The Metropolitan Waterworks and Sewerage System has projected that water demand for Metro Manila will increase to 6,950 MLD (million liters per day) in 2025, 8,300 MLD in 2035, and over 10,000 MLD in 2045. Currently, the water demand is 5,600 MLD, in which 4,000 MLD is sourced from Angat Reservoir through Ipo and Novaliches Reservoir, 200 MLD from Laguna Lake, and about 800 MLD from groundwater. The Angat Reservoir as water source is already topped off at 4,000 MLD, and its storage capacity is slowly decreasing due to sediment deposition. Laguna Lake may be tapped beyond its water permit grant of 300 MLD to perhaps as much as 2,000 MLD (Tabios 2016b), but this has to undergo serious public consultations and negotiations with other stakeholders of the freshwater supply in the lake. Groundwater has become unreliable due to water quality issues and pollution problems. Its usage has currently been reduced to 800 MLD from about 1,500 to 2,000 MLD being extracted in the 1980s, as indicated by the groundwater permits during that period. In view of this, there is an urgent need to seriously plan and seek investments to sequence and stage alternative water sources for Metro Manila to meet its increasing water demands, which will almost double 25 years from now. There are available water sources, but for reasons such as lack of investments, environmental impasse, or simply, complacency on the part of government, these sources are not developed especially for purposes of water security, redundancy, or resilience. Seventy-five to eighty percent of Metro Manila’s water use comes solely from the Angat Reservoir. However, it must be recognized that the Angat Reservoir has a risk of failure. These include possibilities of a dam break due to a massive earthquake; breakage of transmission lines (i.e., tunnels and canals) between Ipo Dam to the Novaliches Portal and La Mesa Treatment Plants or into the Novaliches Reservoir and the Balara Treatment Plants; water contamination along the Bicti–Novaliches open channel conveyance system or as it transits the Novaliches Reservoir by natural means; or even worse, by terrorist attack.