concession of water is assigned to a definite estate, and it is formulated in superficial measurements. The law fixes the volume of water that goes with each unit of surface. If the output of the river is not large enough to provide the volume stated in the law to the whole of the irrigated district, all the lands with definitive rights receive at least an equal amount, and the available water is shared by the canals in proportion to the extent of the surface they irrigate.
“No law could secure for the farmers of Cuyo, even those with definitive rights, a constant supply of water, or save them from suffering in common from the variation in the volume of the torrents, and it was not even possible to guar- antce them water in any permanent fashion. The turno is used everywhere when the water is Jow. Lower down, where the drought lasts nearly the whole year, the turno is the stand- ing rule. At La Paz, on the fringe of the irrigated area, it has to be applied rigorously. The turn of each owner comes every eight, ten, or twelve days. In normal times he receives the suerte de agua; that is to say, the output of a sluice of a fixed size during a half-hour for each hectare (a little over two acres) of land. But if the river runs low, it becomes impossible to supply several neighbors simultaneously, and, in order to avoid making the interval between supplies too long, the duration of the suerte de agua is reduced by half or three- quarters,
“The oases of Cuyo are like the small oases of the north- west as regards the function of those who are engaged in the administration of irrigation. The water-laws give the provin- cial functionaries general directions. Below them, however, to arrange the distribution of the water and the upkeep of the canals in detail, they have allowed to survive, and have merely regulated, certain primitive democratic organisms. At San Juan the superintendence of the irrigation is entrusted to elected municipal councils and the governor of the depart- ment. At Mendoza, the owncrs appoint a council of three delegates and an inspector for each canal, and these settle the annual budget of the canal, submit it to the provincial authori- ties, receive the taxes, carry out the necessary repairs, and so
