Elderberry with an understory of native emergent aquatic plants should work.
Elderberry is extremely easy on a bank, has pleasant flowers, culinary and medicinal uses, makes a great wine.
If you can find a stand of elderberry, 1" diam. cuttings 12 inches long pushed into wet soil grow very easily.
This nursery in your area carries the plants:
https://www.wilcoxnursery.com/product-category/aquatic-emergent-and-wetlands/Beware of why the bank may be eroding, someone may be using herbicide or mowing too close to the bank or just water level fluctuations leaving the bank bare with no intact littoral zone.