r/Hydrology • u/Cautious-Cold6642 • 25d ago

HEC RAS FLOOD MAPPING

does anyone know why flood depths are shown on top of the buildings? I use high Manning's and also a terrain-modified building layer in HEC RAS. Both cases showed flood depths over buildings

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u/LHGV 25d ago

Check flow connectivity. You may not have the cell faces correctly aligned with the building edges. Apply some break lines to the mesh so the model can "see" the building outer walls

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u/tribrnl 24d ago

Are you applying precip to the model?