The Umiray-Angat-Ipo river systems located in Quezon and Bulacan provinces supply 97 percent of the water needs of residents of Metro Manila and suburban areas.
Built in 1967, Angat Dam, which can store up to about 850 million cubic meters, is fed by the Umiray Transbasin, 30 km across the Sierra Madre range from Aurora and Quezon provinces.
From Angat Dam, water flows through concrete diversion tunnels down to Ipo Dam.
The 4,100 million liters per day of water provided by the Umiray-Angat-Ipo river systems are just enough to meet the demands of 13 million people in its service area, according to Metropolitan Waterworks and Sewerage System’s (MWSS) Water Security Legacy Roadmap, implemented beginning in 2011.
The entire MWSS service area spans 1,940 square kilometers of land covering 40 cities and municipalities with a population of about 16.5 million. It is divided into two zones served by MWSS’ two concessionaires—Manila Water Co. and Maynilad Water Services Inc.
The east zone served by Manila Water covers Mandaluyong, Marikina, Pasig, Pateros, San Juan, Taguig, Makati, and parts of Quezon City and Manila. It also services Antipolo City and the Rizal towns of Angono, Baras, Binangonan, Cainta, Cardona, Jala-Jala, Morong, Pililla, Rodriquez, Tanay, Taytay and San Mateo.
The west zone served by Maynilad includes the cities of Manila (except San Andres), Pasay, Parañaque, Caloocan, Muntinlupa, Las Piñas, Valenzuela, parts of Makati and Quezon City, and Navotas and Malabon. Its franchise area also covers the cities of Cavite, Bacoor and Imus, and the towns of Kawit, Noveleta and Rosario.
—INQUIRER RESEARCH
Sources: Inquirer Archives, mwss.gov.ph