The immensity of the Yali Falls dam can be grasped by comparing the same orange construction crane in this photo: the crane beside the Yali spillway
ietnam's $1 billion Yali Falls dam, under construction for the past seven years,
drains into the Se San river which runs through Cambodia to the Mekong. Before the
dam-building began, no study was done of its environmental effect on Cambodia. Now,
as Bou Saroeun reports, a study has been done, and shows that the dam is bringing
death, disease and environmental devastation to Cambodia even before it is fully
EARLIER this year the first reports began to emerge from Ratanakkiri that problems
had developed with the Se San river, and that the source of these problems was upstream
at Vietnam's new Yali Falls dam.
Cambodians along the Se San river told of sudden surges of water drowning five people.
In the single worst case three teenage girls were drowned trying to cross the river.
Villagers spoke of their fishing boats and nets being swept away, livestock being
drowned and crops inundated.
Meetings were held between Vietnamese and Cambodian officials and assurances were
given that there would be no more releases of water without prior warning. At that
point both sides said the matter had been resolved and that was an end to it.
However a report issued this week shows that sudden releases of water were only one
of a host of problems.
A community-based study of the effects of the dam conducted by the Ratanakkiri Fisheries
Office in cooperation with the Non-Timber Forest Products (NTFP) Project funded by
Oxfam, concluded that the dam has caused and is causing serious environmental and
socio-economic problems downstream on the Se San in Cambodia's Ratanakkiri and Stung
The reports says interviews with locals revealed that the death toll from drowning
stood at 32 rather than five - and most of the victims were children.
In addition, locals reported 952 deaths from disease since they perceived a change
in water quality over the past four years. Stock losses have been reported in the
thousands as well as significant numbers of wild animals dying after drinking water
from the river.
A two-day workshop attended by representatives of ethnic minority groups living on
the Tonle Se San, local and international NGOs, and provincial officials, was held
at the end of May to discuss the effect of the dam.
The majority of people living along the affected parts of the Se San are ethnic minorities.
Their representatives who attended the workshop demanded that the clock be turned
"I want the Se San river to be restored to its natural state," said Lamas
Voen from Phi village, Se San commune, O'Yadao district, the closest Cambodian settlement
to the dam.
"We have suffered flooding for four years. I don't know what we are going to
do. We just sit and wait to see what will happen next. You [dam builders] have to
think how hard our lives are."
She complained that the water used to be clear even in the dry season, but now it
was permanently dirty and too unhealthy for humans and animals.
People and 40-gallon drums can be seen on the ground to the left of the crane.
The call for changing the river back was far more dominant than any request for cash
"If they want to give us compensation will they be able to feed us all our lives?
It seems impossible, and what about our children and grandchildren? How are they
going to survive? We want the old Se San back so we can fish and do other activities
the same as before."
According to the study, the water quality has deteriorated greatly since 1996. Surges
of water coming downstream are reddish in color, muddy and have the foul odor of
The report could not quantify the health effects of the water quality, but noted
that people living along the river reported a rapid decline in health once the changes
Locals complain of intense itchiness, lumps and infections on their skin, and eye
irritation. They have also reported other health problems that have coincided with
the sudden rises in water levels.
These included stomach aches, diarrhea, respiratory problems, throat and nose irritation,
dizziness, vomiting and coughing. Many reported family members dying one to five
days after becoming ill.
Bou On, 58, of the Kachok ethnic minority group, represented Kachot village of Ven
Say district at the conference; she said her own health had suffered as a result
of poor water quality.
She complained of itchiness, diarrhea, vomiting and a persistent cough.
"I am not lying about the water quality. It is real," she said, showing
the marks of illness on her body.
"I am sure the water quality has changed a lot since before."
Villagers also complained about the effects the water has had on their livestock.
Sala Kwek, of the Kachok ethnic minority group living in Kachot village, Nhang commune,
Andong Meas district, said that since the dam construction started, his village lost
hundreds of buffalo and cows; sometimes 20 to 30 died each day.
According to the study, villagers claimed that more than 4,900 buffalo have died
of unusual diseases since the water quality problem began in 1996. They also reported
the similar deaths of more than 2,200 cows, 7,800 pigs, 1,600 ducks, tens of thousands
of chickens, and more than 2,500 dogs and cats.
However similar outbreaks of livestock disease have been recorded far away from the
Se San river, though occurring at the same time that locals say the river water quality
started to decline. A CARERE official said that makes it hard to draw definite conclusions
about the cause and effect of the dam on livestock health.
Still, villagers remain convinced that water quality in the Se San river has harmed
their domestic animals, with the greatest effects being noted near the river.
Dr Lena Vought, an expert on lakes, ponds and streams from Lund University in Sweden,
has suggested that the problem may be associated with the presence of toxic blue-green
algae in the Yali reservoir contaminating the Se San.
Since there has never been any detailed water quality surveys conducted in the Se
San in Ratanakkiri, it is difficult to confirm this hypothesis.
But, if blue-green algae is causing the problem, it has probably developed in the
Yali reservoir, where excessive nutrients have been released from the decaying vegetation
causing excessive algae growth.
Dr Vought said in the study that there have been similar cases where water contaminated
with the toxic blue-green algae has proved fatal to livestock.
Ratanakkiri province has some of the richest areas of wildlife in Cambodia, but these
animals too have been seriously affected by the hydrological changes in the Se San
as well as suffering from the effects of the water quality changes.
In Virachey National Park, on the northern side of the Se San river in Ta Veng and
Ven Say districts, reptiles, mammals and birds have died or become ill at a greater
than usual rate.
People from many communities along the Se San have reported finding dead wildlife
near their villages over the past few years. Many villagers believe that the wild
animals had gone down to the Se San river to drink and then died shortly afterwards.
The species most affected were wild boar, barking deer and sambar deer. In addition,
a small number of civet cats, porcupines and rodents have also been found dead in
People from O'Yadao district, near the Vietnamese border, reported finding 10 dead
Gaur near the Se San river over the last year.
The changing water quality is also believed to have harmed fish stocks and habitat.
The number of fish has declined noticeably, with some villagers putting fish stocks
down by as much as 30 percent.
Meanwhile four years of irregular flooding have caused major food shortages to people
in the area.
The belly of a child from Ta Lao village showing skin disease also believed
caused by the Se San
Dry season crops which are planted along the banks of the Se San have been swept
away by the surges of water following discharges from the dam.
Locals now rely on wild potatoes and other tubers to sustain them.
"We have no rice to eat; we survive with the wild potatoes and bamboo shoots
mixed with banana fruit to make the porridge," said Bou On.
She said food that was collected and stored like prahok was no longer available because
of the decline in fish stocks.
Sal Kway, deputy chief of Se San commune, explained how the villagers can no longer
plan how to plant their crops because the unpredictable water levels in the dry season
can wipe out their work - and their seed stocks, which they could not afford to lose.
To Peav, 50, of the Taveng commune committee, echoed Kway's comments and added that
people were being forced to travel increasing distances to forage for food.
He said the tubers and cassava that they rely on for food during the rainy season
when the rice had run out were being destroyed by the excessive flooding.
Peav said he was disappointed that the Government had persuaded the hill tribes people
to come down from the mountains and settle along the Se San river in the vain idea
of national progress.
"How can we progress the country without food to eat?" he asked.
"We want the country to progress, but how can it while we can't grow rice, farm
or even have a garden?"
He said people needed food for their day-to-day living before they can think about
The lack of food security in villages along the Se San river is particularly critical
this year. Lowland areas have been devastated by the floods while the upland swidden
farms have been badly affected by early rains in 1999. Hence very little rice has
been stockpiled since last year. Villages that used to have rice surplus, such as
Ko Piak and Pak Kalan of Ven Say district, are below subsistence level.
In addition, the study said that about 14 types of river plants that villagers used
to collect to eat have been in serious decline over the past few years.
Tobacco, one of the most popular plants that villagers used to grow along the river
bank, is now impossible to cultivate.
Vat Chrang, 30, of Tom Pong Roeung Thom village, said that he and other villagers
were disappointed that they had had to give up on the crop.
"I care more about tobacco than rice; if I don't have tobacco I don't have energy
to harvest or do farm work," he said. "Tobacco is my first energy."
One of the most important dry season occupations for local people living along the
Se San river used to be gold panning.
It was especially important in Andong Meas and O'Yadao districts, where gold is plentiful
in the river bed.
Local people used to rely on gold panning to supply them with funds to buy rice in
years of shortages, and when they wanted to buy a buffalo or a cow, gold panning
was the main means of getting the cash to do so.
Of 59 villages surveyed, 47 reported that they used to do gold panning until the
dam started causing water level fluctuations. In the upper parts of the basin, it
is the fear of surges of water sweeping people away that has stopped people panning.
Further downstream, locals have stopped because the holes they dig in the riverbed
to find the gold silt up when the water rises.
The irregular water pattern of the Se San is now looking likely to force the hill
tribes back to their historical practice of swidden (slash and burn) farming.
Sal Kway said the last few years beside the Se San have been very difficult. He said
they want to abandon their villages but were wary because they realize it would be
against the government's wishes.
"Now that we live along the Se San river we suffer from the floods and if we
go to live in the hills we go against the government policy. I don't know how to
solve this problem," he said.
Vat Chrang's answer is to try to live a double life. He has slashed an area in the
uplands for a rice crop but still lives in his village on the Se San. He said the
situation was not ideal, because the farm is far from the market and he has to spend
two hours each way traveling.
According to the study, other villagers living along the Se San river have adopted
a similar strategy.
For example, 20 Lao families from Hat Pok village have started doing swidden agriculture
in upland areas far from their villages. In Pong and Fang villages, two other Lao
communities in Ven Say district, most of the people in the villages have started
doing swidden agriculture behind their communities, although they have little experience
at this type of farming.
According to villagers in Pong village, the forest behind their village has all been
flattened as a result, and they admit that they are not adept at the technique compared
to the upland farmers.
But many village leaders spoken to by the study team feel they have no option but
to abandon their villages and return to higher ground and farm as their forebears
did - clearing areas of forest and growing crops till the land is exhausted then
The study says that the people living along the Se San river in Ratanakkiri belong
to a diverse array of ethnic groups, and have significant cultural differences.
However, except for the Lao and the Chinese, who are largely Buddhist, the vast majority
of the indigenous people living along the Se San river in Ratanakkiri are animists,
with deep spiritual connections to nature and the spirit world.
Kreung women from Lam Pat village cross the parched river bed of the once mighty Se San
They attribute the flooding and subsequent water damage to forest spirits becoming
Bou On and other workshop participants spoken to by the Post said that before they
learned about Vietnam's Yali Falls dam-building, they used to believe the spirits
were angry with the people but did not know why.
"I sacrificed chickens and sometimes the villagers sacrificed the buffaloes
and cows to the spirits so they would not get angry with us and save us. But nothing
changed," she said.
Most of the people spoken to did not know about the Yali Falls dam until long after
the river became erratic, and attributed the river's behavior to the spirits. Now
that they know about the dam, they are still inclined to think the spirits are playing
One old Tampuan woman, from Kachon Kroam village in Ven Say district, provided a
spiritual explanation for why the people along the Se San river are suffering so
much from the dam.
"I think the spirit of the water and the spirit of the trees are angry with
the humans," she said. "The Vietnamese have blocked the path of the spirits
of the water, and the dam has caused many big trees in the reservoir area to be flooded.
"Therefore, both the spirit of the water and the spirits of the big trees are
angry. When the Vietnamese release the water downstream from the reservoir, it is
like releasing the angry spirits upon us and the spirits make us sick and cause a
lot of us to die."