Xe Lanong 1 Hydropower Dam in Savannakhet is expected to begin releasing water from 11 August as heavy rain increases inflows into the reservoir, raising flood risks for downstream communities.
According to a notice from the hydropower company on 8 August, heavy rain is expected in the dam’s catchment area between 9 and 12 August.
The company expects water flowing into the reservoir to rise from about 650 cubic metres per second to as much as 4,000 cubic metres per second. Water releases could potentially cause downstream water levels to rise significantly.
Following the announcement, the Savannakhet Provincial Administration instructed authorities in nine downstream districts to warn residents in riverside and low-lying areas to prepare for possible flooding.
Officials urged communities to move livestock, farming equipment, boats and other valuables to higher ground and remain alert for further updates.
Rivers already above danger levels
The warning comes as several rivers across Laos have already reached or exceeded danger levels.
Water monitoring data released on 9 August showed the Xe Champhone River in Savannakhet had risen to 8.08 metres, above its 8-metre danger level.
The Xe Bangfai River in Khammouane Province also exceeded its danger level, reaching 15.89 metres at the Mahaxay monitoring station, above the 15-metre threshold.
At the Xe Bangfai Bridge monitoring station, water levels reached 20.86 metres, exceeding the 20-metre warning level.
In response, Nam Theun 2 Power Company said on 9 August that it had temporarily suspended electricity generation and stopped releasing water into the Xe Bangfai River from 7 August to help reduce downstream flood risks.
The company said the measure followed a sharp rise in river levels after several days of continuous rain and would remain in place until conditions improve.
Flood and landslide risks
The Department of Meteorology and Hydrology has also issued a flood and landslide alert for 9 to 10 August.
In Savannakhet, Phin, Thapangthong and Vilabouly districts are among the areas considered at high risk because of expected heavy rainfall.
Other high-risk areas include parts of Houaphanh, Luang Prabang, Khammouane and Salavan provinces.
Phongsaly, Luang Namtha, Xaysomboun, Vientiane and Bolikhamxay are under moderate risk of flash floods and landslides.
Authorities have urged residents and local administrations in affected areas to stay alert and closely monitor weather updates and official warnings.
Flood risks are also expected to increase along parts of the Mekong River.
According to the Mekong River Commission, water levels in some areas are forecast to reach alarm levels between 11 and 14 August.
Alarm levels are expected in Vientiane on 11 August, followed by Thakhek in Khammouane Province and Pakse in Champasak Province on 12 August.
