Floods in China: Can the Three Gorges Dam weather 'once-in-a-century massive floods in the Yangtze River'?
Close to 20 million people across 26 provinces and cities in the areas spanning China's southwestern region to the midstream and downstream areas of the Yangtze River have been displaced due to severe flooding over the past few weeks. The Three Gorges Dam has long been held up as a bulwark against such massive floods in the area, but recent signs that it is literally buckling under the pressure cast doubts on its ability to be an effective flood control mechanism.
This year, severe floods in China have displaced close to 20 million people across 26 provinces and cities. Amid tough challenges in flood control, Chinese State Flood Control and Drought Relief Headquarters raised the emergency response for flood control from level IV to level III, the third-highest in the four-tier system.
Heavy rain has been hitting the area spanning the east of China's southwestern region to the midstream and downstream areas of the Yangtze River since 4 July. Statistics from the China Meteorological Administration (CMA) showed that accumulated precipitation from 1 June to 6 July in Anhui province, Hubei province, Zhejiang province and Chongqing municipality was the highest compared with that of the same period since 1961, with some regions experiencing one to two times more precipitation year-on-year.
As of 2pm on 7 July, the midstream and downstream areas of the Jianli section of Yangtze River, Dongting Lake, and Poyang Lake had water levels that exceeded warning levels by 0.01 metres to 0.75 metres, while water levels of Lake Tai also exceeded warning level by 0.47 metres.
On 7 July, the National Meteorological Center of CMA issued the "orange warning of rainstorm", and predicted that heavy rain would continue to hit the area spanning the east of China's southwestern region to the midstream and downstream areas of the Yangtze River from 7 to 9 July. In addition, within the affected area, some regions of eastern Hubei, southern Anhui, northern Hunan, northern Jiangxi and western Zhejiang would experience heavy downpour, while some other regions of southeastern Hubei, northern Jiangxi and southern Anhui would experience torrential rain. These areas face increasing pressures in flood prevention and control.
Since the start of the flood season, the China Fire and Rescue team has participated in a total of 3672 flood relief cases of various kinds, rescued over 7000 trapped residents, and evacuated over 30,000 people affected by the floods.
Earlier on 2 July, Chinese State Flood Control and Drought Relief Headquarters had launched a level IV emergency response for flood control before raising it to level III on 7 July. After the two departments dispatched work teams to Hubei and Anhui, they sent nine more work teams to Sichuan, Chongqing, Hunan, Jiangxi, Jiangsu, Zhejiang, Henan, Guizhou, Heilongjiang, and Jilin respectively. These teams would be assisting in flood relief and rescue efforts, as well as giving guidance and supervision in areas such as monitoring weather conditions, strengthening defences through embankments and reservoirs, patrolling hazardous areas prone to torrential floods, managing emergency response to greater disasters, and evacuating people living in hazardous areas.
Since the start of the flood season, the China Fire and Rescue team has participated in a total of 3672 flood relief cases of various kinds, rescued over 7000 trapped residents, and evacuated over 30,000 people affected by the floods.
Last year, netizens released satellite photos apparently showing that the dam had warped, and pointed out that the dam was at risk of collapse.
The Three Gorges Dam controversy
Amid rising tension in the Yangtze River Basin flood situation, the Three Gorges Dam project, thought to be the Yangtze River's weapon against floods, is once again put under the spotlight. To make room for possible incoming floodwater, two of the dam's spillways were opened on 29 June for the first time this year, in a bid to increase its floodwater discharge volume.
However, external observers still have their doubts about the project. Last year, netizens released satellite photos apparently showing that the dam had warped, and pointed out that the dam was at risk of collapse. Recently, netizens again released images showing the distortion of the dam, and alleged that official media had confirmed that the dam has warped and that the Ministry of Water Resources was calling for proper flood prevention preparatory works.
...the Three Gorges Dam has been used a total of 53 times in flood prevention, indicating its effectiveness in flood control and disaster mitigation. - Xing Long, senior engineer of the China Three Gorges Corporation hub management centre
Deputy secretary-general of the China Society for Hydropower Engineering Zhang Boting said in a 21 June report by the Science and Technology Daily (《科技日报》) that the claim was purely malicious hype and that the rumours of the dam's distortion had already been clarified last year. He added that in any case, there was no correlation between warping and severe flooding and associating the two would only invite public misunderstanding and anxiety.
According to a China News Service report published on 1 July, senior engineer of the China Three Gorges Corporation hub management centre Xing Long said that since its completion in 2003 until 2019, the Three Gorges Dam has been used a total of 53 times in flood prevention, indicating its effectiveness in flood control and disaster mitigation.
Xing said that the Three Gorges Dam project is the backbone of the flood control system of the middle and lower reaches of the Yangtze River. Situated at the "throat" of the upper reaches of the Yangtze and the middle and lower reaches of the lowland plains, the dam is able to control 95% of the flood volume from the Jingjiang reach of the Yangtze River, as well as two-thirds of the flood volume from above Wuhan.
Since the completion of the dam, Xing said that it has played the role of reducing flood peaks and staggering them, and is an irreplaceable project in terms of regulating massive floods in the upper reaches of the Yangtze River.
The Three Gorges Dam is situated in Yichang city, Hubei province. It is the world's largest hydropower project with a crest height of 185 metres and crest length of 3,035 metres. It has a normal storage level of 175 metres, and a total capacity of 39.3 billion cubic meters. Officials claim that the dam was designed to weather once-in-a-century massive floods in the Yangtze River.