As part of the Israel Natural Gas Lines (INGL) infrastructure project, we conducted a comprehensive geophysical investigation at the Hadera Stream estuary to support the design of an underground gas pipeline installation and sheet pile walls. The work included geophysical surveys, a magnetic survey, exploratory boreholes, manual excavation, underwater inspection, UAV (drone) documentation, and historical aerial imagery analysis. The investigation enabled the detection and mapping of boulders, metallic debris, and other subsurface obstructions, which were verified through boreholes and excavations. The integrated results provided a detailed understanding of subsurface conditions, supporting the safe design and execution of the construction works.