‘Habagat’ boosts Angat’s water reserve

View of Angat Dam from San Lorenzo (Hilltop), Norzagaray, Bulacan (Wikimedia Commons)

MANILA — Downpour from the southwest monsoon or ‘habagat’ is increasing the possibility for water level in Metro Manila’s main water source Angat Dam to soon reach its critical 180-meter minimum operating level (MOL).

“Such occurrence is possible in forthcoming days if the heavy monsoon rain in northern Philippines continues,” said hydrologist Jason Bausa from State weather agency Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA).

He noted ‘habagat’ rain drenched part of the Angat watershed this week so runoff from this downpour helped fill up Angat Dam.

“The southwest monsoon affected quite a wide area,” he said.

In its dam update released Saturday (July 18), PAGASA reported Angat’s water level reached 178.40 meters as of 6 a.m. of the same day.

Such elevation is 2.20 meters higher than Angat’s water level of 176.20 meters 24 hours earlier, noted PAGASA.

Bausa said an estimated 100 millimeters of rain fell during such period, caused Angat’s water to rise that much and already reached a level merely 1.60 meters below the dam’s MOL.

“If such rains continue, Angat’s water level will reach the MOL and even possibly rise beyond this point,” he said.

PAGASA’s forecast is helping raise optimism for Angat Dam.

Monsoon rains will be experienced in central Luzon as well as northern Luzon’s Ilocos Region, Benguet province and Batanes, Calayan and Babuyan islands, PAGASA said in its 5 a.m. 24-hour public weather forecast released Saturday.

“Occasional rains are expected over Metro Manila, Mindoro, Calabarzon and the rest of Cordillera and Cagayan Valley,” PAGASA also said.

For Sunday (July 19), PAGASA likewise forecast monsoon rains in the northern Philippine cities of Tuguegarao, Laoag and Baguio as well as in central Luzon’s Olongapo and Angeles cities.

Angat supplies water for irrigation, power and Metro Manila’s use.

Government’s protocol is to stop water supply for irrigation once water level in Angat dips to the dam’s MOL.

PAGASA reported that this year, Angat’s water level breached the MOL on May 26 and reached an elevation of 179.98 meters as of 6 a.m then.

Even if Angat’s water level rises to the MOL or even surpasses this point, however, Bausa said the public must still practice water conservation, particularly when the El Nino phenomenon was in progress and even expected to intensify.

“We must avoid wasting water saved during the rainy season,” he said.

PAGASA hydrologist Eva Depaz also cited need for waterconservation, noting temperature rise would cause Angat’s water to evaporate.

“Rains can also ease, lessening supply of water to Angat so we need to practice conservation,” she said.

This week, PAGASA data show Angat’s water level rose by a mere 0.02 meters on Thursday (July 16) and reached 175.65 meters then from 175.63 meters the day earlier.

Rise in Angat’s water level was previously higher at 0.26 meters and 0.46 meters during the July 14-15 and July 13-14 periods this year, the data also show.

Depaz said lighter monsoon rain fell on part of Angat watershed during such days.