Manila Water in Monday said the Wawa-Calawis Water Supply System is becoming a major safeguard for water security in Metro Manila’s East Zone as climate change continues to put pressure on traditional water sources.
The multi-phase project is designed to strengthen and diversify water supply for Metro Manila and Rizal Province, reducing dependence on major reservoirs such as Angat Dam.
Phase 1, completed in 2022, established the Calawis Water Supply System using the Tayabasan Weir. The facility currently delivers 80 million liters per day (MLD) to the Calawis Water Treatment Plant, serving nearly one million residents in Antipolo City and nearby areas.
Phase 2 introduces the Upper Wawa Dam, considered the country’s largest new water source in the last 50 years. The dam is expected to supply up to 710 MLD exclusively for Manila Water’s East Zone concession area.
A key component of the project is the Flow Diversion Structure, which distributes raw water to multiple treatment plants to ensure reliable and flexible delivery across the network. The system already supports operations at the Calawis Treatment Plant using water from the Upper Wawa Dam.
Meanwhile, the Kaysakat Water Treatment Plant, targeted for completion by the fourth quarter of 2026, is expected to add 220 MLD to the system through a six-kilometer tunnel and a large transmission pipeline.
Manila Water said the expanded network will improve supply resiliency and help secure continuous water service despite growing demand and climate-related challenges.
“The Wawa-Calawis Water System stands as a symbol of that commitment, an enduring asset designed to serve not only today’s households but also the future of East Zone customers,” said Manila Water Corporate Communications head Dittie Galang.
The project highlights the increasing importance of long-term infrastructure investments as Metro Manila faces rising water demand and greater climate uncertainty.
