I have a flood hazard area polygon that I am creating based off a depth raster for a HUC 8 watershed. My workflow is smooth polygon, create cartographic partitions, intersect with the partition, then repair/check geometry of the intersected polygon (I'm unable to repair/check geometry of the whole polygon as is without the intersection as this will throw a 99999 error and I haven't figured out why). This will fix small geometry issues like self intersections and when I check the geometry it all checks out fine. However, when I dissolve that intersected polygon back to its whole self it has a null geometry for the main stem of the watershed when I repair geometry, even though it was fine while intersected. Any thoughts on why this may be happening or how to fix this without having to delete the whole main stem of the watershed? Thanks.
