Many cities have been asking residents to keep an eye on their nearby street drains and make sure they aren't getting clogged with leaves and stuff. It just takes a minute to get the rake out and clear the grate and prevent clogging. There are just too many drains for the city workers to police. Why wait until it's too late and flooding starts, then try and get the workers to come and clear whenever they fit it in to a busy storm schedule? Prevention! ;-)