Wenyu River Park, with more than 100 gates, spans Chaoyang, Shunyi and Changping. It is not only the largest "green lung" in Beijing's urban area, but also a flood detention area capable of storing six times the water volume of Kunming Lake in the Summer Palace. Recently, the Wenyu South Weir project was completed, which means that the "last piece of the puzzle" of the flood control system of Wenyu River Park is in place, and the key flood control defense line for Beijing's central urban area and the city sub-center has been further consolidated.

Wenyu South Weir also serves ecological conservation and other functions

On the map, the Wenyu South Weir project is located in the southeast direction of Wenyu River Park, and to its north is the already completed Wenyu North Weir. On July 8, a reporter saw at Wenyu South Weir that workers were carrying out the final finishing work. Compared with other weirs in the Wenyu River flood control system, Wenyu South Weir is not large in scale, but its position is very important.

Li Wenyu, head of the office of the Beijing Wenyu River Park Coordination Group, introduced that the Wenyu South Weir project adopts an integrated sluice-weir design. During the non-flood season, the gate is lowered, and the gate base acts as a diversion weir to achieve ecological water replenishment from the river channel to the park. During the flood season, the gate is closed, and the diversion can be remotely controlled by a hydraulic hoist. In the event of a major flood, the Xinbao Sluice downstream controls the discharge of the Wenyu River, and Wenyu South Weir begins to divert water, with floodwater overtopping the weir crest to achieve precise flood diversion.

The Wenyu South Weir project started on April 10 this year. In order to put it into use during this year's flood season, construction workers drove 832 pile foundations in 13 days. Li Wenyu introduced that after the debugging of the Wenyu South Weir gate is completed, the project will be officially completed. After completion, Wenyu South Weir will "catch" the floodwater of Wenyu River Park and store part of the water in the area south of the Qing River.

From the perspective of the overall flood control system of Wenyu River Park, Wenyu South Weir is the "last piece of the puzzle" of this system. After its completion, the flood control system of Wenyu River Park will be fully completed.

In addition, Wenyu South Weir also serves functions such as ecological conservation, and can effectively connect the water system network and eliminate dead-end roads along the river. In the future, citizens in Beijing Wenyu River Park can walk or cycle along the Qing River directly to the banks of the Wenyu River.

Can store and detain 12 million cubic meters of floodwater, equivalent to 6 Kunming Lakes

Wenyu River Park is located at the junction of Chaoyang, Shunyi and Changping districts. Looking back at its past, this place was once a no-man's land where dirty villages and low-end industries gathered. The Beijing Municipal Water Authority coordinated relevant departments to achieve opening to the public through three years of planning and five years of construction.

After completion and opening, Wenyu River Park is not only a micro-vacation destination for citizens' entertainment and leisure, but also effectively connects the flood control layout of Beijing's central urban area and the city sub-center. Specifically, the flood control layout of the central urban area is "storage in the west, discharge in the east, and flood diversion in the north and south." The Qing River is the northern flood diversion channel, and Wenyu River Park is located at the junction of the two rivers where the Qing River enters Wenyu River Park. The Qing River basin covers 165 square kilometers, and the collected water flows into Wenyu River Park to achieve storage and peak shaving. The city sub-center is located in the lower reaches of the North Canal basin. In order to ensure the flood control safety of the city sub-center, a flood control engineering system of "storage in the upper reaches, dredging in the middle, discharge in the lower reaches, and effective flood detention" has been built in its upper reaches. This is the "Tongzhou Weir." Wenyu River Park is precisely the "upper storage" in this flood control engineering system.

Wenyu River Park has super flood storage capacity. According to the comprehensive basin plan, Wenyu River Park can store and detain 12 million cubic meters of floodwater. If calculated based on the 2 million cubic meters of water demand of Kunming Lake in the Summer Palace, Wenyu River Park is equivalent to being able to store and detain 6 Kunming Lakes.

Floods of different levels "take" different flood conveyance channels

Although Wenyu River Park has super flood storage and detention capacity, the park still has a complete flood control layout, namely "one area, three rivers and six sluices and weirs," with the purpose of effective and precise regulation by zone and retaining the functions of citizens' ecological recreation and experience areas.

"One area" refers to the core flood storage and inundation area of the park, where the maximum water storage area is 570 hectares, but it accounts for only one fifth of the park's total area. Among it, 390 hectares are north of the Qing River and 180 hectares are south of it. Only 100 hectares of land on the north side of the entire area were targeted for dredging, and the rest all use the original terrain, minimizing earthwork construction, which is both ecological and efficient.

"Three rivers" refer to the three municipal rivers running through the park - the Qing River, the Wenyu River and the Qingyu Bay - with a total length of 20 kilometers. The three rivers complement each other and undertake key flood conveyance and channel storage functions, serving as the main water conveyance framework of the entire flood control system.

The key to the operation of the flood detention area is the combination of six sluices and weirs, namely the Shenjia Sluice on the Qing River, the Lutuan Sluice and Xinbao Sluice on the Wenyu River, the Qing River Weir at Qingyu Bay, and the Wenyu North Weir and Wenyu South Weir on the Wenyu River.

Li Wenyu introduced that different flood conveyance channels are activated according to different levels of floods. When encountering a flood of 1.25 million cubic meters, the Qing River from the Shenjia Sluice to the confluence and the Wenyu River channel from the Lutuan Sluice to the Xinbao Sluice are used for flood channel storage; when encountering a flood of 3.25 million cubic meters, water flows through Qingyu Bay and the Qing River Weir, activating the core flood detention area of more than 100 hectares; when encountering a flood of 6.25 million cubic meters, the storage and detention capacity of the northern flood detention area will be increased; when encountering a flood of 12 million cubic meters, the Wenyu North Weir and South Weir will be launched simultaneously, and the north side of Qingyu Bay and the south side of the Qing River will absorb floodwater to the maximum extent.

After the flood peak passes, the park's drainage gates are opened to return the accumulated water in the flood detention area in an orderly manner to the Qing River and Wenyu River, and finally discharge it smoothly through the Xinbao Sluice, with closed-loop regulation throughout the whole process, orderly and controllable.

Source: Beijing News website