Downstream Impacts of Hydropower and Development of an International River: A Case Study of Lancang-

Southeast Asia Rivers Network November 2004

Upper Mekong Navigation Channel Improvement Project, have caused unusual rapid water fluctuation. These affect the rich riverine ecosystems, fish, and local livelihoods of fishing communities in downstream areas. On Thai-Lao border, it is found that the fish catch has declined for 50 ydropower and development percent as a result of the water H of the Lancang-Mekong fluctuation. Hydropower and river River have caused adverse impact on developments have created unprec- hydrology of the river, especially for edented transboundary environmental the decreased minimum discharge. issues. Thus, it is important for After the construction of Manwan riparian countries to immediately dam, the mean minimum discharge of monitor the impacts and consider the the Mekong River on Thai-Lao recommendations of the World border declined by 25 percent. The Commission on Dams in decision- trend of the minimum discharge is also making process of the development reduced. The dam operation together projects on the Mekong River, on with river development project; which millions depend. Map: International Rivers Network under construction à¢×è͹à«ÕèÂÇËÇÒ¹ à¢×è͹áˋ§·Õè ó º¹áÁ‹¹éíÒ⢧¡íÒÅѧÍÂًÃÐËNjҧ¡Òá‹ÍÊÌҧ ËÒ¡áŌÇàÊÃç¨ à¢×è͹áˋ§¹Õé¨ÐÁÕ¤ÇÒÁÊÙ§¶Ö§ òùò àÁµÃ

Introduction Since implemented the Mekong development do not exist only navigation channel improvement at the project sites, but across the project in the 2001 dry season, along boundary far downstream. The Mekong River, the longest river Burmese-Lao border, rapids and reefs in Southeast Asia, feeding millions in have been removed. Along with six riparian countries from China to canalization at Krai rapids, now 300 Decrease of Minimum Burma, Laos, Thailand, Cambodia, DWT ships can navigate to the Golden Discharge and Vietnam. Triangle town of Chiang Saen. However, the plan to blast Khon Pi It is widely publicized that only 18 Since 1980s, China has played an Luang rapids on Thai-Lao border has percent of the total water flow of the important role on Mekong development, been halted due to Thai Cabinet Mekong comes from the Lancang. under its ‘Go West’ policy and Lancang resolution in April 2003. This requests However, in dry season it grows for Economic Belt. The Lancang Eco- the new Environmental Impacts nearly 45 percent of the average flow nomic Belt policy, comprising of 1 Assessment and TOR on waterway as far as Cambodia in April . Thus, cascade hydropower dam projects on between Thailand and Laos. water flow form the China’s section the mainstream of the Mekong River, of the Mekong is extremely important industrial estates, and Upper Mekong Downstream Impacts for the flow of the Mekong on Thai- navigation channel improvement Lao border. project for large cargo ships to navigate from Simao of PRC, to Luang Dam construction and removal of Recently, it is reported that the Prabang of Lao PDR. Mekong rapids and shoal mean an unprecedented destruction of the The Manwan and Dachaoshan dams development history of the Mekong 1 International Rivers Network, China’s Upper are already built, Xiaowan and River. The impacts of the Upper Mekong Dams Endanger Millions Downstream, Jinghong dams are under construction. Briefing Paper 3, October: Berkley, 2002.

2 has created an impact Water Fluctuation It is worried that the water fluctuation on minimum discharge of the Mekong, in the Mekong would be more fatal, especially in dry season. According to due to three main factors. Firstly, the Mr. Weerawut Pornrattanaphan, a The Mekong rapids blasting which has completion of which is hydrologist of Water Resource been implemented since the end of only about 280 km upstream of Chiang Department of Thailand, the upper 2001 has created the drastic water Saen. Secondly, the Chinese Mekong dams have decreased the fluctuation. In dry season of 2002- authorities’ plan to remove sand bar minimum discharge of the Mekong at 2003, the Chinese authorities announced along the Mekong between Jinghong Chiang Saen station for 25 percent. the regulation of the river flow, allowing and Guan Lei to allow cargo ships of He stated that during 1962-1992, ships to navigate for one day and then up to 400 DWT to navigate year- before the Manwan dam construction, pause for three days to allow for rapids round4 . Thirdly, the joint agreement the mean of minimum discharge was blasting. More recently in dry season among four upper Mekong countries 752 CMS (Cubic Meter per Second). 2003-2004, it was announced that the to regulate the river water for dry However, during 1993-2003, the mean river was to be opened for traffic only season navigation. 3 of minimum discharge is only 569 five hours in four days . CMS2 . The information also shows that the trend of the minimum During January-April 2004, the most unusual and rapid fluctuation in water discharge is reduced in the long term. 2 Department of Water Resources, Report on This means that the volum of the level was occurred when the Chinese Water Flow of the Mekong River, Bangkok, mekong water is also reduced. (see team constructed dyke at Khrai 2004. Rapids on Lao-Burmese border, 68 3 Xishuangbanna Maritime Authority, table 1) Instruction from the Navigation Improve km downstream of Guan Lei port. ment Timetable, 2003. (see table 2) 4 The Nation 13 August 2004

Table 1 Mekong River at Chiang Saen Minimum Discharge 1962-2003

Source: Department of Water Resources (2004).

3 Table 2 The Mekong River Level at Chiang Saen, Thailand 1991 and 2004

Source: Raw data from Department of Water Resources

Social and Environmental decline of fish. tributaries and wetland areas in the Impacts Northeast Thailand. Mr.Rattaphon Thai Baan Research, a villagers’ Pitaksombat of IUCN’s Mekong research on local knowledge Wetlands Biodiversity Conservation The deterioration of the ecosystem conducted by fishing communities and Sustainable Use Programme means a decrease in food security for along the Mekong in Chiang Rai revealed that the Songkarm River, the local people, as well as disrupted eco- province, found that during the past Mekong’s tributary was also affected. nomic and social structures, which are three years, fish catch has been According to Mr.Rattaphon, the water tightly linked to a healthy ecosystem. reduced for 50 percent. fluctuation also occurred on the According to in-dept research of Songkarm River as far as more than 50 Southeast Asia Rivers Network, Far downstream in northeastern part kilometer from the mouth of the river. fishers along the Mekong on Thai-Lao of Thailand, fishers in Nakorn border in Chiang Rai province Phanom province on the Mekong river Impacts on Lower Mekong complained they could not fish in also insisted that the unusual water Countries conditions where the river rose and fluctuation was witnessed. The then lowered swiftly in a day or two fluctuations harmed their fishing as in the past few dry seasons. As occupation. They said fish did not Downstream impacts of the Upper most of fish in the upper Mekong are move out of its habitat when the Mekong development has also raised migratory species migrating upstream water level is rapidly altered. concern in the lower Mekong coun- for reproduction, fish depend on the tries. As the Prime Minister Hun Sen annual river flow. Thus, the water Moreover, the water fluctuation also warned that Cambodia’s Tonle Sap fluctuation inevitably results in a great affects the water level in the Mekong’s lake, a vital source of fish of the coun-

4 try, could dry up if development projects are not handled carefully on the Mekong River upstream from the lake5 .

5 AP/ENN, February 12, 2003

Recommendations

All riparian government should immediately stop all works on the hydropower and river development on the Lancang-Mekong, and properly conduct comprehensive environmental and social impact assesments according to international standards. These assesments should be carried out in a transparent and participatory manner, with recogniz- ing the health and vitality of the Mekong River and the lives of those who depend on it.

The World Commission on Dams’ strategic priorities such as Gaining Public Acceptance, Comprehensive Options Assesment, Sustaining Rivers and Livelihoods, and Sharing Rivers for Peace, Development and Security, should be considered.

References

[1] Department of Water Resources, Report on Water Flow of the Mekong River, Bangkok,2004. [2] International Rivers Network, China’s Upper Mekong Dams Endanger Millions Downstream, Briefing Paper 3, October: Berkley, 2002. [3] World Commission on Dams, Dams and Development: A New Framework for Decision-Making, London: Earth Scan, 2002. [4] Xishuangbanna Maritime Authority, Instruction from the Navigation Improve- ment Timetable, 2003. [5] AP/ENN, February 12, 2003 Kai, Mekong seaweed, a source of income for women during [6] The Nation, 13 August 2004 dry season, has decreased drastically due to the unususal water fluctuation. For more information, please visit www.searin.org ¡ÒâÖé¹-ŧ¢Í§¹éíÒ⢧·Õè¼Ô´¸ÃÃÁªÒµÔ ʋ§¼Å¡Ãзºµ‹ÍÃкº¹ÔàÇȹáÁ‹¹éíÒ address: 78 Moo 10 Suthep Rd., Tambol ã¹ÀÒ¾¨ÐàËç¹Ç‹Òä¡ ËÃ×ÍÊÒËËÒÂáÁ‹¹éíÒ⢧«Öè§à»š¹ÍÒËÒâͧ»ÅÒ áÅÐ Suthep, Muang, Chiang Mai 50200 ªÒǺŒÒ¹ÃÔÁ½˜›§¹éíÒࢵ¾ÃÁá´¹ä·Â-ÅÒÇ·Ò§µÍ¹º¹ áˌ§µÒÂà¹×èͧ¨Ò¡ THAILAND ÃдѺ¹éíÒŴŧÍ‹ҧÃÇ´àÃçÇ «Öè§äÁ‹à¤Â»ÃÒ¡¯ÁÒ¡‹Í¹ Tel.+66 53 278 334 fax.+66 53 283 609

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