TrustPower is to be allowed to make changes at its Matahina Dam near Whakatane to increase its output.
The Bay of Plenty Regional Council says TrustPower can increase the amount of water going through the turbines - a process known as peaking or ramping - as many times as needed to meet demand on the national grid.
Previously, the company was only allowed to peak twice a day.
The council's consents manager, Helen Creagh, says the company will not be allowed to reduce the minimum flow of the Rangitaiki River from 40 to 20 cubic metres per second.
Ms Creagh says this is an interim decision due to conditions placed on the consent and a final decision is due in February next year.
The council says the changes are different to what was sought by TrustPower and it can appeal.
The dam on the Rangitaiki River was badly damaged in the 1987 Edgecumbe earthquake and was decommissioned for 11 years to allow for repairs to be made.