Itaipu hydroelectric dam aerial view with massive water release

Aerial view of the Itaipu hydroelectric dam with its spillway in operation, releasing a massive volume of water on an overcast day.

About this subject

The Itaipu hydroelectric dam, located on the Paraná River at the border between Brazil and Paraguay, is one of the largest hydroelectric plants in the world by energy generation. Inaugurated in 1984 after a binational treaty signed in 1973, the project involved excavating 63 million cubic meters of earth and rock. The spillway, shown in operation in the image, can discharge up to 62,200 cubic meters of water per second, equivalent to 40 times the average flow of Iguazu Falls. This control structure is essential for regulating the reservoir level and preventing floods, especially during heavy rainfall in the Paraná basin.

The construction of Itaipu displaced about 10,000 families and altered the natural course of the river, but it also boosted the region's economic development. The plant has 20 generating units with an installed capacity of 14,000 MW, and in 2016 it set the world record for annual energy production with 103.1 million MWh. The reservoir stretches 170 km from Foz do Iguaçu to Guaíra, and its flooded area of 1,350 km² hosts diverse aquatic ecosystems.

Culturally, Itaipu is a symbol of international cooperation and engineering. The spillway, in particular, attracts tourists who visit the observation deck to witness the power of the water. The plant also invests in environmental programs, such as water quality monitoring and preservation of riparian forest areas. On overcast days, like the one recorded in the photo, the mist generated by the falling water creates a visual spectacle impressive in scale.

Interestingly, the spillway is not constantly operated; it is only activated when the river flow exceeds the turbines' generation capacity. During dry seasons, it remains closed, and all water is directed to the turbines. The image captures a moment of hydrological relief, when excess water must be released to ensure the structural safety of the dam.

Frequently Asked Questions

What is the generation capacity of the Itaipu dam?

Itaipu has 20 generating units with an installed capacity of 14,000 MW, enough to supply about 15% of Brazil's consumption and 86% of Paraguay's consumption.

Why is the Itaipu spillway opened?

The spillway is opened when the Paraná River flow exceeds the turbines' capacity, preventing the reservoir from exceeding the maximum safety level. This occurs mainly during heavy rainfall periods.

Is Itaipu the largest hydroelectric dam in the world?

Itaipu was the largest in energy generation until 2012, when China's Three Gorges Dam surpassed it. Currently, Itaipu ranks second in installed capacity and holds the record for annual production.