Water supplies at seven major hydropower reservoirs in northern Vietnam may fall short of electricity generation needs from May or June 2027 because of a very strong El Niño, with a worst‑case shortage of up to 4.2 billion cubic metres for domestic and environmental needs. This could risk electricity shortages for households, schools and factories during the hot summer months.

The Ministry forecasts that El Niño will remain very strong through January 2027 before gradually weakening in the first half of summer. The weakening is expected to continue into the early summer, after which conditions may return to neutral.

After the January‑March 2027 irrigation period, combined storage in the seven reservoirs is expected to fall to about 22.4 billion cubic metres, which is roughly 1 billion cubic metres below the minimum required for electricity demand. This shortfall means there will be insufficient water to meet the peak power needs of the hot season.

By early May to early June 2027 most reservoirs could reach dead water levels, stopping normal power generation and raising the risk of electricity shortages. When water falls below the dead level, turbines cannot operate, forcing the grid to rely on other energy sources.

The ministry has urged other ministries, sectors and local authorities to draw up flexible water‑use plans, adjust operating schedules and increase the use of other energy sources to ease pressure on the reservoirs. These measures aim to limit power shortages and keep essential services running through the summer.