In addition, she reported they found animal "activity" in the old spring box. So we have a reasonable explanation.
when I was there Sept 12, there was talk of simply, duh, putting a lid on the top of the box.
For every complex problem there is a solution that is simple, neat, and wrong. - H. L. Mencken
Kathy at Inyo County takes samples from the spring and she reported it's falling apart and the flow has decreased substantially, not worth trying to fix. Apparently it was constructed in the 1930's? That's why they're building a new one at a nearby location where the flow has increased. I'd love to get down there and see it for myself, but unlikely this season.