The use of irrigation in this district raised different technical problems from those of the north-western provinces. In this latitude the torrents of the Andes are formidable when the snows meetmelt, at the beginning of summer. The flood is all the greater and more sudden as the heat is late. From all the ravines of the mountains the muddy waters then converge toward the valley. The flood scours the bed of the river, erodes its banks, and threatens to find a way amongst the estates. Even the towns of Mendoza and San Juan have more than once been in danger. The fear of diverting the flood and of bringing it upon themselves compelled them to be content with raising only light and frail dams in the path of the torrent. At San Juan they used, for a long time, the waters of the Arroyo del EesteroEstero, a small brook fed by infiltration from the Valle de Zenda, and it was some time before they ventured to draw upon the river itself.
THE OASIS DEL RINCON, BELOW SAUJIL (ANDALGALA LINE, PROVINCE OF CATAMARCA).
The dejection-cone, at the foot of which is the very small oasis, is seen resting against the Sierra d'Ambato.
Photograph by the Author.
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THE MONTE AT EL YESO.
Zone of clay hills at the foot of the Sierra de San Antonio, at the edge of the Chaco. Corral (cattle park) made from tree-trunks.