In one embodiment, a bathymetry system includes a base slab, multiple spacer assemblies, a decking layer, multiple computer numerical control routed blocks, a waterproof coating, and multiple floor joints. The spacer assemblies are coupled with a top surface of the base slab, the decking layer is disposed on top surfaces of the spacer assemblies, the blocks are disposed on a top surface of the decking layer, floor joints are disposed between blocks and the decking layer, and the waterproof coating is disposed on top surfaces of the blocks. The top surfaces of the routed blocks are shaped so that the blocks collectively provide a bathymetry profile, such as a bottom contour of a riverbed.