Angat Dam’s lifespan nearly up

The Metropolitan Waterworks and Sewerage System (MWSS) is in a hurry to find new water sources for Metro Manila as Angat Dam’s lifespan is nearing its end, officials said yesterday. 

Engineer Jose Dimatulac, chief of the MWSS engineering department, told participants at the first Forest Summit held in Malolos, Bulacan that siltation is the primary cause of the problem in Angat Dam, the source of 97 percent of the water distributed by MWSS concessionaires in Metro Manila and is the primary source of drinking water for the metropolis’ 12 million residents.

“But if Angat Dam can be rehabilitated, it will last for 50 more years,” he said. He refused to state the number of years or months remaining in Angat Dam’s lifespan.

Water from the Angat Dam reservoir flows through nearby Ipo Dam and then to the La Mesa Dam in Novaliches, Quezon City.

Dimatulac said they have been considering at least four old and new water sources to replace Angat Dam: Laiban Dam in Rizal, which will be supplemented by water flowing from the Kaliwa and Kanan Rivers; the Laguna Lake; the Sumag River; and the Wawa Dam, also in Rizal.

He said that Laiban Dam’s capacity will be doubled when water flowing from the Kaliwa and Kanan Rivers are re-routed to it. 

Dimatulac also told participants at the summit that there is a proposed $1-B project for the utilization of the Laiban Dam. Chinese investors were supposed to fund the project, which was sidelined following the national broadband network scandal.

He said they are also planning a project that will draw 300 million liters of water from Laguna Lake per day for treatment prior to distribution.

Dimatulac added that they are also looking at the possibility of partially reviving the Wawa Dam in the Marikina watershed.

Wawa Dam was the primary source of Metro Manila’s drinking water in the early 1900s, but it was de-commissioned in the 1970s due to low water holding capacity caused by heavy siltation, and pollution caused by Foremost Farm, a large piggery. 

“Another problem with Wawa Dam is the loss of our pipeline from there to the Balara treatment plant,” Dimatulac said, noting that some squatters have cannibalized the pipeline while others used it as a sewerage system.

He said that in case the rehabilitation of the Wawa Dam takes place, they will have to replace the old pipeline.

Dimatulac said that the watersheds of all the dams are either threatened or in a critical state.

He said that Angat Dam’s 63,000-hectare watershed still has at least 80 percent forest cover, while La Mesa’s 2,700-hectare watershed has 85 percent, but only 30 percent of Ipo’s 6,600-hectare watershed has forest cover.

Other officials who participated in the summit – such as Moises Butic, who heads the Provincial Environment and Natural Resources Office (PENRO) and Mendel Garcia of the Angat Watershed Area Team – said increasing deforestation in the watershed areas was due to illegal occupancy, timber poaching, and kaingin farming.

Garcia said at least 800 families have encroached on the Ipo Dam watershed area, and about the same number are living within the Angat watershed.

As this developed, SSMMC members Martin Francisco and Dante Navarro asked the MWSS to fasttrack the approval of an “Environment Army” to support the members of Task Force Kalikasan and the province’s “Green Police” in going after illegal loggers and timber poachers.