That's backwards. When data centers evaporate water for cooling, it becomes vapor that blows away to fall as rain somewhere else then it's gone from the local area or its discharged a waste water. Farm water mostly stays put but plants release it back into the local air, excess irrigation soaks into local groundwater, and only a fraction leaves in the harvested crops.

Farmers can reuse the same local water year after year. Data centers need fresh water constantly because their evaporated water doesn't come back.