TUFLOW
Commercial
Benchmark-setting commercial 1D/2D flood engine with GPU acceleration — dominant in AU/UK flood studies.
Hydraulics & River SystemsActive2D Hydraulic ModellingFlood Mapping
8 tools · Collection
Alternatives to HEC-RAS
HEC-RAS is free, capable and universally accepted — which is why "alternative to HEC-RAS" is usually a question about specific gaps: GPU speed at scale (TUFLOW), sediment and morphodynamics depth (BASEMENT, Delft3D FM), a scriptable open solver (ANUGA, Telemac), FHWA-preferred bridge hydraulics (SRH-2D), or a strong 1D structure library with a free tier (Flood Modeller). This collection maps each alternative to the gap it actually fills.
Flood Modeller
Freemium
Jacobs' 1D/2D river and floodplain suite — a UK practice staple with a genuinely useful free tier.
Hydraulics & River SystemsActiveRiver Modelling2D Hydraulic Modelling
SRH-2D
Free
The US Bureau of Reclamation's free 2D river model — FHWA's preferred engine for bridge hydraulics.
Hydraulics & River SystemsActive2D Hydraulic ModellingRiver Modelling
BASEMENT
Free
ETH Zurich's free 2D hydraulics and morphodynamics simulator — rivers, sediment and hazard mapping.
Hydraulics & River SystemsActive2D Hydraulic ModellingSediment Transport
Iber
Free
Free Spanish 2D hydraulic model — flow, turbulence, sediment and habitat modules behind a full GUI.
Hydraulics & River SystemsActive2D Hydraulic ModellingFlood Mapping
openTELEMAC
Open Source
EDF's open-source finite-element suite for free-surface flow — 2D/3D rivers, estuaries, waves and sediment.
Hydraulics & River SystemsActive2D Hydraulic ModellingCoastal Modelling
ANUGA
Open Source
Open-source 2D shallow-water modelling in Python from Geoscience Australia — strong for dam break and tsunami.
Hydraulics & River SystemsActive2D Hydraulic ModellingDam Break Analysis
Delft3D FM
Open Source
Deltares' open flexible-mesh suite for rivers, estuaries and coasts — hydrodynamics to morphology.
Hydraulics & River SystemsActiveCoastal Modelling2D Hydraulic Modelling