The National Water Resources Board (NWRB) on Monday said water allocation to the Metropolitan Waterworks and Sewerage System ( MWSS) might be reduced due to the decline in water level at Angat Dam despite the onset of rainy season.

As of Monday, Angat Dam's water level is at 162.39 meters, about 171.61 meters off from its minimum operating water level of 180 meters.

NWRB said despite Pagasa's (Philippine Atmospheric, Geophysical and Astronomical Services Administration) declaration that the rainy season has officially begun there is "insignificant rainfall... in Angat reservoir area for the past weeks."

According to the agency, if there will be minimal to no rainfall within the reservoir area, the dam will reach a critical water level which will greatly affect domestic water supply.

"It is estimated that water elevation in the reservoir will breach the low-level mark of 160 meters by the third week of June 2019 if the prevailing conditions in the Angat Dam persist and no sufficient rainfall is received in Angat watershed, considering the current rate of decline in water elevation," NWRB said.

Once the dam's water level plunges below 160, NWRB said they will reduce the approved 46 cubic meter per second allocation to the MWSS.

"This will affect the regular delivery of water service provided by Manila concessionaires, Maynilad and Manila Water. Pressure reduction, water rotation and interruption are expected," the agency said.

Other several measures to manage the water supply in the dam includes the operationalization of the Angat Dam low level outlet which is "the bottom channel capable of releasing water below 160 meters."

Cloud-seeding operations and reactivation of MWSS deep wells will also be implemented.

NWRB appealed to the public to conserve water.

"(M)anaging both the water supply and demand is essential to maintain water availability."

"It is expected that the water level in Angat Dam will increase in the coming months with the onset of the rainy season. Stable water supply will return to its normal state but the public is still encouraged to continue conserving water to help in the Angat reservoir's water level recovery," NWRB explained. Cristina Eloisa Baclig/DMS