There is no cause for alarm on the dwindling water level in Angat Dam as it still does not have an effect on Metro Manila's water supply, the National Water Resources Board (NWRB) said Wednesday.

At the same time, NWRB Executive Director Vicente Paragas said the suspension in Angat plant’s operations from July 7 to 9 “is just part of the plant’s maintenance work.”

Angat plant manager Engr. Rodolfo German earlier said the suspension of the dam’s operations is intended to give the plant’s turbines their needed break.

The Angat plant’s management decided to suspend its operations after the water level in Angat Dam reached the 159-meter mark last Sunday.

As of Wednesday, Angat Dam remained at a “highly critical level” of 159.15 meters, or 22.32 meters short of the dam's normal operating level.

It breached its 179-meter critical level last April.

Paragas explained that Angat Dam still supplies domestic water to Metro Manila using a low-level water outlet, which is capable of operating below a 160-meter water level, going directly to Bulacan’s Ipo Dam and further down to La Mesa Dam in Quezon City.

Angat Dam supplies 97 percent of Metro Manila’s domestic water needs, and irrigates 27,000 hectares of farmlands in Bulacan and Pampanga.

Due to the decreasing water level in Angat Dam, the present allocation for domestic water supply in Metro Manila has been reduced by about 28 percent from the normal 46 cms to 33 cms earlier this year.

Paragas said the current allocation will be implemented until July 31.

Meanwhile, irrigation needs will be temporarily sourced from nearby tributaries.

“We still expect the continuous decline in Angat’s water level because of the low water inflow to the reservoir.

We will be sitting down with the technical working group to decide on whether to retain or reduce the present water allocation,” Paragas said.

The NWRB said the actual historical water inflow in Angat Dam is only 8 percent at present, contrary to the normal inflow of 70 percent.

“But as of now, we still have no problem with Metro Manila’s water supply. The supply is still sustained,” he said.

Paragas also said Angat Dam will not likely breach its lowest level of 158 meters recorded in July 1998 because the NWRB expects rains to prevail over the watershed by the middle of July.