Large-scale physical model studies are necessary to ensure the performance of prototype structures. Though laboratory constructions are usually carried out using several ground control points (GCPs), a high-resolution digital elevation model (DEM) of the physical model is required to perform numerical simulations for various scenarios to reduce the cost and time of physical model studies. In addition, they are also required for accurate and reliable simulation of real-time flood and storm events, hydrologic-hydraulic modeling of river flows, and morphological analysis of rivers. Photogrammetric techniques coupled with high-end image analysis technologies have made the generation of DEMs of required resolution less tedious. This work presents a detailed stepwise methodology to generate a very high-resolution DEM (i.e., three-dimensional model) of a large laboratory setup employing digital single lens reflex (DSLR) imagery, Structure-from-Motion (SfM) Multi-View-Stereo (MVS) processing, and well-distributed GCPs and check points (CPs). Good quality (image quality ≥ 0.5) and overlapped (about 80% in both directions) images are captured using overhung wide-angle lens DSLR cameras, which are later processed using the SfM-MVS approach in the commercial software package Agisoft Metashape. A 1 mm resolution DEM of the 15 m × 4 m laboratory setup is generated herein. A total of 80 GCPs and 32 CPs are used for proper orientation and fine refinement of the DEM. The 2.5D geometry in the form of DEM can be used to carry out numerical modeling. An illustration of the same is presented using HEC-RAS, one of the most adopted hydraulic simulation platforms.