DECLINING water levels at Angat Dam will likely result in water interruptions and power generation, water and energy regulators said.
On Saturday, the National Water Resources Board (NWRB) reduced the water allocation for Metropolitan Waterworks and Sewerage System (MWSS) to 48 cubic meters per second (CMS) from 50 CMS, according to Patrick James B. Dizon, head of the MWSS Angat/Ipo operations management division.
Last week, the NWRB said it will automatically modify the allocation for MWSS once the elevation in Angat Dam drops below the 180-meter minimum operating level.
As of 6 a.m. on Sunday, the water level in Angat Dam had declined to 179.56 meters from 179.99 meters a day earlier.
Mr. Dizon said that the reduced water allocation is expected to affect almost 600,000 customers in areas served by Maynilad Water Services, Inc.
“We think it will replenish for the next months; this is consistent with the projection of PAGASA (the government weather service) for the near-normal rainfall in the watershed,” Mr. Dizon said in a Viber message on Sunday.
PAGASA said El Niño has started, and is expected to last until next year. Nevertheless, it continues to count on an enhanced southwest monsoon until September.
Mr. Dizon, citing historical records, said even during El Niño years, the dams usually replenish between July and October.
He said that MWSS is not expecting any further reduction in its water allocation as reservoir elevation is only expected to hit a low of 177-178 meters by the end of the month.
This water elevation remains adequate for the current MWSS water allocation of 48 CMS, Mr. Dizon said.
Separately, Energy Undersecretary Rowena Cristina L. Guevara said that the Department of Energy is also monitoring the dam water levels because they can also affect the power supply.
“We are monitoring our hydroelectric power plants, particularly Angat Dam which has 218 megawatts (MW) capacity,” Ms. Guevara said in a Laging Handa briefing on Friday.
Ms. Guevara said the department is expecting a reduction in hydroelectric power output of about 75% in December.
She said that due to El Niño the Luzon power grid may likely experience thin reserves which may result in four yellow alerts in the July to August period.
“The National Grid Corp. of the Philippines is preparing ancillary services in case generation supply is inadequate,” she said. — Ashley Erika O. Jose