Hey Tater! I believe if you make a new Switch for when it rains, you can change the event template to have a new page at the very end that's activated on the rain Switch. Then have it so that it autoruns and <Self> Watered is turned on and change the event image. :D
i know this is a very old post but I was hoping you could further elaborate on this. I have a similar thing but with a sprinkler system and i can't figure out how it can water all the crops at the same time
When the in-game day ends and Common Event 119: Overnight Crop Growth runs, add in a switch if the sprinkler system is active. Then in the crop event templates, make a conditional branch at the end of page 9 that checks if that switch is on. If it is, set Switch 211: <Self> Watered? back ON.
