How does it work when a river flows uphill, in Glorantha?
For the regular flow, the logic is obvious - rain falls, runs downwards, collects into a river, flows out to sea, rises as clouds, and so on.
But when a river flows uphill, then you end up with a lot of water further up. But then what happens to it? Does it find some other place to flow back? Get absorbed into the ground? Something has to happen with all that water deposited further up on land!