I’m surprised that you can farm in this game without any kind of water nearby. You should have some kind of body of water connected to the farm land to get yield.
A lot of us suspect the game will implement that mechanic, or something similar eventually. For now, water really isn’t anything but a pretty animation. Creatures can’t swim, drown or need to drink. You can get water to flow, but it doesn’t really affect anything yet. If you browse the forums, you’ll see a lot of people discuss this and the more clever among them even create mods. But the game is still in alpha and there is still much to do. We’ll see what time will bring.