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Preliminary Impact Assessment on

Navigation Channel Improvement Project of the Lancang-Mekong

 Prepared by Southeast Asia Rivers Network-Thailand chapter,

Project for rivers and communities-Chiang Khong

1.Environmental Impacts

1)    Impacts from rapids blasting and river dredging

·        Impacts on Ecosystem and fishes in Mekong

Mekong, between Thai-Lao border from Chiang San-Thailand to Chiang Khong-Thailand and Houy Xai-Lao PDR is the lowest target area of the project. For developers, the area is full of dangerous rocks, rapids, reefs and shoals, but for local villagers, it has it's own specific characters of fertiled ecosystem consisting of complex sub-ecosystems called in local Thai as Khang, Paa, Don, Had, Kog, Long  which are rapids, rock, sand dune in the river, beach and whirlpools, small swamps, pools along the riverside.

      Diversity of fauna is said to be high in those sub-ecosystems. Riverine plants such as Krai, Krai Nak who grow up in dry season when the sand dune and rapids are emerging from the water, by the time of flood season their fruits and leaves will become fishes' food especially for herbivorous fishes, mostly scale.

Also, in the area we can find Kai and Tao, fresh water weeds growing on submerge rapids and pebbles, a significant food for fishes and human along the river.

In the spawing season of fishes, the plants, sand dunes, whirlpools and small swamps are the spawning ground for Mekomg fishes including endangered species such as Giant Catfish, the largest scaless fresh water catfish in the world.     

So, blasting and dredging the river will not only mean a threat to the river's complex ecosystem, riverine plants diversity but also to Mekong fishes' life pattern and fishes' diversity.

·        Impacts on river bank erosion and change in water way

           According to villagers, the so-called rapids, shoals and reefs in the river are natural physical structure controlling the river flow, maintaining the river channel help in reducing rapid velocity of the flow in narrow section, hence prevent riverbank erosion.

          Removing them, the consequences would be, original navigation channel shallowed up from the river sediment, waterway changing and rapid flow of the river would cause riverbank erosion.

2)    Impact from large vessels navigation and ports building

·        Impacts on riverbank erosion and change in water way

         Building ports protruding riverbank would effect on change in water way, based on Chiang Khong people experience where a port is built upstream of the town, the consequences are that riverbank downstream of the port collapsed and sediment on another side of the river, change in navigation channel that is dangerous for local navigation as local navigators and fishers have to recognize the new channel so as to navigate in the right channel.

·        Increase in water turbidity

        Navigation of large vessels would increase in water turbidity in the river as the ships' turbines will stir up the river sediment. When turbidity is high, light can not go through to the depth hence will effect on Kai and Tao and aquatic organisms growth, thus cutting the food chain of aquatic lives in Mekong and effecting fishes living condition.


2.Social and Cultural Impacts

1)    Impacts from rapids blasting and river dredging

           Communities along the area can be separated into 2 major groups, land based communities and river based communities. There way of life have been relying on the river since their ancestors as most of them are fishers, Kai-Tao collectors and do riverside vegetation including those who have boats and sometimes hired for freight, ferry and tourist sight seeing, either for their major income or subsidies.

·        Impacts on fisheries

          As mentioned, blasting and dredging the river will effect on Mekong fishes lifecycle and the living condition. The consequences will be reduction of fishes, as it already appeared as a result of Man Wan dam gates closing-opening in China for blasting rapids effecting on changes in water condition of the Mekong thus causing the problem.

          Meaning, destruction of communities' fishing grounds and access to their living condition, threatening their food security and the end of fishers communities.

·        Losing of natural vegetable and herbal plant resources and food security

          As sand dune and the riverside are food sources for local people who can just go picking naturally grown vegetables and herbal and other edible plants, for either family consumption or selling in local market as subsidize such as Kai and  Tao.

Experienced by the Chiang Khong villagers at Ban Muang Kan where they generally collect Kai between March-May. This year the Mekong water level has been fluctuating since the Man Wan dam gates closing-opening for rapid blasting effecting on Kai growth and the villagers can not at all collect any Kai, thus effecting on villagers income as they usually earn 500-600 Baht per day as selling in local market.

The destruction means a threat to communities' income and food security.

2)    Impacts from large vessels navigation and ports building

·        Impacts on fishers and local navigators

         Local fishers and navigators will be the most affected groups from large vessels navigation for large vessels with high DWT will cause large waves smashing the riverside, very dangerous for small local boats navigation. Even at present, based on Chiang Khong people experience, Lao freighter ships about 30 DWT travelling from Chiang Khong to Luang Prabang cause the problem. Accidents occurred when if the small boats could not be unanchored and turn their heads toward the waves on time the waves reach the shore.

·        Impacts on riverside vegetation

           Riverside vegetation is very important for villagers along the river especially those living by the river as the riverside are common area, fertiled and nurished with natural fertilization of Mekong sediment. A family would use around 1-2 rai of land, customary land rights, to do vegetable and herbal farming either for family consumption or for sell in local market.

Effects on riverside vegetation will mostly come from follow up activities as local development projects such as embankment in Sob Som-Chiang khong where people lost their common customary lands for the project without any compensation.

The small area for a family is very significant for their food security as they do not have to buy foods and can even earn income from it, some family earn 200-300 Thai Bht per day.

·        Impacts on house-boat community

          Communities along Mekong are not only inland communities but some are boat-house communities such as in Nam Guang-Lao PDR, they do fishing and trading. Big waves from large vessels navigation will cause house-boat wreck therefore ending the boat-house communities in Mekong.

·        Impacts on water supply

          Communities along Mekong use the Mekong water for daily life uses, including bathing, washing and especially for drinking. The rapid blasting and large vessels navigation and it's follow up activities will cause water pollution and increase in water turbidity. This will effect on People culture relating to Mekong river.

·        Impacts on culture

          Blasting and dredging the river will make it useless and inaccessible for villagers, thus would be the end of indigenous knowledge on fishes, fishing, baiting and local fishing tools and communities, inter-communities, inter-nationalities social relationships along the Mekong as they  have been created upon the river usage for generations and the way of life of Mekong people relying on the river since ancestors.



The preliminary assessment has shown that blasting rapids and dredging the river for commercial navigation and tourism will have negative impacts on..

1.     Destruction of the diverse complex ecosystem of the Mekong river.

2.     Threats to Mekong fishes' lifecycle and species as some are endangered species, only found in Mekong river.

3.     Riverbank erosion and water channel change, which would effect on local people and navigators lives and security.

4.     Negative social im pacts on communities along the river are that they will loss their fishing grounds, natural food sources and access to resources, thus threatening their income and food security.

5.     Loosing the fishing grounds will end up the indigeneous fishing knowledge and culture amassing since their ancesstors, including communities, inter-communities relationships along the river as they have been created upon the common river usage for generations.

6.     The project and it's follow up activities will be the cause of water pollution and increase in water turbidity of the river, thus will effect on villagers' water supply especially drinking water as they use the Mekong water as the source of water supply.

7.     Navigation of large vessels will pose threats to villagers' life and property safety while the follow up activities will alter the pattern of land use, thus will also pose threats to villagers' income and food security as it will destroy the riverside vegetation.

The losses can not be compensate with merely employment of some villagers as labours during construction period of the project.

The Navigation Channel Improvement project, targeted on commercial and tourisms, thus is inappropriate in any environmental, social and cultural aspects.                 


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