Camp Mystic owners successfully appealed to the Federal Emergency Management Agency to redesignate some buildings that had been considered part of a flood-hazard zone.

“It’s hard not to feel like you are surrounded by a higher power when you’re down there, because it’s just so beautiful,” my friend Olivia Marrus told me.

Since its construction in 1926, the camp — which promised cabins “snugly arranged” in a “picturesque bend” in the river — repeatedly experienced flood disruptions, including evacuations or damage to s...