HEC-RAS Supplementary Guide Coverage

The official HEC-RAS Guides and Tutorials site includes a short Guides section for modeling techniques, RAS Mapper workflows, and troubleshooting notes. This page maps those supplementary guides to current ras-commander APIs and example notebooks so users can tell what is automated today and what still requires HEC-RAS or RAS Mapper.

Source: USACE HEC-RAS Guides and Tutorials.

Coverage Matrix

Guide	ras-commander coverage	Current APIs and examples	Follow-up need
Downloading Terrain Data	Partial	Usgs3depAws discovers USGS 3DEP projects and downloads 1 m tiles; RasTerrain.create_terrain_hdf() creates RAS Terrain HDFs; RasMap.add_terrain_layer() registers terrain layers; notebook examples/920_terrain_creation.ipynb demonstrates the workflow.	Add 10 m/30 m direct download parity, product-table selection helpers, and a single documented acquisition-to-terrain workflow.
GDAL Projection File Warning	Documentation only	RasMapValidation.check_layer_crs() and HdfBase.get_projection() can inspect CRS metadata; RasTerrain._generate_prj_from_raster() can emit ESRI WKT from a raster CRS.	Keep as troubleshooting guidance. No notebook is needed.
Skip SRS Translation For Terrain Imports	Documentation only	RasTerrain.create_terrain_hdf() currently requires an explicit project .prj; ras-commander does not intentionally skip source-raster SRS translation.	Keep as a manual RAS Mapper workaround and document when not to automate it.
Export Channel Data for Terrain	Gap	GeomCrossSection, HdfXsec, and geometry parsers can read cross sections; RasTerrain can build terrain from rasters.	Add XS-to-GeoTIFF channel export and merge workflow before writing a notebook.
Re-projecting Model Geometry	Gap	ras-commander can read CRS metadata and validate layer CRS; eBFE helpers include targeted raster reprojection for delivery repair.	Add a public model-geometry reprojection API with preflight, backup, and post-conversion QA.
Creating a Terrain Dataset to Model a Flume Experiment	Partial	Synthetic raster creation can feed RasTerrain.create_terrain_from_rasters(); RasTerrainModWriter can create channel cuts, high-ground levee/road lines, and fill-surface terrain modifications.	A focused notebook is feasible after the channel-export gap is resolved or with a raster-first synthetic terrain approach.
Modeling Steep Reaches	Partial	RasPlan.update_plan_intervals() adjusts computation/output intervals; RasPlan manages HDF output settings; RasModPuls supports a different 2D storage-outflow extraction workflow.	Add 1D Hydrologic Unsteady Routing / Modified Puls region setup and rating-curve import support if this RAS feature is in scope.
Aligning Cell Faces in Channels with Refinement Regions	Medium	GeomMesh.add_refinement_region(), set_refinement_region_spacing(), set_breakline_spacing(), and generate() support refinement regions and mesh regeneration when a current geometry HDF exists; notebook examples/230_mesh_sensitivity_analysis.ipynb covers mesh sensitivity and refinement management.	Add a flowline-buffer-to-refinement-region helper and a guide-specific notebook when mesh authoring coverage is stable.
Creating a Combined 1D/2D Model	Partial	GeomLateral and RasGeometry read lateral structures and SA/2D connections; HdfMesh, HdfResultsMesh, and RasCheck support 2D results and stability review; notebooks examples/202_2d_plaintext_geometry.ipynb, 410_2d_hdf_data_extraction.ipynb, and 412_2d_detail_face_data_extraction.ipynb cover parts of the review workflow.	Add connection-authoring or audit helpers before a full combined-model build notebook.
Modeling Weirs in 2D Areas	Gap	GeomLateral can read SA/2D connection profiles and gates; HdfStruc can list SA/2D connection results; RasCheck contains structure and velocity checks.	Add SA/2D connection and 2D internal weir creation/editing APIs, including overflow-method and mesh-placement QA.

CRS and SRS Troubleshooting Notes

RAS Mapper expects project projection files in an ESRI-compatible .prj form. When a raster or projection file carries CRS metadata that HEC-RAS cannot translate, first inspect the data outside the model and only then decide whether a manual RAS Mapper workaround is appropriate.

Recommended ras-commander checks:

Python

from ras_commander import RasMapValidation
from ras_commander.terrain import RasTerrain

RasMapValidation.check_layer_crs("terrain_source.tif", expected_epsg=5070)
RasTerrain._generate_prj_from_raster("terrain_source.tif", "Projection.prj")

Use the manual "skip SRS translation" workflow only when the raster is already in the intended project coordinates and the embedded SRS is missing or malformed. Do not use it to hide a real CRS mismatch; a bad mismatch will usually show up later as misplaced terrain, bad geometry associations, or failed 2D property-table extraction.

Notebook Scope

The current notebook set already covers terrain creation, mesh sensitivity, terrain modifications, SA/2D parsing, 2D HDF extraction, and map-layer validation. New notebooks should be added only when the underlying API can perform the repeatable part of the guide without relying on manual GUI actions.

Candidate follow-up notebooks:

Guide	Notebook scope
Flume terrain	Build a small synthetic terrain from a raster, register it in RAS Mapper, and inspect the result.
Refinement-region cell alignment	Convert channel flowlines to buffered refinement regions, set spacing, regenerate mesh, and compare face alignment.
Combined 1D/2D model review	Audit lateral structures, terrain associations, mesh cells, time-step/HDF settings, and key stability outputs on a real example project.
2D weir review	Inspect SA/2D connection profiles, mesh faces, max velocity, and submergence indicators once authoring/editing APIs exist.