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I was able to create a contour raster based on my 2-foot contours. Pretty neat how ArcGIS Pro does that. However, I am trying to create the same thing using floodplain cross-sections I obtained from FEMA and the Flood Risk Information System (FRIS).

Everywhere I search I get how to create cross-sections FROM a raster. I want to go the other way (cross-sections TO a raster). The attached image shows the flood zones with the cross-section lines on top. If I can get the cross-section lines into a raster, I can then calculate the difference between the cross-section raster and the contour line raster.

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Assuming your cross sections are attributed with elevation values you can use those lines to create a Triangulated Irregular Network (TIN) using ArcGIS tools detailed here and here.
After your TIN is created you can export that TIN to a raster using the tools detailed here.

Keep in mind that these tools require a 3D analyst extension. If you do not have a 3D Analyst extension it is possible to accomplish this using QGIS (freeware) but you should post that as another question.

Finally, keep in mind that recently updated FEMA products will use elevations that reference NAVD88 but older FEMA products reference NGVD29. Here in western Washington some flood depths nearest salt water reference NAVD88 and flood depths a 1/2 mile upstream reference NGVD29! So some investigative work will be necessary to ensure an accurate surface output in a consistent vertical datum.

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  • Thank you for providing this. We do have the 3D Analyst and the Spatial Analyst extensions. I'll go ahead and create a TIN using the tools you mentioned. I'll also keep in mind the NAVD issue. Always something. Aug 22, 2023 at 18:20

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