Parts of the Angat Reservoir in Bulacan have dried up as its water level fell to a critical low, raising concerns over the country's main water source, officials said.

The Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA) said the reservoir's water level has dropped to just over 152 meters above sea level, below its minimum operating level of 156 meters and far from its normal operating level of 180 meters.

Large muddy areas have emerged as the water continued to recede, although some parts of the reservoir still hold water.

PAGASA said continuous rainfall in the watershed is needed to replenish the reservoir and improve its water level.

The local government of San Jose del Monte, Bulacan has met with the Metropolitan Waterworks and Sewerage System, National Water Resources Board, National Irrigation Administration, and Local Water Utilities Administration to discuss long-term measures to address the declining water supply.

Authorities warned that the reservoir's water level could fall further to 149 meters by the weekend if conditions do not improve.

(with reports from Unang Balita)