MANILA - Regulators and water concessionaires are preparing for the possibility that Angat Dam's water may fall further and cause more supply interruptions.
Water at Angat Dam already fell below the reservoir's 180-meter critical level last April as El Niño caused below-average rainfall across the country.
But the National Water Resources Board (NWRB) said the water at the dam may fall even lower, breaching the 160-meter level, which could trigger service interruptions or result in poorer water quality.
The NWRB explained that Angat Dam's level was at 164.9 meters and was still sufficient to supply the 46 cubic meters per second allocation to Maynilad and Manila Water.
But if rains don't fall in sufficient quantities soon, the water level at the dam is projected to fall at a rate of 0.38 meters per day, which means it will dip below 160 meters in the next 10 days.
If this happens, authorities may opt to reduce allocation to water concessionaires which will lead to further service interruptions, or open the dam's low-level outlet to maintain the water allocation for consumers.
The NWRB, however, said Angat's low level outlet releases murkier water, which treatment plants may find harder to purify.
"May question of water quality, yun ang binabantayan namin, mino-monitor natin but for now, during our discussion, mukhang manageable ang water quality issue," said NWRB Executive Director Sevillo David.
(There's a question of water quality, that's what we're monitoring, but for now, during our discussion, it looks like the water quality issue is manageable.)
Maynilad Water Supply Operations head Ronaldo Padua said they may need to use more chemicals to treat water.
"Nag-stock naman kami ng mga water treatment chemicals, na posibleng tataas ang aming kunsumo para lang ma-address ang tinatawag na manganese at saka yung high turbidity mula doon sa Angat," Padua said.
(We've stocked up on water treatment chemicals and may consume more of them just to address the manganese and high turbidity from Angat.)
Manila Water, meanwhile, said that if treatment plants can't handle the water quality issue, they may need to cut production which will impact consumers.
The Ayala-led concessionaire is still dealing with supply issues in its concession area.
"Ngayon pa lang kami nakakaahon pero ang sitwasyon namin ay very unstable, very volatile," said Manila Water corporate communications head Jeric Sevilla.
(We are just starting to recover but our situation is still very unstable, very volatile.)
Sevilla added that Manila Water still has a supply deficit of around 40 million liters per day.
The Metropolitan Waterworks and Sewerage System has asked elders of the indigenous Dumagats who reside in the mountains and forests around Angat to conduct a ritual to ask the heavens for rain.
Authorities also appealed to consumers to continue conserving water.
Angat Dam's normal high water level is 210 meters.