I'm smart enough to know that homeless people aren't bad folks, and that homelessness doesn't mean scaring customers away or even mean uncleanliness. Landscapers and other folks that get stinky, dirty, and sweaty are welcomed in.

And I've "let" homeless folks into places I work before and given folks water. The McDonalds I've worked at did not charge for water. I'll also mention that water fountains aren't all that useful during winter.