MANILA (UPDATE) - The water level in La Mesa Dam on Friday reached its lowest in 12 years and may go down to its critical level of 69 meters in one to two days.

As of 6 a.m. Friday, La Mesa Dam's water level was at 69.16 meters, 7 meters lower compared to the same period last year, according to the latest data from PAGASA dam monitoring.

Manila Water earlier cited increased water demand of around 1.7 billion liters per day as a cause of the decreasing water level.

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Jeric Sevilla, head of Manila Water's corporate communications, urged the public to monitor the Facebook and Twitter accounts of Manila Water for the announcement of water interruption schedule.

• 'Biglaang water interruption inaasahan sa tag-init'

"Kinakailangan tayo magreduce ng pressure o rotational na water-no water situation para ang ultimate objective kasi natin wala pong lugar na mawawalan ng tubig ng 24 hours," he told radio DZMM.

Sevilla said the scheduled water interruptions may last 3 months as the country experiences El Niño or drought.

"Ito po kasing sitwasyon na ito ay baka po tumagal throughout the summer. Siguro in the next 3 months," he said.

Sevilla also issued an apology for the areas which were affected by water interruptions that were not included on the list earlier provided by Manila Water.

"Humihingi po tayo ng paumahin doon, hindi rin po natin inaasahan, akala po natin makakabawi yung reservoir, mare-refill ito pero sa dami po ng kumbaga nag-ipon ng tubig, nagkaroon ng spike sa demand. Ang nangyari hindi na-refill yung mga reservoir," he said.

Meanwhile, the water level of Angat Dam, which supplies 97 percent of water in Metro Manila, is at 201.75 meters. This is still over its critical level of 180 meters.

La Mesa Dam is part of the important Angat-Ipo-La Mesa water system.

It is an earth dam that serves as a primary sedimentation basin,
ensuring that there is water service in the East Zone of Metro Manila during the dry months. It has a maximum storage capacity of 50.5 million cubic meters and should have enough water for 19 days of Manila Water’s supply requirements.

The water from La Mesa dam comes from the Angat Reservoir and Dam, which serves 3 purposes: (1) supply domestic and industrial water requirements of Metro Manila, (2) provide irrigation for 31,000 hectares of land in Pampanga and Bulacan, (3) and generate hydroelectric power for the Luzon Grid. It is also crucial in reducing flooding to downstream towns and villages.

For water service interruptions, please check Maynilad's Twitter page.

- Kristine Sabillo and Gillan Ropero, ABS-CBN News