Reconnaissance of sedimentation in the Rio Pilcomayo Basin, May 1975, Argentina, Bolivia, and Paraguay

The Río Pilcomayo "Alto" (Bolivia) and "Superior" (Bolivia, Argentina, and Paraguay) transport large quantities of sediment for the size of the basin. The Río Pilcomayo "Inferior" (Argentina and Paraguay) seems to carry little sediment. The large loads of the "Alto" and "Superior" must be considered before dams or irrigation projects are started. The shifting channel and flooding of the Río Pilcomayo "Superior" also are problems to be considered before development. The Río Pilcomayo "Alto" basin has relatively little deposition whereas the "Superior" basin has considerable deposition. A part of the "Superior" channel is filled with sediment to the top of its banks. The upstream limit of filling is moving farther upstream each year causing the place of overbank flooding to move upstream also.

More data must be collected and more observations made before a complete analysis of the sediment movement in the basin can be made.