Who do I talk to about grading?

My property has some drainage problems that have led to flooding in the past. I'd like to correct them, but I'm not really sure who to talk to. I've tried a couple landscapers, but didn't have much confidence in their suggested approaches. Is there any kind of professional certification I should be looking for when I talk to these people?

Edit: I sent a message to the local university extension office, and they said they didn't know who would be able to help.