Mitigation measures do have real fiscal costs, both for government and for
private citizens.
Buildings constructed to building codes that offer high
levels of resistance will be more expensive than a building not
built to code (all other things being equal).
Levees are expensive to construct and maintain, both in
actual cost and in the broader costs of allocating land use.
And many of these measures are highly specific to individual
hazards. For example, a space
in a residence hardened to provide protection against tornado
impacts is of little value in protecting against flooding, and a
levee system that is very effective against flooding does little to
control tornado impacts.
