An immediate and temporary answer, would be to ask every legal adult for 20$, doing so can purchase MRE's and water, that being said, it would also be important to consider the energy of a people as a whole, it is said that when you focus on two things, you give only half your effort; hence, the way we can handle this problem is to first have a national food drive whereby all citizens donate all foods for the homeless, that and to ask business in participating by donating and or buying at a fair price their goods, say canned goods that are easy to produce.
Essentially, cheap canned goods, asking of donations nation wide, provide a cheap source of immediate sustenance, asking for financial donation of 20$ from citizens.
This not being a solution, for the time stimulates the matter until a proper solution can be created.