When we lived in California, the Herons and cranes thought Koi ponds were "In and Out" drive thrus! Vegas doesn't have bird problems, just a little heat issue around Jul/Aug. With my other ponds, we used planters to keep all the plants in place, we simply raised the planters so that the rim was about 1/4" from the surface, that way the Koi's don't rip them up.