The Juruá River is the most winding river in the Amazon Basin. Beginning in the highlands of east-central Peru and crossing into northwestern Brazil before it eventually empties into the Amazon River, it exhibits curvature and sluggishness as it traverses the low, half-flooded forest countryside.
The Juruá River, taking into consideration its significant meandering, is calculated to exceed 3,200 km (2,000 mi) in length, one of the longest tributaries of the Amazon River. Its banks are sparsely inhabited, and many tributaries were first mapped via satellite in the late 1970s.
The river's headwaters are in the highlands of the Ucayali region in east-central Peru. It then flows northward through the state of Acre in northwestern Brazil. Upon entering the state of Amazonas, the river meanders eastward and then east-northeastward through the lowlands of Brazil, emptying into the stretch of the Amazon known as the Solimões, near the town of Tamaniquá.
The Juruá is the most winding river in the Amazon Basin. It exhibits the curvature, sluggishness and general features of the Purus River as it traverses the low, half-flooded forest countryside. Its extensive meanders traverse floodplains studded with lakes surrounded by wetland forest.
The river's waters are turbid with relatively high nutrient levels. The river flows through the Purus várzea ecoregion most of its length, surrounded by the Juruá-Purus moist forests ecoregion.
The river is navigable and unobstructed for a distance of 1,823 km (1,133 mi) above its junction with the Amazon. Its banks are sparsely inhabited, and many tributaries were first mapped via satellite in the late 1970s.
Map depicting the Amazon River drainage basin with the Juruá River highlighted
The Juruá Basin headwaters arise in the Ucayali department in Peru. The sources are in the Serra del Divisor, an Amazonian mountain range divided by Brazil and Peru. The highest peak in the region is approximately 878 m (2,900 ft).
The basin is approximately 188,000 sq km (72,600 sq mi). It is relatively narrow in its middle and lower reaches, and more than 90% lies within the Brazilian states of Amazonas and Acre. In addition, the basin has approximately 28,000 sq km (10,800 sq mi) of wetlands.
Annual precipitation in the Juruá Basin typically ranges from approximately 1,800 - 2,200 mm (70 - 86 in), and yearly river level fluctuations in the middle sections range from 12 - 15 m (40 - 50 ft).
The river is usually in flood from December through mid-May. In their lower courses, floods last until August because of the backwater effect of the Solimões (Amazon River).
Water from the Juruá accounts for approximately 2% of the Amazon River's total annual discharge.
The Juruá Basin has extensive protected areas in its headwaters and lower reaches. In addition to areas set aside for indigenous peoples, the Serra do Divisor National Park occupies approximately 85,000 sq km (32,800 sq mi) in the upper Juruá watershed in Brazil.