SRH-2D — The Complete Guide: A 2D Flow and Sediment Model for Rivers, Bridges and Floodplains
SRH-2D is a two-dimensional hydraulic model for streams and rivers, developed by the US Bureau of Reclamation together with the FHWA. Unlike a one-dimensional model that assumes an averaged cross-section, it solves the velocity field in plan — so it suits cases where flow is not parallel to the channel.
SRH-2D — 2D Flow and Sediment Transport Model
U.S. Bureau of Reclamation
Two-dimensional hydraulic model for streams and rivers, including sediment transport and bed morphology.
Get it from the vendorWhat you get
- Bridges and culverts — contractions, flow around piers and pressure flow.
- Floodplains — water spreading beyond the main channel.
- Tributary junctions and bypasses — complex flow in plan.
- All flow regimes — subcritical, supercritical and transitions between them.
- Sediment — multi-size transport with the bed level changing over time.
What is free and what is not
The model itself is a free download with no registration, and it runs on Windows. But building the mesh and viewing results are usually done in the Aquaveo SMS interface, which is a separate commercial product. SMS has a free Community edition that supports SRH-2D, but it is limited to one mesh and one simulation and cannot export to GIS or CAD formats. Full work requires a paid licence.
Related tools
When one dimension is enough, or for 2D with a complete free interface — HEC-RAS. For unstructured meshes that are fully open source — TELEMAC-MASCARET. To prepare the elevation model — QGIS.
HEC-RAS
US Army Corps of Engineers
1D/2D hydraulic model for rivers, bridges and culverts, with floodplain mapping. The world standard.
Get it from the vendor
TELEMAC-MASCARET
EDF / Consortium
Hydrodynamic system for rivers and coasts on unstructured meshes — flow, waves, sediment and quality.
Get it from the vendor
QGIS
QGIS.org
Open-source GIS for spatial analysis, layer work and map production.
Get it from the vendor
HEC-HMS
US Army Corps of Engineers
Rainfall-runoff hydrological model — infiltration, unit hydrograph and routing. Pairs with HEC-RAS.
Get it from the vendorThe bottom line
SRH-2D is a proven professional model for bridges and rivers, but plan the interface question in advance: the free SMS edition suits learning and small projects.