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SALWEEN WATCH HOTMAIL OUT
BACKGROUND DOCUMENTS RELATING TO THE SALWEEN MEGADAM Salween Watch 24th February 1999 Vol.1 --------------------------------------- RECENT DAM PLANS FOR THE MAIN FLOW OF THE SALWEEN RIVER
The 5 potential dam sites on the Salween that have been mentioned within the past 10 years, from closest to the Chinese border to where the river meets the sea the sites are as follows: 1. TA HSANG: The most recent of the dam plans concerns an area in the south central Shan State apparently some 40 kilometres north of the Ta Hsang river crossing. A study of the stretch of river lasting 3 weeks was completed in November by a group apparently including Thai company personnel, Burmese and Thai officials and 3 Japanese. It is possible that the survey is part of the study called for by the Asian Development Bank in 1994. Until the recent activities, since 1994 no known field study of the river has been done. It is not immediately obvious why the latest site to be studied is considered to be of interest unless it's altitude and its proximity to the Nam Kok River in the Shan State are the deciding factors. The Nam Kok, as mentioned in the previous paper is to be part of the Kok - Ing - Nan Water Diversion Project, aimed at filling the Sirikit Dam. The relatively high altitude may help reduce the height the Salween's water may have to be raised artificially for diversion. This could mean that although very high, the dam would not be quite high as it would be if made lower down on the river valley. However, the location is far from the border and there is still no obvious way to bring water from such a site to Thailand other than by pumping it up and through a large mountain. Pumping would make water diversion more expensive and difficult. The Ta Hsang site is also very far from the industrial centres that could use the electricity. It is also an area of active and persistent conflict. [Note: Any really large diversion of water is likely to simply be too costly to be pumped. A volume of 10 - 30 billion cubic feet of water is an enormous amount, requiring an enormous amount of energy to lift over a very long period of time. To be feasible such a large amount of water would have to be able to flow mostly or completely by gravity down from the Ta Hsang site. The altitude of the Kok River and Ping River at the places into which the water is most likely to be sent are at, or are higher than 1,500 feet. The bottom of the Salween River at Ta Hsang, the highest site on the river that has been examined, is roughly calculated at being no higher than 800 feet (244 metres) above sea level, and are probably closer to 700 feet above sea level. For water to flow by gravity down to the Ping and Kok Rivers a dam wall of no less than 730 feet (222 metres) high would have to be built. It may need to be up to 100 feet higher. The cost of such an undertaking would be exceptional. Electricity Generating Authority of Thailand documentary sources state that the dam would aim to produce 3,300 megawatts of electricity, while the Japanese Electric Power Development Corporation says 3,600 megawatts. 2. MONG HTA - HOMONG: North west of Mong Hta and Mong Kyawt, and north east of Homong in the Shan State, at a place where water would be backed up to near Piang Luang and sent through tunnels into the Mae Taeng stream and thence into the Ping and Chaophraya Rivers. The site of the 6,000 megawatt dam would be completely in Burma. It would be at least 200 meters high to raise the water level as high as possible. Diverted water would have to be pumped up at very high cost. The site is also far from industrial areas and existing power transmission lines. The flood area would stretch far up into the Shan State cutting it in two. No figures are available as to the cost. Two options were initially considered but one, that of pumping the water up to a shorter tunnel through the mountains, would have required over 1,200 megawatts of electricity, nearly twice the peak capacity of the Bhumiphol Dam. 3. WEI GYI: The site at Wei Gyi on the Thai Burma border section of the Salween. According to the Japanese Electric Power Development Corporation study the dam would be 4,540 megawatts. It is far from watersheds that flow into the Chaophraya River. Because it is separated by 2 mountain ranges and a wide valley the diversion of water into the other watershed is simply not practical. It would require 300 kilometres of high voltage transmission line to be put in place, but is not so far from Rangoon or Chiang Mai. It could flood 700 square kilometres - possibly even up to 1000 km2 of forest, riverine and farm land. This dam cost was estimated at US$3 billion. Another earlier estimate which is thought to be for the same area priced the dam at US$5.85 billion. The Norwegian dam building consultancy company Norconsult, in their Greater Mekong Subregional Development Programme study for the Asian Development Bank estimated that it would be possible to build a dam on the same site to produce 7,800 megawatts of electricity. It would presumably cost far more than US$3 billion to make. 4. DAGWIN: The smaller lower Salween dam at Dagwin, a short distance down from the Weigyi dam on the same stretch of the Thai-Burma border. According to the EPDC study the dam would complement the Weigyi dam as a pumped storage facility. It could produce up to 792 megawatts of electricity but would basically serve to trap the water released by the Weigyi dam and would use off-peak power to pump water back up into the Weigyi dam to produce more reliable peak time power. It's flood area would not be so large, but its estimated US$900 million cost is high for the amount of usable power it would produce. Also no water diversion would be practical. 5. HAT GYI: Near to Myaingyingu, at a place called Hat Gyi (also called Hutgyi). This is where there is a particularly powerful rapid that becomes a waterfall when the water flow is reduced in the dry season. It is beside and part of the Kahilu Wildlife Sanctuary. The Burmese Generals favour this site although Thai officials have not favoured this site at all. It is completely in Burma, and is the closest to Rangoon and Mandalay. A very significant amount of Karen and Thai soil would be flooded by this dam if built, unless it was made very low. Because of its low elevation the cost of pumping water into the Chaophraya would be very high. However its flood waters could be pumped up to one of the 2 planned diversion dams at Nam Ngao and thence into the Teun River and the Bhumipol Dam. (Note: If the Hat Gyi site is "developed" the diversion dam at Mae Lama Luang / Mae Ramu Klo may be unnecessary as the area would be flooded by the Hat Gyi Dam. According to EGAT documents the Hat Gyi site is intended to produce only 400 megawatts of electricity.
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