MANILA, Philippines -  Rotating brownouts on Wednesday affected areas being serviced by the Mindanao grid due to low water levels in several hydropower plants.

The National Grid Corporation of the Philippines said the entire Mindanao grid is placed on red alert from 10 a.m. to 10 p.m. Wednesday.

"Contingency reserve is zero due to generation deficiency brought about by reduced capabilities of hydro plants (Agusan plants, 50% reduction and Pulangi plants-75 % reduction) due to very low water inflow," the NGCP said.

It added that the rotating brownouts will be implemented in some areas where there are no imbedded generators.