This is one of the world's most contaminated bodies of water. A great heritage has been lost. The once vast salmon runs are now memorialized in museums, replaced by cultivated hatchery fish.
It's a story repeated around the world, where humans lack the capacity to self-organize and manage their civilizations effectively. Their engineering is of poor quality, their technology nowhere near as finely tuned as Mother Nature's.
The film includes footage from One Flew Over the Cuckoos Nest, a movie Ken Kesey somewhat despised. In the film, Chief Bromden is put in there for alcoholism, whereas in Kesey's novel his distress is specifically owing to the flooding of Celilo Falls, which took place in 1957 (one year before I was born, so I've never seen them except in archival records).
Suicide rates and alcoholism soared when Celilo and Kettle Falls were destroyed in the name of "progress" (a tricky word), by The Dalles Dam and Grand Coulee Dam respectively.
The prospect of removing some of these dams, or allowing them to simply decay, is broached. Given the current level of greed for power, that may not happen for awhile, but these people are patient.
Barge traffic depends on keeping the river navigable (trains don't care so much). However, if the uber-toxins under Hanford further contaminate the river, those dams may be the least of our problems.
Christopher set some records with his 13 month swim in icy cold currents, with interruptions to raise some money. He has since tackled other bodies of water. He reminds me of Roz Savage, whom I've been writing about recently (again), who also ministers about the ecosystem, the interconnectedness of all things.
I include the Celilo Falls episode in my Martian Math curriculum, as an example of terraforming. However I don't imply that terraforming, while transforming, is always for the better or towards making a planet more habitable for human beings. We might like it to be, but humans make mistakes. A few mushroom clouds make that point in this film.