Most disaster planning involves a government organisation overseeing the process and in the US case this would be FEMA.
I assume FEMA would requisition supplies and materials at hand for the general good and these goods would be repaid by the government after the emergency. What is not known is how even FEMA and similar organisations (the military, police or private groups for instance) are spread across the former USA and how much they can retrieve for survivors to use. As a side note many preppers who refuse to share are going to run afoul of these organisations.
FEMA may well have lists of essential materials, supplies and resources they must secure in the event of a general emergency and no doubt The Project got its hands on those lists.
EDIT: I note that The Morrow Project was written before FEMA existed. I bet that it was partially at least prompted by Mr Morrow and thoroughly infiltrated by The Morrow Project.
Wikipedia page on the Federal Emergency Management Agency
Federal Emergency Management Agency homepage