Prolonged heavy rains, rising river levels and strong currents contributed to the collapse of a portion of the flood control structure at the ongoing Nangueg West Bridge project in Narvacan, Ilocos Sur, according to Department of Public Works and Highways (DPWH) sources.

The bridge remains under construction and had not yet been opened to regular traffic when the damage occurred.

DPWH sources said continuous rainfall caused the river to rise and washed away about 20 meters of a temporary compacted-earth access road beneath the bridge. The washout altered the water flow, directing stronger currents toward the flood control structure and increasing hydraulic pressure on the affected section.

The contractor, Satrap Construction Co. Inc., likewise attributed the damage to strong water currents brought by heavy rains and Typhoon Maymay. In an August 10, 2026 letter to DPWH officials, the contractor said the increased river level and strong current caused part of the revetment to slip and collapse.

Satrap said it would undertake repairs, including reconstruction of the collapsed revetment and assessment of the existing foundation.

DPWH sources cautioned against immediately attributing the damage to construction defects or poor workmanship, saying the project was being implemented according to approved plans and specifications and that construction materials had undergone required testing.

Still, the precise cause and extent of the damage remain subject to engineering assessment. The collapse does not by itself establish a construction defect, but the affected foundation and construction conditions will need to be examined before further work proceeds.