Beneficial Use--For Whose Benefit?

Today water use is legitimized through proof of “beneficial use”. The principle of beneficial use exhibits itself in the first and second century AD case of the Barbegal Aqueduct and Mill located on the territory of the commune of Fontvielle, near the town of Arles in southern France  There, water was trained by Roman engineers to move by aqueduct to an elevated location where it could fall over a progression of wheels, the motion of which was transferred by gears to grinding wheels used to grind grain into flour which could be baked into bread sufficient to feed the town of Arles.  The use was “beneficial.”
The principle can also be observed some thousand years later in the “mill monopoly” enjoyed by lords of the manor in early medieval English feudal law, a law which was indeed administered by the lord himself.  The monopoly derived from the lord’s control of the only (or limited) milling capacity of the manor, the mandate that all within the manor must grind their grain at the lord’s mill (subject of course to a fee or tax), and the protection of the water flow which turned the mill’s grindstone through a “praedial servitude” upon upstream properties who might competitively divert water essential to turning the mill’s water wheel.  The creation of this microcosm of water, agronomic and economic interdependence was “beneficial” to its participants, the lord most of all, as it was essentially a closed economy.  It only had extra-manorial impact when density of use on a given stream put manors in competition.  When the praedial servitude was asserted through actions in “nuisance” against upstream users, the defense necessarily became that the upstream user also had a water right by virtue of its riparian position, a right in which no new beneficial use need be shown.
Somewhere along the historical timeline, most notably in the late eighteenth century with its advent of English industrialization, beneficial use began to be regarded as the economic betterment of a particular water user, as opposed to the broader public.  Betterment of a single interest was perceived to be the implied betterment of all.  Thus, beneficial use became to mean simply work of any kind which generated individual wealth.  Water could, in essence, be owned if one could use it to make money—public good had departed from the definition.
Putting water to beneficial use is, of course, the means by which appropriative water rights are perfected..  Modern statutory definitions of beneficial use are essentially lists of purposes, all of which, with the exception of domestic, are economic until environmental purposes were added.
At the common law, the converse of beneficial use was “waste.”  Waste may be evidenced by insufficient purpose, insufficient conservation of resource or insufficient benefit.  It has been fashionable at periods of judicially sanctioned economic self interest to allege that it is wasteful to permit a watercourse to run in its natural way, to leave water in the ground in its natural setting, or to permit water to run its way to the sea. Environmentally conscious post-industrialists have, of course eschewed such thoughts.