TA SANG DAM PROJECT IN SOUTHERN SHAN STATE
prepared by SOUTHEAST ASIA RIVERS NETWORK
April, 1999
Size and Type of Dam
The Ta Sang dam project is currently in the pre-feasibility study stage. According to preliminary studies, the dam will be built on the Salween River in the southern part of Shan State in Burma, near to Ta Sang, which lies 370 km east of Taunggyi, and about 130 km from the BP-1 Thai-Burma border crossing.
This project will be located somewhere between 12 km north of the Ta Sang ferry crossing and 5 km south of the ferry crossing. This area is mountainous and the river is narrow, passing through steep sided gorges. The river bed consists of layers of sandstone and siltstone, suitable for
construction of either a concrete faced rock-fill dam (CRF dam), a roller compacted concrete dam (RCC dam), a gravity dam, or an arch-gravity dam. The type of dam built will depend on the land on either side of the site. The electric power generator will be at the base of the dam.
The latest results of the survey show that the full supply level (FSL) will be between 320-370 metres above sea-level. At each site there can be an installed electricity production capacity of between 1,500-5,000 megawatts. The sites have been chosen because of their access to roads from BP-1 and the fact that they can send 500kV AC to join the Burmese grid and 500 kV DC
to Thailand.
This project will involve building another dam downriver to control the water that is released from the turbines 16 hours a day, 6 days a week.
One cost of the project may involve having to move the bridge at Ta Sang up to Kunhing on Highway 4.
From the survey, the two most interesting plans are to build an RCC and electric power generator at site 840, 6 kilometres north of Ta Sang, and at site 725, 2 kilometres south of Ta Sang. However, there is still not sufficient geological data to make a final decision.
One plan is to build a CFR at site 840, with an underground generator (this kind of dam is very common in Japan.) The site and type of dam will depend on the geological survey and drilling during the feasability study.
Level of water
The water level has been chosen at 350 meters above sea-level. The higher the level, the more possibility for attracting investment. However, the engineering survey, the social and environmental impact assessments and the amount of water will all be factors affecting the chosen level.
The size of the generators
The assessment shows that the lowest energy generation may be between 2,500 to 4,000 megawatts. A quarter of the electricity produced will be sent to Burma. The rest will be sent to Thailand.
If there are 6 turbines, each would produce 550 megawatts. (6x 550 = 3,300 megawatts.)
The cost and duration of the project
The CFR project at site 840 will cost 3,397 million US dollars, and take about 6 years. The RCC dam at site 840 will cost about 3,076 million US$ and at site 725 will cost 3,316 million US$, and will take about 5 years.
The details about the respective dams can be summarised as follows:
Project at Project at
site 840 site 840 Site 725
dam type
CFR dam RCC dam RCC dam
dam site
6 km north 6 km north 2 km
south of Ta Sang of Ta San of Ta Sang
catchment area 207,000 km2
average flow rate 2,583 cm3/sec
Full Supply Level 350 m above sea level
max. reservoir 660 km2
surface area
reservoir highest 36,100 km3
storage volume
highest live storage 14,200 km3
volume
max. height of dam 188 m 193 m 190 m
dam crest length 768 m 783 m 955 m
rate of water flow 430.5 cm3/sec
into turbines
head of turbines 142 m 145 m 147 m
installed capacity 3,327 3,399 3,434
including all 6
turbines (megawatts)
electricity produced 16,076 16,136 16,307
per year at upper dam
(gigawatts/hr)
electricity produced 6,930 7,923 8,001
per year at lower dam
(gigawatts/hr)
total electricity 23,005 24,059 24,308
produced
per year (gw/hr)
cost (million US$) 3,397 3,075 3,316
length of time to 6 yrs 5 yrs 5 yrs
build
Note: The Electricity Generating Authority of Thailand has been contacting
academics in Thailand to conduct an EIA for the project.
More information about dams and water diversion projects in Salween River Basin please contact:
Southeast Asia Rivers Network(SEARIN-Thailand)
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