needed. So what are the options available to make this work?
Material
First let's talk material. There are generally two options: polyethylene and neoprene. Poly irrigation dams are manufactured in a similar manner to poly tarps: an inner woven scrim of HDPE coated in LDPE laminate. Neoprene irrigation dams have an inner woven nylon mesh coated in synthetic rubber.
Polyethylene Pros and Cons
Pro: waterproof
Pro: a more affordable option
Pro: available in more than one material weight
Con: can lose its flexibility in the coldest of waters
Neoprene Pros and Cons
Pro: waterproof
Pro: retains its flexibility in the coldest of waters
Pro: difficult to accidentally cut with a shovel
Con: a more expensive option
Rolls vs Pre-Cut Segments
When purchasing irrigation dams, you also have the choice between buying the material by the roll or buying individual pieces. If you purchase a roll, you are committing to a specific depth, but you can cut the material to whatever width you need. It can be more affordable in the long run to buy in bulk in this manner. However, if you purchase individual pre-cut segments, you can more affordably mix and match depths, as each piece can be a different depth and width.