World records set by South-to-North Water Diversion Project

The South-to-North Water Diversion Project is a key strategic infrastructure project for China to alleviate severe water shortage in its northern provinces. With its eastern, central and western routes, the project links China's four main rivers — the Yellow River, the Huaihe River, the Haihe River, and the Yangtze River. The project has set multiple new world records, including its construction scale, water diversion distance, population benefited, population resettlement, and complexity of engineering. As the world's largest project of its kind ever undertaken, the South-to-North Water Diversion Project is bound to exert a far-reaching impact.

I. World's largest scale of construction

The South-to-North Water Diversion Project is the world's largest water diversion project, crossing the drainage basins of the Yangtze River, the Huaihe River, the Yellow River, and the Haihe River, involving more than 10 provinces. The ambitious project is consisted of countless hydraulic engineering sub-projects including reservoirs, lakes, canals, river ways, dams, pump stations, tunnels, aqueducts, buried culverts, inverted siphons, PCCP pipes, ditches, etc. Its complexity, scale, and difficulty are unprecedented at home and abroad. In total, 1.78 billion cubic meters of earth and stone was excavated, 620 million cubic meters was filled, and 65 million cubic meters of concrete was used, just in the first phase of the project's eastern and central routes.

II. World's largest water diversion volume

Once completed, the project will divert 44.8 billion cubic meters of water annually to the population centers in northern China. The water will be diverted through three routes: 14.8 billion cubic meters through the eastern route, 13.0 billion cubic meters through the central route, and 17.0 billion cubic meters through the western route. The first phase projects of the eastern and central routes are currently underway, and they will be able to divert 18.27 billion cubic meters of water after completion.

III. World's longest water diversion distance

The total planned length of the project's eastern, central and western routes is 4,350 kilometers. The ongoing first phase sub-projects of the eastern and central routes measure 2,899 kilometers in the mainlines and approximately 2,700 kilometers in auxiliary branch lines, reaching six provinces and one city.

A bird's eye view of the Taocha Canal Head Works Project on the central route.

IV. World's largest population benefited

The South-to-North Water Diversion Project targets water shortage in China's northern areas, particularly in the drainage basins of the Yellow River, the Huaihe River, and the Haihe River, which in 2002 had a total population of 438 million. In the first phase sub-projects of the eastern and central routes alone, 253 county-level or above cities gain direct water supply, benefiting 110 million people. Water supply through the project has brought about vast opportunities for those areas to restructure and grow their industries and economies. Meanwhile, the project supplements water to the lower reaches of the Yellow River, thus enabling the northwestern areas to improve water resource carrying capacity. After the elevation project of the Danjiangkou Dam, 3.3 billion cubic meters of storage capacity was added, which with the coordination of flood control projects can effectively prevent flooding and protect more than 700,000 people living in the middle and lower reaches of the Hanjiang River.

The central route stretches through downtown area of Jiaozuo city, Henan province.

V. World's largest scope of benefited areas

The South-to-North Water Diversion Project targets water shortage problems in China's northern areas, in particular the drainage basins of the Yellow River, the Huaihe River, and the Haihe River[]. The total area of diverted water supply is 1.45 million square kilometers, equal to 15 percent of China's land area. The first phase sub-projects of the eastern and central routes have created approximately 180,000 jobs annually. The completion of the project will highly improve the water resources and drive the socio-economic development, thus creating more jobs while producing benefits for agriculture, flood control, shipping, stagnant water drainage, and ecological protection. Adjusted for inflation, the project is estimated to generate an annual economic benefit worth 53.3 billion yuan.

The central route stretches through Zhengzhou city, Henan province.

VI. World's largest number of resettlement due to water projects – migrants of the Danjiangkou Dam in the central route

About 345,000 people were resettled due to the elevation project of the Danjiangkou Dam in the project's central route, and the resettlement was mainly completed in 2010-11. In 2011, 190,000 people were resettled, marking a world record in resettlement due to water projects. The two provinces involved, Henan and Hubei, set up migrant relocation headquarters to ensure improved housing, traffic, medical service, and education for resettled people.

Resettled people living in Xichuan county, Henan province.

VII. World's largest scale of pump station cluster – the Pump Station Cluster Project of the Eastern Route

The first phase of the project's eastern route's mainline totals 1,467 kilometers. Thirteen cascade pump stations, 22 pivots and 34 pump stations are established along the route, with the total hydraulic head of 65 meters. The stations are equipped with 160 hydroelectric generators, with the overall installed capacity of 366.2 kilowatts and the total design flow of 4,447.6 cubic meters per second. After completion, the highly concentrated pump station cluster will reach international advanced level in pump manufacturing, and in other aspects.

Shaji Pump Station in Suqian, Jiangsu province (eastern route of the project).

VIII. World's first case of large-tube water tunnels traversing under subway – the Buried Culvert Project in the 4th Ring Road of Beijing (central route)

The Buried Culvert Project in the 4th Ring Road of Beijing (central route) has two pressurized water tunnels with the inner diameter of four meters, which traverse under Beijing's Wukesong Subway Station. It was the world's first case of large-tube water tunnels traversing under a running subway. The nearest distance between the buried culvert and the subway is only 3.67 meters, while the largest settlement of the subway is merely three millimeters.

Completion of the tunnel lining of the Buried Culvert Project in the 4th Ring Road of Beijing.

IX. World's largest U-type aqueduct – the Tuanhe Aqueduct Project in the central route

The Tuanhe Aqueduct Project in the central route is a U-type aqueduct with three-dimension prestressing. The inner diameter of the aqueduct is nine meters, the single span 40 meters, and the maximum flow 420 cubic meters per second. All three parameters are unprecedented.

An overlook of the Tuanhe Aqueduct in the Central Route.

X. China's deepest water diversion shaft – shaft of the Yellow River Crossing Project of the central route

Located around 30 kilometers to the west of Zhengzhou, the Yellow River Crossing Project of the Central Route is designed to transfer water diverted from the Yangtze River through the central route, to cross the Yellow River. The large, cylinder structure shaft was built in the high permeable foundation of fine sand, on the bank of the Yellow River. With an inner diameter of 16.4 meters and a depth of 50.5 meters, the shaft has a design flow of 265 cubic meters per second and an increasing flow of 320 cubic meters per second. Double-layered, the shaft's outer layer is an underground diaphragm wall with the thickness of 1.5 meters and a depth of 76.6 meters, and its inner layer is made with concrete steel with the thickness of 0.8 meters. It is by far China's largest and deepest shaft, also with the most complicated geological conditions and most difficult engineering conditions.

An upward view of the shaft.

XI. China's largest water tunnel that goes through giant rivers – the Yellow River Crossing Tunnel of the central route

To adjust to the wandering and silt-foundation features of the Yellow River, the Yellow River Crossing Tunnel Project is consisted of two tunnels which are both 4,250 meters long and seven meters in inner diameter. Both tunnels have a two-layered structure, with the inner layer and the outer layer separated by a permeable barrier so that each layer can endure water pressure both in and out of the tunnel. This kind of structure is a first in the world. The Yellow River Crossing Tunnel Project has been completed, setting a new record for China's long-distance underwater tunnel construction in soft soil.

Inside the Yellow River Crossing Tunnel Project.

XII. China's largest scale dam elevation project – the Danjiangkou Dam Elevation Project

By pouring concrete on the body of the original dam, the Danjiangkou Dam Elevation Project elevates both the concrete dam and the core earth-rock dam. After elevation, the height of the dam increased from 162 meters to 176.6 meters, with the normal water level rising from 157 meters to 170 meters, adding 11.6 billion cubic meters of reservoir capacity. Specific structural technologies were applied during the elevation project to blend the original concrete with the newly poured. Without affecting the dam's normal operation, the project successfully elevated the dam along with fracture detection and repairing, making it one of the most complicated cases of the world's dam elevation projects.

The Danjiangkou Dam after elevation.

XIII. Cutting edge technologies applied in mechanized construction of large scale concrete canal

The South-to-North Water Diversion Project diverts water through long-distance routes that traverse land with complicated geological and topographical conditions. An array of devices with domestic intellectual property rights were developed to tackle various problems. Compared with devices of the same category developed overseas, the molding machine used in the South-to-North Water Diversion Project is two-thirds lighter, with 66 percent greater power and 80 percent less cost. A great many research results have been achieved in large channel slope stability and optimization technology, new structure type, mechanized lining comprehensive construction technology, mechanized lining series complete equipment, etc., filling China's blanks in design and manufacture, construction process and engineering technology of large scale channel mechanized molding equipment.

The construction site of channel mechanized lining at the Xichuan section of the central route.

XIV. Cutting edge technologies applied in PCCP pipe engineering at the Beijing section of the central route

Through the construction and quality control of ultra large diameter Prestressed Concrete Cylinder Pipe (PCCP), a full set of technical parameters concerning PCCP design and cathodic protection, which also comply with China's regulatory system and material standards, were established. A quality control standard was set up concerning the installation of ultra large diameter PCCP in ditches and tunnels. An array of pioneering technologies have been developed, including test probes for the cathodic protection of PCCP, materials and processes of mechanized spray of PCCP external anti-corrosive coating, installation of ultra large diameter PCCP in ditches using goliath crane, installation processes and technologies for PCCP in tunnels, etc.

Construction site of pipeline laying.