Brazil grew quickly as a nation. With a steadily growing population, heavy demands for energy were placed on the government. If the government did not find a way to meet Brazil’s ever increasing energy needs, the country could easily fall into economic crisis. Determining a source for energy was not as difficult as it may seem. Oil and gas are not available in large enough amounts to be a solution. Brazil did not have a high enough budget to import fuel from overseas, so it was forced to find a source within its own borders. Brazil happens to be home to ten percent of all the freshwater in the world. Hydropower quickly became a topic of discussion and a hopeful solution for the energy hungry country.
Simply having a lot of water in the country did not make planning a hydropower dam any easier than in other countries. To meet the high energy demands, Brazil would need to dam a body of water that would be great enough to produce the amount of energy needed. The Iguazu River came up as a choice, as it feeds one of the largest waterfalls in Brazil. The River Parana, however, is the seventh largest river in the world, much bigger and holding much more water than the Iguazu. The river also had bedrock strong enough to hold the weight of the massive dam walls. And so, the Parana river was destined to be dammed at Itaipu, becoming the world's most powerful hydroelectric dam in a matter of years.
The dam was constructed on the border of Paraguay and Brazil, jointly funded by the Brazilian government and outside investors. In 1975 construction began by first diverting the Parana to another course. The massive diversion channel used to reroute the water had to be carved through the rock of the riverbank. This channel temporarily redirected water so that construction could take place. The engineer in charge was Piero Sembenelli. He took charge during the three years that it took to complete the diversion channel. Digging the channel resulted in waste soil known as spoil piling up around the site. The pile became as high as Rio de Janeiro's famous Sugarloaf mountain. In October 1978, dynamite blasted away the diversion channel and the Parana river changed course. Additional temporary dams were built as well to prevent the flow of water into the places where the dam was being built. Diverting the river took three years, just the beginning of a project that would take over a decade to complete.
Hydroelectric dams require a lot of planning and years of hard work to create. The dam required a massive amount of manpower and engineers. Workers from all over Brazil were encouraged to come and be a part of the construction. Iguazu falls was just a small town before the dam was built, but it soon bloomed into a major city. The goal was to make the dam as tall as possible because the taller the dam is, the further the water will drop, and more energy is produced. The water drops onto turbines causing them to spin, which creates electricity. The Parana riverbed at Itaipu was only 50 meters deep, so a series of smaller dams were incorporated to increase energy production. Itaipu was designed to stand on its own, unlike other dams. Considered a gravity dam, Itaipu was built hollow so the base could be built even wider with same amount of concrete and walls would slope more gently pushing water pressure down to the base where the dam is strongest
In June of 1979 construction began on the main dam. Soon after there were issues found in the bedrock under the dam. About 20 meters underneath the surface, there was a layer of crumbled rock that was not strong enough to hold the 11 ton dam. The weak rock had engineers desperately searching for a solution. They eventually came up with the idea to fix the crumbled layer by drilling it and filling it with concrete. Another issue that came up in constructing the dam was the concrete formation and settlement. When concrete is allowed to set, the substance reacts with water and creates heat. When setting large amounts of concrete, the core sets slowly in comparison to the surface causing cracks. Brazil’s fluctuating air temperatures did not help in this process. Allowing the concrete to set in the sun put to much heat on the concrete which also caused cracks. Engineers discovered that to successfully build the dam, the concrete must be cooled before it was allowed to settle.
The construction of the dam came with great environmental and social impact. The Parana river valley would have to be flooded in order for the dam to work efficiently. This flooding would result in destruction of 600 square kilometers of agricultural land and 470 square kilometers of rainforest. Due to this, 40,000 people had to leave. The Parana River Valley was home to families for generations, eight and half thousand families were devastated as they were forced to say goodbye to their homes. The Itaipu dam was the first dam project to attempt a major rescue plan. The conservationists hoped to save 30,000 animals. They did a study of the area and found that it was home to 129 species of birds, 32 mammals, 9 reptiles, and many more species of plants and fungi. The dam would ultimately turn the parana river valley into a giant reservoir, flooding an area twice the size of chicago with a depth of 100 meters. Conservationists would spend the entire 14 day reservoir filling period in boats desperately grabbing any animals they could off of the ever diminishing islands.
In October of 1982, seven years into building the dam, the river was allowed to flow back down its original course. Flooding the entire valley, a reservoir was created that held water at a pressure equal to 4,00 bulldozers pushing against the walls of Itaipu. When the water in the reservoir gets to be too high, it causes a wave without causing a flood. A spillway is built to manage the wave and allow overflow to travel safely. Water flies over the spillway at 64 million meters per second. Lifting the slew skates allowed the water to transform into the biggest man made waterfall in the world. Itaipu became one of the most impressive dam structures in the world, stretching 7 kilometers across Brazil.
The dam did have some setbacks. To start, miles of rock had been altered, forever changing the landscape near the dam. In addition to that, approximately 145 workers died in accidents related to the construction of the dam. The energy of the water coming off the spillway was a concern to scientists as a cause of erosion which would weaken the dam over time. A ramp was built to help dissipate the energy coming over the spillway so that damage would be avoided downstream. Huge volumes of water traveling at such high speeds were dangerous. Luckily scientists studied the area and concluded that the dam had been designed exactly right and erosion was not worsening over time. The dams electricity was sent to Rio de Janeiro and Sao Paulo. Powerlines long enough to stretch around the globe one and a half times were erected to carry the electricity.
In 1991 Itaipu became the most powerful hydroelectric plant on the planet. It met the energy demands of 24 million Brazilians easily for the first ten years. In 2002, however, thirteen turbines came to a halt and lights went out in Rio and Sao Paulo. People were trapped in elevators and dark buildings, wondering what was going on. The cause of the power outage was a collapsed powerline. The collapse caused the transmission system to be unable to cope with the level of power being generated, this tripped a switch which shut the dam off. Soon enough the problem was corrected and electricity began flowing to the cities once more. The Itaipu dam is just one Brazilian dam, yet Brazil receives about ninety percent of its energy from hydroelectric power sources. Due to hydroelectric power, cities are able to grow and electricity can be provided even in the poorest favelas of the country. Itaipu has been voted one of the seven wonders of the world by engineers, and has increased growing global awareness of alternative energy sources.