Xiaolangdi Dam

The Xiaolangdi hydroelectric power station on the Yellow River, located 180 kilometres from Zhengzhou, 40 kilometres from Luoyang, and 600 kilometres from Beijing, marks the achievement of a longstanding aspiration, namely, to “tame” the Yellow River, the cradle and scourge of Chinese civilisation. The structure consists of a sloping earth-core rockfill dam 154 metres high and 1,317 metres long at the crest, a water intake 112 metres high and 278 metres wide, and an underground power plant 252 metres long, 26 metres wide, and 61 metres high. From 1994 to 1999, Dumez-GTM took part in building this power plant as the lead contractor in the joint venture in charge of the project. The primary objective was to control sedimentation in the Yellow River to mitigate its destructive flooding. One of the defining characteristics of this structure, however, is that it meets a multiplicity of objectives, including power-generation and improved use of water for agriculture in the region.

BACKGROUND

The Yellow River is both one of the cradles of Chinese civilisation and the source of very destructive flooding. In the past 3,000 years, the river has broken through embankments built to contain its flow and changed its course no fewer than 26 times. Consequently, it comes as no surprise that, in 1952, Chinese authorities sought to reinforce the safety of riverside residents. The idea of building a dam emerged in the 1980s. On April 9, 1991, the project was approved in the fourth session of the People’s National Congress, joining the list of major construction projects in the eighth five-year plan. The entire project was completed in January 2001, 13 months ahead of schedule. Construction on our lot lasted nearly 64 months from August 1994 to December 1999 and was completed 7 months ahead of the contract deadline of July 2000.

TECHNICAL OVERVIEW

In accordance with the importance placed on the need to protect against floodwaters and to optimize the use of water, the country’s minister for water resources was given responsibility for the project.
Our lot included construction of all underground structures associated with power-generation: the power plant (252 m long, 26 m wide, 61 m high) containing six 300-megawatt turbines with 26.5-metre spacing. Our lot also included construction of the underground transformer chamber (175 m long, 15.2 m wide, 17.8 m high), 6 power tunnels (6.5 m in diameter, 1,700 m long), access tunnels (2,000 m long, with cross-sections from 10 to 90 m²), drainage tunnels (2,800 m long, with cross-sections from 7 to 13 m²), tail-race channels (3 of them, each 900 m long, 12.6 m wide, and 19.6 m high as well as 3 open channels, each 200 m long, with return and protection structures) along with consolidation grouting and construction of permanent roadways.

The main purpose of the Xiaolangdi project is to control flooding during the rainy season and prevent ice from forming in winter, which may damage embankments. The dam is also designed to reduce sedimentation in the lower section of the Yellow River, provide water for irrigation as well as industrial and residential use, and produce hydroelectric power.

IMPACT

The dam causes sedimentation in upstream reservoirs, thereby enabling control over the level of the river bed downstream. The structure impedes the blocks of ice that damage embankments and regulates rising waters that cause seasonal flooding. Flooding downstream has dropped from a major flood once every 60 years to once every 1,000 years. The course of the Yellow River is expected to remain unchanged for 20 years. The hydroelectric power station meets part of the demand for energy in Henan province. In addition, the dam’s capacity helps to enhance the use of irrigation in the region, thereby increasing the land available for agriculture.
As in the case of any dam of this size, construction required the relocation of over 180,000 persons living upstream from the site. The resettlement scheme was the most detailed of its kind ever implemented in China, providing a model for future projects. Overall, the standard of living has risen since this resettlement. The Xiaolangdi hydroelectric power station is both a landmark project with respect to population relocation and the first construction project of this type in China to take account of environmental impacts.

 

Project participants

Client
Ministry of Water Resources of China

Project management
Canadian International Project Managers

Key figures

Implementation dates
August 1994 to December 1999

Excavation
1,380 million m3

Concrete
267,000 m3