It has been a long since I did one of these, but they were always popular, so I'm bringing it back.
I've thought about this subject before, because of a local flood control project which is ruinously expensive for a small town like mine, but it is also required for economic growth and risk mitigation. We have to go, hat in hand, to Congress to ask for $100M to complete this project, because it exceeds the fiscal capacity of the city to pay for that unassisted.
I hadn't know some of the mortgage underwriting bits of this.
A more detailed look at the specific Federal laws in question.