I looked A to Z on the Texas A&M site but could not find this plant. Not saying it is not there, I just could not make the connection.

Three pictures below. Leaves below the surface are slender. Ones floating on top are more roundish.

Not the best pics and more close up would have been better. Leaned as far out over the creek that I could to get them. If need more will take a rake and pull some out so can get better pics.

From what I can see reminds me of Sago Pond weed.

It looks like it, but from what I read Sago does not have any surface leaves, only under water leaves.

Here are some more pictures. It definitely has some surface leaves. Where the under water leaves are very slender, the surface ones are roundish. Quite different.

An underwater shot is great for showing where/how the plant is growing, but a focused close-up of the plant (preferably showing all visible leaf-structures) is sometimes needed for ID-purposes. Do these photos closely resemble your plant?