MANILA - The construction of China-funded Kaliwa Dam in Infanta, Quezon could provide another source of water amid the shortage in parts of Metro Manila, the Metropolitan Waterworks and Sewerage System (MWSS) said Wednesday.

MWSS Administrator Reynaldo Velasco said Manila Water and Maynilad will each receive 50 percent of the resource from Kaliwa Dam, which is expected to provide up to 600 million liters a day.

He said the target completion of the dam is in 2023, but it might be finished earlier if the project's Chinese contractors could make shorter the 27-km tunnel which will connect the water source to the treatment plant.

The P18.72-billion dam is funded by official development assistance from China.

“We have already agreed with the contractor that instead of just going from one place, one point straight all the way, I asked them if they can do it both ends so that instead of 27 kms, it will be about 13.5 and hopefully it will cut the tie about one half. If they can do that I think they can do that before 2022,” Velasco said.

But the project’s realization also depends on one important thing: it still has to secure an environmental compliance certificate (ECC) from the Department of Environment and Natural Resources.

The construction of the said dam has been met with protests from environment groups and locals because of concerns on its alleged environmental impact and unauthorized use of ancestral land.

Environment Undersecretary Benny Antiporda, meanwhile, said there is no pending ECC application for the Kaliwa Dam.

He added that the agency has listed down the requirements for the ECC but that no movement for the project’s ECC application has been made.

Manila Water, in charge of the capital's east zone, is "rushing" to energize its treatment plant in Cardona, Rizal within the month, MWSS chief regulator Patrick Ty earlier said.

The concessionaire has been grappling with short supply from the Angat dam and the declining water level at the La Mesa Dam, its emergency source, due to lack of rains, leading to water interruptions in parts of Metro Manila.

• Manila Water 'rushing' treatment plant to ease shortage: MWSS

Maynilad, which serves the West Zone of Metro Manila, is "unlikely" to experience a shortage, its chairman Manny Pangilinan said Wednesday.

• Manila Water admits project delays worsened supply problem