Consider me skeptical. Sand bags do add bulk, but not strength or water impermeability.
The spillway cladding was clearly undercut and has given way, leaving the earthen dam below exposed..I'd note that the spillway appears poorly supported at best, probably not designed for heavy use.
If there is renewed rain, that expensively air lifted sand won't help.
What is needed is to lower the water level of the impoundment and a subsequent reconstruction of at least that part of the dam and the spillway.