Torrent control at Cerro Divisadero, Chile

Abstract

The results of the evaluation of works and proposals for building new check dams and channel dredgings at the Cerro Divisadero torrents, Coyhaique, XI Region, Chile, are presented. The success of stream works and channel dredgings to control torrential processes at Cerro Divisadero was confirmed. Slope treatment and longitudinal walls have proved less successful due to their short range effect.
A great number of severely damaged old wooden check dams, active torrential zones and channel cross sections whose discharge capacities are insufficient to evacuate peakflow were identified.
It is urgent to initiate a new stabilization phase to complete the consolidation of Los Coigües, Los Saltos and Mackay torrents. Building a total of 50 new check dams is proposed. Of these, 13 will replace severely damaged dams and the others will be located in active torrential zones. More than 2.000 meters of channel dredgings are projected at the alluvial fans of the main torrens. Almost US$ 878.000 are needed to finance the complete project.