HEC-RAS
The world's most used hydraulic model: free 1D/2D river analysis, sediment, water quality and flood mapping.
EDF's open-source finite-element suite for free-surface flow — 2D/3D rivers, estuaries, waves and sediment.
by EDF R&D / TELEMAC Consortium
The openTELEMAC-MASCARET suite, led by EDF R&D, solves free-surface hydrodynamics by finite elements on unstructured meshes: TELEMAC-2D/3D for flow, GAIA for sediment and morphodynamics, TOMAWAC for waves and MASCARET for 1D. It carries decades of production use in European river, estuarine and coastal engineering, including safety-critical EDF studies.
Fully open source with an active consortium, it scales to large parallel runs and is a serious free alternative to Delft3D for estuarine and coastal work. Expect a steeper setup curve than desktop-GUI packages; the QGIS and BlueKenue toolchains ease model building.
Other hydraulics & river systems tools covering similar workflow stages.
The world's most used hydraulic model: free 1D/2D river analysis, sediment, water quality and flood mapping.
FHWA's free culvert analysis program — the reference implementation of HDS-5 culvert hydraulics.
Open-source 2D shallow-water modelling in Python from Geoscience Australia — strong for dam break and tsunami.
ETH Zurich's free 2D hydraulics and morphodynamics simulator — rivers, sediment and hazard mapping.
GPU reimplementation of the CaMa-Flood global river routing model — continental flood simulation on PyTorch/Triton.
Deltares' open flexible-mesh suite for rivers, estuaries and coasts — hydrodynamics to morphology.