The Angat Hydropower Corporation, which is the operator of the Angat Hydro-Electric Powerplant (AHEPP), will undertake major repair and rehabilitation of its existing penstock in conjunction with the modernization of the powerplant. The primary objective of the undertaking is to prolong the lifespan of the plant to ensure a stable water supply for the domestic and irrigation water supply. To achieve this, a Total Plant Shutdown (TPS) of AHEPP is required for 61-days, starting from 06 November 2023 to 06 January 2024.

To ensure water supply for the domestic and irrigation water supply during the TPS, the Metropolitan Waterworks and Sewerage System (MWSS), together with Maynilad and Manila Water, spearheaded the creation of comprehensive guidelines on the operation of the Angat Dam spillway and low-level outlet. These guidelines have been unanimously agreed upon by members of the Interagency Technical Working Group on Angat Dam Operations and Management, including the National Water Resources Board (NWRB), the National Power Corporation (NPC), the National Irrigation Administration (NIA), MWSS as well as other key stakeholders such as Maynilad, Manila Water and Angat Hydroelectric Corporation.

With the current water level of Angat Reservoir at 209.48-meter, which is near its Normal High-Water Level (NHWL) of 210-meters, the MWSS assures a continuous supply of raw water for the MWSS service areas in Metro Manila, Bulacan, Cavite, and Rizal Provinces throughout the entire TPS period.