Overview
Laos is a landlocked Southeast Asian country whose drainage is dominated by the Mekong River system. Nearly all rivers in Laos ultimately flow into the Mekong, which continues south to the South China Sea. The waterways range from perennial highland streams to large lowland rivers and play central roles in transport, agriculture, fisheries and hydroelectric power.
Major rivers and tributaries
The following list is arranged by where each river drains; tributaries are indented beneath the larger stream they feed. For a cross-reference and mapping resources, see the detailed list and materials on identifying tributaries.
- Mekong River (main stem)
- Nam Ou
- Nam Ngum
- Nam Theun
- Nam Khan
- Sekong (Xe Kong)
- Xe Bang Fai
- Xe Xou
- Nam Kading
- Nam Hinboun
- Nam Song
- Nam Lik
- Nam Suang
- Smaller seasonal streams and plateau drains
Geography and development
Rivers in Laos originate in its uplands and plateaus, carving steep valleys and broad floodplains. Many have been the focus of hydropower development in recent decades, with dams built for electricity export as well as domestic supply. Hydrology is highly seasonal: a pronounced monsoon causes large wet-season flows and lower dry-season levels.
Ecology, economy and culture
The rivers support fisheries that are vital for food security and host significant freshwater biodiversity, including migratory fish. Communities rely on river floodplain agriculture, riverine transport, and cultural practices tied to the waterways. Conservation concerns include habitat alteration from dams, sediment changes, and impacts on fish migration.
Notes and distinctions
Although landlocked, Laos's river network connects it to regional waterways and downstream countries. Local names often include the Lao word for river, "Nam" (water), or variations like "Xe" and "Xek." This list groups rivers by drainage rather than administrative boundaries to reflect their hydrological relationships.