I've heard it's generally a good idea to fill niche spaces with something you want before something undesirable comes in. I planted Vellisnaria americana in my 1-acre pond last year and it grew nicely over the summer. Though I had to collect the shoots from nearby river for transplanting. The shallow area we planned covers <30% of the pond surface area, which is about right according to literature I've read. At the deep edge of the shallow area, we made a rock reef/crayfish habitat to help control the vegetation.

Good luck with your planting.
SC