Manila Water, the East Zone Concessionaire of MWSS, expects the construction of its P8.2 billion Calawis Water Supply System Project to be completed in June 2023. The raw water for this facility comes from the Tayabasan River, located in Brgy. Calawis, Antipolo City. This area is part of the Upper Marikina Watershed, which Manila Water is helping to grow and maintain.

The Calawis Water Supply System Project is projected to provide additional 80 million liters per day (MLD) of treated water to 919,784 population in Antipolo City and nearby towns. At present, while preparing to commence full operations, the facility is already able to supply treated water to some areas of the city including the Antipolo Government Center. The Calawis Water Supply System Project is composed of the 80 MLD water treatment plant (WTP), pumping stations, reservoirs, and 21 kilometers of primary transmission line.

Degremont Compact Units (UCD)

The WTP used Degremont Compact Units (UCD), which are prefabricated, modular water and wastewater treatment plants engineered for efficient production, transportation, and installation. This technology significantly reduces footprint requirement and time for construction. The project also used pipe jacking technology, a trenchless method of installing pipes, on a portion of the pipelaying contract and for the two (2) river crossings to bring potable water to the customers.

Manila Water Senior Project Manager Engr. Vince Siat indicated that the project required the valuable cooperation and buy-in of key stakeholders in order to successfully complete and operate the project. “Manila Water was able to establish good relationship with relevant Local Government Units, the Department of Environment and Natural Resources, the Department of Public Works and Highways, the affected Indigenous People- the Dumagat Remontados of Antipolo City, and the National Commission of Indigenous People which enabled us to proceed with a successful development of the project. The Project team has ensured that the project complies with all necessary laws and regulations emphasizing the company’s adherence to social and environmental sustainability,” Engr. Siat added.

The Calawis Water Supply System Project is part of the company’s Water Supply Masterplan, which aims to ensure water security and supply reliability in the East Zone for the next decades, while lessening dependence on Angat Dam.