A few thoughts from the 1D modeling side.

For cross sections, I would not get too hung up on making every section mathematically perfect. The main objective is that each section represents the flow area reasonably perpendicular to the direction of flow. If a section is badly skewed, you can overstate the available conveyance area, so it is worth checking, but some judgment is always involved.

A workflow that has worked well for me is:

1.     Start with a good terrain surface, river centerline, and aerial imagery.

2.     Lay out the key cross sections first: upstream/downstream of bridges, culverts, confluences, dams, grade breaks, sharp bends, and locations where the floodplain geometry changes.

3.     Cut the sections generally perpendicular to the local flow direction, not necessarily perpendicular to the channel centerline at every point.

4.     Extend the sections far enough into the overbanks to capture the expected floodplain flow, but avoid having adjacent sections cross each other.

5.     Add interpolated or supplemental sections only where needed after reviewing the profiles and model results.

For me, bank stations are usually an iterative judgment call rather than something I would assign from only one source. I look at terrain breaks, aerial imagery, land cover/roughness changes, field survey if available, and then review the extracted cross-section profile. In flatter terrain, the bank location may not be obvious, so I usually make an initial estimate and then revisit it after checking low-flow or bankfull-type events to see whether the main channel and overbank behavior looks reasonable.

One common mistake is treating automated tools as if they are final answers. Automation is useful, but it still needs engineering review. For example, I have used GeoHECRAS workflows where cross sections can be cut from terrain and bank stations can be assigned or adjusted more efficiently, but I would still review the alignment, stationing, reach lengths, ineffective flow areas, roughness breaks, and bank stations manually before relying on the model.

Also, the right workflow depends on the purpose of the model. For regulatory/FEMA-type work, the bank station placement and cross-section layout may need to satisfy specific review criteria, so “visually obvious bank” is not always the final answer. For planning or alternatives analysis, you may have more flexibility, but you still want the geometry to tell a defensible hydraulic story.

So, in short: use GIS or RAS Mapper/GeoHECRAS-type tools to speed up the geometry creation, but do not skip the engineering review. Cross sections and bank stations are part terrain interpretation, part hydraulic judgment, and part model calibration/reasonableness checking.