The West is a land of limitations. Mountains, deserts, rocks, soils and the arid climate all place limitations on farmers and ranchers. There are places where you can grow crops and places you simply can’t.
A significant limitation on farmers and ranchers is imposed by water. Water is required for drinking and for domestic use. Water is required for livestock. Without irrigation water, most crops cannot be raised in southern Idaho. Mother Nature does not provide enough rain to grow hay, grain or potatoes.
Idaho’s Constitution recognizes water is a limited resource and further recognizes that certain uses of water have preferences over other uses.
Section 3 of Article XV of the Idaho Constitution states that “priority of appropriation” governs the use of water in Idaho. In other words, the first person in time to divert water and put it to beneficial use has the better water right. If there is a water shortage, the person with the earlier water right gets the water, and the person with the later water right gets none.
Notwithstanding, the Idaho Constitution also states that when there is insufficient water, those using water for domestic purposes have preference over those claiming water for any other purpose. This notion is further codified by Idaho Code § 42-227 which authorizes drilling and use of a well for domestic purposes as a permitted use that does not require a water right.
“Domestic” purposes include the use of water for homes, organization camps, public campgrounds, livestock and irrigation of up to half an acre of land, if the total use is not in excess of 13,000 gallons per day.
In addition, the Idaho Constitution states that water appropriated for agricultural use has preference over those using water for manufacturing. But, in any organized mining district, mining uses of water have preference over manufacturing and agricultural purposes.
So for example, an agricultural water right with an earlier priority date will be trumped by a domestic water right with a later priority date. However, the law requires those with junior water rights who claim the use of water based upon the preferences outlined in the Idaho Constitution to pay just compensation for the taking of water.
When water is insufficient, as is sometimes the case, preferences for the use of water will trump priorities.