Uninstall the mod and hope it works, if not:

1. Go to your mod options and in Events.EventsMod untick anything you don't want to occur again
2. Enable Dev Mode, and under Open Debug Actions Menu, click remove Remove Game Condition and remove it

If this menu is blank, navigate to your save folder, open the .rws file with Notepad++ and CTRL+F the name of the event and it will bring you to it, replace the True in permanent to False, and change the -1 in Duration to 1

upon loading the game the condition will be instantly removed.

I'm not sure if this would work with Flood seems it actually changes the tiles of the map but this should work with Solar superstorm (SolarSuperstorm) , Ice flurry , Ice storm , Supervolcano eruption, SuperNova , Ionized Atmosphere , Super Heatwave , Endlessday , Volcanic Winter .