The Metropolitan Waterworks and Sewerage System (MWSS) wants to recommend maintaining the current water supply allocation to sufficiently meet the demand during the summer season.

MWSS Division Manager Patrick Dizon told Manila Bulletin on Thursday, April 25, that they will be meeting with the National Water Resources Board (NWRB) to discuss retaining the 50 cubic meters per second (cms) allocation for May.

“Based on the meeting with the members of the technical working group, they’re recommending [the NWRB] that there should be no deduction on MWSS’ part… I’m confident that the NWRB board will approve this,” he said.

This collective agreement stemmed from the forecast of the Philippine Atmospheric, Geophysical, and Astronomical Services Administration (PAGASA) as the country witnesses the ongoing effects of the scorching weather.

PAGASA recently announced the possibility of a 46-degree dangerous heat index in Metro Manila.

“[Sufficient water supply] would ease the burden of the prolonged heat. This is why we’ve requested to maintain the allocation to 50 cms.”

While Metro Manila’s concessionaires are making current mitigation efforts– Manila Water and Maynilad, the MWSS still hopes to lower the dependency on Angat Dam.

“We have a water security plan ng MWSS to decrease the dependency on the Angat Dam further. We have the Wawa Dam and Kaliwa Dam projects [to help with this].”

From the current 90 percent dependency rate, the state-run agency hopes to bring it down to 80 percent in the coming years.

“The Wawa Dam is almost complete,” Dizon said. “We’re planning to inaugurate this May but we’re scheduling it. Operations are expected to begin by December 2025.”

The Kaliwa Dam, another construction that has been said to alleviate reliance on Angat, would be operational by yearend 2027.

Meanwhile, Dizon also shared that the water supply in Angat would continue to decline and reach below the minimum operating level by next month.

“We projected based on PAGASA’s rainfall projection,” he explained.

“[We’re forecasting that this] will heat up to 170 m and reservoir by the end of May which is below the minimum operating level of 180 m. But this shouldn’t go down to the critical level of 160 meters. The lowest will probably be 178 meters.”

The MWSS noted Angat’s elevation has gone down to 190.07 meters as of Thursday. This is 8.7 meters lower than the record of 198.77 meters earlier this month.