If I didn’t hate wetlands enough because they were mosquito-infested swamps of no use to human beings, I would hate them because of how much extra work they cause when they get imported to OSM.

http://tools.geofabrik.de/osmi/?view=multipolygon&lon=-89.81616&lat=29.59161&zoom=9&overlays=invalid_geometry_hull,duplicate_ways,intersections,intersection_lines,ring_not_closed_hull,ring_not_closed,unconnected_end_nodes,touching_inner_rings_hull,touching_inner_rings,role_mismatch_hull,role_mismatch,ways,role_markers,way_end_nodes,way_nodes

Sorry environmentalists :)