STS51I-37-0037 Paraná River, Brazil August 1985 This low-oblique, southwest-looking photograph shows a small portion of the Paraná River. The Paraná, 2485 miles (3999 kilometers) long, is the Western Hemisphere’s third longest river. The Paranapanema River, 500 miles (805 kilometers) long, can be seen entering the Paraná from the east. Near the center of the photograph, partial construction of a new dam is discernible. Now completed, the dam holds the Pôrto Primavera Reservoir. Presently, the dark green vegetation in the floodplain of the Paraná is covered with water from the reservoir, which is used not only to generate electricity but also to irrigate the agricultural fields on either side of the river.