Irrigation was a technique for distributing water.
While on Amerind, James T. Kirk proposed a system to irrigate the local fields and double the food supply. It would depend on a canal bringing water from a lake to the lodge. (TOS: "The Paradise Syndrome")
While acting as a priest in the Fair Haven holoprogram, The Doctor told a story about two feuding farmers, one of which at one point clogged an irrigation ditch belonging to the other. (VOY: "Spirit Folk")