Global warming, amirite?

If this is horror, this is all reaction, no information. Did the river do something magical? Is it a drought? Did the river vanish? A river stopping flow would stay where it is, and likely begin to rise, causing a flood. And that’s the opposite of a drought. But Applejack is standing in the mud, meaning the water vanished. Has all the water vanished? A day where there’s no water in Equestria is the sort of “baddy of the week” plot that has stupid motivations to do something impossible, and be well animated, that you’d see in the 80s MLP.

This looks intresting. The mud looks nice.
Who needs a river? She can wallow herself in mud. Getting all covered and muddy.