In view of bottleneck problems in cloud-based delivery of inland waterway 3D models,such as client-side installation dependency,model bloat,and non-editable outputs,a dedicated 3D cloud design platform is developed.It leverages layered dynamic lightweight rendering and 3D data lightweight storage to keep cloud model size comparable to the original design,effectively avoiding data inflation from meshing and tiling in traditional workflows.Model modification and conversion are shifted to real-time online operations,achieving function upgrade of transforming the system from a “display platform” into an “interactive design platform”.In the application of a 2.8 km waterway project segment,3D dredging volumes generated via online cross and longitudinal section design automatically produce quantity takeoffs meeting code requirements.The platform overcomes the limitation of traditional cloud-based products that support only static browsing of building information modeling (BIM) and geographic information system (GIS) models,enabling an integrated “create-edit-render-apply” 3D design loop directly in web browsers,offering an efficient,lightweight,and iterative cloud solution for digital inland waterway design.