The dozer guy is here

It pretty exciting and scary at the same time. I know so little and yet know the most of anyone on the project. Worse is someone with even less knowledge than I have tries to fight me over what to do, what he has always seen done. Not the dozer guy, just a guy. Dozer guy know his stuff but has only dug farm ponds nothing like natural swimming before.
I am building a dog training pond. The backside will be the dam and planted. This is one of the areas I need the most help. What plants are good choices??? I am thinking shallow rooted, matting or thick growing and has to hold everything in place over the winter rains. Waterlily and lotus for the inside and???, I have some cannas growing now I plan to add for color at the top pf the dam. Planning to plant underwater plantsalso, hornwort and???
I have Missouri native wildflower mix but he thinks it will die back and be open to erosionor the outside of the backside of the pond, pushing Bermuda grass. The front of the pond will have the cool diving dock, beach, and trees for shade.  I need planting suggestions for the back and all the advise I can get. We are digging now to find clay and I am seeing color (red). Oh so exciting!

I have no idea of the root structure, but what about Cardinal Flower? It doesn't mind wet feet, and attracts pollinators.

Cardinal flower looked good till I saw how toxic it is. I have barely on my list for everything the day the dozer leaves. I have a pound of native wildflower mix to add to the barley in some areas. I am searching the mdc.mo.gov sites too. Such big plans lol

with the Missouri Wildflower Mix, If seeded now is recommended because the seeds need to stratify.  Most will come up in the spring though there might be a few that will germinate no such as bluebonnet.

If there is a possibility for erosion why not plant winter rye grass now which will help with erosion and then die back in the spring allowing for the seed mix to come up.

While searching for some threads about natural swimming pool plants I found this:

https://www.reflectionswatergardens.com/blogs/guide-to-natural-swimming-pool-plants/

And a thread for you or others:

https://permies.com/t/40/7994/Natural-Swimming-Pool#217137

Almost all tank damn mixes have annual rye and teff (basically annual rye but for summer. I don’t think mine had any flowers but it also had Bermuda and some deep rooted clumping grasses like Klein and bluestem.

Actually here is the one I used. It’s suited for Texas but I’m sure you can find one suited for your area. Basically you need something fast to stabilize until the perennials come up. Depending on where you are you can remove the summer annual but those grasses are super cheap anyways.

I would lean heavily into what dozer guy says assuming he’s been vetted out good and has a lot of experience. I’ve regretted every time I didn’t take my guys advice other than when he told me to fertilize the crap out of it. They do this all the time.