I have a 2-3 acre impoundment that I would like to naturalize with emergent aquatic plants like N. luteal and/or N. odorata. Currently it is choked with eurasian Milfoil. Is this allowed? If so, how do I obtain stocking materials ? Thanks.
Yes, you can remove the invasive Eurasian milfoil and replace it with native species. Before doing anything though, you should contact the Michigan Department of Environment, Great Lakes, and Energy (formerly the Department of Environmental Quality) to see if you need a permit. Here is the website: https://www.michigan.gov/egle/0,9429,7-135-3313_71520---,00.html
Nymphaea odorata is a great choice, but Nelumbo lutea is a state threatened plant and therefore legally protected. I'm not sure if this matters, but there are some other species (maybe a Nuphar or floating leaf Potamogeton) that you may have a better chance of getting your hands on.
Here is a short list of native plant companies in Michigan. https://www.mnppa.org/members.html I'm not sure if they have any aquatic plants, but if they don't, I hope they could direct you to a company that does.