The statements in this article are based on reliable sources and are repeated at the end of this article
If someone clears all the gates of the Three Gorges Dam, how long will it take for the 39.3 billion cubic meters of Three Gorges Reservoir to be released?
If, like a math problem, water is released and water continues to pour in, how long will it take?
We all know the enormity of the Three Gorges Dam project, but even if we can visit it on a regular basis, the public's understanding of it is still only the tip of the iceberg, and the whole picture is unknown.
The discharge time of such a "reservoir" is also affected by the amount of water, the number of gates, and the flow rate, so let's take a look at it.
01
Water conservancy projects have been a matter of pride for the Chinese nation for more than 2,000 years.
At that time, the conditions of Shu were unique, and it was very suitable for growing grain, but there was a drawback, that is, floods often occurred.
Therefore, under the difficult conditions at that time, they tried all means to split the mountains and open up stones, and actually created a world miracle, that is, the Dujiangyan Water Conservancy Project.
Even now this water conservancy project is still working, which is a miracle, so we people have a special feeling for the construction of the dam.
The Three Gorges Dam is no exception, and as early as the early 20th century, Mr. Sun proposed the idea that it would greatly promote the economic development of the Three Gorges Basin.
However, all of them were shelved for various reasons, and it was not until the end of the 20th century that substantial progress was made with the efforts of hundreds of experts and leaders, and the project was finalized.
As one of the largest water conservancy projects in the mainland and even in the world, the role of the Three Gorges Dam should not be underestimated, and it can effectively cope with previous flood disasters.
However, in addition to the high investment required for this project, there is also the problem of resettlement of residents.
According to the plan at the time, if the Three Gorges Dam were to be built, hundreds of cities could be submerged, and more than 1 million people would be displaced, which was absolutely unprecedented.
Although the cost is as high as tens of billions, the people's feelings for their hometown are the top priority, and the responsible departments spend all their efforts to do everyone's ideological work.
In fact, these problems were not limited to the construction of the Daxia Dam, but fortunately, we overcame them one by one, and it took more than ten years to finally complete it.
02
Have you ever wondered when the Three Gorges Dam was released? Some people speculate that the Three Gorges Dam released water during drought times, but is this actually the case?
Often, large reservoirs such as the Three Gorges play a crucial role in flood control and drought control, storing flood water when the rainy season comes, releasing water when crops need to be irrigated.
However, the Three Gorges Dam operates in a somewhat unusual way, with the amount of water released from the dam actually relatively low between April and May, mainly to reserve storage capacity for the peak flooding season in July and August.
The Three Gorges Reservoir is a core task of flood control and water regulation, and the storage system monitors two critical water levels: 175 meters is the design maximum operating level to ensure the safety of the dam, and 145 meters is the flood control limit level, below which it is conducive to power production and waterway traffic.
In terms of environmental coordination, the Three Gorges Reservoir stores water during the dry season and strives to maintain a water level between 145 and 175 meters, which not only helps to improve the efficiency of shipping, but also optimizes the generation of electricity.
The main role of the Three Gorges Dam is to block, slow down the flow of water, weaken the flood peak, regulate the flood peak, and at the same time regulate the release of water, and prepare the free up storage capacity for the upcoming next round of flood peak.
The core function of the Three Gorges Reservoir is not to intercept all floodwaters, but to spread the flood flow into multiple batches to ease the flood load in the middle and lower reaches of the Yangtze River, thereby reducing the threat of flooding.
03
The reservoir's water level has climbed to 176 metres, which is equivalent to more than 50 storeys in the height of a typical residential floor, and the Three Gorges Project's staggering capacity is 39.3 billion cubic metres.
This feat of water storage is the result of careful consideration by the designers, covering multiple dimensions such as flood control, farmland irrigation, and various hydraulic needs.
Although the design limit has not yet been reached, the water level of the Three Gorges Project has reached a high of 173.35 meters in previous water transfer tests, and the accumulated water volume has reached a huge 6.8 billion cubic meters.
If we fill the spectacular Three Gorges Reservoir with water, will you wonder how long it will take to drain it?
The magnificent Three Gorges Dam not only has the main building and diversion building, but also has a total extension of 3,335 meters, of which the main dam body spans 2,335 meters across the river surface, and the highest point is as high as 181 meters.
There are a total of 54 sluice gates in the magnificent reservoir of the Three Gorges, which are distributed over the barrage section of the dam and flood discharge facilities.
The 483-metre length of the flood section is covered with 22 surface holes 8 m wide and 23 deep water holes 9 m wide, while 9 auxiliary outlets are arranged in the barrage section.
Under an ideal scenario, if there is no water coming from upstream and all 54 gates are at full capacity, the release of water from the Three Gorges Reservoir could bottom out in about five and a half days, based on a maximum discharge rate of 79,000 cubic meters per second.
However, in reality, as the water level of the reservoir decreases, the efficiency of flood discharge also decreases, so it is estimated that it may take up to 9 days to drain the water if the water level continues to drop.
But let's not forget that there is still water coming upstream, and it can take 20 to 25 days to discharge all the water from the Three Gorges Reservoir after the flood peak has passed, as the flood inflows and the continuous acceleration of the flood season.
If the flood in the upper reaches of the flood season continues, coupled with days of rain and abnormal weather, the flood discharge time can only be further extended.
04
In fact, it seems like a fantasy to think about how long it will take for the Three Gorges Dam to run out of water, because the chance of such a thing happening is close to zero.
First and foremost, this approach is meaningless.
It would be catastrophic if the Three Gorges Reservoir did discharge all the accumulated water all at once.
All the water will rush to the lower ground, and even the Gezhouba under it will not be able to stop such a huge current, and the downstream flood control will face tremendous pressure, so will it become a self-digging grave?
If the Three Gorges Reservoir really releases all the water, how can the power generation function of the Three Gorges Hydropower Station be guaranteed?
Therefore, the dewatering time based on data is only theoretical, not feasible in reality, and it is enough for us to reverie in private.
Such doubts beg the question of whether the collapse of the Three Gorges Dam would have been catastrophic if it were to be attacked by a foreign country.
You can rest assured that the Three Gorges Dam is located deep in China's interior, and its geographical location is so unlikely that a foreign military strike would have to travel more than 1,000 kilometers to reach it through thousands of mountains and rivers.
From a legal point of view, international law clearly stipulates that any vandalism of dams is strictly prohibited, since such acts are always the ultimate victims, and such inhumane acts have been universally condemned.
And the most important thing is that the mainland has long considered this problem, so there is no need to worry about the 24-hour guard at the Three Gorges Dam.
Although the Three Gorges Dam will not be fully opened to release water, it is a miracle that it proves its importance and role.
Reference Sources:
China Three Gorges Corporation - Decoding the Three Gorges Project|Ten Years of Witnessing "175 Meters"
China Economic Weekly - How much pressure will the Three Gorges Dam put on the flood peaks in the Yangtze River basin?
Xinhuanet - How do these water conservancy projects divert and store floodwaters?
China Fire Protection - The Dazzling "Flame Blue" on the Three Gorges Dam
CCTV News - Shocking! The Three Gorges Dam opened 10 holes for flood discharge, which plays a key role