Most Impressive Megaprojects Under Construction

When we talk about huge engineering projects, few of them come close to the sheer size and cost of the largest dam in the world. Let me introduce you to the Three Gorges Dam in China, which is one of the largest engineering projects ever built. It took almost two decades and a lot of manpower to bring it to life. Located in Hubei province in China, the Three Gorges Dam is the largest hydroelectric power station in the world and produces clean, renewable energy. This dam's capacity is so massive that the amount of water it holds slows down the Earth's rotation. NASA scientists calculated that a single shift of the water mass stored by the dam increases the length of the Earth's day by 0.06 microseconds. That's not enough for you to notice, but not many things on Earth can claim to do that. It also makes the Earth slightly more round in the middle. Talk about a bulging effect. The dam was built on the Yangtze River, which is the longest river in Asia and almost as long as the Amazon River. The dam has a height of 180 meters and is 2.3 kilometers long. Construction on this giant of a project cost a whopping 32 billion dollars. Today, it provides energy for approximately 20 million people. Building the dam created a massive artificial lake. Here's a satellite map showing areas flooded by the reservoir. This feat of engineering is so unique that it is now an international tourist attraction. So why was it built? Well, there are several reasons why. The main reason for building this dam was to prevent further flooding downstream. This was a huge problem because the mighty Yangtze River was known as a wild river. When it broke its banks, it left destruction in its wake. The dam construction had first been considered in 1919, but the civil war and cultural revolution in China delayed it. In 1954, an estimated 33,000 people were killed by the flooding of the Yangtze River. Many more flooding disasters followed and something needed to be done. To build a dam that will span the length of the Yangtze River, China decided to go big. Really big. Approximately 28 million cubic meters of concrete were used to build it. That's the equivalent of 11,200 Olympic swimming pools. Or in other words, that's the equivalent of every citizen of Russia filling up their bathtub with concrete. Construction began in 1994 and it took over 17 years and over 40,000 workers to pull it off. But you can bet that with such a huge project, there were some after effects. When completed, the dam's reservoir started filling up, but it flooded over 1,500 cities and towns. There was a lot of criticism about this from the locals and the international community. How did the government solve it? Well, more than 1 million people had to be relocated. That's a lot of people to move around and there's still controversy about it to this day. But China believes the long-term effects justify the short-term inconvenience. It's now possible to control the flow of water, which eliminates the chances of flooding downstream. The dam now protects over 15 million people by reducing the risk of flooding. The other key reason why it was important to build the dam was in order to generate electricity. China's dreams of becoming a big industrial and manufacturing powerhouse were not going to happen without a large supply of sustainable power. The desire for great power gave birth to the idea for a massive dam and the Three Gorges Dam does the trick. It provides renewable green energy, which does not pollute the environment. It has helped China reduce its carbon dioxide emissions and there's even power available for many provinces around China, such as Shanghai. Although the initial cost of building the dam was enormous, the dam will eventually pay for itself and start making profits. You must be wondering how this behemoth was built. To build something on one of the largest rivers in the world, it wasn't going to be easy. So during construction, they first made stone coffer dams to block off parts of the river. They kept a small open portion for the river to continue flowing as they built the first section of the dam. They went about the next step by placing tons of earth into the dry riverbed. They followed that up by building a concrete coffer dam on top of it. This enabled them to work on the rest of the dam. Once construction was completed, the coffer dams were removed to allow water to reach the turbines. Inside the dam, there are huge 32 turbines with the capacity to produce 700 megawatts each. Millions of liters of water flow through the huge concrete tubes to these turbines every minute, creating electricity. To keep the foundations of this structure strong, it has spillway gates and concrete chutes in case of emergency. They can hurl excess water over 100 meters downstream and protect the system from damage. The dam was also built to improve shipping on the Yangtze River because the gorges are very dangerous to navigate. So two series of ship locks have been installed near the dam and they are the biggest ship locks in the world. The dam has staircase locks designed to keep up with the highest river traffic. Each is made up of five stages and it will take you four hours to get through the locks. Since the system is working so well, it can now handle more than 150 freight ships per day. This allows China to reach their goal of increasing river shipping capacity from 10 million to 100 million tons annually. They also brought about the smaller passenger boats too. In addition to the canal locks, there is a ship lift. Yeah, you heard it right, an elevator for ships. The lift rises over 100 meters and uses counterweights within the concrete walls to elevate the ships. It will take you about 40 minutes to get to the top. The ship lift's construction started in October 2007 and completed in 2016, so it didn't exist when the project was officially opened in 2006. But you have to admit that it's one of the coolest things about this dam. The engineers of the Three Gorges Dam crafted the design to reduce its impact on the environment. It now holds the largest volume of water for a dam, storing approximately 40 billion cubic meters of water. That's enough to fill up a bathtub for every person on earth 25 times. Mother Nature is not always kind when you try to tame her. However, China is confident that because of the modern materials and techniques they use, they have reduced the risk of the dam being damaged during an earthquake or other natural disaster. So what are the good and bad effects of having the Three Gorges Dam? Well, let me share the bad ones with you first. For starters, millions of tons of sediment become trapped yearly at the Shanghai province, which is 1600 kilometers away, rests on a massive sedimentary plain. The thing about sediment is that it strengthens the bed on which Shanghai is built. So if there's less new sediment, then Shanghai becomes more vulnerable. And no one wants to see the whole of Shanghai sinking away because of this. To counter this, engineers have built massive sluice gates inside the dam. When gates are opened, floodwater moves the sediment through the dam, sending it downstream to where it's needed most. There's also been a potential impact on plants and wildlife. The region around the river has always had a rich biodiversity, but the dam disrupts aquatic and plant life because it has changed how things flow downstream. Right now, half of those plant species are endangered, while forests around the dam are decreasing more and more each year. Like the saying goes, every cloud has a silver lining, and China hopes the long-term benefits will outweigh the short-term problems. So what's the good side of the dam? Well, for starters, it provides a huge amount of power that will cater to China for generations to come. A big advantage of the dam is that it generates green power, which has helped China reduce coal consumption by almost a full percentage point, thus avoiding millions of tons of greenhouse gas emissions. It has also supplied water to nearby cities and agricultural areas, boosted shipping along the channel, and created a historic landmark. However you look at it, the Three Gorges Dam already has its place carved out in history. But what do you think about the Three Gorges Dam? Do you think its long-term benefits and flooding protection justifies the environmental impact? Let us know in the comments below. Also, make sure to leave a like and subscribe to Top Luxury. It really helps the channel to grow. But for now, thank you for watching, and we'll see you in the next video.