The Paulo Afonso Hydroelectric Complex (Complexo Hidrelétrico de Paulo Afonso), also known as the Paulo Afonso Complex, is a system of three dams and five hydroelectric power plants on the São Francisco River near the city of Paulo Afonso in Bahia, Brazil. The complex exploits an 80 m (260 ft) natural gap on the river, known as the Paulo Afonso Falls. Constructed in succession between 1948 and 1979, the dams support the Paulo Afonso I, II, III, IV and Apollonius Sales (Moxotó) power plants which contain a total of 23 generators with an installed capacity of 4,279.6 MW.

Paulo Afonso I was the first large power plant constructed in Brazil and the complex constitutes the densest area of dams in Brazil. The complex provides electricity to areas in northeastern Brazil and is the main tourist attraction in the region.

Apollonius Sales (Moxotó)

The Appollonius Sales Dam and power plant were originally known as Moxotó but were renamed after Appollonius Sales, the founder of CHESF. The dam is a 30 m (98 ft) high, 2,825 m (9,268 ft) long rock and earth-fill embankment dam. The dam withholds a 1,200,000,000 m³ (4.2×10¹⁰ cu ft) capacity reservoir with a surface area of 100 km² (39 sq mi) and catchment area of 630,000 km² (240,000 sq mi). The dam and its reservoir are primarily intended to regulate water flow to PA I, II and III 4 km (2.5 mi) downstream. On the dam's west side, it supports a 20 floodgate spillway with a 28,000 m³/s (990,000 cu ft/s) capacity. The power plant is located on the east side of the dam near the reservoir's shore and contains four generators, each with Kaplan turbines. Each generator has an nameplate capacity of 100 MW for a total installed capacity of 400 MW.

Paulo Afonso I, II, III

Situated directly on top of the Paulo Afonso Falls, the Delmiro Gouveia Dam supports Paulo Afonso I, II and III. The dam is 20 m (66 ft) high, 4,707 m (15,443 ft) long and is a concrete gravity type. The reservoir formed by the dam has a 26,000,000 m³ (920,000,000 cu ft) capacity and surface area of 4.8 km² (1.9 sq mi). The dam has one uncontrolled spillway and a controlled spillway on its outer linings while also supporting four controlled spillways on the front of the falls. These four surface spillways when open, discharge water below and essentially recreate the falls.

All three power plants are about 82 m (269 ft) underground and adjacent to one another. PA I lies in the center and is housed in a 60 m (200 ft) long, 31 m (102 ft) high and 15 m (49 ft) wide cavern. It contains three 60 MW generators with Francis turbines, for an installed capacity of 180 MW. The generators are Vertical Sync-type and were manufactured by Westinghouse. The turbines were manufactured by Dominion Engineering Works. PA II is a 104 m (341 ft) long, 36 m (118 ft) high and 18 m (59 ft) wide power house. It contains six Vertical Sync-type generators with Francis turbines. Two of the generators are 70 MW, one is 75 MW and the remaining three are 76 MW, for a total installing capacity of 443 MW. The generators were manufactured by S. Morgan Smith and Hitachi while the turbines by Voith. PA III's power house is 127 m (417 ft) long, 46 m (151 ft) high and 18 m (59 ft) wide. It contains four 198.55 MW Vertical Sync-type generators manufactured by Siemens for an installed capacity of 794.2 MW. Each generator utilizes a Francis turbine manufactured by Voith.

Paulo Afonso IV

The Paulo Afonso Dam located 2 km (1.2 mi) southwest of the falls is 35 m (115 ft) high and 7,430 m (24,380 ft) long. The dam is an earth and rock-fill type but contains 1,053 m (3,455 ft) in length of concrete structures which include the power plant's intake and the spillway. The spillway is composed of eight floodgates and has a maximum discharge capacity of 10,000 m³/s (350,000 cu ft/s). The dam withholds a 127,500,000 m³ (4.50×10⁹ cu ft) capacity reservoir with a surface area of 12.9 km (8.0 mi). The reservoir receives water through a channel that originates near the southern end of the Appolonius Sales Reservoir and continues south, skirting the city. The PA IV power house is also underground and is 210 m (690 ft) long, 52 m (171 ft) high and 24 m (79 ft) wide. It contains six 410.4 MW generators for an installed capacity of 2,462.4 MW. Each generator is a SíncronoVertical-type manufactured by Siemens and utilizes vertical shaft Francis turbines that were manufactured by Voith.

Paulo Afonso Hydroelectric Complex
Country	Brazil
Locale	Paulo Afonso
Status	Operational
Commission date	1954–1979
Owner(s)	CHESF
Power station information
Generation units	23
Power generation information
Installed capacity	4,279.6 MW