Ufficio Periferico di Cagliari

versione italiana


Yacyretá Dam







Dam type

The reservoir is delimited by earth dams and concrete structures:

1)   left lateral dam (12 km long), built with watertight soils and of homogeneous section;

2)   main left dam (1.8 km long), of zoned section, with a central clay core and sand outer zones;

3)   navigation lock, 27 m wide;

4)   main branch closing dam (1.9 km long), of zoned section with a clay core directly founded on the rock bed, sand outer zones and rock protection;

5)   main spillway, 342 m long;

6)   hydroelectric powerhouse, 808 m long;

7)   Yacyretá Island lateral dam (18.7 km long), of zoned section with central clay core and sand outer zones;

8)   Aña-Cuá Branch spillway, 304 m long;

9)   Aña-Cuá Branch closing dam (3.6 km long) and right lateral dam (25.7 km long), both having the same section as the Yacyretá Island dam.

Construction period


Structural height

42 m

Gross storage capacity

21,000 Mm³

Volume of the dam

62,000,000 m³ embankments, 3,600,000 m³ concrete

Maximum controllable water surface

83.00 m a.s.l.

Maximum water surface

84.50 m a.s.l.

Crest elevation

86.00 m a.s.l.

Crest length

65.2 km

Maximum discharge capacity

Main spillway: 55,000 m³/s;

Aña-Cuá Branch spillway: 40,000 m³/s;

Power plant: 16,000 m³/s.

Nameplate capacity of the powerplant

The open-air powerhouse houses 20 Kaplan turbines, each of 160 MW capacity, providing a total installed generating capacity of 3,200 MW. The annual energy generation of Yacyretá power plant can reach 20 TWh.


Yacyretá Dam (see satellitar image) starts from the Argentinean (left) bank of the Paraná River, crosses the navigable river branch, downstream from the Apipé rapids, and continues along the Yacyretá Island for some 18.7 km. After crossing the Aña-Cuá branch, the dam stretches over the Paraguayan bank, parallel to the river.

The main works, namely powerhouse, main spillway, main dam and navigation lock, are located on the navigable branch of the river. The navigation lock, 270 m long and 27 m wide, allows the passage of vessels having a maximum draft of 3,65 m to clear the level difference of 23.60 m.

Under the Yacyretá Island dam, the right lateral and the river closing dams, a watertight cut-off wall has been built. It was necessary to excavate a 60 cm wide trench in alluvial ground. The trench excavation was carried out by means of a specially framed digging clamshell with a Kelly system tackle. The trench was then filled with a mix of bentonite cement. The cut-off wall totals 48 km in length and creates an area of 872,000 m².

In order to assist fishes migration, specially framed structures have been built at both ends of the powerhouse. Fishes are attracted towards the main entrance of the structures by means of an induced water current and they are concentrated in a pool. Fishes are then lifted up from the concentration pool, using two specially framed 15 m³ capacity transfer tanks, and released into the reservoir. Up to 1,800 kg of fish can be lifted at a time.



Pagina creata da Luigi Ghinami email

Ottimizzata per una risoluzione 800x600 o superiore

Ultimo aggiornamento: 4 agosto 2005