CURIOUS WATER-RIGHTS 85 



in this way grafted upon the Tunuyan above La Paz, 

 the rights of which are definitive and ancient. 



At Mendoza and San Juan the water-rights, codified 

 in provincial laws which date, like the dams, from the 

 end of the nineteenth century, are very different from 

 the water-rights which hold in the Andean provinces 

 of the north-west. The variety of the physical con- 

 ditions is reflected in the institutions. Here water is 

 not an object of private ownership independently of 

 the soil. The 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 varia- 

 tion in the volume of the torrents, and it was not even 

 possible to guarantee them water in any permanent 

 fashion. The turno is used everywhere when the water 

 is low. Lower down, where the drought lasts nearly 

 the whole j^ear, the turno is the standing 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 

 neighbours 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. 



