We use a lot of water growing nuts in California. From 2015: https://www.motherjones.com/environment/2015/01/almonds-nuts... "it takes about a gallon of water to grow one almond, and nearly five gallons to produce a walnut. Residents across the state are being told to take shorter showers and stop watering their lawns, but the acreage devoted to the state’s almond orchards have doubled in the past decade. The amount…
This is poor logic influenced by the politics of the LA aqueduct and water project. Nuts are calorie dense, and most foods require as much if not more water per calorie. Food simply requires a lot of water. For example, A 5 oz glass of wine takes 34 gallons. A head of iceberg lettuce takes 16 gallons of water. You will note that the motherJones article compares almond water things like home use, not other food source…
Many crops around the world receive zero irrigation, the only water they get comes from rain. Much of the cereal grains (not all, but still much) are grown without irrigation.
In Iowa we drain the land by putting porous pipes a few feet down which are interlinked and drain into the rivers. If we didn’t, the water table comes up all the way to the surface and much of the land would be ephemeral ponds for significant portions of the year.