Jiangnan is good, and the scenery is old. In the cold spring, the Wangjia River in Yueyang City, Hunan Province was shrouded in a layer of mist, and the cold wind still could not stop the footsteps of tourists. 73-year-old Mr. Xie, who lives in the Changlian community not far away, comes to the river for a few laps almost every day. "The environment here is good. I like to come here, but it used to be a black and stinky river. The change is really big."

Not only Wangjia River, because of the problems of direct sewage discharge, weak pipe network infrastructure, and insufficient treatment efficiency of sewage treatment plants and stations, black and odorous water bodies appeared in Yueyang Dongfeng Lake and Nanhu Lake, and the surrounding living environment was affected. The rivers and lakes are connected, and the Yangtze River Ecology is also threatened.

To protect a river and clear water, change is imperative. For more than three years, the Three Gorges Group has fully participated in the work of protecting the Yangtze River in Yueyang, and has closely cooperated with Yueyang City to jointly explore the urban sewage treatment method.

Open up the "last mile" of urban pollution control

On Baishiling Road in Luojiapo District, workers are carrying out the renovation project of rainwater and sewage diversion of the municipal pipe network. Rainwater and sewage diversion, as the name suggests, is to separate rainwater and sewage, and use a pipeline for transport. In addition, the collection, utilization and centralized management and discharge of rainwater can reduce the impact of rainwater on the treatment efficiency of sewage treatment plants, increase the concentration of sewage influent, and ensure the treatment efficiency of sewage treatment plants.

"The rivers and lakes are sick, and the black and odorous water is the symptom. First of all, we must intercept sewage to prevent further pollution caused by direct sewage discharge. The diversion of rain and sewage is the key. The key lies in the pipeline network. Go where you should go." The on-site staff introduced.

In the past three years, the Three Gorges Group has built a sewage interception pipe network of about 9 kilometers in Yueyang, a new municipal sewage pipe network of about 176 kilometers, and a rainwater pipe network of about 88 kilometers. The total number of kilometers is equivalent to the distance between Yueyang and Changsha. The municipal rainwater and sewage pipeline network has built a major artery for sewage circulation, but it is not enough for the builders of the Yangtze River protection.

Under the spacious and tidy roads of Yinshan Community in the Dongfeng Lake Basin, the rain and sewage pipe network has been redesigned. "We are very supportive of the rain and sewage pipeline renovation project, because it is a major event that benefits the country and the people." Mr. Liu, a resident of the community, praised. Auntie Wang, who lives in the Xiawang Group residential area in the main city of Yueyang, is even more impressed. Due to the poor supporting pipeline network in the old community in the early days, the community used to have serious "waterlogging", and now there is no water accumulation on the road due to heavy rain. This is due to the diversion of rain and sewage and the transformation of sponge cities - complete rain and sewage pipe network to solve the overflow of sewage in rainy days, reduce the pollution of the first rain, reduce the amount of pollution entering the rivers and lakes, and open up the "one kilometer" of the source of sewage collection. Up to now, the central urban area of Yueyang has completed the renovation of rainwater and sewage in 87 districts, and 30% of the project design and planning has been completed.

Coordinate onshore and offshore integrated governance

In the Luowang Road area on the west bank of the Wangjia River, an underground CSO storage tank is under construction, echoing the Wangjia River Living Water Park.

"The pipeline network in this area is mainly constructed by the confluence system, and it is difficult to realize the diversion of all rain and sewage in the near future. In order to better control the overflow pollution of the confluence system, the confluent sewage is directly transported to the sewage treatment plant for treatment on sunny days or when the rainfall is small. If the confluent sewage exceeds the processing capacity of the pipeline network or sewage treatment plant, it will enter the storage tank for temporary storage, and then send it to the sewage treatment plant, which is also the way to intercept sewage at the end.” The person in charge of the Wangjiahe area site introduced. At present, the Three Gorges Group has built a total of 5 storage tanks in Yueyang, with a total storage capacity of 75,500 cubic meters, effectively preventing sewage from being discharged directly into the lake.

On the banks of the river and lake, a domestic sewage circulation network is being rolled out. The sewage flows from the residential area to the sewage pipe network of the city's main road, to the adjustment storage tank or to the sewage treatment plant.

It must be managed on the shore, and it must be treated in the water.

In the Wangjia River, the silt at the bottom of the river is pounded and loosened by a cutter suction boat, pumped out of the water surface by a mud pump, and finally pressed into a mud cake by a plate and frame filter press to achieve effective internal source control.

In Dongfeng Lake, through the construction of ecological revetments and artificial wetlands, the pavement along the lake is paved with permeable materials, and the coast is sponged, and aquatic plants and aquatic animals are placed in the lake to form a balanced food chain and ecological network, forming a complete energy flow, material flow and information flow conversion, in order to achieve the fundamental purpose of ecological restoration.

Plants, networks, rivers, and lakes are integrated. Three Gorges Group has always adhered to the concept of "basin overall planning, regional coordination, systematic governance, and both symptoms and root causes", and adopted "source control and pollution interception, endogenous governance, ecological restoration, living water circulation, long-term governance and long-term cleanup" system governance. means to coordinate on-shore and off-shore integrated management. Now, from black and odorous water bodies to clear water and green shores, Yueyang City has been awarded the "National Demonstration City for Black and odorous water body management". "Until spring and Jingming, the waves are not disturbed, the sky is bright, and the sky is full of blue." Tourists strolling on the shore, fish flying to the shallow bottom, is the actual effect of jointly grasping the protection of the Yangtze River.

Plug in "wisdom wings" for flood control

In the family hospital of Yueyang No. 2 Hospital, the underground pipe network renovation project is still going on. The construction worker, Li Jiang, picked up his mobile phone to take pictures and scan the pipe network. This is part of his daily work.

On the inside of the neatly stacked pipe network, each QR code becomes the identity card of the pipe network, and the words "special for the protection of the Yangtze River" are striking. "We have our own digital management platform for the pipe network. We will fill in the report in the background every time we perform a step, so that we can control the progress. After the pipe network is laid, we will use the CCTV small robot to detect the situation of the pipe network in the pipeline. Quality control." Li Jiang said.

With the rapid development of science and technology, informatization, digitization and intelligence will add power to the conservation work of the Yangtze River, and this is also the meaning of the sustainable, systematic and high-quality development of the conservation work.

On July 8, 2021, the Yueyang Municipal People's Government and the Three Gorges Corporation signed the "Urban Smart Water Steward Cooperation Framework Agreement", and Yueyang became the first pilot and demonstration city of the "Urban Smart Water Steward" in the Yangtze River Economic Belt, taking the lead in entering a new stage of water control.

The term "water steward" originated in Europe and originally referred to the supply of drinking water to residents. For example, the French Suez Group, one of the world's largest water companies, is known as "the water steward of 30 countries". On this basis, Three Gorges Group further expands the connotation of "water steward", not limited to water supply, but also raw water transportation from water source to water plant, tap water supply from water plant to water end, and sewage collection and treatment from water end to sewage treatment plant. As well as the treatment of tail water discharge after reaching the standard, ecological management of rivers and lakes, urban flood control and drainage, etc., are unified into the whole process and full cycle management and control.

To be a good "water steward", you must first have a smart "brain". The premise of system "management" is to "know" in an all-round way, and to fully understand the characteristics of the water system, the characteristics of the watershed, the geographical characteristics of the city, the laying of the pipe network, the water supply and drainage Dynamic and so on.

On July 20, 2021, the platform of the first phase of urban smart water steward "appeared" in Yueyang Dongfeng Lake, attracting countless "eyes". On the big blue screen, taking the Dongfeng Lake area as a pilot, you can see the water assets, the status of the pipeline network, real-time monitoring, dispatching, etc., which can realize the closed-loop management of "comprehensive perception-scientific evaluation-smart early warning-dispatching decision-making" in the region .

The protection of the Yangtze River is not negotiated! Ways are always more difficult than difficult! "Professional things have to be done by professional people," said Luo Yueli, a second-level inspector of the Standing Committee of the Yueyang Municipal People's Congress. The Three Gorges Group, which originated and developed and grew stronger than the Yangtze River, exerts the advantages of "knowledge" water in water control, and then moves towards "smart" water. In 2022, the Three Gorges Group will build a "full-element, full-cycle, integrated, The one-stop 'smart city water steward platform' provides scientific and technological support for building full custody services for the urban water industry as a "water steward". Editor/Sang Xiaomei