These are spillway outlets at Shasta Dam. They’re used to control the water level in the dam and the water flow in the river, by releasing water independently of the turbine generator output.
It’s around 500 feet down from where I was standing, and it was here I rediscovered my dislike for heights. Not an o-my-fsm-get-me-out-of-here-now dislike, but more why-is-this-a-good-idea.
October 9, 2009. Shasta Dam, California.