At most dams, the levels are 13 to 23 meters higher than the minimum requirement for safe power generation, it said Friday.
Water is flowing rapidly into reservoirs in Son La, Lai Chau and Tuyen Quang provinces.
With the flood season expected to arrive soon, NLDC will keep coal- and gas-fired plants running at moderate levels and prioritize hydropower.
In May and June Hanoi and other northern localities suffered frequent load shedding due to low water levels and reduced output at hydropower plants.
But power output at some hydropower plants has now doubled or tripled from May-end.
Deputy Minister of Industry and Trade Do Thang Hai has assured there will be no more power shortage in the north this year.