It turns out that a chipmunk was the cause of the pond waterfall issues. I know this because one started digging a new hole and got some more dirt in the pond last week. But this time, I caught him red-handed. When I rebuilt, I backfilled with some rocks, but apparently I wasn’t thorough enough. He was digging near the top, so I just had to remove a couple of large rocks and backfill with some smaller ones, and that seemed to fix the issue. Not knowing if this is going to happen again, I opted not to rebuild the actual waterfall part. I basically stacked a bunch of rocks and ran the water return behind them. I just about have all of the sediment removed from the pond, too. I bought a filter sock, and it has been doing a great job of filtering out the debris.
On a cool note, a pair of toads took up residence in the pond long enough to lay a bunch of eggs, so I have a pondful of tadpoles right now. I noticed that their numbers were dwindling, and then I found a fish that survived in the pond, so I guess that explains it. Hopefully, he won’t eat all of them! I’m holding off on buying additional fish until the tadpoles are bigger than a fish’s mouth. Haha.