"a supplying of water to land," 1610s, from Latin irrigationem (nominative irrigatio) "a watering," noun of action from past participle stem of irrigare (see irrigate).
Artificial provision of water to sustain growing plants.
Note: Irrigation accounts for the greatest part of water usage in the western United States.
As streams were few in Palestine, water was generally stored up in winter in reservoirs, and distributed through gardens in numerous rills, which could easily be turned or diverted by the foot (Deut. 11:10). For purposes of irrigation, water was raised from streams or pools by water-wheels, or by a shaduf, commonly used on the banks of the Nile to the present day.