Heavy rain and strong winds damaged sections of the medium- and low-voltage network, toppling power poles, damaging transformers and triggering landslides at several locations. No damage was reported to the 110-kV transmission network.
EVNNPC said crews restored one medium-voltage line and 25 of 39 affected substations as soon as weather conditions allowed.
The utility said its member companies remained on 24-hour standby, mobilising personnel and equipment to inspect damage and restore electricity as soon as it was safe to do so.
In Son La Province, prolonged heavy rain raised the risk of landslides near power facilities in Chieng Hoa, Chieng Lao, Muong Bu, Muong La and Ngoc Chien communes.
As a precaution, the provincial power company temporarily cut or reduced electricity supply in high-risk areas early on Sunday and rerouted power where possible to minimise disruptions.
Flooding damaged two medium-voltage power lines, interrupting supply to 821 customers and 14 substations. Repair crews were working to restore electricity once weather and terrain conditions improved.
The company said electricity supply in the rest of Son La remained stable while it continued monitoring weather conditions and maintaining emergency response teams.
