PT Pembangkit Pusaka Parahiangan is currently undertaking an engineering design and structural rehabilitation project for the existing waterway structure of PLTM Pusaka-1, which has experienced damage and deformation. These issues are the result of very slow ground movement of the creeping type originating from the higher western slope adjacent to the waterway, which has gradually affected the structure and disrupted the water discharge essential for power plant operations since the early operational stage.

At present, the concrete waterway has developed numerous cracks, but no significant water leakage has occurred, as the surface of the channel is protected by a 2 mm thick HDPE geomembrane, maintaining the integrity of the water flow.

At STA 2+200, the structure has undergone a slight shift toward the east, and uplift movement has been observed between STA 2+150 and STA 2+275, resulting in reduced water flow capacity due to flow obstruction. A 35 cm high crest elevation was constructed behind STA 2+150 to allow water to pass over the uplift zone. However, this caused overtopping at around STA 2+190, limiting the power plant’s maximum operational output to 6.7 MW.

This project aims to restore the waterway structure to its original condition, ensuring it can deliver a steady discharge of 7 m³/s, sufficient to support power generation up to 8.8 MW.