Judgement call - when does disaster become normal?

I ran across this article in the Orlando Business Journal - Drought disaster loan deadline approaches.

So I'm wondering, if the climate actually changes in a place and drought becomes the norm, when does the government decide that the losses due to drought are no longer a disaster? Same with flooding - if the hundred-year flood becomes the 2-year flood, does flood insurance still work?

Should be interesting to see how such matters are handled in the future.