I didn't mention pollution while filming this video, however, it's a very serious concern in today's time for wild water. Flood water like what is pictured can carry untold amounts of contaminants and even if boiled, should only be drank as a last resort. This subject deserves an entire video of its own.
This section of the river that created this backflow is far inland away from many sources of pollution.
Finding clean water in the wilderness is a challenge pretty much no matter where you are. But wherever you are, water tends to behave the same. It follows gravity and flows downhill and pools. How we get clean water from that source, is pretty simple. filter it, boil it, purify it, or risk it. I don't advise the latter.