The Nam Ngum Dam
Spillway piers with runners for future radial gates
by Tod Kennedy
THE MEKONG river zigzags through Thailand, Laos, Cambodia and South Vietnam. These four riparian countries have formed the Mekong Committee to jointly develop the vast river basin under the auspices of the United Na tions. One of the priority projects of the Committee is to build a hydroelec- tric station on Nam Ngum, a major tributary of the Mekong in upper Laos. The site of this project is located at about 70 km north of Vientiane, the capital.
Preliminary feasibility studies were completed in 1964, and in 1966 the Nam Ngum Development Fund was established to secure sufficient capital for the construction of the initial stage of the project. In addition to Laos, other countries including Australia, Canada, Denmark, France, Japan, Hol- land, New Zealand, Thailand and the U.S. have contributed the necessary US$30 million to the fund.
The authority responsible for the construction work is the Laotian Na- tional Mekong Committee. Acres In- ternational are managing engineers for the project while Nippon Koei, who handled the initial feasibility studies, have been retained as consulting en- gineers.
The Nam Ngum power station plans to have an installed capacity of 135 MW eventually. As the electrical load in Laos at present has a peak demand of only about 9 MW, all sur- plus electricity will be bought by Thai- land in the immediate future. Initially, therefore, the station will only have two generating units of 15 MW each, with provision for the installation of three more units of 35 MW each.
Dam
The dam is of the concrete gravity type and is about 70 metres in height with a crest length of 470 metres. The water intakes are formed in the upper section of the dam and are connected to the penstocks which run down the back slope of the dam to the power- house. Fixed wheel submersible gates are provided in the intake section of
Far East BUILDER, August 1971
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