The transformation of the lower section of the Desaguadero river basin in La Pampa, Argentina, over the past 140 years

Abstract

This article deals with the transformation of the lower section of the Desaguadero basin in Argentina, specifically in the province of La Pampa, during the 20^th century. This basin is part of the so-called South American arid diagonal, one of the largest in the country, with a nival regime and Atlantic slope where it drains through the Colorado River. Within the province of La Pampa, the river is called Salado-Chadileuvú-Curacó. Since the beginning of the century, intensive uses such as irrigation and hydroelectric generation in the Cuyo provinces of San Juan and Mendoza, led to alterations in the water flow until it finally dried up before joining the Colorado River. Only on a few occasions in the present century has this sector been reactivated. However, the accounts and chronicles of travelers, scientists and military men from the mid and late 19^th century show an active basin with high flows, which supported two projects to channel it and transform it into a navigable waterway. The objective of this work is to show the consequences of intensive water use and its repercussions in this sector of the basin.

The analysis was carried out from the critical physical geography disciplinary field where power relations, their impact and consequences in the physical space are considered. The methodology is qualitative, considering crucial, for a study of a wide temporal range, the contribution of history and archival work as well as the re-reading of historical material generated at the end of the 19th century. This information was contrasted with field work in January-February 2023, where interviews were conducted and various points of the affected area were visited over an extension of about 1,350 km.

As a result, the deterioration of the basin is the result of the confluence of intensive projects in the middle section that have had repercussions in a large part of the Desaguadero, but are accentuated in the interior of the Pampa. This is articulated with political decisions that prioritized the economic and technical aspects, ignoring their consequences. At present, there is another factor that deepens this water shrinkage associated with the advance of extractivism in the mountain range and Pampean area, and global warming.

Keywords: Desaguadero watershed; Water; Desertification; Extractivism.