08/10/2026
Assessment of BalogโBalog Dam tunnel components
October 8, 2026
Brgy. Maamot, San Jose, Tarlac
The BBMPII Project Manager, Manager of the Construction Management Division, Chief of the Dam Aspect Section, tunneling supervisors, and the Head of the Design Unit of the Engineering Division conducted an on-site evaluation of the Balog-Balog Storage Dam tunnel components today. Design engineers and geologists from NIA Central Office were called in to assist the assessment.
The activity followed a collapse at the diversion tunnel excavation face near the outlet portal. Immediate assessment by BBMPII and the contractor indicates the collapse was likely caused by the tunnel faceโs proximity to a mapped fault, compounded by poor ground quality that undermined stability despite existing support measures used during drillโandโblast excavation.
The inspection included the inlet portal of the diversion tunnel and the irrigation and power tunnel, where the team recorded ground condition observations and collected data to inform final engineering recommendations. The activity concluded with a meeting at the contractorโs temporary facilities to review findings and coordinate next steps. BBMPII, the contractor, and NIA Central are working together under close oversight to determine the safest tunneling approach. Personnel safety and longโterm structural integrity remain the top priorities.
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