Over the past decade, tens of thousands of villagers once dependent upon the abundant resources of the Sesan River have suffered due to the construction of the Yali Falls Dam, located 80 km upstream of the Cambodian border in Vietnam. Since 1996, the dam has altered the flows of the
Massive water releases, especially between 1999 and 2001 when partial operation commenced, have resulted in flash flooding causing the deaths of at least 39 people, loss of livestock, and destruction of rice fields and vegetable gardens. Following public outcry, measures to mitigate the impacts were proposed by the Cambodian and Vietnamese governments in 2001 and 2007, although in reality these have been almost entirely ineffective.
In Vietnam, around 8,500 people were displaced to make way for the Yali Falls Dam. Years later, research has found that land shortages, poor quality housing and sanitation continue to take a toll on the health and well-being of these mainly ethnic minority people.
To this day, 55,000 villagers from 16 ethnic minority groups in Cambodia's Ratanakiri and Stung Treng provinces and many thousands more in Vietnam's central highlands continue to suffer due to lost rice production, drowned livestock, lost fishing income, and damages to rice reserves, boats, fishing gear and houses as a result of rapid and daily river level fluctuations. They have received neither compensation nor remedy for the situation. Despite this, four other major hydropower projects are now in operation or under construction on the Sesan River in Vietnam, compounding the impacts of Yali Falls Dam. These new dams require the resettlement of at least 9,500 people.
Despite the devastating downstream impacts experiences from Vietnam's upstream hydropower cascade, Cambodian communities are now threatened with plans to build three more hydropower projects along the Sesan River inside Cambodia. The approved 400 MW Lower Sesan 2 Dam in Stung Treng province is the most advanced of these projects and threatens to negatively impact fish stocks as far away as Vietnam, Laos and Thailand.