Xiaolangdi Dam

BW

The Xiaolangdi Dam is a large dam on the Yellow River ( Huang He) in China. It is in the area of Mengjin and Jiyuan, 40 km north of Luoyang in Henan Province. The dam serves multiple purposes. A hydroelectric power plant generates 1800 MW. The dam is also used for irrigation, water supply, flood protection and control of sediments.

Dam

The dam is located about 130 km below the Sanmenxia Dam and 128 km above the Huayuankou Dam. It consists of riprap and has been built earthquake-proof. The overflow has a means to prevent displacement of the overflows with ice floes. Construction began in 1994 and was created on 11 years of continuous. In January 2004 the first power plant turbine was put into operation. The total construction cost is estimated at 4.2 billion U.S. dollars. The dam is 154 m high and 1370 m (possibly 1317 or 1667 m ) long.

Irrigation

Two million hectares are irrigated by the dam. In order to remove water and to derive, there are nine large studs. The Yellow River loses through the irrigation of large areas much water, so that it sometimes dries up during dry periods. In recent decades, he had several times so little water that he at times did not reach the sea, as happened in 1972 and 1997.

Flood protection

The country is often of high water, but also drought and famine been hit. The dam is a 10,000 -year flood withstand and mitigate it, for example, the case should discharge of 45,000 m³ / s to 27,500 m³ / s are reduced. Below the dam large formerly flood-prone area for agriculture are available. With the construction of the dam is the probability that the two major flood polder Dong Ping Hu and Beijindi must be flooded lower. For Dong Ping Hu, the probability is now once in 100 years, for Beijindi once in 1000 years. With this project, 103 million people in northern China, several large cities and industry will be protected against flooding.

Sediments

The mud of the Yellow River is deposited in the lower reaches and causes a steady increase in the riverbed, so the dikes must always be higher. Every year they have to be increased by 10 cm, which is a huge cost and also can not go on permanently, because the dikes are uncertain. The dam is intended for 20 years can absorb sediments.

Resettlements

The project was partially funded by the World Bank. The environmental impacts have been studied, among other things, the conditions of the World Bank to fulfill. For the protection of historical sites and the public health and welfare plans have been drawn up. Approximately 181,000 people had to be resettled, mostly rural population. You get compensation and new residential areas with at least as good houses and earning potential as before.

Alternatives

The following alternatives to the construction of the dam have been considered:

• An increase in the dikes of a 1000 -year flood would have been very costly, and the deposition of sediments would not have prevented the lower reaches.
• Measures to prevent the erosion of Lössbodens in the catchment area would be better in the long term, but would not improve the flood protection. Irrigation and power generation would not have been possible.
• An additional spillway channel next to the river would have caused great cost, interrupted communications and transport connections and irrigation, and 700000-930000 people would have to be resettled.
• For an extension or construction of the existing channels should have been 500,000 people resettled.