Generally Federal and State Governments don’t buy Property Insurance. It would be very costly and a source of possible corruption as to which carrier gets all the premiums paid by taxpayers.
Availability of Dam Insurance -- Association of Dam Safety Officials
I’m wondering about insurance because, depending on homeowners/businesses/property owners/local govt’s coverage, a whole lotta folks may not be covered for a variety of things like loss of business, property damage, costs incurred by evacuating. Hopefully if that’s the case, the dam’s owner has coverage.