Growing up in Illinois, one of my U.S. senators was Everett Dirksen, one of the last "old style" orators of a bygone era. A quote attributed to him is, "A billion here, a billion there. Pretty soon you're talking real money." What I recall from my boyhood is that it was "a million here, a million there" since billions were not normally mentioned in the 1960s.
Illustrative of the concept of today and disaster recovery is this news item, Repair of California’s Oroville Dam Exceeds $1 Billion. One important item to note is that FEMA may reject some of the repair claims being made by California. You can duke it out with them, but they do seem to hold the purse strings.