The city doesn't clean out drains. So trash and leaves build up and no rainwater can work through the detritus to drain off the streets, thus the flooding. Every Day is Opening Day Except for the Freaking Drains, y'all!
Flooding? I think not. In case you haven't heard, Shirly F. has fixed our sewers, therefore flooding is not possible. That was just a temporary, street grade retention pond.