Stop 10 West Lake waters. This reservoir reduces the once-in-a-century flood to once in 50 years.

China Net News July 16 th "Coming! 8250！ 8400！ 8460！ ….. "At 4 o’clock in the morning of July 11th, in the central control room of Wudu Reservoir Management Center, Xu Hui, director of the dispatching department, stared at the monitoring screen-the maximum flood peak brought by the heavy rainfall in the whole basin was about to be put into storage.

The flood was fierce. With the sudden increase of the inflow, Xu Hui unconsciously put his hand on the chair of his colleague. It was not until the peak value of the flood peak displayed by the water regime monitoring system began to slowly drop from 8490 m/s that Xu Huicai released his hand and called his colleagues to report to the provincial flood control office immediately and inform the downstream relevant departments of the flood situation.

8490m3/s！ This peak value is unprecedented in the measured data of Wudu reservoir dam site area, and far exceeds the measured maximum peak flow of 6230 m/s on September 2, 1978. These two sets of data surfaced in my mind, and Xu Hui had some feelings: Without Wudu Reservoir, the disasters suffered by Jiangyou, Mianyang, Santai and other cities downstream would be unimaginable.

Wudu Water Diversion Project is a large-scale backbone water conservancy project of the West-to-East Water Diversion Project in Sichuan Province, which is known as the "Second Dujiangyan". Wudu Reservoir, as its water source project, is the first controlled backbone reservoir in the upper reaches of Fujiang River, which has assumed the important functions of flood control and irrigation. Facing the severe test of the biggest flood since 1949, the Wuyin Project handed over a beautiful answer sheet-as of 6: 00 pm on July 11th, Wudu Reservoir had intercepted a total of 150 million m of floods, equivalent to intercepting the water of 10 West Lakes; The maximum interception per second is 4900 m, which is equivalent to stopping the water volume of two Olympic standard swimming pools every second.

Scientific flood regulation reduces the once-in-a-century flood to once-in-50 years

Since July 9, there have been continuous rainstorms in Mianyang City, and on July 11, major rivers such as Fujiang River have been flooded-at 8 am, the water level of Nanba Water Station of Fujiang River exceeded the warning level by 1.43 meters; At 10 o’clock in the morning, the flood peak discharge of Fujiang Bridge in Mianyang City reached 12,200 m/s, the warning water level was 1.75 m, and the guaranteed water level was 0.55 m … This was the biggest flood in Mianyang since 1949, and Wudu Reservoir played an important regulating role in intercepting this fierce flood.

"If Wudu Reservoir hadn’t cut its peak by 4,900 m/s, the flood peak flow of Minjiang Bridge in Mianyang City would have reached 17,100 m/s, exceeding the once-in-a-century flood standard." Yang Xiangqian, deputy director of Wudu Reservoir Management Center, said. The design function of Wudu Reservoir is to raise the flood control standard of Mianyang downstream from once every 50 years to once every 100 years.

It is understood that there are many rivers in Mianyang’s jurisdiction. There are only three rivers flowing through Mianyang’s urban area, namely Fujiang, Anchangjiang and Furong Creek. Among them, Furong Creek of Anchangjiang is a natural river without flood control capacity. In the upper reaches of Mianyang City, there are two main rivers, namely Pingtong River and Tongkou River, which will also transit Mianyang City after Jiangyou, Qinglian and Fujiang meet. Pingtong River and Tongkou River are also natural rivers and do not have flood regulation capacity. Before the completion of Wudu Reservoir in 2012, the Fujiang River Basin suffered heavy flood losses in 1921, 1930, 1936, 1945, 1954, 1978, 1981 and 1998. It was not until Wudu Reservoir was established that the Fujiang River Basin from Jiangyou City to Santai County had the function of flood regulation.

"If the Fujiang River Basin from Jiangyou to Santai is likened to a pool, then Anchang River, Furong River, Pingtong River and Tongkou River, as their tributaries, are like four water pipes without valves, and the amount of water in the pool is regulated by Wudu Reservoir, the only valve." Yang Xiangqian said that it depends on science to adjust this unique "valve" and reduce the once-in-a-century flood to once in 50 years.

In this flood regulation, Wudu Reservoir Management Center roughly predicted that the flood peak flow of more than 8,000 m/s will be put into the reservoir on July 11th, and immediately strengthened the monitoring of relevant water and rain conditions and data collection. According to the requirement of "always putting people’s lives and property safety first", the flood control benefit of the reservoir was fully exerted-at 9: 00 on July 10th, the flood flow entering Wudu Reservoir reached 3,340 m/. At 4 o’clock on July 11th, Wudu Reservoir ushered in the maximum flood peak of 8,490 m/s of this heavy rainfall. In order to ensure the safety of the downstream urban and rural residents, the management center adjusted the flood according to the dispatching instruction of the Provincial Flood Control Office to discharge 3,500 m/s and eliminate the peak of 4,990 m/s. As of 18 o’clock on July 11th, the inflow and outflow were 3,120 m/s and 3,400 m/s respectively.

Allocate the reservoir in advance to leave enough storage capacity for 150 million cubic meters of flood.

It takes about 10 West Lakes to hold a flood of 150 million m, which is a big challenge for Wudu Reservoir with a flood control capacity of 86 million m and a flood interception capacity of 154 million m..

After it is predicted that there will be a large amount of flood, in order to reserve enough flood storage capacity, Wudu Reservoir increased its discharge at 2500 m/s as early as 14: 00 on July 10, and gradually increased its discharge to 3500 m/s after 20: 00 on the same day. By 3: 00 on July 11th, before the flood peak of this round arrived rapidly, the management center controlled the water level of the reservoir at an elevation of 645.33m, ensuring sufficient storage capacity.

"Everyone should be impressed by the mathematical application problems of water injection and water discharge. A water tank that was originally filled with a lot of water will easily overflow if the water injection amount is greater than the water discharge amount; Our discharge must be carried out according to the dispatching instruction, which is equivalent to a relatively limited value of’ water discharge’. However, the’ water injection quantity’ of flood is uncontrollable, and once the’ water injection quantity’ exceeds the allowable range of’ water discharge quantity’, it is very dangerous. Therefore, in order to reduce the risk of uncontrollable water injection, we must lower the water level in the water tank in advance, so as to ensure safety. This time we can successfully complete the flood interception task, and it is very important to vacate the warehouse in advance. " Yang said forward.

On July 12th, according to the provincial and municipal orders, Wudu Reservoir began to lower its water level. By 8: 00 am on the 13th, the water level of the reservoir had dropped to 640 meters, freeing up 150 million cubic meters of flood control capacity, making full preparations for the next flood. "In the next step, we will conscientiously implement the requirements of the provincial and municipal dispatching meeting on July 11 and today’s meeting, and continue to strictly inspect and maintain the reservoir dam facilities and equipment to ensure that the equipment is in good working condition; Strictly on duty to ensure smooth communication information; Strictly implement the dispatch order, ensure the scientific and orderly dispatch, resolutely win the battle against flood control, and make due contributions to Mianyang flood control and disaster reduction. " Yang said forward.

Supervision in place to ensure good operation conditions of reservoir facilities and equipment　

Whether every facility and equipment in the reservoir works well or not is a major event related to the flood control safety of the reservoir. Every year after the flood season, the Operation and Dispatching Section of Wudu Reservoir will organize departmental engineers and technicians to make routine inspections of 19 flood and rain forecasting stations in the reservoir area.

"A thousand miles of embankment collapsed in the ant nest. In order to ensure the safe operation of the reservoir, we have carried out every safety responsibility. Except routine inspection before and after the flood season, all computer equipment, network communication equipment, gate control system equipment, electrical equipment, water level detection equipment, etc. should be inspected once every half month, ranging from whether an intercom is charged or not to whether the gate can be opened and closed at any time. All kinds of equipment defects and faults should be found and eliminated in time to ensure that the equipment is in a timely manner. Xu Hui said.

According to reports, during the flood interception process, due to the early inspection and maintenance work in place, all the facilities and equipment of the reservoir have not had problems, ensuring the excellent completion of the flood interception task.