Forest garden plants for floodplain

Our house in the NC Piedmont is on a urban creek that floods about once/year, usually in hurricane season. Our "back 40" is wooded and we mostly ignore it, but I would love to turn it into a miniature forest garden. It is mostly made up of smallish hardwoods and alot of the undergrowth is an invasive type of honeysuckle shrub. The soil is like a sand box. We do have some interesting spring ephemerals - spring beauties, mayapple, trout lily. Otherwise it's pretty boring, would appreciate suggestions of any useful type of plant especially food, medicinal, and pollinator plants.

things that come to mind that would do well in a once a year flooding understory are things that don't mind having their feet wet. do you have a patch of wild ramps? if so, you could tend and expand it. other things in the allium family (wild onions, chives, leeks, garlic bulbs) may also do well.

nettles are a big one that have delicious and nutritious greens that can be cut a couple times a year for soups and tea. their leaves are some of the most densely packed nutrient rich medicines around!

meadowsweet may do well with all the moisture - a famous strewing herb, it also has various medicinal components (can take a fever down) and is absolutely beautiful. good pollinator as well. Jerusalem artichokes also do well in just about any environment and will keep you in tubers for a lifetime!

Mulberry, elderberry, blackberry, Black Willow, Canada Onion, maybe Linden. Hazelnuts?

I have a similar problem on back acreage near creek.   I am currently watching stuff die, I plant new things back there every year to see how it fares and a foot of rain in the last week....well stuff's dying.  
 I do grow elderberries, mullberry trees, may-haw trees, Chickasaw plum trees and some pawpaws back there.   They are all getting big now and get flooded several times a year.