Things that are standing magical effects, or activatable ones. Like: here is a stela that is a prayer for food, if you have hunger issues and pour a bucket of water over it it will reduce your hunger. (Pouring a bucket of water over a stela is an actual ancient practice.) Here is a healing stela, pour a bucket of water over it for health restoration (not that healing is hard in-game, but, you know, it's a thing that one could do). Here is a fertility stela, pour a bucket of water over it to bonemeal crops in a three block radius around the stone. Etc.
Prefer "use bucket on block" to scanning for water source, to avoid water-replication abuse.
Initial implementation for this should focus on the fertility effect (ie, bonemeal the surroundings). Can extend to more once we have the basic implementation in place.
Things that are standing magical effects, or activatable ones. Like: here is a stela that is a prayer for food, if you have hunger issues and pour a bucket of water over it it will reduce your hunger. (Pouring a bucket of water over a stela is an actual ancient practice.) Here is a healing stela, pour a bucket of water over it for health restoration (not that healing is hard in-game, but, you know, it's a thing that one could do). Here is a fertility stela, pour a bucket of water over it to bonemeal crops in a three block radius around the stone. Etc.
Prefer "use bucket on block" to scanning for water source, to avoid water-replication abuse.