Since the beginning of the Han Dynasty 2,300 years ago, there have been 214 major floods recorded, averaging 1 flood every ten years. Within this past century, there have been five major floods that were recorded to have claimed hundreds of millions of lives, millions of acres of farmland, destroyed thousands of homes, and billions of dollars of damage. In 1998, a flood of such catastrophic level in the Three Gorges area caused 4,000 casualties, left 14 million people homeless, and created $24 billion in economic loss.
The proponents of the Three Gorges Dam believe that it will serve to protect 15 million people and 1.5 million acres of farmland in areas of the Yangtze River that are vulnerable to flooding. In order to do this, the water height of the reservoir upstream from the dam will change according to season. During the dry season, from November to April, the water level will be allowed to reach 185 meters above sea level, but during the flooding months, the water level will be reduced to 135 meters in order to attempt to contain flood waters.
The Three Gorges Dam can also be harnesed to alleviate droughts upstream from the dam. Click here for the most current news on drought prevention in the Yangtze area:
Reservoir Flooding of the Three Gorges Dam
By the time of it’s completion in 2009, the Three Gorges Dam will produce enough electricity to supply 3% of China’s total energy needs. The demand for energy is increasing so rapidly in China that the initial estimate in 1993 for energy production capacity was 10% of China's total energy needs.With a total of 26 turbines, each generating 700 megawatts, the dam will have a total generating capacity of 18.2 million kilowatts. The dam will generate as much energy as 18 coal power plants and will have 20 times as much power capacity as the Hoover Dam in the US. The rate of energy production, equivalent to burning 11,000 barrels of oil per hour, is enough to supply Beijing with power for one year.
The project is part of China’s initiative to move towards green energy usage. China is currently the second largest emitter of greenhouse gases in the world. Coal is the main energy source, accounting for two thirds of all electricity produced in the country. Coal power is not only a nonrenewable resource, but also generates immense amounts of pollution, including carbon dioxide, sulfur dioxide, and carbon monoxide.
By 2020, China wants 15% of total energy production to come from renewable resources. Hydroelectric power is a critical non-carbon energy source that will help reduce energy consumption and air pollution. By substituting coal-produced energy with hydroelectric energy from the Three Gorges Dam, China will reduce annual coal consumption by 40-50 tons, effectively reducing the amount of pollution released into the atmosphere. Hydropower currently accounts for 6% of the national power supply, and by 2020 China aims to triple hydroelectric power capacity to 300 gigawatts.
Water Spillway of the Three Gorges Dam
The Three Gorges dam will enable better navigation to boost Yangtze River trade, which accounts for 80% of China’s inland shipping. The Three Gorges area of the Yangtze is notorious for dangerous shipping conditions. The elevated water levels of the reservoir upstream from the dam will enable larger ships to travel further inland on the Yangtze. In order to facilitate transportation, the dam will have a 5 tier ship lock system to enable ships to pass through the dam. A ship elevator is to be installed by the project’s completion in 2009 that will be capable of lifting passenger or cargo ships of 3,000 tons. This new transportation system is said to cut transport costs by one third and increase shipping on the Yangtze from 3 million tons to 50 million tons per year.
The river city of Chongqing is expected to undergo great economic development as a result of the increased trade on the Yangtze. Chongqing was recently approved to be the fourth centrally-administered municipality of China, after Beijing, Shanghai, and Tianjin. It is expected to undergo an urbanization rate of 70% within the next 12 years, with it’s population reaching 21 million by 2020.
Ship Lock System of the Three Gorges Dam