PULANGI 4 is now below its minimum operating capacity at 280.40 meters above sea level (masl) as of July 22, Mindanao Power Monitoring Committee (MPMC) said.
Based on National Power Corp. (Napocor) data, the dam's water level as of July 22 was at 280.40 masl, 0.62 masl or 62 cm. drop from 281.02 masl recorded on July 17.
The minimum operating capacity of Pulangi 4 is at 282 masl.
The normal high water level for the dam is at 285 masl. It currently has 4.6 masl below normal.
The dam, however, is still operating and is churning about 60 megawatts from 20 MW last July 21 in Mindanao, much higher with 40MW.
"Pulangi 4 is still operating. In fact it is generating 60 MW out of 250 MW potential output. It does not necessarily mean na kung lower sa minimum operating capacity ang current level ng dam it will automatically stop from operating, it depends on the situation," Romeo Montenegro of the Mindanao Development Authority (Minda) said, adding that it generates power after Pulangi 4 unit 3 was synchronized as of 1:18 p.m. Thursday from economy shutdown.
The water rainfalls from the consecutive two nights of rain can be attributed to the increased power generation capacity of the dam from 20 MW of July 21 to 60 MW of July 22.
Meanwhile, the water level of Lake Lanao is at 699.24 meters above sea level (masl), .09 masl or 9 cm. away before breaching its minimum operating capacity at 699.15 masl.
The normal high water level for the lake is at 701.10 masl.
The water level of Agus 4 stands at 358.31 masl, which is nearing its minimum operating level of 357 masl, and is lower as compared to 358.88 masl of July 17. The dam has a normal high water level of 359 masl.
Based on the latest monitoring of the MPMC, rotation brownouts for each Distribution Utilities and Electric Cooperatives in Mindanao are averaging at one to four hours per feeder.
With the unstable power situation, DLPC said the duration of the power interruptions may increase or decrease "depending on the curtailment imposed by the National Grid Corporation of the Philippines (NGCP) at any given time of the day and the variability of the load of DLPC relative to the time of the day."
As of 1 p.m. Thursday, July 23, the NGCP website showed a power supply shortage of 229 MW for Mindanao, with available supply pegged at only 1,150 MW against the peak demand of 1,379 MW.