OSM does not route anyone anywhere, that is done by third party routing software. Unless there is a real legal prohibition on using the ford, access=no and the other similar tags which you have added are incorrect and should be removed. Access tags reflect the legal position, not personal opinions on suitability for a mode of transport.

Adding flood_prone=yes seems quite reasonable.

You could also consider adding hazard=flooding and possibly depth, see:
https://wiki.openstreetmap.org/wiki/Tag%3Ahazard%3Dflooding
https://wiki.openstreetmap.org/wiki/Tag:ford%3Dyes

It can take time for routing software to update from OSM data - what are you using?