Laos has constructed over 70 dams on the Mekong River and its tributaries since 2010, transforming the nation into a major regional electricity supplier while incurring mounting environmental costs, according to environmental groups and international researchers. The country, which markets itself as the “battery of Southeast Asia,” sells power to Thailand, Vietnam, Cambodia, and Myanmar. Government targets aim to increase generation capacity from approximately 10,000 megawatts to 30,000 megawatts by 2030.
Most facilities are run-of-river dams that channel water through turbines without large reservoirs, though they still require substantial infrastructure development. “The sheer number of dams in such a short period is unprecedented for a country of this size,” said Dr. Somsak Chanthavong, a hydrologist at the National University of Laos.
“We are seeing cumulative impacts that were not fully assessed when individual projects were approved.” Construction has cleared extensive forest areas for access roads, transmission lines, and worker camps. Satellite data from Global Forest Watch indicates that forest loss in dam construction zones rose by 40 percent between 2015 and 2023 compared to the previous decade.
River Ecosystems and Fisheries Under Pressure
The Mekong River supports one of the world’s most productive inland fisheries, supplying protein for 60 million people across Southeast Asia. Dams obstruct fish migration routes, alter water flow patterns, and trap sediment that nourishes downstream floodplains.
“Fish catches in the lower Mekong have declined by an estimated 30 percent over the past 15 years,” said Dr. Khamphone Vongxay, a fisheries biologist at the Mekong River Commission. “Dams are a primary driver, along with overfishing and climate change.” Sediment trapping behind dams also depletes the Mekong Delta of nutrients, accelerating erosion and saltwater intrusion in Vietnam. A 2024 study in Nature Sustainability found that Laos’ dams trap up to 60 percent of sediment that would otherwise reach the delta.
The Nam Theun 2 dam, one of the largest, diverted water from the Nam Theun River into a reservoir that flooded 450 square kilometers of forest. Downstream communities report diminished fish numbers and altered water quality.
Social Displacement and Inadequate Compensation
Hydropower projects have displaced an estimated 100,000 people in Laos since 2000, according to International Rivers. Many resettled communities receive insufficient compensation and struggle to sustain their livelihoods.
“We were promised new houses, schools, and jobs,” said Bounthong Sisouphanh, a village chief in Khammouane province whose community was relocated for the Nam Theun 2 dam. “But the land we got is poor for farming, and the fishing is not the same.” The Lao government maintains a resettlement policy requiring developers to restore incomes to pre-project levels, but implementation varies. A 2023 World Bank audit, which helped finance Nam Theun 2, found that many households still had lower incomes than before relocation.
Regulatory Gaps and Enforcement Challenges
Laos lacks a comprehensive environmental impact assessment system for hydropower projects. The Ministry of Energy and Mines approves most dams, while the Ministry of Natural Resources and Environment holds limited authority to enforce mitigation measures.
“There is a fundamental conflict of interest when the same ministry that promotes dam construction also oversees environmental compliance,” said Dr. Anoulak Kittikhoun, a policy analyst at the Stimson Center’s Southeast Asia program. “Independent oversight is almost nonexistent.” International lenders such as the Asian Development Bank and the World Bank impose environmental safeguards on financed projects, but many dams are built by Chinese and Thai companies with fewer requirements. The Xayaburi dam, the first on the mainstream Mekong in Laos, was constructed by a Thai company and began operating in 2019 despite objections from downstream countries.
Energy Exports Versus Environmental Protection
Laos exports approximately 70 percent of its hydropower, generating revenue for infrastructure and poverty reduction programs. The government contends that clean energy helps combat climate change by displacing coal-fired power in importing countries.
“Hydropower is a renewable resource that provides stable electricity and foreign exchange,” said a spokesperson for the Lao Ministry of Energy and Mines, who spoke on condition of anonymity. “We are committed to sustainable development and are working with international partners to improve environmental management.” Environmental groups argue that benefits are overstated. A 2024 International Union for Conservation of Nature report found that methane emissions from tropical reservoirs can make some dams worse for the climate than fossil fuels.
The report also noted that most electricity from Laos’ dams serves industrial users in Thailand, not rural communities in Laos that still lack reliable power. Strengthening enforcement of existing laws, establishing independent monitoring, and shifting toward smaller, less destructive projects could help address these challenges.
Without such changes, the environmental costs of Laos’ hydropower boom will continue to grow, undermining the resources the dams depend on.
