You might google "rain garden Georgia" to find suggestions for plants that would tolerate shade and occasional flooding.
Hope some knowledgeable Georgia gardeners can add more assistance. .
Pat

Jewel Weed and ferns are among the few plants that like both shade and water.

Itea "Little Henry" is a neat shrub. Has some funky flowers and loves the moist soil. I prune mine a bit, just because. It does sucker a bit, so it will fill in nicely for what you want. Not too tall, not too short. Should get about 2 - 3' and spread about 3'.

Tough plant will tolerate shade (as mine does behind an apple tree). It sucks up the water from the downspout.

Jim

If you're refering to a "dry creek" that channels stormwater through and off of your lot, I have daylillies growing like weeds next to mine.