Homeless people will die. The folks on the hill aren't concerned about this. They're concerned about the essential workers. The small business owners. The good ones who fit nicely into the mold that was created to shape them after their birth.
Some of the hill folk consider the rain a cleansing. After all, the homeless people were part of the dirt.
The folks on the hill know that they will never flood, but the smart ones are concerned about a real danger. An ever-present danger. They are worried about the day when the serfs will have had enough and decide to climb the hill.
The flood will be red on that day, and it will be a cleansing that was a long time coming.