Of immense and increasing importance is the availability of water for domestic, agricultural and commercial use – especially in the arid western states.  There, the doctrine of prior appropriation converges with the Public Trust Doctrine. The four key cases of the last decade are discussed in chapter VI of The Public Trust Doctrine in Motion. Some excerpts from chapter VI:

“Two doctrines, one ancient, one modern, both dealing with water, are coming into play in the water wars that have occurred, and will increasingly occur as the supply of water slacks behind population and commercial growth, as seen most prominently today in the western states. The ancient doctrine, the Public Trust Doctrine, nearly two millennia old, originally pertained to all “running” waters. Later, under the English Common Law, the doctrine was restricted to only waters that ebbed and flowed with the tide.  The English Common Law was brought to the American colonies, and was the accepted law until after the Revolution. But as discussed in Chapter I, as this country developed, the scope of the doctrine was expanded to cover all navigable waters, whether tidal or not. Then, in some states, including western states, the doctrine was further expanded to include all waters, whether navigable or not, if they can be put to a public purpose. In Hawaii, the Supreme Court went so far as to recognize all water – irrespective of whether it is surface or ground, tidal or non-tidal, navigable or non-navigable – as being within the scope of the Public Trust Doctrine.”

“The Doctrine of Prior Appropriation, on the other hand, originated out of the necessity of miners in western U.S. territories, especially pre-statehood California, to have water diverted great distances from the rivers and lakes to where they were mining. As discussed by the Montana Supreme Court in its 2002 Basin 411 case:

“Miners in California developed a water use system as an alternative to the riparian water system prevalent in England and the eastern United States. While riparians allowed owners of land abutting the water source to control it, the more arid climes of the American West required a different approach. Prior appropriation, adapting flexibly to the needs of a developing society, allowed diversion to a distant location and simply required use of the water for a beneficial purpose. Western states adopted the miners’ customs through both court decisions and codification, and the doctrine of prior appropriation became the law of the western states.”

“As the doctrine of prior appropriation developed, it became the common law that four elements were needed to secure a valid appropriation right: intent, notice, diversion and application to beneficial use. “Beneficial use” traditionally meant the use of water for irrigation and mining, both of which required the water to be diverted, sometimes miles, from its source.  As the west was opened, cattle and other live stock ranged the vast lands. Watering livestock from rivers and lakes was regarded as a beneficial use.  Ranchers, under the prior appropriation system, could secure rights to water their livestock, even though no “diversion” was necessary, for the cow, sheep or horse would simply walk into the water to drink. The use of water for domestic purposes clearly was a beneficial use, as was any commercial use of water. As time went on, swimming pools and lawn sprinkling became common, and were seen as beneficial uses of water. Never, however, was it viewed as a beneficial use to use river water for water in the river, or use lake water for water in the lake. Under the law of prior appropriation that was “waste.”

“Of great significance, a core principle of the doctrine of prior appropriation is: first in time is first in right. Thus, priority of a right to water is not determined by its use, but solely by time. Whoever secures their water right first has a superior claim to the water, regardless of what use is made of the water. The term “beneficial use” has no hierarchy of uses; any use that is beneficial qualifies. The only hierarchy is in time: first in time, first in right.

“These two doctrines would peacefully co-exist for decades, as long as there was sufficient water for everybody. But as supply lagged behind demand, it was inevitable that the ancient Public Trust Doctrine that vested the public with a trust right to have sufficient water in the lakes and rivers in order to enjoy all of their trust rights, would clash with the new Doctrine of Prior Appropriation, which viewed leaving water in its natural state as ‘waste.’”

In chapter VI, “Water Rights: A Confluence of Two Doctrines”, the four major State cases of the last decade are discussed.

“All four of these Study Cases involve attempts by the State to reserve enough water in the State’s steams and lakes to protect and preserve the public’s trust rights in their trust waters. Instream and inlake minimum flows are most often required for the protection of fish and wildlife habitat, as the Montana, Hawaiian and California cases illustrate. But such minimum flows may also be justified under the Public Trust Doctrine, as the Nevada Supreme Court noted, to assure that the public will always be able to ‘ marvel at this massive glittering body of water lying majestically in the midst of a dry mountainous desert.’”