Garage drain backing up after a heavy rain
We just had new gutters and downspouts installed a few weeks ago. We had a brief, heavy rain today, and our garage drain backed up, shooting water up like a geyser. We live in Ohio, in a ranch house, with a full basement. The basement drains are completely dry and no water came in. Yet the garage, which is on the ground floor (higher than the basement, of course), flooded like crazy.
I assume part of the problem is the new gutters, because they are clean and unclogged, are letting so much rain in the drains can't handle it. Could this be a simple problem that one of the drains from the gutters are clogged, and if so, how can I verify this? Any other suggestions? While the rain was heavy, we've had worse with no problems.
Thank you for any advice you can give.