Hydroelectric project

The Yaciretá/Yacyreta (the “cradle of the moon” in Guarani) Dam is located on the Paraná River in the northernmost part of Argentina near the border with Panama. It is a nearly 70 km long earth dam which includes four main concrete structures measuring almost 3.4 million cubic metres. This construction comprises a 236 m navigation lock, a main weir with 18 radial gates that are each 15 m wide and a discharge rate of 55,000 m3/s, a hydroelectric power plant with 20 Kaplan turbines with a diameter of 9 m (annual production of 17,000 GWh) and a secondary weir (on the second arm of the Paraná River) with radial gates and a discharge rate of 40 000 m3/s.

BACKGROUND

Already in 1958, the Argentine government thought that construction of a large dam would contribute to the development and progress of the country. In fact, hydroelectric power allows electricity to be distributed throughout a country at a relatively low cost of operation. Also, the Paraná River and its tributaries make up the third largest river network in the world after the Amazon and the Mississippi. So, this river is a good location for this construction. The idea of building a hydroelectric power plant on the Paraná River was born from the desire to support Argentina in its economic, demographic and technological development. This is why, in 1958, an agreement was signed between Argentina and Paraguay to create a commission. This commission carried out technical and economic feasibility studies which culminated in a project to build the Yaciretá Dam jointly.

TECHNICAL OVERVIEW

This has 3 levees and 2 dams (on the 2 arms of the Paraná). The earth and rock-filled levees with a waterproof core are 70 km long and 43 m high. The levee backfill represents 70 million cubic metres of predominantly loose materials.
The concrete structures, that is, the four main structures, have a volume of around 3.4 million cubic metres of concrete (50% for the plant). The 20 turbines in the power plant have a unit productive flow rate of 730 m3/s for a rated head of 21.3 m.
The land we came across was a classic alluvial series consisting of all the sandy clay facies, including gravel, silt and conglomerates. Sealing the Yaciretá Dam required implementing techniques used for special foundations: slurry walls, injections, exploratory drilling, shafts, drains and anchor walls. The dam was sealed by building a 60 cm-thick cement-bentonite slurry wall after stripping the topsoil and partially positioning the dam core. The average depth of the wall was 19 m, within a range of 10 and 35 m.
Beyond coordination and logistics needs, the project’s major challenge was closing off the Paraná River, which has an impressive discharge rate (up to 53,000 m3/s recorded) when flowing through the two arms (1000 and 2000 m) on either side of Yaciretá Island. The river was closed using a combined method. We at first built a submerged ledge 400 m downstream from the closing bulkhead, which raised the upstream level without causing an increase in the speed of the water jet above the ledge. Following this, a relatively calm water body was created downstream from the closing bulkhead.

This project had 7,500 people working on the site and because of this, more than 20,000 people were housed, fed, received medical care, trained and entertained.

IMPACT

Yaciretá is one of the largest dams in the world. Located between Argentina and Paraguay on the Paraná River, the second longest river in Latin America, this massive hydroelectric project fulfils several objectives. Firstly, it generates electricity. Then, it facilitates river transport (a lock provides a navigation channel to Brazil by raising the level of the water upstream from the dam). Finally, it helps fishing and the irrigation of agricultural land.
The power plant has an installed capacity of 3,200 MW. As much as 2,630 million litres of water can pass through each Kaplan turbine per hour, so this means 52,600 m3 per hour for 20 turbines. The electricity produced annually is more or less 17,000 GWh, which represents more than 50% of the hydroelectric power generation in Argentina.
At the same time, the construction of this hydroelectric dam has supported the economic, demographic and technological development of Argentina and Paraguay.

Project participants

Client
Entidad Binacional Yacyretá

Project management
Cidy – Harza – Lahmeyer & Partners

Key figures

Implementation dates
December 1983 to June 2001  

Drainage basin
1,000,000 km2

Average discharge
11,900 m3/s

Record discharge
53,000 m3/s

Testimonial

« For Argentina to progress, we must develop its potential to the maximum using modern techniques (…). Water is our first and foremost untapped resource. »

Comision Asesora de Planificacion Hidroelectrica, 1958